Skip to main content
Select Source:

Leukemia

Leukemia

Definition

Leukemia is a cancer that starts in the organs that make blood, namely the bone marrow and the lymph system. Depending on specific characteristics, leukemia can be divided into two broad types: acute and chronic. Acute leukemias are the rapidly progressing leukemias, while the chronic leukemias progress more slowly. The vast majority of childhood leukemias are of the acute form.

Description

The cells that make up blood are produced in the bone marrow and the lymph system. The bone marrow is the spongy tissue found in the large bones of the body. The lymph system includes the spleen (an organ in the upper abdomen), the thymus (a small organ beneath the breastbone), and the tonsils (an organ in the throat). In addition, the lymph vessels (tiny tubes that branch like blood vessels into all parts of the body) and lymph nodes (pea-shaped organs that are found along the network of lymph vessels) are also parts of the lymph system. The lymph is a milky fluid that contains cells. Clusters of lymph nodes are found in the neck, underarm, pelvis, abdomen, and chest.

The cells found in the blood are the red blood cells (RBCs), which carry oxygen and other materials to all tissues of the body; white blood cells (WBCs) that fight infection; and platelets, which play a part in the clotting of the blood. The white blood cells can be further subdivided into three main types: granulocytes, monocytes, and lymphocytes.

The granulocytes, as their name suggests, have particles (granules) inside them. These granules contain special proteins (enzymes) and several other substances that can break down chemicals and destroy microorganisms, such as bacteria. Monocytes are the second type of white blood cell. They are also important in defending the body against pathogens.

The lymphocytes form the third type of white blood cell. There are two main types of lymphocytes: T lymphocytes and B lymphocytes. They have different functions within the immune system. The B cells protect the body by making "antibodies." Antibodies are proteins that can attach to the surfaces of bacteria and viruses. This "attachment" sends signals to many other cell types to come and destroy the antibody-coated organism. The T cells protect the body against viruses. When a virus enters a cell, it produces certain proteins that are projected onto the surface of the infected cell. The T cells recognize these proteins and make certain chemicals that are capable of destroying the virus-infected cells. In addition, the T cells can destroy some types of cancer cells.

The bone marrow makes stem cells, which are the precursors of the different blood cells. These stem cells mature through stages into either RBCs, WBCs, or platelets.

Chronic leukemias

In chronic leukemias, the cancer starts in the blood cells made in the bone marrow. The cells mature and only a few remain as immature cells. However, even though the cells mature and appear normal, they do not function as normal cells. Depending on the type of white blood cell that is involved, chronic leukemia can be classified as chronic lymphocytic leukemia or chronic myelogenous leukemia.

Chronic leukemias develop very gradually. The abnormal lymphocytes multiply slowly, but in a poorly regulated manner. They live much longer and thus their numbers build up in the body. The two types of chronic leukemias can be easily distinguished under the microscope. Chronic lymphocytic leukemia (CLL) involves the T or B lymphocytes. B cell abnormalities are more common than T cell abnormalities. T cells are affected in only 5% of the patients. The T and B lymphocytes can

be differentiated from the other types of white blood cells based on their size and by the absence of granules inside them. In chronic myelogenous leukemia (CML), the cells that are affected are the granulocytes.

Chronic lymphocytic leukemia (CLL) often shows no early symptoms and may remain undetected for a long time. Chronic myelogenous leukemia (CML), on the other hand, may progress to a more acute form.

Acute leukemias

In acute leukemia, the maturation process of the white blood cells is interrupted. The immature cells (or "blasts") proliferate rapidly and begin to accumulate in various organs and tissues, thereby affecting their normal function. This uncontrolled proliferation of the immature cells in the bone marrow affects the production of the normal red blood cells and platelets as well.

Acute leukemias are of two types: acute lymphocytic leukemia and acute myelogenous leukemia. Different types of white blood cells are involved in the two leukemias. In acute lymphocytic leukemia (ALL), the T or B lymphocytes become cancerous. The B cell leukemias are more common than T cell leukemias. Acute myelogenous leukemia, also known as acute nonlymphocytic leukemia (ANLL), is a cancer of the monocytes and/or granulocytes.

Leukemias account for 2% of all cancers. Because leukemia is the most common form of childhood cancer, it is often regarded as a disease of childhood. However, leukemias affect nine times as many adults as children. Half of the cases occur in people who are 60 years of age or older. The incidence of acute and chronic leukemias is about the same. According to the estimates of the American Cancer Society (ACS), approximately 29,000 new cases of leukemia were diagnosed in 1998. Internationally, leukemia is the fourth most common cancer among people age 15 to 19 years old.

Causes & symptoms

Leukemia strikes both sexes and all ages and its cause is mostly unknown. However, chronic leukemia has been linked to genetic abnormalities and environmental factors. For example, exposure to ionizing radiation and to certain organic chemicals, such as benzene, is believed to increase the risk for getting leukemia. A 2003 study from the Electric Power Research Institute showed possible links between metallic drainpipes and childhood baths. Chronic leukemia occurs in some people who are infected with two human retroviruses (HTLV-I and HTLV-II). An abnormal chromosome known as the Philadelphia chromosome is seen in 90% of those with CML. The incidence of chronic leukemia is slightly higher among men than women.

Acute lymphoid leukemia (ALL) is more common among Caucasians than among African-Americans, while acute myeloid leukemia (AML) affects both races equally. The incidence of acute leukemia is slightly higher among men than women. People of Jewish ancestry have a higher likelihood of getting leukemia. A higher incidence of leukemia has also been observed among persons with Down syndrome and some other genetic abnormalities.

A history of diseases that damage the bone marrow, such as aplastic anemia , or a history of cancers of the lymphatic system puts people at a high risk for developing acute leukemias. Similarly, the use of anticancer medications, immunosuppressants, and the antibiotic chloramphenicol also are considered risk factors for developing acute leukemias.

The symptoms of leukemia are generally vague and non-specific. A patient may experience all or some of the following symptoms:

  • weakness or chronic fatigue
  • fever of unknown origin
  • weight loss that is not due to dieting or exercise
  • frequent bacterial or viral infections
  • headaches
  • skin rash
  • non-specific bone pain
  • easy bruising
  • bleeding from gums or nose
  • blood in urine or stools
  • enlarged lymph nodes and/or spleen
  • abdominal fullness

Diagnosis

Like all cancers, leukemias are best treated when found early. There are no screening tests available. If the doctor has reason to suspect leukemia, he or she will conduct a thorough physical examination to look for enlarged lymph nodes in the neck, underarm, and pelvic region. Swollen gums, enlarged liver or spleen, bruises , or pinpoint red rashes all over the body are some of the signs of leukemia. Urine and blood tests may be ordered to check for microscopic amounts of blood in the urine and to obtain a complete differential blood count. This count will give the numbers and percentages of the different cells found in the blood. An abnormal blood test might suggest leukemia, however, the diagnosis has to be confirmed by more specific tests.

A doctor may perform a bone marrow biopsy to confirm the diagnosis of leukemia. During the biopsy, a cylindrical piece of bone and marrow is removed, generally from the hip bone. These samples are sent to the laboratory for examination. In addition to diagnosis, the biopsy is also repeated during the treatment phase of the disease to see if the leukemia is responding to therapy.

A spinal tap (lumbar puncture) is another procedure that the doctor may order to diagnose leukemia. In this procedure, a small needle is inserted into the spinal cavity in the lower back to withdraw some cerebrospinal fluid and to look for leukemic cells.

Standard imaging tests, such as x rays, computed tomography scans (CT scans), and magnetic resonance imaging (MRI) may be used to check whether the leukemic cells have invaded other areas of the body, such as the bones, chest, kidneys, abdomen, or brain. A gallium scan or bone scan is a test in which a radioactive chemical is injected into the body. This chemical accumulates in the areas of cancer or infection, allowing them to be viewed with a special camera.

Treatment

Alternative therapies should be used only as complementary to conventional treatment, not to replace it. Before participating in any alternative treatment programs, patients should consult their doctors concerning the appropriateness and the role of such programs in the overall cancer treatment plan. Appropriate alternative treatments can help prolong a patient's life or at least improve quality of life, prevent recurrence of tumors or prolong the remission period, and reduce adverse reactions to chemotherapy and radiation.

The effectiveness of most anti-cancer drugs used to treat leukemia can be reduced when patients take mega doses of antioxidants. These antioxidants , in patients not undergoing chemotherapy, can be very helpful in protecting the body against cancer. However, taken during chemotherapy, these antioxidants protect the cancer cells from being killed by treatment. Because high-dose supplementation of antioxidants can interfere with conventional chemotherapy treatment, patients should only take them at dosages much above the recommended daily allowance (RDA).

Dietary guidelines

The following dietary changes may be helpful:

  • Avoiding fatty and spicy foods, which may be harder to digest.
  • Eating new and exciting foods. Tasty foods stimulate appetite so that patients can eat more and have the energy to fight cancer.
  • Increasing consumption of fresh fruits and vegetables. They are nature's best sources of antioxidants, as well as vitamins and minerals.
  • Eating multiple (five or six) meals per day. Small meals are easier to digest.
  • Establishing regular eating times and not eating around bedtime.
  • Avoiding foods that contain preservatives or artificial coloring.
  • Monitoring weight and eating adequate calories and protein.

Nutritional supplements

A naturopath or nutritional physician may recommend some of the following nutritional supplements to boost a patient's immune function and help fight cancer:

  • Vitamins and minerals. Vitamins that are of particular benefit to cancer patients include beta-carotene, B-complex vitamins, (especially vitamin B6, vitamins A, C, D, E and K. The most important minerals are calcium, chromium, copper, iodine , molybdenum, germanium, selenium, tellurium, and zinc . Many of these vitamins and minerals are strong antioxidants. However, patients should not take mega doses of these supplements without first consulting their doctor. Significant adverse or toxic effects may occur at high dosage, which is especially true for minerals. It is prudent to avoid use of antioxidants when undergoing chemotherapy or radiation therapy since these treatments kill the cancer by producing oxidants. Antioxidants can undermine the effectiveness of treatment.
  • Other nutritional supplements that may help fight cancer and support the body include essential fatty acids (fish or flaxseed oil), flavonoids, pancreatic enzymes (to help digest foods), hormones such as DHEA , melatonin or phytoestrogens, rice bran, and mushroom extracts. It is best to check with a nutritional physician or other licensed provider when adding these supplements.

Traditional Chinese medicine

Conventional treatment for leukemia is associated with significant side effects. These adverse effects can be reduced with Chinese herbal preparations. Patients should consult an experienced herbalist who will prescribe remedies to treat specific symptoms that are caused by conventional cancer treatments.

Juice therapy

Juice therapy may be helpful in patients with cancer. Patients should mix one part of pure juice with one part of water before drinking. Daily consumption of the following juice may be helpful by reducing toxic burden to the liver:

  • carrot and beet juice with a touch of radish or dandelion root
  • grapes, pear, and lemon
  • carrot, celery, and parsley
  • carrot, beet, and cucumber juices

Homeopathy

There is conflicting evidence regarding the effectiveness of homeopathy in cancer treatment. Because cancer chemotherapy may suppress the body's response to homeopathic treatment, homeopathy may not be effective during chemotherapy. Therefore, patients should wait until after chemotherapy to try this relatively safe alternative treatment.

Acupuncture

Acupuncture is the use of needles on the body to stimulate or direct the meridians (channels) of energy flow in the body. Acupuncture has not been shown to have any anticancer effects. However, it is an effective treatment for nausea , a common side effect of chemotherapy and radiation.

Other treatments

Other therapies that may help the leukemia patient include meditation, qigong, yoga , and t'ai chi , all of which can aid in stress reduction. Guided imagery can increase immune function and decrease pain and nausea.

Allopathic treatment

There are two phases of treatment for leukemia. The first phase is called induction therapy. The main aim of the treatment is to reduce the number of leukemic cells as far as possible and induce a remission in the patient. Once the patient shows no obvious signs of leukemia (no leukemic cells are detected in blood tests and bone marrow biopsies), the patient is said to be in remission. The second phase of treatment is then initiated. This is called continuation or maintenance therapy; the aim in this case is to kill any remaining cells and to maintain remission for as long as possible.

Chemotherapy is the use of drugs to kill cancer cells. It is usually the treatment of choice and is used to relieve symptoms and achieve long-term remission of the disease. Generally, combination chemotherapy, in which multiple drugs are used, is more efficient than using a single drug for treatment.

In 2002, scientists announced the discovery of a gene that triggers the death of leukemia cells. Identification of this gene can lead to better targeting of chemotherapy drugs (that involve a vitamin A derivative) for acute promyelocytic leukemia (APL). Another advancement in leukemia treatment occurred in the same year. A new drug was found to cancel the effects of mutations of a gene known as the main culprit in AML, an aggressive, treatment-resistant form of leukemia. Further study was needed on both new discoveries, but they were thought important to improving treatment of two forms of leukemia. Later in 2002, Gleevec, a new antileukemia drug that even proved successful at treating chronic myeloid leukemia, was heralded in clinical trials.

Because leukemia cells can spread to all the organs via the blood stream and lymph vessels, surgery is not considered an option for treating leukemias.

Radiation therapy, which involves the use of x rays or other high-energy rays to kill cancer cells and shrink tumors, may be used in some cases. For acute leukemias, the source of radiation is usually outside the body (external radiation therapy). If the leukemic cells have spread to the brain, radiation therapy can be given to the brain.

Bone marrow transplantation (BMT) is a process in which the patient's diseased bone marrow is replaced with healthy marrow. There are two methods of bone marrow transplant. In an allogeneic bone marrow transplant, healthy marrow is taken from a donor whose tissue is either the same as or very closely resembles the patient's tissue. First, the patient's bone marrow is destroyed with very high doses of chemotherapy and radiation therapy. Healthy marrow from the donor is then given to the patient through a needle in a vein to replace the destroyed marrow.

In the second type of bone marrow transplant, called an autologous bone marrow transplant, some of the patient's own marrow is taken out and treated with a combination of anticancer drugs to kill all abnormal cells. This marrow is then frozen and saved. The marrow remaining in the patient's body is destroyed with high-dose chemotherapy and radiation therapy. The marrow that was frozen is then thawed and given back to the patient through a needle in a vein. This mode of bone marrow transplant is currently being investigated in clinical trials.

Biological therapy or immunotherapy is a mode of treatment in which the body's own immune system is harnessed to fight the cancer. Substances that are routinely made by the immune system (such as growth factors, hormones, and disease-fighting proteins) are either synthetically made in a laboratory or their effectiveness is boosted and they are then put back into the patient's body. This treatment mode is also being investigated in clinical trials all over the country at major cancer centers.

Expected results

Like all cancers, the prognosis for leukemia depends on the patient's age and general health. According to statistics, more than 60% of leukemia patients survive for at least one year after diagnosis.

Acute myelocytic leukemia (AML) has a poorer prognosis rate than acute lymphocytic leukemias (ALL) and the chronic leukemias. In the last 15 to 20 years, the five-year survival rate for patients with ALL has increased from 38% to 57%.

Interestingly enough, since most childhood leukemias are of the ALL type, chemotherapy has been highly successful in their treatment. This is because chemotherapeutic drugs are most effective against actively growing cells. Due to the new combinations of anti-cancer drugs being used, the survival rates among children with ALL have improved dramatically. Eighty percent of the children diagnosed with ALL now survive five years or more, as compared to 50% in the late 1970s.

According to statistics, in chronic lymphoid leukemia, the overall survival for all stages of the disease is nine years. Most of the deaths in people with CLL are due to infections or other illnesses that occur as a result of the leukemia.

In CML, if bone marrow transplantation is performed within one to three years of diagnosis, 50-60% of the patients survive three years or more. If the disease progresses to the acute phase, the prognosis is poor. Less than 20% of these patients go into remission.

Prevention

Most cancers can be prevented by changes in lifestyle or diet, which will reduce risk factors. However, in leukemias, there are no such known risk factors. Therefore, at the present time, there are no real prevention recommendations for leukemia. People who are at an increased risk for developing leukemia because of proven exposure to ionizing radiation or exposure to the toxic liquid benzene, and people with Down syndrome, should undergo periodic medical checkups. Some experts recommend limiting toxic exposures, eating a whole foods diet, refraining from smoking , exercise, and fluids, and even intermittent fasting as possible prevention measures. In 2003, new research found that adult women who took aspirin two or more times a week had a 50% lower risk of developing adult leukemia. Scientists continue to work on a possible vaccine for leukemia. They made some progress in 2002, discovering a gene transfer model that might trigger immunity against leukemia cells.

Resources

BOOKS

Berkow, Robert, et al., eds. Merck Manual of Diagnosis and Therapy, 16th ed. Merck Research Laboratories, 1992.

Dollinger, Malin. Everyone's Guide to Cancer Therapy. Somerville House Books Limited, 1994.

Labriola, Dan. Complementary Cancer Therapies: Combining Traditional and Alternative Approaches for the Best Possible Outcome. Roseville, CA: Prima Health, 2000.

Morra, Marion E. Choices. Avon Books, 1994.

Murphy, Gerald P. Informed Decisions: The Complete Book of Cancer Diagnosis, Treatment and Recovery. American Cancer Society, 1997.

PERIODICALS

"Cancer Killing Gene Found by Dartmouth Researchers." Cancer Weekly (April 9, 2002):17.

"Contact Voltage and Magnetic Fields as Possible Factors in Leukemia Pilot Study." Journal of Environmental Health (December 2002):4751.

"Cytokine and CD154 Gene Transfer Generate Immunity Against Leukemia." Immunotherapy Weekly (October 23, 2002):16.

"Drug Blocks Gene Mutation Effect in Lethal Leukemia." Genomics & Genetics Weekly (June 21, 2002):13.

"Leukemia Incidence Lowest in Patients 15-30 Years of Age (Incidence Drops at Age 20)." Internal Medicine News (May 1, 2002):37.

"New Drug Significantly Improves Survival Even for Patients with Late-Stage Disease." Cancer Weekly (December 31, 2002):6.

"Study: Regular Use of Aspirin May Lower Risk of Adult Leukemia." Women's Health Weekly (July 10, 2003):36.

ORGANIZATIONS

American Cancer Society. 1599 Clifton Road, N.E., Atlanta, Georgia 30329. (800) 227-2345. http://www.cancer.org.

Cancer Research Institute. 681 Fifth Avenue, New York, N.Y. 10022. (800) 992-2623. http://www.cancerresearch.org.

The Leukemia and Lymphoma Society. 600 Third Avenue, New York, NY 10016. (800) 955-4572. http://www.leukemia.org.

National Cancer Institute. 9000 Rockville Pike, Building 31, Room 10A16, Bethesda, Maryland, 20892. (800) 422-6237. http://wwwicic.nci.nih.gov.

Oncolink. University of Pennsylvania Cancer Center. http://cancer.med.upenn.edu.

OTHER

Rosenberg, Z'ev. "Treating the Undesirable Effect of Radiation and Chemotherapy with Chinese Medicine." Oriental Chinese Journal. http://www.healthypeople.com.

Mai Tran

Teresa G. Odle

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"Leukemia." Gale Encyclopedia of Alternative Medicine. . Encyclopedia.com. 13 Sep. 2018 <http://www.encyclopedia.com>.

"Leukemia." Gale Encyclopedia of Alternative Medicine. . Encyclopedia.com. (September 13, 2018). http://www.encyclopedia.com/medicine/encyclopedias-almanacs-transcripts-and-maps/leukemia-0

"Leukemia." Gale Encyclopedia of Alternative Medicine. . Retrieved September 13, 2018 from Encyclopedia.com: http://www.encyclopedia.com/medicine/encyclopedias-almanacs-transcripts-and-maps/leukemia-0

Learn more about citation styles

Citation styles

Encyclopedia.com gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, Encyclopedia.com cannot guarantee each citation it generates. Therefore, it’s best to use Encyclopedia.com citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

http://www.mla.org/style

The Chicago Manual of Style

http://www.chicagomanualofstyle.org/tools_citationguide.html

American Psychological Association

http://apastyle.apa.org/

Notes:
  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most Encyclopedia.com content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.

Leukemias, Acute

Leukemias, Acute

Definition

Leukemia is a cancer that starts in the organs that make blood, namely the bone marrow and the lymph system. Depending on their characteristics, leukemias can be divided into two broad types. Acute leukemias are the rapidly progressing leukemias, while the chronic leukemias progress more slowly. The vast majority of the childhood leukemias are of the acute form.

Description

The cells that make up blood are produced in the bone marrow and the lymph system. The bone marrow is the spongy tissue found in the large bones of the body. The lymph system includes the spleen (an organ in the upper abdomen), the thymus (a small organ beneath the breastbone), and the tonsils (an organ in the throat). In addition, the lymph vessels (tiny tubes that branch like blood vessels into all parts of the body) and lymph nodes (pea-shaped organs that are found along the network of lymph vessels) are also part of the lymph system. The lymph is a milky fluid that contains cells. Clusters of lymph nodes are found in the neck, underarm, pelvis, abdomen, and chest.

The cells found in the blood are the red blood cells (RBCs), which carry oxygen and other materials to all tissues of the body; white blood cells (WBCs) that fight infection; and the platelets, which play a part in the clotting of the blood. The white blood cells can be further subdivided into three main types: granulocytes, monocytes, and lymphocytes.

The granulocytes, as their name suggests, have particles (granules) inside them. These granules contain special proteins (enzymes) and several other substances that can break down chemicals and destroy microorganisms, such as bacteria. Monocytes are the second type of white blood cell. They are also important in defending the body against pathogens.

The lymphocytes form the third type of white blood cell. There are two main types of lymphocytes: T lymphocytes and B lymphocytes. They have different functions within the immune system. The B cells protect the body by making "antibodies." Antibodies are proteins that can attach to the surfaces of bacteria and viruses. This "attachment" sends signals to many other cell types to come and destroy the antibodycoated organism. The T cells protect the body against viruses. When a virus enters a cell, it produces certain proteins that are projected onto the surface of the infected cell. The T cells recognize these proteins and make certain chemicals that are capable of destroying the virus-infected cells. In addition, the T cells can destroy some types of cancer cells.

The bone marrow makes stem cells, which are the precursors of the different blood cells. These stem cells mature through stages into either RBCs, WBCs, or platelets. In acute leukemias, the maturation process of the white blood cells is interrupted. The immature cells (or "blasts") proliferate rapidly and begin to accumulate in various organs and tissues, thereby affecting their normal function. This uncontrolled proliferation of the immature cells in the bone marrow affects the production of the normal red blood cells and platelets as well.

Acute leukemias are of two types: acute lymphocytic leukemia and acute myelogenous leukemia. Different types of white blood cells are involved in the two leukemias. In acute lymphocytic leukemia (ALL), it is the T or the B lymphocytes that become cancerous. The B cell leukemias are more common than T cell leukemias. Acute myelogenous leukemia, also known as acute nonlymphocytic leukemia (ANLL), is a cancer of the monocytes and/or granulocytes.

CHARLOTTE FRIEND (19211987)

Charlotte Friend was born to Russian immigrants, Morris Friend and Cecilia (Wolpin), on March 11, 1921, in New York City. At three years of age, her father died of a heart condition. Friend's decision to pursue a career in medicine may well have been influenced by her father's death and by her mother's occupation as a pharmacist. As a child, Friend read books about bacteriologists and, by age ten, she knew that she wanted to study bacteriology. She attended Hunter College, enlisting in the U.S. Navy after her graduation in 1944.

Friend attended Yale University, earning her Ph.D. in bacteriology in 1950. After working for the Memorial Sloan-Kettering Institute for Cancer Research, she became an associate professor at Cornell University in 1952. Friend began researching cancer and became particularly interested in leukemia and its cause. She believed that a virus caused the disease and confirmed this theory by using an electron microscope to photograph the virus in mice. Her findings were initially met with much skepticism but she was able to develop a vaccine that was used successfully with mice, which added credibility to her theory. Her breakthroughs have led medical researchers to new methods of treating cancer and to a greater understanding of the disease.

Friend was a prolific writer who published 113 original papers, 49 abstracts, book chapters, and reviews, many of which she completed individually. She was diagnosed with lymphoma and died on January 13, 1987.

Leukemias account for 2% of all cancers. Because leukemia is the most common form of childhood cancer, it is often regarded as a disease of childhood. However, leukemias affect nine times as many adults as children. Half of the cases occur in people who are 60 years of age or older. The incidence of acute and chronic leukemias is about the same. According to the estimates of the American Cancer Society (ACS), approximately 29,000 new cases of leukemia were diagnosed in 1998.

Causes and symptoms

Leukemia strikes both sexes and all ages. The human T-cell leukemia virus (HTLV-I) is believed to be the causative agent for some kinds of leukemias. However, the cause of most leukemias is not known. Acute lymphoid leukemia (ALL) is more common among Caucasians than among African-Americans, while acute myeloid leukemia (AML) affects both races equally. The incidence of acute leukemia is slightly higher among men than women. People with Jewish ancestry have a higher likelihood of getting leukemia. A higher incidence of leukemia has also been observed among persons with Down syndrome and some other genetic abnormalities.

Exposure to ionizing radiation and to certain organic chemicals, such as benzene, is believed to increase the risk of getting leukemia. Having a history of diseases that damage the bone marrow, such as aplastic anemia, or a history of cancers of the lymphatic system puts people at a high risk for developing acute leukemias. Similarly, the use of anticancer medications, immunosuppressants, and the antibiotic chloramphenicol are also considered risk factors for developing acute leukemias.

The symptoms of leukemia are generally vague and non-specific. A patient may experience all or some of the following symptoms:

  • weakness or chronic fatigue
  • fever of unknown origin
  • weight loss that is not due to dieting or exercise
  • frequent bacterial or viral infections
  • headaches
  • skin rash
  • non-specific bone pain
  • easy bruising
  • bleeding from gums or nose
  • blood in urine or stools
  • enlarged lymph nodes and/or spleen
  • abdominal fullness

Diagnosis

Like all cancers, acute leukemias are best treated when found early. There are no screening tests available.

If the doctor has reason to suspect leukemia, he or she will conduct a very thorough physical examination to look for enlarged lymph nodes in the neck, underarm, and pelvic region. Swollen gums, enlarged liver or spleen, bruises, or pinpoint red rashes all over the body are some of the signs of leukemia. Urine and blood tests may be ordered to check for microscopic amounts of blood in the urine and to obtain a complete differential blood count. This count will give the numbers and percentages of the different cells found in the blood. An abnormal blood test might suggest leukemia; however, the diagnosis has to be confirmed by more specific tests.

The doctor may perform a bone marrow biopsy to confirm the diagnosis of leukemia. During the biopsy, a cylindrical piece of bone and marrow is removed. The tissue is generally taken out of the hipbone. These samples are sent to the laboratory for examination. In addition to diagnosis, the biopsy is also repeated during the treatment phase of the disease to see if the leukemia is responding to therapy.

A spinal tap (lumbar puncture) is another procedure that the doctor may order to diagnose leukemia. In this procedure, a small needle is inserted into the spinal cavity in the lower back to withdraw some cerebrospinal fluid and to look for leukemic cells.

Standard imaging tests, such as x rays, computed tomography scans (CT scans), and magnetic resonance imaging (MRI) may be used to check whether the leukemic cells have invaded other areas of the body, such as the bones, chest, kidneys, abdomen, or brain. A gallium scan or bone scan is a test in which a radioactive chemical is injected into the body. This chemical accumulates in the areas of cancer or infection, allowing them to be viewed with a special camera.

Treatment

There are two phases of treatment for leukemia. The first phase is called "induction therapy." As the name suggests, during this phase, the main aim of the treatment is to reduce the number of leukemic cells as far as possible and induce a remission in the patient. Once the patient shows no obvious signs of leukemia (no leukemic cells are detected in blood tests and bone marrow biopsies), the patient is said to be in remission. The second phase of treatment is then initiated. This is called continuation or maintenance therapy, and the aim in this case is to kill any remaining cells and to maintain the remission for as long as possible.

Chemotherapy is the use of drugs to kill cancer cells. It is usually the treatment of choice and is used to relieve symptoms and achieve long-term remission of the disease. Generally, combination chemotherapy, in which multiple drugs are used, is more efficient than using a single drug for the treatment. Some drugs may be administered intravenously through a vein in the arm; others may be given by mouth in the form of pills. If the cancer cells have invaded the brain, then chemotherapeutic drugs may be put into the fluid that surrounds the brain through a needle in the brain or back. This is known as intrathecal chemotherapy.

Because leukemia cells can spread to all the organs via the blood stream and the lymph vessels, surgery is not considered an option for treating leukemias.

Radiation therapy, which involves the use of x rays or other high-energy rays to kill cancer cells and shrink tumors, may be used in some cases. For acute leukemias, the source of radiation is usually outside the body (external radiation therapy). If the leukemic cells have spread to the brain, radiation therapy can be given to the brain.

Bone marrow transplantation is a process in which the patient's diseased bone marrow is replaced with healthy marrow. There are two ways of doing a bone marrow transplant. In an allogeneic bone marrow transplant, healthy marrow is taken from a donor whose tissue is either the same as or very closely resembles the patient's tissues. The donor may be a twin, a brother or sister (sibling), or a person who is not related at all. First, the patient's bone marrow is destroyed with very high doses of chemotherapy and radiation therapy. Healthy marrow from the donor is then given to the patient through a needle in a vein to replace the destroyed marrow.

In the second type of bone marrow transplant, called an autologous bone marrow transplant, some of the patient's own marrow is taken out and treated with a combination of anticancer drugs to kill all the abnormal cells. This marrow is then frozen to save it. The marrow remaining in the patient's body is destroyed with high-dose chemotherapy and radiation therapy. The marrow that was frozen is then thawed and given back to the patient through a needle in a vein. This mode of bone marrow transplant is currently being investigated in clinical trials.

Biological therapy or immunotherapy is a mode of treatment in which the body's own immune system is harnessed to fight the cancer. Substances that are routinely made by the immune system (such as growth factors, hormones, and disease-fighting proteins) are either synthetically made in a laboratory or their effectiveness is boosted and they are then put back into the patient's body. This treatment mode is also being investigated in clinical trials all over the country at major cancer centers.

Prognosis

Like all cancers, the prognosis for leukemia depends on the patient's age and general health. According to statistics, more than 60% of the patients with leukemia survive for at least a year after diagnosis. Acute myelocytic leukemia (AML) has a poorer prognosis rate than acute lymphocytic leukemias (ALL) and the chronic leukemias. In the last 15 to 20 years, the five-year survival rate for patients with ALL has increased from 38% to 57%.

Interestingly enough, since most childhood leukemias are of the ALL type, chemotherapy has been highly successful in their treatment. This is because chemotherapeutic drugs are most effective against actively growing cells. Due to the new combinations of anticancer drugs being used, the survival rates among children with ALL have improved dramatically. Eighty percent of the children diagnosed with ALL now survive for five years or more, as compared to 50% in the late 1970s.

Prevention

Most cancers can be prevented by changes in lifestyle or diet, which will reduce the risk factors. However, in leukemias, there are no such known risk factors. Therefore, at the present time, no way is known to prevent leukemias from developing. People who are at an increased risk for developing leukemia because of proven exposure to ionizing radiation or exposure to the toxic liquid benzene, and people with Down syndrome, should undergo periodic medical checkups.

Resources

ORGANIZATIONS

American Cancer Society. 1599 Clifton Rd., NE, Atlanta, GA 30329-4251. (800) 227-2345. http://www.cancer.org.

Cancer Research Institute. 681 Fifth Ave., New York, N.Y. 10022. (800) 992-2623. http://www.cancerresearch.org.

Leukemia Society of America, Inc. 600 Third Ave., New York, NY 10016. (800) 955-4572. http://www.leukemia.org.

National Cancer Institute. Building 31, Room 10A31, 31 Center Drive, MSC 2580, Bethesda, MD 20892-2580. (800) 422-6237. http://www.nci.nih.gov.

Oncolink. University of Pennsylvania Cancer Center. http://cancer.med.upenn.edu.

KEY TERMS

Antibodies Proteins made by the B lymphocytes in response to the presence of infectious agents, such as bacteria or viruses, in the body.

Biopsy The surgical removal and microscopic examination of living tissue for diagnostic purposes.

Chemotherapy Treatment with drugs that act against cancer.

Computerized tomography (CT) scan A series of x rays put together by a computer in order to form detailed pictures of areas inside the body.

Cytokines Chemicals made by the cells that act on other cells to stimulate or inhibit their function. Cytokines that stimulate growth are called "growth factors."

Immunotherapy Treatment of cancer by stimulating the body's immune defense system.

Lumbar puncture A procedure in which the doctor inserts a small needle into the spinal cavity in the lower back to withdraw some spinal fluid for testing. Also known as a "spinal tap."

Magnetic resonance imaging (MRI) A medical procedure using a magnet linked to a computer to picture areas inside the body.

Maturation The process by which stem cells transform from immature cells without a specific function into a particular type of blood cell with defined functions.

Radiation therapy Treatment using high-energy radiation from x-ray machines, cobalt, radium, or other sources.

Remission A disappearance of a disease as a result of treatment. Complete remission means that all disease is gone. Partial remission means that the disease is significantly improved by treatment, but residual traces of the disease are still present.

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"Leukemias, Acute." Gale Encyclopedia of Medicine, 3rd ed.. . Encyclopedia.com. 13 Sep. 2018 <http://www.encyclopedia.com>.

"Leukemias, Acute." Gale Encyclopedia of Medicine, 3rd ed.. . Encyclopedia.com. (September 13, 2018). http://www.encyclopedia.com/medicine/encyclopedias-almanacs-transcripts-and-maps/leukemias-acute

"Leukemias, Acute." Gale Encyclopedia of Medicine, 3rd ed.. . Retrieved September 13, 2018 from Encyclopedia.com: http://www.encyclopedia.com/medicine/encyclopedias-almanacs-transcripts-and-maps/leukemias-acute

Learn more about citation styles

Citation styles

Encyclopedia.com gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, Encyclopedia.com cannot guarantee each citation it generates. Therefore, it’s best to use Encyclopedia.com citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

http://www.mla.org/style

The Chicago Manual of Style

http://www.chicagomanualofstyle.org/tools_citationguide.html

American Psychological Association

http://apastyle.apa.org/

Notes:
  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most Encyclopedia.com content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.

Leukemias, Acute

Leukemias, acute

Definition

Leukemia is a cancer that starts in the organs that make blood, namely the bone marrow and the lymph system. Depending on their characteristics, leukemias can be divided into two broad types. Acute leukemias are the rapidly progressing leukemias, while the chronic leukemias progress more slowly. The vast majority of the childhood leukemias are of the acute form.

Description

The cells that make up blood are produced in the bone marrow and the lymph system. The bone marrow is the spongy tissue found in the large bones of the body. The lymph system includes the spleen (an organ in the upper abdomen), the thymus (a small organ beneath the breastbone), and the tonsils (an organ in the throat). In addition, the lymph vessels (tiny tubes that branch like blood vessels into all parts of the body) and lymph nodes (pea-shaped organs that are found along the network of lymph vessels) are also part of the lymph system. Lymph is a milky fluid that contains cells. Clusters of lymph nodes are found in the neck, underarm, pelvis, abdomen, and chest.

Blood is made up of red blood cells (RBCs), which carry oxygen and other materials to all tissues of the body; white blood cells (WBCs), which fight infection; and platelets, which play a part in the clotting of the blood. The white blood cells can be further subdivided into three main types: granulocytes, monocytes, and lymphocytes.

The granulocytes, as their name suggests, contain particles (granules). These granules contain special proteins (enzymes) and several other substances that can break down chemicals and destroy microorganisms, such as bacteria. Monocytes are the second type of white blood cell. They are also important in defending the body against pathogens.

The lymphocytes form the third type of white blood cell. There are two main types of lymphocytes: T lymphocytes and B lymphocytes. They have different functions within the immune system. The B cells protect the body by making antibodies, which are proteins that can attach to the surfaces of bacteria and viruses. This attachment sends signals to many other cell types to come and destroy the antibody-coated organism. The T cells protect the body against viruses. When a virus enters a cell, it produces certain proteins that are projected onto the surface of the infected cell. The T cells recognize these proteins and make certain chemicals that are capable of destroying the virus-infected cells. In addition, the T cells can destroy some types of cancer cells.

The bone marrow makes stem cells, which are the precursors of the different blood cells. These stem cells mature through stages into RBCs, WBCs, or platelets. In acute leukemias, the maturation process of the white blood cells is interrupted. The immature cells (blasts) proliferate rapidly and begin to accumulate in various organs and tissues, thereby affecting their normal function. This uncontrolled proliferation of the immature cells in the bone marrow affects the production of the normal red blood cells and platelets as well.

Acute leukemias are of two types: acute lymphocytic leukemia and acute myelogenous leukemia. Different types of white blood cells are involved in the two leukemias. In acute lymphocytic leukemia (ALL), it is the T or the B lymphocytes that become cancerous. The B cell leukemias are more common than T cell leukemias. Acute myelogenous leukemia, also known as acute nonlymphocytic leukemia (ANLL), is a cancer of the monocytes and/or granulocytes.

Demographics

Leukemias account for 2 percent of all cancers. Because leukemia is the most common form of childhood cancer, it is often regarded as a disease of childhood. However, leukemias affect nine times as many adults as children. Half of the cases occur in people who are 60 years of age or older. The incidence of acute and chronic leukemias is about the same.

Leukemia strikes both sexes and all ages. The human T-cell leukemia virus (HTLV-I) is believed to be the causative agent for some kinds of leukemias. However, as of 2004, the cause of most leukemias is not known. Acute lymphoid leukemia (ALL) is more common among Caucasians than among African-Americans, while acute myeloid leukemia (AML) affects both races equally. The incidence of acute leukemia is slightly higher among men than women. People with Jewish ancestry have a higher likelihood of getting leukemia. A higher incidence of leukemia has also been observed among persons with Down syndrome and some other genetic abnormalities.

Causes and symptoms

Exposure to ionizing radiation and to certain organic chemicals, such as benzene, is believed to increase the risk of developing leukemia. Having a history of diseases that damage the bone marrow, such as aplastic anemia, or a history of cancers of the lymphatic system puts people at a high risk for developing acute leukemias. Similarly, the use of anticancer medications, immunosuppressants, and the antibiotic chloramphenicol are also considered risk factors for developing acute leukemias.

The symptoms of leukemia are generally vague and non-specific. A patient may experience all or some of the following symptoms:

  • weakness or chronic fatigue
  • fever of unknown origin
  • weight loss that is not due to dieting or exercise
  • frequent bacterial or viral infections
  • headaches
  • skin rash
  • non-specific bone pain
  • easy bruising
  • bleeding from gums or nose
  • blood in urine or stools
  • enlarged lymph nodes and/or spleen
  • abdominal fullness

Diagnosis

Like all cancers, acute leukemias are most successfully treated when found early. There were as of 2004 no screening tests available.

If the doctor has reason to suspect leukemia, he or she will conduct a very thorough physical examination to look for enlarged lymph nodes in the neck, underarm, and pelvic region. Swollen gums, enlarged liver or spleen, bruises , or pinpoint red rashes all over the body are some of the signs of leukemia. Urine and blood tests may be ordered to check for microscopic amounts of blood in the urine and to obtain a complete differential blood count. This count gives the numbers and percentages of the different cells found in the blood. An abnormal blood test might suggest leukemia; however, the diagnosis has to be confirmed by more specific tests.

The doctor may perform a bone marrow biopsy to confirm the diagnosis of leukemia. During the biopsy, a cylindrical piece of bone and marrow is removed. The tissue is generally taken out of the hipbone. These samples are sent to the laboratory for examination. In addition to diagnosis, the biopsy is also repeated during the treatment phase of the disease to see if the leukemia is responding to therapy.

A spinal tap (lumbar puncture) is another procedure that the doctor may order to diagnose leukemia. In this procedure, a small needle is inserted into the spinal cavity in the lower back to withdraw some cerebrospinal fluid and to look for leukemic cells.

Standard imaging tests, such as x rays, computed tomography scans (CT scans), and magnetic resonance imaging (MRI) may be used to check whether the leukemic cells have invaded other areas of the body, such as the bones, chest, kidneys, abdomen, or brain. A gallium scan or bone scan is a test in which a radioactive chemical is injected into the body. This chemical accumulates in the areas of cancer or infection, allowing them to be viewed with a special camera.

Treatment

There are two phases of treatment for leukemia. The first phase is called induction therapy. As the name suggests, during this phase, the main aim of the treatment is to reduce the number of leukemic cells as far as possible and induce a remission in the patient. Once the patient shows no obvious signs of leukemia (no leukemic cells are detected in blood tests and bone marrow biopsies), the patient is said to be in remission. The second phase of treatment is then initiated. This is called continuation or maintenance therapy, and the aim in this case is to kill any remaining cells and to maintain the remission for as long as possible.

Chemotherapy is the use of drugs to kill cancer cells. It is usually the treatment of choice and is used to relieve symptoms and achieve long-term remission of the disease. Generally, combination chemotherapy, in which multiple drugs are used, is more efficient than using a single drug for the treatment. Some drugs may be administered intravenously (through a vein) in the arm; others may be given by mouth in the form of pills. If the cancer cells have invaded the brain, then chemotherapeutic drugs may be put into the fluid that surrounds the brain through a needle in the brain or back. This is known as intrathecal chemotherapy.

Because leukemia cells can spread to all the organs via the blood stream and the lymph vessels, surgery is not considered an option for treating leukemias.

Radiation therapy, which involves the use of x-rays or other high-energy rays to kill cancer cells and shrink tumors, may be used in some cases. For acute leukemias, the source of radiation is usually outside the body (external radiation therapy). If the leukemic cells have spread to the brain, radiation therapy can be given to the brain.

Bone marrow transplantation is a process in which the patient's diseased bone marrow is replaced with healthy marrow. There are two ways of doing a bone marrow transplant. In an allogeneic bone marrow transplant, healthy marrow is taken from a donor whose tissue is either the same as or very closely resembles the patient's tissues. The donor may be a twin, a sibling, or a person who is not related at all. First, the patient's bone marrow is destroyed with very high doses of chemotherapy and radiation therapy. Healthy marrow from the donor is then given to the patient through a needle in a vein to replace the destroyed marrow.

In the second type of bone marrow transplant, called an autologous bone marrow transplant, some of the patient's own marrow is taken out and treated with a combination of anticancer drugs to kill all the abnormal cells. This marrow is then frozen and saved. The marrow remaining in the patient's body is destroyed with high-dose chemotherapy and radiation therapy. The marrow that was frozen is then thawed and given back to the patient through a needle in a vein. This mode of bone marrow transplant is in the early 2000s being investigated in clinical trials.

Biological therapy or immunotherapy is a mode of treatment in which the body's own immune system is harnessed to fight the cancer. Substances that are routinely made by the immune system (such as growth factors, hormones, and disease-fighting proteins) are either synthetically made in a laboratory or their effectiveness is boosted and they are then put back into the patient's body. This treatment mode is also being investigated in the early 2000s in clinical trials all over the United States at major cancer centers.

KEY TERMS

Antibody A special protein made by the body's immune system as a defense against foreign material (bacteria, viruses, etc.) that enters the body. It is uniquely designed to attack and neutralize the specific antigen that triggered the immune response.

Biopsy The surgical removal and microscopic examination of living tissue for diagnostic purposes or to follow the course of a disease. Most commonly the term refers to the collection and analysis of tissue from a suspected tumor to establish malignancy.

Chemotherapy Any treatment of an illness with chemical agents. The term is usually used to describe the treatment of cancer with drugs that inhibit cancer growth or destroy cancer cells.

Computed tomography (CT) An imaging technique in which cross-sectional x rays of the body are compiled to create a three-dimensional image of the body's internal structures; also called computed axial tomography.

Cytokines Chemicals made by the cells that act on other cells to stimulate or inhibit their function. They are important controllers of immune functions.

Immunotherapy A mode of cancer treatment in which the immune system is stimulated to fight the cancer.

Lumbar puncture A procedure in which the doctor inserts a small needle into the spinal cavity in the lower back to withdraw spinal fluid for testing. Also known as a spinal tap.

Magnetic resonance imaging (MRI) An imaging technique that uses a large circular magnet and radio waves to generate signals from atoms in the body. These signals are used to construct detailed images of internal body structures and organs, including the brain.

Maturation The process by which stem cells transform from immature cells without a specific function into a particular type of blood cell with defined functions.

Radiation therapy A cancer treatment that uses high-energy rays or particles to kill or weaken cancer cells. Radiation may be delivered externally or internally via surgically implanted pellets. Also called radiotherapy.

Remission A disappearance of a disease and its symptoms. Complete remission means that all disease is gone. Partial remission means that the disease is significantly improved, but residual traces of the disease are still present. A remission may be due to treatment or may be spontaneous.

Prognosis

Like all cancers, the prognosis for leukemia depends on the patient's age and general health. According to statistics, more than 60 percent of the patients with leukemia survive for at least a year after diagnosis. Acute myelocytic leukemia (AML) has a poorer prognosis rate than acute lymphocytic leukemias (ALL) and the chronic leukemias. Between 1985 and 2004, the five-year survival rate for patients with ALL increased from 38 to 57 percent.

Interestingly enough, since most childhood leukemias are of the ALL type, chemotherapy has been highly successful in their treatment. This is because chemotherapeutic drugs are most effective against actively growing cells. Due to the new combinations of anticancer drugs being used, the survival rates among children with ALL have improved dramatically. Eighty percent of the children diagnosed with ALL as of 2004 survive for five years or more, as compared to 50 percent in the late 1970s.

Prevention

Most cancers can be prevented by changes in lifestyle or diet, which will reduce the risk factors. However, in leukemias, there are as of 2004 no such known risk factors. Therefore, as of 2004, no way is known to prevent leukemias from developing. People who are at an increased risk for developing leukemia because of proven exposure to ionizing radiation or exposure to the toxic liquid benzene, and people with Down syndrome, should undergo periodic medical checkups.

Parental concerns

Parents of a child with leukemia must balance their own fears for their child's health with the child's fears and worries. Also, given the large financial burden leukemia treatment entails, parents will want to make sure they are aware of what and what is not covered by their insurance. Parents can find a variety of sources, written and online, that will help them deal with the new circumstances of themselves and their family .

Resources

Campana, Dario, and Ching-Hon Pui. "Childhood Leukemia." In Clinical Oncology. Edited by Martin D. Abeloff. London: Churchill Livingstone, 2000.

Thompson, George H. "The Neck." In Nelson Textbook of Pediatrics. Edited by Richard E. Behrman et al. Philadelphia: Saunders, 2004.

Tubergen, David G., and Archie Bleyer. "The Leukemias." In Nelson Textbook of Pediatrics. Edited by Richard E. Behrman et al. Philadelphia: Saunders, 2004.

ORGANIZATIONS

American Cancer Society. 1599 Clifton Rd., NE, Atlanta, GA 303294251. Web site: <www.cancer.org>.

Cancer Research Institute. 681 Fifth Ave., New York, NY 10022. Web site: <www.cancerresearch.org>.

Leukemia Society of America Inc. 600 Third Ave., New York, NY 10016. Web site: <www.leukemia.org>.

National Cancer Institute. Building 31, Room 10A31, 31 Center Drive, MSC 2580, Bethesda, MD 208922580. <www.nci.nih.gov>.

Lata Cherath, PhD Rosalyn Carson-DeWitt, MD

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"Leukemias, Acute." Gale Encyclopedia of Children's Health: Infancy through Adolescence. . Encyclopedia.com. 13 Sep. 2018 <http://www.encyclopedia.com>.

"Leukemias, Acute." Gale Encyclopedia of Children's Health: Infancy through Adolescence. . Encyclopedia.com. (September 13, 2018). http://www.encyclopedia.com/medicine/encyclopedias-almanacs-transcripts-and-maps/leukemias-acute-0

"Leukemias, Acute." Gale Encyclopedia of Children's Health: Infancy through Adolescence. . Retrieved September 13, 2018 from Encyclopedia.com: http://www.encyclopedia.com/medicine/encyclopedias-almanacs-transcripts-and-maps/leukemias-acute-0

Learn more about citation styles

Citation styles

Encyclopedia.com gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, Encyclopedia.com cannot guarantee each citation it generates. Therefore, it’s best to use Encyclopedia.com citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

http://www.mla.org/style

The Chicago Manual of Style

http://www.chicagomanualofstyle.org/tools_citationguide.html

American Psychological Association

http://apastyle.apa.org/

Notes:
  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most Encyclopedia.com content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.

leukemia

leukemia (lōōkē´mēə), cancerous disorder of the blood-forming tissues (bone marrow, lymphatics, liver, spleen) characterized by excessive production of immature or mature leukocytes (white blood cells; see blood) and consequently a crowding-out of red blood cells and platelets. It was first named by Rudolf Virchow in 1887.

See also cancer.

Incidence and Cause

Leukemia is seen in animals, such as cats, guinea pigs, and cattle, as well as in humans. In humans it can occur at any age, but most types are more prevalent in older people. Possible causes include exposure to certain chemicals (e.g., benzene), chromosomal abnormalities such as Down syndrome, exposure to ionizing radiation, certain drugs (e.g., alkylating agents used in cancer treatment), and infection with retroviruses such as HTLV-I, a relative of the AIDS virus. All of these agents are suspected of causing mutations or other disruptions that interfere with the normal regulation of cell growth and division in leukocytes.

Types

Leukemias are classified as either lymphocytic or myeloid, depending on the type of leukocyte affected. In addition, leukemias are classified as either acute, referring to a rapidly progressing disease that involves immature leukocytes, or chronic, referring to a slower proliferation involving mature white cells. In acute leukemias, immature nonfunctioning leukocytes called blast cells proliferate.

The myeloid leukemias affect white blood cells (myelocytes) that give rise to granulocytes (phagocytic white blood cells that mount an inflammatory immune response). They include chronic myeloid leukemia (CML) and acute myeloid leukemia (AML), also called acute nonlymphocytic leukemia (ANLL). The lymphocytic leukemias affect the white blood cells that give rise to various types of lymphocytes. They include acute lymphocytic leukemia (ALL); chronic lymphocytic leukemia (CLL), also called chronic granulocytic leukemia; and hairy cell leukemia (HCL), a chronic leukemia named for the cells' tiny hairlike projections. The lymphocytic leukemias are sometimes referred to as B cell leukemias or T cell leukemias depending upon whether they arise in antibody-producing B cells (HCL, CLL, and some cases of ALL) or in the T cell lymphocytes involved in cell-mediated immunity (some cases of ALL). (See immunity for a further explanation of the cells of the immune system.) Each of these types may be further classified into subtypes. Most childhood leukemias are of the acute lymphocytic type; acute myeloid leukemia is the most common type of adult leukemia.

Symptoms

Many of the symptoms of acute leukemia can be attributed to anemia, which results from the attrition of red blood cells as they are crowded out by the leukemic cells. Frequent infections result from a dearth of functioning white blood cells. Bone tenderness may also be present. Hemorrhaging may develop because blood-clotting elements are scarce. Blasts may congregate in the lymph nodes, spleen, and liver, causing enlargement and pain, or they may invade the central nervous system, causing dizziness, headache, or fever. If untreated, death can supervene rapidly in acute leukemia.

Patients with chronic leukemias often have no symptoms and may be hard to diagnose, but less virulent versions of the symptoms seen in the acute leukemias may be present. Death from chronic leukemia is usually from infection.

Treatment

The diagnosis of leukemia is confirmed by finding a disproportionate number of leukocytes in tissue obtained from a bone marrow biopsy. The course of treatment is based upon the type of cell affected, the progression of the disease, and the age of the patient. Some slowly progressing forms may require no treatment. Improved treatments have increased survival from some types of leukemia considerably.

Treatment may include chemotherapy with anticancer drugs, radiation therapy, blood and plasma transfusions, and bone marrow transplantation. In bone marrow transplantation, healthy bone marrow (either donated by a closely matched donor or treated marrow from the patient) is infused into the patient after the patient has undergone a course of marrow-destroying very high dose chemotherapy. Recent studies have indicated that blood from a newborn infant's umbilical cord and placenta (called cord blood) can be used effectively instead of marrow transplants in some leukemias. Biological therapy (sometimes called immunotherapy) is also used. Biological therapies include monoclonal antibodies; interferons; maturation drugs, such as all-trans retinoic acid; and tyrosine kinase inhibtors, such as imantinib mesylate (also known as STI-571 and Gleevec). These therapies may enhance the body's natural reaction to leukemia by bolstering the immune response, may inhibit the gene that drives cell proliferation, or may encourage maturation of immature leukemic cells or reproduction of needed healthy blood elements.

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"leukemia." The Columbia Encyclopedia, 6th ed.. . Encyclopedia.com. 13 Sep. 2018 <http://www.encyclopedia.com>.

"leukemia." The Columbia Encyclopedia, 6th ed.. . Encyclopedia.com. (September 13, 2018). http://www.encyclopedia.com/reference/encyclopedias-almanacs-transcripts-and-maps/leukemia

"leukemia." The Columbia Encyclopedia, 6th ed.. . Retrieved September 13, 2018 from Encyclopedia.com: http://www.encyclopedia.com/reference/encyclopedias-almanacs-transcripts-and-maps/leukemia

Learn more about citation styles

Citation styles

Encyclopedia.com gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, Encyclopedia.com cannot guarantee each citation it generates. Therefore, it’s best to use Encyclopedia.com citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

http://www.mla.org/style

The Chicago Manual of Style

http://www.chicagomanualofstyle.org/tools_citationguide.html

American Psychological Association

http://apastyle.apa.org/

Notes:
  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most Encyclopedia.com content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.

leukaemia

leukaemia Leukaemia is a general neoplastic condition of the tissues that form white blood cells (leucocytes), such that abnormal white cells accumulate in vast numbers. They accumulate first in the organs of origin (for example, granulocytes in bone marrow and lymphocytes in lymph nodes); circulate in excessive number in the blood and collect in the rest of the body, resulting in organ dysfunction. The various types of leukaemia may take an acute or chronic form. The causes of leukaemia are unknown and clusters of cases sometimes occur in children. Claims have been made that these clusters are caused by exposure to radiation, but infection by an unknown virus is a more likely cause. Many leukaemias can now be successfully treated by chemotherapeutic agents.

Alan W. Cuthbert

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"leukaemia." The Oxford Companion to the Body. . Encyclopedia.com. 13 Sep. 2018 <http://www.encyclopedia.com>.

"leukaemia." The Oxford Companion to the Body. . Encyclopedia.com. (September 13, 2018). http://www.encyclopedia.com/medicine/encyclopedias-almanacs-transcripts-and-maps/leukaemia

"leukaemia." The Oxford Companion to the Body. . Retrieved September 13, 2018 from Encyclopedia.com: http://www.encyclopedia.com/medicine/encyclopedias-almanacs-transcripts-and-maps/leukaemia

Learn more about citation styles

Citation styles

Encyclopedia.com gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, Encyclopedia.com cannot guarantee each citation it generates. Therefore, it’s best to use Encyclopedia.com citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

http://www.mla.org/style

The Chicago Manual of Style

http://www.chicagomanualofstyle.org/tools_citationguide.html

American Psychological Association

http://apastyle.apa.org/

Notes:
  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most Encyclopedia.com content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.

Leukemia

LEUKEMIA

DEFINITION


Leukemia (pronounced loo-KEE-mee-uh) is a form of cancer (see cancer entry) in which the body produces too many white blood cells. Many forms of leukemia have been identified. They are divided into two general types: acute and chronic. An acute condition comes on fairly quickly. A chronic disorder develops more slowly over time.

DESCRIPTION


Blood contains three types of cells: red blood cells, white blood cells, and platelets (pronounced PLATE-lits). Each type of cell has a special function in the body. Red blood cells carry oxygen from the lungs to the rest of the body. White blood cells fight invading organisms, such as bacteria and viruses. Platelets are involved in the process of blood clotting.

All blood cells form in the soft tissue that fills the center of bones. This tissue is called bone marrow. All three types of blood cells arise out of a primitive type of cell known as a stem cell. A stem cell can develop into a red blood cell, a white blood cell, or a platelet, depending on conditions.

Leukemia is caused by the overproduction of white blood cells. This has two effects on the body. First, the white blood cells may not mature properly as they develop. They may lack the ability to kill foreign bodies in the bloodstream. This defect seriously damages the immune system and the body loses its ability to fight off infections.

Second, so many white blood cells may form that they pack the bone marrow until there is not enough room for red blood cells and platelets to develop. Without red blood cells, the body's cells do not get enough oxygen, and the condition known as anemia (see anemias entry) develops. Anemia is characterized by general weakness, headache, pale skin, and dizziness. It can become a life-threatening disorder. Without platelets, blood cannot clot properly and simple injuries can lead to serious blood loss.

There are three types of white blood cells. Each has a special role to play in the immune system. The three types are granulocytes (pronounced GRAN-yuh-lo-site), lymphocytes (pronounced LIM-fuh-sites), and monocytes (pronounced MON-uh-sites). Leukemia may result in the overproduction of any one type of white blood cell. Each type of leukemia is named for two characteristics:

  • Whether it is acute or chronic
  • Whether it affects granulocytes, lymphocytes, or monocytes

Leukemia: Words to Know

Acute:
A condition that comes on fairly quickly.
Bone marrow:
Soft, spongy material found in the center of bones.
Bone marrow biopsy:
A procedure by which a sample of bone marrow is removed and studied under a microscope.
Bone marrow transplantation:
A procedure in which healthy bone marrow is injected into a leukemia patient's bones.
Chronic:
A condition that develops slowly and lasts a long time or is reoccuring.
Immune system:
A network of organs, tissues, cells, and chemicals designed to fight off foreign invaders, such as bacteria and viruses.
Lumbar puncture:
A procedure in which a thin needle is inserted into the space between vertebrae in the spine and a sample of cerebrospinal fluid is withdrawn for study under a microscope.
Platelets:
Blood cells that assist in the process of blood clotting.
Red blood cells:
Blood cells that carry oxygen from the lungs to the rest of the body.
Stem cells:
Immature blood cells formed in bone marrow.
White blood cells:
Blood cells that fight invading organisms, such as bacteria and viruses.

For example, one form of leukemia develops very slowly. It results in the overproduction of granulocytes. That form of leukemia is called chronic granulocytic leukemia. The same disease is also known by another name, chronic myelogenous (pronounced my-uh-LAJ-uh-nuhs) leukemia.

Another form of leukemia occurs rapidly. It results in the overproduction of lymphocytes. That form of leukemia is called acute lymphocytic leukemia.

Leukemias account for about 2 percent of all cancers. It is the most common form of cancer among children. For that reason, leukemia is sometimes called a disease of childhood. However, leukemias affect nine times as many adults as children. Half of all cases of the disease occur in people over sixty. The incidence of acute and chronic leukemias is about the same.

CAUSES


No one knows what causes leukemia. Researchers have strong suspicions about four possible causes, however. They are radiation, chemicals, viruses, and genetic factors.

  • Radiation. The term "radiation" refers to various forms of energy, such as X rays and ultraviolet (UV) light found in sunlight. Radiation can tear chemicals apart, thus damaging or destroying cells. Some researchers believe that exposure to radiation can cause some forms of leukemia.
  • Chemicals. Some types of chemicals are known to be carcinogens (pronounced car-SIN-o-genz). A carcinogen is anything that can cause cancer. Chemicals can cause cancer by damaging cells and the substances within them.
  • Viruses. Some researchers believe that some types of leukemia are viral infections. A virus is a very small organism that can cause a disease. The link between viruses and leukemia is strong in some cases, but it has not been proved.
  • Genetics. Leukemia tends to occur in some families more commonly than in others. This suggests that at least some forms of leukemia may be hereditary.

SYMPTOMS


The symptoms of leukemia are generally vague. A patient may experience all or some of the following symptoms:

  • Weakness or chronic fatigue
  • Fever of unknown origin
  • Unexplained weight loss
  • Frequent bacterial or viral infections
  • Headaches
  • Skin rash
  • Bone pain with no known cause
  • Easy bruising
  • Bleeding from gums and nose
  • Blood in urine or stools
  • Enlarged lymph nodes and/or spleen
  • Fullness in the stomach

DIAGNOSIS


The first step in diagnosing leukemia occurs when a patient sees a doctor for one or more of the described symptoms. The doctor must then try to find the cause of these symptoms. The doctor first performs tests to rule out other medical conditions.

The first specific test for leukemia is likely to be a blood test. A blood test shows the relative amounts of red and white blood cells. An unusually large number of white blood cells might suggest the possibility of leukemia.

A more specific test is a bone marrow biopsy. A bone marrow biopsy is conducted with a long, thin needle that is inserted into the marrow of a bone. A bone in the hip or chest is usually chosen for this procedure. A sample of

the bone marrow is removed and studied under a microscope. The presence of abnormal blood cells is the basis for diagnosing leukemia.

If there is still doubt, an additional test may be performed. This test is a lumbar puncture (spinal tap). In a lumbar puncture, a thin needle is inserted into the space between vertebrae in the patient's spine. A sample of cerebrospinal fluid is withdrawn. Cerebrospinal fluid is a liquid that surrounds the tissues in the brain and spine. The presence of abnormal blood cells indicates that the patient has leukemia.

TREATMENT


Treatment of leukemia takes place in two steps. The goal of the first step is to bring the disease into remission. Remission means two things. First, no symptoms of the disease remain. Second, no abnormal white blood cells can be found in bone marrow. Two forms of treatment are used in this first step: chemotherapy and radiation.

Chemotherapy involves the use of certain chemicals that can kill cancer cells. These chemicals may be given orally (by mouth) or intravenously (through a vein in the arm).

THE NATIONAL BONE MARROW DONOR REGISTRY

Bone marrow transplantation (BMT) works only under very special circumstances. Specifically, bone marrow from a donor and a patient must match very closely. Usually this means the donor must be related to the patient, but not always. Sometimes non-relatives will also have very close matches. The question is how to find those non-relatives.

The task is not as easy as making a public announcement on the radio or television or in the newspaper. Experts estimate that the chance of the bone marrow of two unrelated people matching is somewhere between 1 in 10,000 to 1 in 20,000. How can doctors find that very rare person who can donate bone marrow to a patient?

Until the 1980s, there was no good answer to that question. Then, bone marrow transplant registries started springing up around the world. A bone marrow transplant registry is an office that keeps records of people's bone marrow types. In the United States, the National Bone Marrow Donor Registry (NBMDR) was created in 1986. People who wish to be considered as bone marrow donors must have a blood test. The results of that test are recorded at the NBMDR. When a leukemia patient needs a BMT, records are searched at the NBMDR. With luck, a good match is found and a bone marrow transplant can be conducted.

Radiation involves the use of high-energy rays, such as X rays, to kill cancer cells. A common source of radiation used to treat leukemia is the radioactive element cobalt 60. A radioactive element is an element that gives off high-energy radiation. A patient is placed on a table beneath a small piece of cobalt 60 contained in a large machine. The energy given off by the cobalt 60 is aimed at the patient's body. It kills cancer cells and may lead to remission.

Once remission has been achieved, treatment moves to the second step. The goal of this step is to treat the patient's bone marrow. Unless the bone marrow is changed, it will continue to produce abnormal white blood cells and the leukemia will eventually return.

The usual method for treating bone marrow is with a bone marrow transplantation. In a bone marrow transplantation, healthy bone marrow is injected into the patient's bones. If the transplantation is successful, the new bone marrow will start producing normal blood cells and the basic cause of leukemia will have been corrected.

Bone marrow transplantation is a difficult procedure. The bone marrow injected into a patient must be very similar to his or her own bone marrow. For this reason, close relatives may be the only people who can donate bone marrow for the procedure.

If foreign bone marrow is used for transplantation, the patient's immune system will attack it as if the transplanted bone marrow is a bacterium, virus, or some other disease-causing organism. In the process, the patient's immune system may start to kill off the cells in his or her body. There are drugs that can prevent this type of immune system reaction, but the drugs are quite dangerous and have serious side effects.

Alternative Treatment

Many alternative treatments are available that may prove helpful in combating the side effects of traditional cancer therapies. These alternatives, however, should not replace prescribed cancer treatments; rather, they are suggested to work in conjunction with conventional treatment.

Body work therapy such as acupuncture (Chinese therapy involving the use of fine needles), acupressure (Chinese therapy that involves applying pressure to certain points in the body), reflexology, and massage may help calm the patient and reduce stress. Relaxation techniques such as yoga and meditation may relieve nausea and discomfort. An exercise program, designed in consultation with a physician, may help promote physical and mental strength. A well-balanced diet high in fresh fruits and vegetables and whole grains and low in fats, sugar, and alcohol is suggested for overall well-being.

PROGNOSIS


The prognosis for various forms of leukemia varies widely. Three important factors are the patient's age and general health, and the time since diagnosis. That is, younger patients who are otherwise in good health have the best chance for survival if their leukemia is diagnosed early.

Prognosis also varies depending on the form of leukemia. In general, patients with chronic forms of the disease tend to live longer than those with acute forms. The average survival rate for patients with chronic leukemia is about nine years. By contrast, only about half of all patients with acute myelogenous leukemia survive five years. For acute lymphocytic leukemia, the survival rate is even less.

Medical progress has greatly improved the prognosis for leukemia over the past thirty years. Surgeons are becoming much more proficient at bone marrow transplantations. As a result, more and more patients face the possibility not only of remission but also a cure.

PREVENTION


Until the cause or causes of leukemia are found, there is no way to prevent the disease.

FOR MORE INFORMATION


Books

Dollinger, Malin. Everyone's Guide to Cancer Therapy. Toronto: Somerville House Books, Ltd., 1994.

Murphy, Gerald P. Informed Decisions: The Complete Book of Cancer Diagnosis, Treatment and Recovery. Atlanta, GA: American Cancer Society, 1997.

Siegel, Dorothy Schainman, and David E. Newton. Leukemia. New York: Franklin Watts, 1994.

Organizations

American Cancer Society. 1599 Clifton Road NE, Atlanta, GA 30329. (800) 2272345. http://www.cancer.org.

Cancer Care, Inc. 1180 Avenue of the Americas. New York, NY 10036. (800) 813HOPE. http://www.cancercareinc.org.

Cancer Research Institute. 681 Fifth Avenue, New York, NY 10022. (800) 9922623. http://www.cancerresearch.org.

Leukemia Society of America, Inc. 600 Third Avenue, New York, NY 10016. (800) 955-4572. http://www.leukemia.org.

National Cancer Institute. 31 Center Drive, Bethesda, MD 208922580. (800) 4CANCER. http://www.nci.nih.gov.

Web sites

Oncolink. [Online] University of Pennsylvania Cancer Center. http://cancer.med.upenn.edu (accessed on October 13, 1999).

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"Leukemia." UXL Complete Health Resource. . Encyclopedia.com. 13 Sep. 2018 <http://www.encyclopedia.com>.

"Leukemia." UXL Complete Health Resource. . Encyclopedia.com. (September 13, 2018). http://www.encyclopedia.com/medicine/news-wires-white-papers-and-books/leukemia

"Leukemia." UXL Complete Health Resource. . Retrieved September 13, 2018 from Encyclopedia.com: http://www.encyclopedia.com/medicine/news-wires-white-papers-and-books/leukemia

Learn more about citation styles

Citation styles

Encyclopedia.com gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, Encyclopedia.com cannot guarantee each citation it generates. Therefore, it’s best to use Encyclopedia.com citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

http://www.mla.org/style

The Chicago Manual of Style

http://www.chicagomanualofstyle.org/tools_citationguide.html

American Psychological Association

http://apastyle.apa.org/

Notes:
  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most Encyclopedia.com content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.

leukaemia

leukaemia (loo-kee-miă) n. any of a group of malignant diseases in which increased numbers of certain immature or abnormal leucocytes are produced. This leads to increased susceptibility to infection, anaemia, and bleeding. Other symptoms include enlargement of the spleen, liver, and lymph nodes. Leukaemias may be acute or chronic depending on the rate of progression of the disease. They are also classified according to the type of white cell that is proliferating abnormally, as in lymphocytic l. or monocytic l. (see also hairy cell, lymphoblast, myeloblast, myeloid (leukaemia)). Leukaemias are treated with cytotoxic drugs, monoclonal antibodies, or (occasionally) radiotherapy.
www.lrf.org.uk Website of the Leukaemia Research Fund

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"leukaemia." A Dictionary of Nursing. . Encyclopedia.com. 13 Sep. 2018 <http://www.encyclopedia.com>.

"leukaemia." A Dictionary of Nursing. . Encyclopedia.com. (September 13, 2018). http://www.encyclopedia.com/caregiving/dictionaries-thesauruses-pictures-and-press-releases/leukaemia

"leukaemia." A Dictionary of Nursing. . Retrieved September 13, 2018 from Encyclopedia.com: http://www.encyclopedia.com/caregiving/dictionaries-thesauruses-pictures-and-press-releases/leukaemia

Learn more about citation styles

Citation styles

Encyclopedia.com gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, Encyclopedia.com cannot guarantee each citation it generates. Therefore, it’s best to use Encyclopedia.com citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

http://www.mla.org/style

The Chicago Manual of Style

http://www.chicagomanualofstyle.org/tools_citationguide.html

American Psychological Association

http://apastyle.apa.org/

Notes:
  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most Encyclopedia.com content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.

Leukemia

Leukemia

Sams Story

What Is Leukemia?

What Causes Leukemia?

What Are the Symptoms of Leukemia?

How Is Leukemia Diagnosed?

How Is Leukemia Treated?

Living with Leukemia

Resources

Leukemia (loo-KEY-me-a) is a type of cancer in which the body produces a large number of immature, abnormally shaped blood cells. It usually affects the white blood cells, or leukocytes (LOO-ko-sites), which help the body fight infections and other diseases.

KEYWORDS

for searching the Internet and other reference sources

Acute lymphocytic leukemia

Bone marrow transplantation

Neoplasms

Oncology

Leukemia

Sams Story

Sam had been looking forward to the basketball season for weeks. Now that it had actually started, though, he was having trouble keeping up during practice and in games. He just did not have the energy that he usually had, and he felt pain in his joints like never before. He found that he always needed to ask the coach to give him breaks during games. His teammates accused him of being out of shape, but Sam knew that it was more than that. His mother noticed that, even though he was playing less, he had more bruises than he did last season. Eventually, Sam was forced to sit out for a few weeks with a bad case of what appeared to be the flu. He felt constantly weak and tired, and he kept getting fevers. His mother decided that it was time to see the doctor and figure out what was going on.

After hearing about Sams symptoms, the doctor ran some blood tests. These showed that Sam had leukemia, and further testing indicated that it was a type called acute lymphocytic (lim-fo-SIT-ik) leukemia, or ALL. This is the most common type of leukemia in children.

Overall, leukemia accounts for about one third of cancer cases in children. However, like most other types of cancer, it is much more common in adults. Each year, roughly 27,000 adults and 2,000 children in the United States are diagnosed with leukemia.

What Is Leukemia?

Leukemia is a type of cancer that affects the bone marrow, the soft, spongy center of the bone that produces blood cells. White blood cells, or leukocytes, help the body fight infections and other diseases. Red blood cells, or erythrocytes (e-RITH-ro-sites), carry oxygen from the lungs to the bodys tissues and take carbon dioxide from the tissues back to the lungs. Platelets help form blood clots that control bleeding.

These cells are normally produced in an orderly, controlled way as the body needs them, but with leukemia, the process gets out of control. In most cases, the marrow produces too many immature white blood cells (called blasts), that are abnormally shaped and cannot carry out their usual duties. This explains why the disease is called leukemia, which literally means white blood. As these blasts multiply and crowd the bone marrow, they interfere with the production of other types of blood cells. When the blasts move into the body, they can collect in different places, causing swelling or pain.

Different types of leukemia are described according to how quickly the disease develops and what type of blood cell is affected:

  • Acute (a-KUTE) leukemia gets worse quickly, with fast multiplication of abnormal, immature blasts.
  • Chronic (KRON-ik) leukemia worsens gradually. Abnormal blasts are present, but they are more mature and can carry out some of their functions.
  • Lymphocytic leukemia affects certain white blood cells called lymphocytes (LIM-fo-sites), which control the bodys immune response by finding and destroying foreign substances.
  • Myelogenous (my-e-LOJ-e-nus) leukemia affects other types of white blood cells in the bone marrow.

Understanding Leukemia Lingo

Many of the terms associated with leukemia, including the name of the disease itself, are derived from the Greek language. Breaking down the words into their Greek roots makes them easier to understand.

  • Leuk- or leuko- means white or colorless and is used to form the words leukemia and leukocyte.
  • -ernia means blood and is found in the words leukemia and anemia.
  • -cyte means cell and is used to form the words leukocyte, erythrocyte, and lymphocyte.
  • Erythr- or erythro- means red. Erythrocytes are red blood cells.
  • Chron- or chrono- means time. Chronic leukemia develops over a long period of time.

In all, there are four main forms of the disease: acute lymphocytic leukemia (ALL), acute myelogenous leukemia (AML), chronic lymphocytic leukemia (CLL), and chronic myelogenous leukemia (CML). Another less common form is called hairy cell leukemia, a chronic condition in which the cells develop projections that look like tiny hairs.

What Causes Leukemia?

In most cases of leukemia, doctors cannot pinpoint a specific cause. However, researchers have identified a few possible risk factors*. Studies have shown that people who are exposed to high or repeated doses of radiation*, such as Japanese survivors of the atomic bomb dropped at Hiroshima, and people with other types of cancer who have been treated with radiation therapy*, are more likely to develop leukemia. Workers who are exposed to certain chemicals, such as the benzene found in gasoline, also develop leukemia more frequently. In addition, certain viruses may play a role in the disease, although this is still under investigation.

* risk factors
are anything that increases the chance of developing a disease.
* radiation
is energy that is transmitted in the form of rays, waves, or particles. Only high-energy radiation, such as that found in x-rays and the suns ultraviolet rays, has been proven to cause human cancer.
* radiation therapy
is a treatment that uses high-energy radiation from x-rays and other sources to kill cancer cells and shrink cancerous growths.

Researchers also are studying how a persons genes* may be involved in causing leukemia. In studying the cells of people who have the disease, researchers have found that they often share certain genetic abnormalities.

* genes
are chemicals in the body that help determine a persons characteristics, such as hair or eye color. They are inherited from a persons parents and are contained in the chromosomes found in the cells of the body.

Some people have suggested a possible connection between childhood leukemia and the low-energy waves given off by high-voltage electric power lines. However, recent studies have not shown a relationship.

What Are the Symptoms of Leukemia?

When someone has leukemia, the abnormal, immature white blood cells that form cannot help the body fight off infections. As a result, the person may have frequent infections and develop flu-like symptoms, such as fever and chills. As these cells keep multiplying and move out into the body, they tend to collect in the lymph nodes* or in organs such as the liver* or spleen*. This may cause pain and swelling. If the cells collect in the central nervous system (the brain and spinal cord), they may cause headaches, vomiting, confusion, loss of muscle control, or seizures.

* lymph nodes
are round masses of tissue that contain immune cells that filter out harmful microorganisms.
* liver
is a large organ located in the upper abdomen that cleanses the blood and aids in digestion by secreting a substance called bile.
* spleen
is an organ near the stomach that helps the body fight infections and use red blood cells effectively.

The oversupply of white blood cells also interferes with the normal production of red blood cells and platelets, causing bleeding problems and a disorder called anemia (a-NEE-me-a). The person may look pale or feel weak and tired. They also may bleed or bruise easily, or find that their gums are swollen or bleeding. Other possible symptoms of leukemia include loss of appetite and/or weight; tiny red spots under the skin; sweating, especially at night; and bone or joint pain.

How Is Leukemia Diagnosed?

Doctors who see patients with these symptoms usually start by doing a full physical exam and feeling for swelling in the liver, the spleen, and the lymph nodes under the arms, in the groin, and in the neck. They also may take a sample of blood and examine it under a microscope to see what the cells look like and to determine the number of mature cells versus immature cells. Although blood tests may reveal that a patient has leukemia, they may not show what type it is. Another test called bone marrow aspiration may be necessary to check further for leukemia cells or to tell what type of leukemia a patient has. In this test, the doctor inserts a needle into a large bone, usually the hip, and removes a small sample of bone marrow. The sample then is examined under a microscope for leukemia cells.

If leukemia is present, the doctor may order additional tests to look for abnormal cells in other parts of the body. A spinal tap involves taking a sample of the fluid that fills the spaces in and around the brain and spinal cord, so that it can be checked for leukemia cells. Chest x-rays and special scans can reveal signs of the disease elsewhere in the body.

How Is Leukemia Treated?

Once acute leukemia is diagnosed, doctors start treating it right away, because it tends to worsen quickly. The goal is to bring about a complete remission, which means that there is no evidence of leukemia in the bone marrow or blood. Then doctors can give further treatment to help prevent a relapse, which means a return of the signs and symptoms of the disease after a period of improvement. Many people with acute forms of leukemia can be cured today. Just a few decades ago, ALL was considered incurable, but now it is one of the most curable forms of cancer.

Chronic leukemia sometimes is detected through a routine blood test before symptoms appear. People with chronic leukemia may not need treatment right away if they are not having symptoms yet. Doctors monitor the disease until treatment is needed. It usually can not be cured, but it can be controlled.

Chemotherapy

The most common treatments for leukemia are chemotherapy (kee-mo-THER-a-pee), radiation therapy, and/or bone marrow transplantation. In chemotherapy, patients take one or more anticancer drugs by mouth or intravenously, through a tube in one of the veins. In certain cases, doctors need to inject the drugs directly into the fluid that surrounds the brain and spinal cord. Chemotherapy can cause side effects, such as hair loss, nausea, fatigue, or easy bruising, depending on the drugs used. Most side effects go away gradually between treatments or after treatment stops.

Radiation therapy

In radiation therapy, doctors use a special machine to deliver high-energy rays that damage cancer cells and stop them from growing. The rays may be directed to one specific area of the body where leukemia cells have collected, such as the spleen, or to the whole body. Like chemotherapy, radiation therapy can cause temporary side effects, such as fatigue, hair loss, nausea, or red, dry, itchy skin.

Bone marrow transplantation

In bone marrow transplantation, doctors give high doses of chemotherapy and radiation to destroy all of the patients bone marrow, in order to kill the cells that are the source of the cancer. Then they give the patient healthy bone marrow from a donor whose tissue is similar, ideally from an identical twin or sibling. They also might give bone marrow that was removed from the patient earlier and specially treated to remove any leukemia cells. A patient who has a bone marrow transplant usually stays in the hospital for several weeks. The risk of infection is high until the transplanted bone marrow begins to produce enough white blood cells.

Biological therapy

The newest form of treatment under investigation is called biological therapy, which uses substances produced by the body to increase its ability to fight off leukemia. Scientists have identified several substances that are involved in the immune response, which is the bodys way of protecting itself from infections and other diseases. Today scientists can produce some of these substances in the lab and use them to help the body defend itself against leukemia and other forms of cancer.

Living with Leukemia

Living with leukemia can be difficult. Not only can the disease make someone feel sick, but the treatments can, too. Fortunately, though, these treatments often make the disease go into remission. Once this happens, patients still need to see their doctors often for follow-up visits and tests. That way, if the leukemia comes back, it will be detected as quickly as possible.

Having leukemia can be difficult emotionally, too. It is scary for patients to find out that they have a form of cancer and to worry about what the future may hold. Some people withdraw, get angry, or get depressed when they are diagnosed with leukemia. However, with the support of family, friends, support groups, and health professionals, a spirit of realistic optimism can win out.

See also

Anemia

Cancer

Radiation Exposure Conditions

Resources

Books

Keene, Nancy. Childhood Leukemia: A Guide for Family, Friends, and Caregivers. Sebastopol, CA: OReilly and Associates, 1997. This book is written mainly for parents, but it offers a wealth of practical advice on coping with childhood leukemia.

Organizations

American Cancer Society, 1599 Clifton Road Northeast, Atlanta, GA 30329-4251. This large nonprofit organization provides information about leukemia in both children and adults. Telephone 800-ACS-2345 http://www.cancer.org

Leukemia Society of America, 600 Third Avenue, New York, NY 10016. This nonprofit organization provides extensive information about leukemia to the public. Telephone 800-955-4572 http://www.leukemia.org

National Bone Marrow Transplant Link, 29209 Northwestern Highway, Number 624, Southfield, MI 48034. A support organization for bone marrow transplant patients. Telephone 800-LINK-BMT http://comnet.org/nbmtlink

U.S. National Cancer Institute, Building 31, Room 10A03, 31 Center Drive, Bethesda, MD 20892-2580. This U.S. government agency provides detailed information about leukemia and posts a fact sheet What You Need to Know About Leukemia at its website. Telephone 800-4-CANCER http://rex.nci.nih.gov http://cancernet.nci.gov/wyntk_pubs/index.html

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"Leukemia." Complete Human Diseases and Conditions. . Encyclopedia.com. 13 Sep. 2018 <http://www.encyclopedia.com>.

"Leukemia." Complete Human Diseases and Conditions. . Encyclopedia.com. (September 13, 2018). http://www.encyclopedia.com/medicine/encyclopedias-almanacs-transcripts-and-maps/leukemia

"Leukemia." Complete Human Diseases and Conditions. . Retrieved September 13, 2018 from Encyclopedia.com: http://www.encyclopedia.com/medicine/encyclopedias-almanacs-transcripts-and-maps/leukemia

Learn more about citation styles

Citation styles

Encyclopedia.com gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, Encyclopedia.com cannot guarantee each citation it generates. Therefore, it’s best to use Encyclopedia.com citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

http://www.mla.org/style

The Chicago Manual of Style

http://www.chicagomanualofstyle.org/tools_citationguide.html

American Psychological Association

http://apastyle.apa.org/

Notes:
  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most Encyclopedia.com content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.

leukaemia

leukaemia Any of a group of cancers in which the bone marrow and other blood-forming tissues produce abnormal numbers of immature or defective leucocytes. This over-production suppresses output of normal blood cells and platelets, leaving the person vulnerable to infection, anaemia and bleeding. Acute lymphoblastic leukaemia (ALL) is predominantly a disease of childhood; acute myelogenous leukaemia (AML) is mainly seen in older adults. Both forms are potentially curable.

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"leukaemia." World Encyclopedia. . Encyclopedia.com. 13 Sep. 2018 <http://www.encyclopedia.com>.

"leukaemia." World Encyclopedia. . Encyclopedia.com. (September 13, 2018). http://www.encyclopedia.com/environment/encyclopedias-almanacs-transcripts-and-maps/leukaemia

"leukaemia." World Encyclopedia. . Retrieved September 13, 2018 from Encyclopedia.com: http://www.encyclopedia.com/environment/encyclopedias-almanacs-transcripts-and-maps/leukaemia

Learn more about citation styles

Citation styles

Encyclopedia.com gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, Encyclopedia.com cannot guarantee each citation it generates. Therefore, it’s best to use Encyclopedia.com citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

http://www.mla.org/style

The Chicago Manual of Style

http://www.chicagomanualofstyle.org/tools_citationguide.html

American Psychological Association

http://apastyle.apa.org/

Notes:
  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most Encyclopedia.com content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.

leukemia

leu·ke·mi·a / loōˈkēmēə/ (Brit. leu·kae·m·ia) • n. a malignant progressive disease in which the bone marrow and other blood-forming organs produce increased numbers of immature or abnormal leukocytes. These suppress the production of normal blood cells, leading to anemia and other symptoms. DERIVATIVES: leu·ke·mic / -ˈkēmik/ adj.

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"leukemia." The Oxford Pocket Dictionary of Current English. . Encyclopedia.com. 13 Sep. 2018 <http://www.encyclopedia.com>.

"leukemia." The Oxford Pocket Dictionary of Current English. . Encyclopedia.com. (September 13, 2018). http://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/leukemia-0

"leukemia." The Oxford Pocket Dictionary of Current English. . Retrieved September 13, 2018 from Encyclopedia.com: http://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/leukemia-0

Learn more about citation styles

Citation styles

Encyclopedia.com gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, Encyclopedia.com cannot guarantee each citation it generates. Therefore, it’s best to use Encyclopedia.com citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

http://www.mla.org/style

The Chicago Manual of Style

http://www.chicagomanualofstyle.org/tools_citationguide.html

American Psychological Association

http://apastyle.apa.org/

Notes:
  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most Encyclopedia.com content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.

leukaemia

leukaemia See cancer.

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"leukaemia." A Dictionary of Biology. . Encyclopedia.com. 13 Sep. 2018 <http://www.encyclopedia.com>.

"leukaemia." A Dictionary of Biology. . Encyclopedia.com. (September 13, 2018). http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/leukaemia

"leukaemia." A Dictionary of Biology. . Retrieved September 13, 2018 from Encyclopedia.com: http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/leukaemia

Learn more about citation styles

Citation styles

Encyclopedia.com gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, Encyclopedia.com cannot guarantee each citation it generates. Therefore, it’s best to use Encyclopedia.com citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

http://www.mla.org/style

The Chicago Manual of Style

http://www.chicagomanualofstyle.org/tools_citationguide.html

American Psychological Association

http://apastyle.apa.org/

Notes:
  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most Encyclopedia.com content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.

leukaemia

leukaemia •Grasmere • cashmere •Emyr, premier •macadamia, Mesopotamia •academia, anaemia (US anemia), Bohemia, Euphemia, hypoglycaemia, leukaemia (US leukemia), septicaemia (US septicemia), uraemia •bulimia, Ymir •arrhythmia • Vladimir • encomia •costumier • Windermere •Hermia, hyperthermia, hypothermia

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"leukaemia." Oxford Dictionary of Rhymes. . Encyclopedia.com. 13 Sep. 2018 <http://www.encyclopedia.com>.

"leukaemia." Oxford Dictionary of Rhymes. . Encyclopedia.com. (September 13, 2018). http://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/leukaemia

"leukaemia." Oxford Dictionary of Rhymes. . Retrieved September 13, 2018 from Encyclopedia.com: http://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/leukaemia

Learn more about citation styles

Citation styles

Encyclopedia.com gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, Encyclopedia.com cannot guarantee each citation it generates. Therefore, it’s best to use Encyclopedia.com citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

http://www.mla.org/style

The Chicago Manual of Style

http://www.chicagomanualofstyle.org/tools_citationguide.html

American Psychological Association

http://apastyle.apa.org/

Notes:
  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most Encyclopedia.com content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.

leukemia

leukemia •Grasmere • cashmere •Emyr, premier •macadamia, Mesopotamia •academia, anaemia (US anemia), Bohemia, Euphemia, hypoglycaemia, leukaemia (US leukemia), septicaemia (US septicemia), uraemia •bulimia, Ymir •arrhythmia • Vladimir • encomia •costumier • Windermere •Hermia, hyperthermia, hypothermia

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"leukemia." Oxford Dictionary of Rhymes. . Encyclopedia.com. 13 Sep. 2018 <http://www.encyclopedia.com>.

"leukemia." Oxford Dictionary of Rhymes. . Encyclopedia.com. (September 13, 2018). http://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/leukemia

"leukemia." Oxford Dictionary of Rhymes. . Retrieved September 13, 2018 from Encyclopedia.com: http://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/leukemia

Learn more about citation styles

Citation styles

Encyclopedia.com gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, Encyclopedia.com cannot guarantee each citation it generates. Therefore, it’s best to use Encyclopedia.com citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

http://www.mla.org/style

The Chicago Manual of Style

http://www.chicagomanualofstyle.org/tools_citationguide.html

American Psychological Association

http://apastyle.apa.org/

Notes:
  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most Encyclopedia.com content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.

Leukemia

Leukemia

History

Leukemia types and treatment

Resources

From the Greek words for white (leukos) and blood (hemia), leukemia refers to abnormally shaped and functioning leukocytes (white blood cells). Because the leukocytes multiply at an uncontrolled and rapid rate, leukemia is considered a cancer of the blood. Depending on their characteristics, leukemias can be divided into two broad types. Acute leukemias are the rapidly progressing leukemias, while the chronic leukemias progress more slowly. The vast majority of the childhood leukemias are of the acute form.

As of 2004, according to the Leukemia & Lymphoma Society, over 110,000 people will be diagnosed with leukemia, Hodgkin and non-Hodgkin lymphoma, and myeloma in any one year. (These diseases are oftentimes grouped together because they are all cancers that originate in the bone marrow or lymphatic tissues.) Eight percent of all cancers (approximately 1.3 million annually) are due to this group of diseases. According to statistics provided by the American Cancer Society (ACS), as of 2005, more than 65% of the patients with leukemia survive for at least one year after diagnosis.

Leukemia is neither contagious nor infectious, nor acquired from the mother prior to or during birth, but some researchers have suggested genetic predispositions exist for rare forms of leukemia, such as hairy-cell leukemia (HCL) that affects lymphocytes. Emerging evidence links leukemia to the Human T-Cell Lymphotropic Virus (HTLV), the Epstein-Barr Virus (EBV), and HIV (human immunodeficiency virus), although causes and risk factors are still poorly understood and fervently contested among scientists. Current research points to the cause of leukemia as a result of an acquired genetic injury to the DNA (deoxyribonucleic acid) of a cell, which then multiplies in its damaged form until the disease state is reached.

Leukemia begins in the bone marrow and spreads through the lymph and blood system to tissues, organs, and sometimes testicles, brain, and spinal fluid. Leukocytes normally attack, kill, and help to expel invading microbes, but the leukocytes of patients with leukemia are abnormally shaped, increased in number, and immature of development (termed lymphoblasts). As the lymphoblasts multiply and spread, they outnumber and overwhelm the erythrocytes that transport oxygen and carbon dioxide in opposite directions, and hamper the function of platelets (thrombocytes), which help blood to clot.

History

In 1827, French physician Alfred Velpeau (17951867) autopsied the body of a man who had experienced fever, weakness, pain, pus-filled blood, and headaches, and whose spleen weighed 10 lb (4.5 kg). Twelve years later, two more French physicians reported similar cases of fever, weakness, and enlarged organs, but suggested that the pus-filled blood actually contained white blood cells, or leukocytes. Scottish physicians found leukocytes when they conducted several more autopsies in 1845, including a man whose liver and spleen weighed 11 lb (4.9 kg) and 8 lb (3.6 kg), respectively. Also in 1845, German pathologist Rudolph Virchow (18211902) coined a new term,weisses blut (white blood) to describe an imbalance between leukocytes and red blood cells, or erythrocytes. In 1890, German physician Paul Ehrlich (18541915) discovered that leukocytes varied by shape, kind, and function. In 1910, the same year that he discovered Salvarsan, the first magic bullet used against syphilis, Ehrlich discovered the poisonous extracts of mustard plants that were eventually developed into the first biological weapons. When inhaled, these mustard gases badly damaged lymph glands and the bone marrow, where white blood cells originate.

French physicist Pierre Curie (18591906) had weakness and swollen organs and glands until he was killed in 1906 by a horse-drawn carriage. In 1903, he and his Polish-born wife, French scientist Marie Curie (18671934), along with French physicist Henri Becquerel (18521908), shared the Nobel Prize in physics. Following her discovery of the highly radioactive materials radium and polonium (she coined the term radioactivity), Marie Curie pioneered the battlefield use of primitive x-ray machines (protected only by fabric gloves and a thin metal screen) to locate bullets and shrapnel in wounded soldiers. Curie died in 1934 after experiencing the same pain and headaches, fatigue, swollen glands and organsas did her daughter and son-in-law. Neither scientist linked his or her symptoms to the burns they experienced with each exposure to radium.

When Velpeau first peered through his microscope in 1827 at his globules of pus in the blood, he was actually seeing leukemia, a disease name given by Virchow in 1847. The fevers, headaches, engorged glands, and swollen organs that those French, German, and Scottish patients had developed, and the cause of Marie Curies death, were leukemia. The disease that the American researchers were trying in 1942 to treat with highly toxic chemical therapies (nitrogen mustard), in extension of Ehrlichs earlier work with mustard plant extracts, was also leukemia.

Leukemia types and treatment

Leukemia specialists recognize four types of the disease. Distinctions between acute and chronic stages of leukemia depend upon the number and ratio of lymphoblasts (immature leukocytes), erythrocytes, and thrombocytes (platelets). Acute myeloid leukemia (AML) and acute lymphocytic leukemia (ALL) are diagnosed in over 13,000 Americans in any given year (as of the first few years of 2000s), whereas chronic lymphocytic leukemia (CLL) and chronic myeloid leukemia (CML) accounted for over 12,000 more cases in the same year. Over 4,600 Americans are diagnosed annually with rare forms such as erythro-leukemia (affecting red blood cells), hairy-cell leukemia (HCL) and monocytic leukemia. Patients with leukemia can experience thrombocytopenia (insufficient platelets), which causes internal bleeding and excessive bruising, anemia (insufficient erythrocytes), which results in weakness, pale complexion, and dizziness due to insufficient oxygen, and leukopenia (insufficient disease-fighting leukocytes), which allows recurrent fevers and infections.

Due to increased skills, new technologies, and greater public awareness, more leukemia cases are being diagnosed. Leukemia accounts for nearly one-third of all new cases of cancer in children, but most cases are diagnosed in adults. Five-year survival rates for most forms of leukemia have dramatically risen, from roughly 5% in the early 1960s to 38% by the mid-1970s and 1980s. After diagnosis, greater than 40% of

KEY TERMS

Lymphoblast Immature white blood cells.

Lymphocyte White blood cells that originate in the spongy tissue of the bone marrow.

Marrow stem cell Immature blood-forming cells, normally fewer than one in 100,000 of the cells in the bone marrow.

Remission A period of time when neither disease causes nor associated symptoms can be found.

all patients with leukemia in the 2000s now survive for at least five years.

Researchers suspect that genetic, behavioral, and especially environmental factors cause leukemia. Morbidity (sickness) and mortality (death) rates vary greatly by gender, race, ethnicity, geography, and socioeconomic class. Forms of ionizing radiation, such as what Japanese survivors of atomic bombing experienced, are implicated strongly in three major forms of leukemia, but non-ionizing forms of radiation (present in electricity) have also been linked to leukemias epidemiology, or disease patterns across time. Exposure to benzene, which occurs in petroleum, chemical, shoe, and rubber manufacturing, and in painting and printing, correlates strongly to leukemia, but its use has been banned in the United States since 1945, although it is used elsewhere. Long-term exposure to agricultural fertilizers and infectious agents associated with livestock, pesticides, and diesel fuel and exhaust, have all been suggested as risk factors for the development of leukemia.

Both improved and new therapies have greatly reduced morbidity and mortality from leukemia. The hormone erythropoietin, for example, helps oxygen-carrying erythrocytes to multiply, which might help to treat some leukemia-caused anemias. Standard treatment options range from chemotherapy to biological therapies, from surgery to radiation, from radiation and chemotherapy combined to marrow stem cell transplantation. Surgery can be used to remove swollen and enlarged lymph nodes or organs such as the spleen that cause severely decreased platelets in the bone marrow and bloodstream. Drug therapy is usually the first option, and the ultimate goal is complete remission, in which no lymphoblasts are seen in the blood and bone marrow is normal. Biotherapy (immunotherapy) works with synthesized forms of naturally occurring substances in the body (interferon and interleukins) to disrupt the multiplication and spread of immature cells (lymphoblasts). Homeopathic remedies treat leukemia as a character trait, as the bodys expression of an insult to the system. Due to earlier detection and improved therapies, leukemia is no longer considered a virtual death sentence, and many people remain in remission decades after treatment.

See also Lymphatic system.

Resources

BOOKS

Henderson, Edward S., T. Andrew Lister, and Mel F. Greaves, eds. Leukemia. Philadelphia, PA: Saunders, 2002.

Lackritz, Barbara. Adult Leukemia:A Comprehensive Guide for Patients and Families. Cambridge, MA: OReilly, 2001.

Romero, Rafael, ed. Focus on Leukemia Research. New York: Nova Biomedical Books, 2005.

Scheinberg, David A., and Joseph G. Jurcic, eds. Treatment of Leukemia and Lymphoma. Amsterdam, Netherlands: Elsevier, 2004.

PERIODICALS

Christensen, Damaris. Old drug, new uses?Science News 162, (2002): 29698.

OTHER

Leukemia and Lymphoma Society. Fighting Blood Cancers. <http://www.leukemia-lymphoma.org/hm_lls> (accessed accessed November 30, 2006).

Reynal, Florence (Ministry of Foreign Affairs, France). Maria Curie: A Nobel Prize Pioneer at the Pantheon. <http://www.diplomatie.gouv.fr/label_france/ENGLISH/SCIENCES/CURIE/marie.html> (accessed November 30, 2006).

Lawrence Hammar

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"Leukemia." The Gale Encyclopedia of Science. . Encyclopedia.com. 13 Sep. 2018 <http://www.encyclopedia.com>.

"Leukemia." The Gale Encyclopedia of Science. . Encyclopedia.com. (September 13, 2018). http://www.encyclopedia.com/science/encyclopedias-almanacs-transcripts-and-maps/leukemia

"Leukemia." The Gale Encyclopedia of Science. . Retrieved September 13, 2018 from Encyclopedia.com: http://www.encyclopedia.com/science/encyclopedias-almanacs-transcripts-and-maps/leukemia

Learn more about citation styles

Citation styles

Encyclopedia.com gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, Encyclopedia.com cannot guarantee each citation it generates. Therefore, it’s best to use Encyclopedia.com citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

http://www.mla.org/style

The Chicago Manual of Style

http://www.chicagomanualofstyle.org/tools_citationguide.html

American Psychological Association

http://apastyle.apa.org/

Notes:
  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most Encyclopedia.com content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.

Leukemia

Leukemia

Leukemia is a disease of the blood-forming organs. Primary tumors are found in the bone marrow and lymphoid tissues, specifically the liver, spleen, and lymph nodes. The characteristic common to all types of leukemia is the uncontrolled proliferation of leukocytes (white blood cells) in the blood stream. This results in a lack of normal bone marrow growth, and bone marrow is replaced by immature and undifferentiated leukocytes or "blast cells." These immature and undifferentiated cells then migrate to various organs in the body, resulting in the pathogenesis of normal organ development and processing.

Leukemia occurs with varying frequencies at different ages, but it is most frequent among the elderly who experience 27,000 cases a year in the United States to 2,200 cases a year for younger people. Acute lymphoblastic leukemia, most common in children, is responsible for two-thirds of all cases. Acute nonlymphoblastic leukemia and chronic lymphocytic leukemia are most common among adultsthey are responsible for 8,000 and 9,600 cases a year respectively. The geographical sites of highest concentration are the United States, Canada, Sweden, and New Zealand. While there is clear evidence that some leukemias are linked to genetic traits, the origins of this disease in most cases is mysterious. It seems clear, however, that environmental exposure to radiation, toxic substances, and other risk factors plays an important role in many leukemias.

See also Cancer; Carcinogen; Radiation exposure; Radiation sickness

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"Leukemia." Environmental Encyclopedia. . Encyclopedia.com. 13 Sep. 2018 <http://www.encyclopedia.com>.

"Leukemia." Environmental Encyclopedia. . Encyclopedia.com. (September 13, 2018). http://www.encyclopedia.com/environment/encyclopedias-almanacs-transcripts-and-maps/leukemia

"Leukemia." Environmental Encyclopedia. . Retrieved September 13, 2018 from Encyclopedia.com: http://www.encyclopedia.com/environment/encyclopedias-almanacs-transcripts-and-maps/leukemia

Learn more about citation styles

Citation styles

Encyclopedia.com gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, Encyclopedia.com cannot guarantee each citation it generates. Therefore, it’s best to use Encyclopedia.com citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

http://www.mla.org/style

The Chicago Manual of Style

http://www.chicagomanualofstyle.org/tools_citationguide.html

American Psychological Association

http://apastyle.apa.org/

Notes:
  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most Encyclopedia.com content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.

Leukemia

Leukemia

From the Greek words for white (leukos) and blood (hemia), leukemia refers to abnormally shaped and functioning leukocytes (white blood cells). Because the leukocytes multiply at an uncontrolled and rapid rate , leukemia is considered a cancer of the blood. Leukemia is neither contagious nor infectious, nor acquired from the mother prior to or during birth , but some researchers have suggested genetic predispositions exist for rare forms of leukemia, such as hairy-cell leukemia (HCL) that affects lymphocytes. Emerging evidence links leukemia to the Human T-Cell Lymphotropic Virus (HTLV), the Epstein-Barr Virus (EBV), and even HIV, although causes and risk factors are still poorly understood and fervently contested among scientists. Current research points to the cause of leukemia as a result of an acquired genetic injury to the DNA of a cell , which then multiplies in its damaged form until the disease state is reached.

Leukemia begins in the bone marrow and spreads through the lymph and blood system to tissues, organs, and sometimes testicles, brain , and spinal fluid. Leukocytes normally attack, kill, and help to expel invading microbes, but the leukocytes of patients with leukemia are abnormally shaped, increased in number, and immature of development (termed lymphoblasts). As the lymphoblasts multiply and spread, they outnumber and overwhelm the erythrocytes that transport oxygen and carbon dioxide in opposite directions, and hamper the function of platelets (thrombocytes), which help blood to clot.

History

In 1827, French physician Alfred Velpeau autopsied the body of a man who had experienced fever, weakness, pain , pus-filled blood, and headaches, and whose spleen weighed 10 lb (4.5 kg). Twelve years later, two more French physicians reported similar cases of fever, weakness, and enlarged organs, but suggested that the "pus-filled blood" actually contained white blood cells, or leukocytes. Scottish physicians found leukocytes when they conducted several more autopsies in 1845, including a man whose liver and spleen weighed 11 lb (4.9 kg) and 8 lb (3.6 kg), respectively. Also in 1845, German pathologist Rudolph Virchow coined a new term, weisses blut (white blood) to describe an imbalance between leukocytes and red blood cells, or erythrocytes. In 1890, another German physician, Paul Ehrlich, discovered that leukocytes varied by shape, kind, and function. In 1910, the same year that he discovered Salvarsan, the first "magic bullet" used against syphilis, Ehrlich discovered the poisonous extracts of mustard plants that were eventually developed into the first biological weapons. When inhaled, these "mustard gases" badly damaged lymph glands and the bone marrow, where white blood cells originate.

The French physicist Pierre Curie had weakness and swollen organs and glands until he was killed in 1906 by a horse-drawn carriage. In 1903, he and his Polish wife, Marie Curie (along with Henri Becquerel) shared the Nobel Prize in Physics . Following her discovery of the highly radioactive materials radium and polonium (she coined the term "radioactivity"), Marie Curie pioneered the battlefield use of primitive x-ray machines (protected only by fabric gloves and a thin metal screen) to locate bullets and shrapnel in wounded soldiers. Curie died in 1934 after experiencing the same pain and headaches, fatigue, swollen glands and organs—as did her daughter and son-in-law. Neither scientist linked his or her symptoms to the burns they experienced with each exposure to radium.

When Velpeau first peered through his microscope in 1827 at his "globules of pus in the blood," he was actually seeing leukemia, a disease name given by Virchow in 1847. The fevers, headaches, engorged glands, and swollen organs that those French, German and Scottish patients had developed, and the cause of Marie Curie's death, were leukemia. The disease that the American researchers were trying in 1942 to treat with highly toxic chemical therapies (nitrogen mustard), in extension of Ehrlich's earlier work with mustard plant extracts, was also leukemia.


Leukemia types and treatment

Leukemia specialists recognize four types of the disease. Distinctions between acute and chronic stages of leukemia depend upon the number and ratio of lymphoblasts (immature leukocytes), erythrocytes, and thrombocytes (platelets). Acute myeloid leukemia (AML) and acute lymphocytic leukemia (ALL) were diagnosed in 13,200 Americans in 1999, whereas chronic lymphocytic leukemia (CLL) and chronic myeloid leukemia (CML) accounted for 12,300 more cases in the same year. Another 4,600 Americans were diagnosed with rare forms such as erythroleukemia (affecting red blood cells), hairy-cell leukemia (HCL) and monocytic leukemia. Patients with leukemia can experience thrombocytopenia (insufficient platelets), which causes internal bleeding and excessive bruising, anemia (insufficient erythrocytes), which results in weakness, pale complexion, and dizziness due to insufficient oxygen, and leukopenia (insufficient disease-fighting leukocytes), which allows recurrent fevers and infections.

Due to increased skills, new technologies, and greater public awareness, more leukemia cases are being diagnosed. Leukemia accounts for nearly one-third of all new cases of cancer in children, but most cases are diagnosed in adults. Five-year survival rates for most forms of leukemia have dramatically risen, from roughly 5% in the early 1960s to 38% by the mid-1970s and 1980s. After diagnosis , greater than 40% of all patients with leukemia now survive for at least five years.

Researchers suspect that genetic, behavioral, and especially environmental factors cause leukemia. Morbidity (sickness) and mortality (death) rates vary greatly by gender, race, ethnicity, geography, and socioeconomic class. Forms of ionizing radiation , such as what Japanese survivors of atomic bombing experienced, are implicated strongly in three major forms of leukemia, but nonionizing forms of radiation (present in electricity ) have also been linked to leukemia's epidemiology , or disease patterns across time . Exposure to benzene , which occurs in petroleum , chemical, shoe, and rubber manufacturing, and in painting and printing , correlates strongly to leukemia, but its use has been banned in the United States since 1945, although it is used elsewhere. Long-term exposure to agricultural fertilizers and infectious agents associated with livestock , pesticides , and diesel fuel and exhaust, have all been suggested as risk factors for the development of leukemia.

Both improved and new therapies have greatly reduced morbidity and mortality from leukemia. The hormone erythropoietin, for example, helps oxygen-carrying erythrocytes to multiply, which might help to treat some leukemia-caused anemias. Standard treatment options range from chemotherapy to biological therapies, from surgery to radiation, from radiation and chemotherapy combined to marrow stem cell transplantation. Surgery can be used to remove swollen and enlarged lymph nodes

or organs such as the spleen that cause severely decreased platelets in the bone marrow and bloodstream. Drug therapy is usually the first option, and the ultimate goal is complete remission, in which no lymphoblasts are seen in the blood and bone marrow is normal. Biotherapy (immunotherapy) works with synthesized forms of naturally occurring substances in the body (interferon and interleukins) to disrupt the multiplication and spread of immature cells (lymphoblasts). Homeopathic remedies treat leukemia as a character trait, as the body's expression of an insult to the system. Due to earlier detection and improved therapies, leukemia is no longer considered a virtual death sentence, and many people remain in remission decades after treatment.

See also Lymphatic system.


Resources

books

Lackritz, Barbara. Adult Leukemia: A Comprehensive Guide for Patients and Families. Cambridge: O'Reilly, 2001.

Teeley, Peter, and Philip Bashe. The Complete Cancer Survival Guide. New York: Doubleday, 2000.

periodicals

Christensen, Damaris. "Old drug, New uses?" Science News 162, (2002): 296–98.

organizations

Leukemia and Lymphoma Society. 1311 Mamaroneck Ave. White Plains, NY 10605 (914) 949–5213. <http://www.leukemia.org/hm_lls>.

other

Reynal, Florence. "Marie Curie: A Nobel Prize Pioneer at the Pantheon." August 1995 [cited January 22, 2003].

<http://www.france.diplomatie.fr/label_france/index/gb/sciences-techno01.html>


Lawrence Hammar

KEY TERMS

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Lymphoblast

—Immature white blood cells.

Lymphocyte

White blood cells that originate in the spongy tissue of the bone marrow.

Marrow stem cell

—Immature blood-forming cells, normally fewer than one in 100,000 of the cells in the bone marrow.

Remission

—A period of time when neither disease causes nor associated symptoms can be found.

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"Leukemia." The Gale Encyclopedia of Science. . Encyclopedia.com. 13 Sep. 2018 <http://www.encyclopedia.com>.

"Leukemia." The Gale Encyclopedia of Science. . Encyclopedia.com. (September 13, 2018). http://www.encyclopedia.com/science/encyclopedias-almanacs-transcripts-and-maps/leukemia-0

"Leukemia." The Gale Encyclopedia of Science. . Retrieved September 13, 2018 from Encyclopedia.com: http://www.encyclopedia.com/science/encyclopedias-almanacs-transcripts-and-maps/leukemia-0

Learn more about citation styles

Citation styles

Encyclopedia.com gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, Encyclopedia.com cannot guarantee each citation it generates. Therefore, it’s best to use Encyclopedia.com citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

http://www.mla.org/style

The Chicago Manual of Style

http://www.chicagomanualofstyle.org/tools_citationguide.html

American Psychological Association

http://apastyle.apa.org/

Notes:
  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most Encyclopedia.com content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.

Leukemias, Acute

Leukemias, Acute

Definition

Acute leukemia is a type of cancer in which excessive quantities of abnormal white blood cells are produced.

Description

Medical science classifies acute leukemia by the type of white blood cell that undergoes mutation. The most common of these are:

  • Acute lymphoblastic leukemia (ALL), in which excessive quantities of lymphoblasts, or immature lymphocyte white blood cells, are produced.
  • Acute myeloblastic leukemia (AML), also known as acute nonlymphocytic leukemia (ANLL), in which excessive quantities of other types of immature white blood cells are produced.

Acute leukemias progress rapidly, while the chronic leukemias progress more slowly. The vast majority of the childhood leukemias are of the acute form.

The cells that make up blood are produced in the bone marrow and the lymphatic system. Bone marrow is the spongy tissue found in the large bones of the body. The lymphatic system includes the spleen (an organ in the upper abdomen), the thymus (a small gland beneath the breastbone), and the tonsils (a mass of lymphatic tissue located in the throat). In addition, the lymphatic vessels (tiny tubes that branch like blood vessels into all parts of the body) and lymph nodes (pea-shaped organs that are found along the network of lymphatic vessels) are also part of the lymphatic system. Lymph is a milky fluid that contains cells. Clusters of lymph nodes are found in the neck, underarm, pelvis, abdomen, and chest.

The cells found in the blood include red blood cells (RBCs) that carry oxygen and other materials to all tissues of the body; white blood cells (WBCs) that fight infection; and platelets, which play an important role in the clotting of the blood. White blood cells can be further subdivided into three main types: granulocytes, monocytes, and lymphocytes.

The granulocytes, as their name suggests, have particles (granules) inside them. These granules contain special proteins (enzymes) and several other substances that can break down chemicals and destroy microorganisms, such as bacteria. Monocytes are the second type of white blood cell. They are also important in defending the body against pathogens.

Lymphocytes are the third type of white blood cell. There are two primary types of lymphocytes—T lymphocytes and B lymphocytes—with different functions in the immune system. B cells protect the body by making antibodies. Antibodies are proteins that can attach to the surfaces of bacteria and viruses. This "attachment" sends signals to many other cell types to come and destroy the antibody-coated organism. T cells protect the body against viruses. When a virus enters a cell, it produces certain proteins that are projected onto the surface of the infected cell. T cells recognize these proteins and make certain chemicals that are capable of destroying the virus-infected cells. In addition, T cells can destroy some types of cancer cells.

Bone marrow makes stem cells, which are the precursors of the different blood cells. These stem cells mature through stages into RBCs, WBCs, or platelets. In acute leukemias, the maturation process of the white blood cells is interrupted. The immature cells (or "blasts") proliferate rapidly and begin to accumulate in various organs and tissues, thereby affecting their normal function. This uncontrolled proliferation of the immature cells in the bone marrow affects the production of the normal red blood cells and platelets as well.

As noted, there are two types of acute leukemias—acute lymphocytic leukemia and acute myelogenous leukemia. Different types of white blood cells are involved in the two leukemias. In acute lymphocytic leukemia (ALL), it is the T or the B lymphocytes that are involved. The B cell leukemias are more common than T cell leukemias. Acute myelogenous leukemia, also known as acute nonlymphocytic leukemia (ANLL), is a cancer of the monocytes and/or granulocytes.

Leukemias account for 2% of all cancers. Because leukemia is the most common form of childhood cancer, it is often regarded as a disease of childhood. However, leukemias affect far more adults than children. Half of the cases occur in people who are 60 years of age or older. The incidence of acute and chronic leukemias is about the same. According to the estimates of the American Cancer Society (ACS), approximately 29,000 new cases of leukemia are diagnosed each year in the United States. Of these, 27,000 will be diagnosed in adults, 2,000 in children.

Causes and symptoms

Leukemia strikes both sexes and all ages. The human T-cell leukemia virus (HTLV-I), a virus with similarities to the human immunodeficiency virus (HIV), is believed to be the causative agent for some kinds of leukemias, but this has not yet been proven, and the cause of most leukemias is not known. Acute lymphoid leukemia (ALL) is more common among Caucasians than among African-Americans, while acute myeloid leukemia (AML) affects both races equally. The incidence of acute leukemia is slightly higher among men than women. People with Jewish ancestry have a higher likelihood of getting leukemia. A higher incidence of leukemia has also been observed among persons with Down syndrome and some other genetic abnormalities.

Reports in Science News cited studies that found a gene that regulates folic acid metabolism in the body to be more prevalent in acute lymphocytic leukemia (ALL) patients. Folic acid is known to be involved in the process of DNA maintenance and repair, and this gene diverts folic acid from this function. It is therefore hypothesized that this gene plays a role in the development of ALL, and that folic acid supplementation could lower the risk for developing ALL. This gene has not been found to play a part in other leukemias, such as AML.

Exposure to ionizing radiation, such as occurred in Japan after the atomic bomb explosions, has been shown to increase the risk of getting leukemia. Electromagnetic fields are suspected of being a possible cause, as are certain organic chemicals, such as benzene. Having a history of diseases that damage the bone marrow, such as aplastic anemia, or a history of cancers of the lymphatic system puts people at a high risk for developing acute leukemias. Similarly, the use of anticancer medications, immunosuppressants, and the antibiotic chloramphenicol are also considered risk factors for developing acute leukemias.

The symptoms of leukemia are generally vague and non-specific. A patient may experience all or some of the following symptoms:

  • weakness or chronic fatigue
  • fever of unknown origin, chills and flu-like symptoms
  • weight loss that is not due to dieting or exercise
  • frequent bacterial or viral infections
  • headaches
  • skin rash
  • non-specific bone pain
  • easy bruising
  • bleeding from gums or nose
  • blood in urine or stools
  • swollen and tender lymph nodes and/or spleen
  • abdominal fullness
  • night sweats
  • petechiae, or tiny red spots under the skin
  • more rarely, sores in the eyes or on the skin

Diagnosis

For a successful outcome, treatment for acute leukemia must begin as soon as possible, but there are no screening tests available. If the doctor has reason to suspect leukemia, he or she will conduct a very thorough physical examination to look for enlarged lymph nodes in the neck, underarm, and pelvic region. Swollen gums, enlarged liver or spleen, bruises, or pinpoint red rashes all over the body are some of the signs of leukemia. Urine and blood tests may be ordered to check for microscopic amounts of blood in the urine and to obtain a complete differential blood count. This count will give the numbers and percentages of the different cells found in the blood. An abnormal blood test might suggest leukemia; however, the diagnosis must be confirmed by more specific tests.

The doctor may perform a bone marrow biopsy to confirm the diagnosis of leukemia. During the biopsy, a cylindrical piece of bone and marrow is removed. The tissue is generally taken out of the hipbone. These samples are sent to the laboratory where they are examined under a microscope by a hematologist, oncologist, or pathologist. In addition to the diagnostic biopsy, another biopsy will also be performed during the treatment phase of the disease to see if the leukemia is responding to therapy.

A spinal tap (lumbar puncture) is another procedure that the doctor may order to diagnose leukemia. In this procedure, a small needle is inserted into the spinal cavity in the lower back to withdraw some cerebrospinal fluid and to look for leukemic cells.

Standard imaging tests, such as x rays, computed tomography scans (CT scans ), and magnetic resonance imaging (MRI) may be used to check whether the leukemic cells have invaded other areas of the body, such as the bones, chest, kidneys, abdomen, or brain. A gallium scan or bone scan is a test in which a radioactive chemical is injected into the body. This chemical accumulates in the areas of cancer or infection, allowing them to be viewed with a special camera.

Treatment

As noted, treatment must be begun as soon as possible. The goal of treatment is remission, or an arresting of the disease process of the leukemia. There are two phases of treatment for leukemia. The first phase is called induction therapy. As the name suggests, during this phase, the primary aim of the treatment is to reduce the number of leukemic cells as much as possible and induce a remission in the patient. Once the patient shows no obvious signs of leukemia (no leukemic cells are detected in blood tests and bone marrow biopsies), the patient is said to be in remission.

The second phase of treatment is then initiated. This is called continuation or maintenance therapy, and the goal is to kill any remaining cancer cells and to maintain the remission for as long as possible.

Chemotherapy

Chemotherapy is the use of drugs to kill cancer cells. It is usually the treatment of choice in leukemia, and is used to relieve symptoms and achieve long-term remission of the disease. Generally, combination chemotherapy, in which multiple drugs are used, is more efficient than using a single drug for the treatment. Some drugs may be administered intravenously through a vein in the arm; others may be given by mouth in the form of pills. If the cancer cells have invaded the brain, then chemotherapeutic drugs may be put into the fluid that surrounds the brain through a needle in the brain or back. This is known as intrathecal chemotherapy. Because leukemia cells can spread to all the organs via the blood stream and the lymphatic vessels, surgery is not considered an option for treating leukemias.

In 2005, the U.S. Food and Drug Administration (FDA) approved clofarabine (Clolar) for the treatment of children with refractory or relapsed acute lymphoblastic leukemia (ALL). Clofarabine is the first new leukemia treatment approved specifically for children in more than a decade. Clofarabine is indicated for the treatment of pediatric patients ages one to 21 years with relapsed or refractory ALL after at least two prior regimens. The most common adverse effects after clofarabine treatment, regardless of causality, were gastrointestinal tract symptoms, including vomiting, nausea, and diarrhea; hematologic effects, including anemia, leucopenia, thrombocytopenia, neutropenia, and febrile neutropenia; and infection. Careful hematologic monitoring during therapy is important.

Radiation

Radiation therapy, which involves the use of x rays or other high-energy rays to kill cancer cells and shrink tumors, may be used in some cases. For acute leukemias, the source of radiation is usually outside the body (external radiation therapy). If the leukemic cells have spread to the brain, radiation therapy can be given to the brain.

Bone marrow transplantation

Bone marrow transplantation is a process in which the patient's diseased bone marrow is replaced with healthy marrow. There are two ways of doing a bone marrow transplant. In an allogeneic bone marrow transplant, healthy marrow is taken from a donor whose tissue is either the same as or very closely resembles the patient's tissues. The donor may be a twin, a brother or sister (sibling), or a person who is not related at all. First, the patient's bone marrow is destroyed with very high doses of chemotherapy and radiation therapy. Healthy marrow from the donor is then given to the patient through a needle in a vein to replace the destroyed marrow.

In the second type of bone marrow transplant, called an autologous bone marrow transplant, some of the patient's own marrow is taken out and treated with a combination of anticancer drugs to kill all the abnormal cells. This marrow is then frozen to preserve it. The marrow remaining in the patient's body is destroyed with high-dose chemotherapy and radiation therapy. The marrow that was frozen is then thawed and given back to the patient through a needle in a vein. This type of bone marrow transplant is currently being investigated in clinical trials.

Biological therapy or immunotherapy is a mode of treatment in which the body's own immune system is harnessed to fight the cancer. Interferon is a biological therapy that is increasingly being used. Substances that are routinely made by the immune system (such as growth factors, hormones, and disease-fighting proteins) are either synthetically made in a laboratory or their effectiveness is boosted and they are then put back into the patient's body. This treatment mode is also being investigated in clinical trials all over the country at major cancer centers.

Prognosis

Like all cancers, the prognosis for leukemia depends on the patient's age and general health. According to statistics, more than 60% of the patients with leukemia survive for at least a year after diagnosis. Acute myelocytic leukemia (AML) has a poorer prognosis rate than acute lymphocytic leukemias (ALL) and the chronic leukemias. In the last 20 years, the five-year survival rate for patients with ALL has increased from 38% to 57%.

Interestingly enough, since most childhood leukemias are of the ALL type, chemotherapy has been highly successful in their treatment. This is because chemotherapeutic drugs are most effective against actively growing cells. Due to the new combinations of anticancer drugs being used, the survival rates among children with ALL have improved dramatically. Ninety-five percent of all childhood ALL patients will enter remission, and 60-75% will remain in remission after five years, depending upon the type. T-cell ALL is considered curable in half of all cases, while B-cell ALL is rarely, if ever curable. The worst prognosis is for non-typable ALL, whose victims are usually below one year of age.

Health care team roles

In most cases, a diagnosis of leukemia is made in a physician's office, a general medical clinic, or emergency room by a primary care practitioner. Children and adolescents with leukemia are likely to be diagnosed by their primary care physician, or pediatrician. However, oncologists, or physicians that specialize in the diagnosis and treatment of cancer are also often involved. Hematologists, physicians that specialize in the diagnosis and treatment of disorders of the blood and the organs that produce blood cells, may become involved through consultation. A pathologist, or physician who specializes in studying tissue and cell samples, often to assist other physicians in reaching the correct diagnosis, also may be consulted.

KEY TERMS

Antibodies— Proteins made by the B lymphocytes in response to the presence in the body of infectious agents, such as bacteria or viruses.

Biopsy— The surgical removal and microscopic examination of living tissue for diagnostic purposes.

Chemotherapy— Treatment with drugs that act against cancer.

Computerized tomography (CT) scan— A series of x rays put together by a computer in order to form detailed pictures of areas inside the body.

Cytokines— Chemicals made by the cells that act on other cells to stimulate or inhibit their function. Cytokines that stimulate growth are called growth factors.

Immunotherapy— Treatment of cancer by stimulating the body's immune defense system.

Lumbar puncture— A procedure in which the doctor inserts a small needle into the spinal cavity in the lower back to withdraw some spinal fluid for testing. Also known as a spinal tap.

Magnetic resonance imaging (MRI)— A medical procedure using a magnet linked to a computer to picture areas inside the body.

Maturation— The process by which stem cells transform from immature cells without a specific function into a particular type of blood cell with defined functions.

Radiation therapy— Treatment using high-energy radiation from x-ray machines, cobalt, radium, or other sources.

Remission— A disappearance of a disease as a result of treatment. Complete remission means that all disease is gone. Partial remission means that the disease is significantly improved by treatment, but residual traces of the disease are still present.

Both registered nurses and licensed practical nurses provide direct care to leukemia patients in general hospitals, homes, or other healthcare facilities. Good supportive nursing care and observation are necessary to:

  • Prevent or monitor for the infections to which leukemia patients are so susceptible.
  • Monitor for anemia and bleeding.
  • Assist in treatments such as chemotherapy, radiation, bone-marrow transplantation, or in giving blood transfusions.
  • Monitor vital signs.
  • Provide teaching regarding the prevention of infection, the normal course of leukemia, including the fatigue so many patients feel, the signs and symptoms of anemia, and good dental care (both leukemia and chemotherapy are apt to cause sensitivity in the mouth, vulnerability to infection and bleeding).

Clinical laboratory scientists draw blood samples that are ordered by the physician to monitor the leukemia from the outset, during treatment, and also during remission. Radiologic technologists take x rays to visualize and monitor parts of the body that may be affected by the leukemia.

Prevention

Most cancers can be prevented by changes in lifestyle or diet, which will reduce the risk factors. However, in leukemias, there are no such known risk factors. Therefore, at the present time, no way is known to prevent leukemias from developing. People who are at an increased risk for developing leukemia because of proven exposure to ionizing radiation or exposure to the toxic liquid benzene, and people with Down syndrome, should undergo periodic medical checkups.

Resources

BOOKS

Hiddemann, Wolfgang, et al.Acute Leukemias IX New York: Springer, 2003.

Icon Health Publications Acute Leukemia—A Medical Dictionary, Bibliography, and Annotated Research Guide to Internet References San Diego: Icon Health Publications, 2004.

Parker, James N., and Philip M. Parker The Official Parent's Sourcebook on Childhood Acute Lymphoblastic Leukemia San Diego: Icon Health Publications, 2002.

Pui, Ching-Hong Treatment of Acute Leukemias: New Directions for Clinical Research Totowa, NJ: Humana Press, 2003.

PERIODICALS

Bauer, Jeff. "Intensive Leukemia Treatment Equalizes Survival Rates for Black and White Children." RN (January 2004): 18.

Hill, Garick, et al. "Recent Steroid Therapy Increases Severity of Varicella Infections in Children with Acute Lymphoblastic Leukemia." Pediatrics (October 2005): 1010-1011.

Kirn, Timothy F. "ALL Gene Predicts Children's Response to Chemotherapy: Chance of Long-Term Remission: 87%." Family Practice News (May 15, 2004): 58.

Lilleyman, John. "Simple Deliverable Therapy Needed for Childhood Leukemia." The Lancet (Aug. 30, 2003): 676.

LoBuono, Charlotte. "First Leukemia Drug in 10 Years Cleared for Kids." Drug Topics (Feb. 7, 2005): 52.

Mohn, Angelika, et al. "Persistence of Impaired Pancreatic B-Cell Function in Children Treated for Acute Lymphoblastic Leukemia." The Lancet (Jan. 10, 2004): 127.

ORGANIZATIONS

American Cancer Society. 1599 Clifton Road, N.E., Atlanta, Georgia 30329. (800) 227-2345. 〈http://www.cancer.org〉.

Cancer Research Institute. 681 Fifth Avenue, New York, N.Y. 10022. (800) 992-2623. 〈http://www.cancerresearch.org〉.

The Leukemia & Lymphoma Society. 1311 Mamaroneck Ave., White Plains, NY 10605. (914) 949-5213. www.leukemia-lymphoma.org

Leukemia Society of America, Inc. 600 Third Avenue, New York, NY 10016. (800) 955-4572. 〈http://www.leukemia.org〉.

OTHER

University of Pennsylvania Cancer Center. Oncolink. 〈http://cancer.med.upenn.edu〉.

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"Leukemias, Acute." Gale Encyclopedia of Nursing and Allied Health. . Encyclopedia.com. 13 Sep. 2018 <http://www.encyclopedia.com>.

"Leukemias, Acute." Gale Encyclopedia of Nursing and Allied Health. . Encyclopedia.com. (September 13, 2018). http://www.encyclopedia.com/medicine/encyclopedias-almanacs-transcripts-and-maps/leukemias-acute-1

"Leukemias, Acute." Gale Encyclopedia of Nursing and Allied Health. . Retrieved September 13, 2018 from Encyclopedia.com: http://www.encyclopedia.com/medicine/encyclopedias-almanacs-transcripts-and-maps/leukemias-acute-1

Learn more about citation styles

Citation styles

Encyclopedia.com gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, Encyclopedia.com cannot guarantee each citation it generates. Therefore, it’s best to use Encyclopedia.com citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

http://www.mla.org/style

The Chicago Manual of Style

http://www.chicagomanualofstyle.org/tools_citationguide.html

American Psychological Association

http://apastyle.apa.org/

Notes:
  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most Encyclopedia.com content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.

Leukemias, Acute

Leukemias, acute

Definition

Acute leukemia is a type of cancer in which excessive quantities of abnormal white blood cells are produced.

Description

Medical science further classifies acute leukemia by the type of white blood cell that undergoes mutation. The most common of these are:

  • Acute lymphoblastic leukemia (ALL), in which excessive quantities of lymphoblasts, or immature lymphocyte white blood cells, are produced.
  • Acute myeloblastic leukemia (AML), also known as acute nonlymphocytic leukemia (ANLL), in which excessive quantities of other types of immature white blood cells are produced.

Acute leukemias progress rapidly, while the chronic leukemias progress more slowly. The vast majority of the childhood leukemias are of the acute form.

The cells that make up blood are produced in the bone marrow and the lymphatic system . Bone marrow is the spongy tissue found in the large bones of the body. The lymphatic system includes the spleen (an organ in the upper abdomen), the thymus (a small gland beneath the breastbone), and the tonsils (a mass of lymphatic tissue located in the throat). In addition, the lymphatic vessels (tiny tubes that branch like blood vessels into all parts of the body) and lymph nodes (pea-shaped organs that are found along the network of lymphatic vessels) are also part of the lymphatic system. Lymph is a milky fluid that contains cells. Clusters of lymph nodes are found in the neck, underarm, pelvis, abdomen, and chest.

The cells found in the blood include red blood cells (RBCs) that carry oxygen and other materials to all tissues of the body; white blood cells (WBCs) that fight infection ; and platelets, which play an important role in the clotting of the blood. White blood cells can be further subdivided into three main types: granulocytes, monocytes, and lymphocytes.

The granulocytes, as their name suggests, have particles (granules) inside them. These granules contain special proteins (enzymes) and several other substances that can break down chemicals and destroy microorganisms, such as bacteria . Monocytes are the second type of white blood cell. They are also important in defending the body against pathogens.

Lymphocytes are the third type of white blood cell. There are two primary types of lymphocytes—T lymphocytes and B lymphocytes—with different functions in the immune system . B cells protect the body by making antibodies. Antibodies are proteins that can attach to the surfaces of bacteria and viruses . This "attachment" sends signals to many other cell types to come and destroy the antibody-coated organism. T cells protect the body against viruses. When a virus enters a cell, it produces certain proteins that are projected onto the surface of the infected cell. T cells recognize these proteins and make certain chemicals that are capable of destroying the virus-infected cells. In addition, T cells can destroy some types of cancer cells.

Bone marrow makes stem cells, which are the precursors of the different blood cells. These stem cells mature through stages into either RBCs, WBCs, or platelets. In acute leukemias, the maturation process of the white blood cells is interrupted. The immature cells (or "blasts") proliferate rapidly and begin to accumulate in various organs and tissues, thereby affecting their normal function. This uncontrolled proliferation of the immature cells in the bone marrow affects the production of the normal red blood cells and platelets as well.

As noted, there are two types of acute leukemias—acute lymphocytic leukemia and acute myelogenous leukemia. Different types of white blood cells are involved in the two leukemias. In acute lymphocytic leukemia (ALL), it is the T or the B lymphocytes that are involved. The B cell leukemias are more common than T cell leukemias. Acute myelogenous leukemia, also known as acute nonlymphocytic leukemia (ANLL), is a cancer of the monocytes and/or granulocytes.

Leukemias account for 2% of all cancers. Because leukemia is the most common form of childhood cancer, it is often regarded as a disease of childhood. However, leukemias affect far more adults than children. Half of the cases occur in people who are 60 years of age or older. The incidence of acute and chronic leukemias is about the same. According to the estimates of the American Cancer Society (ACS), approximately 29,000 new cases of leukemia are diagnosed each year in the United States. Of these, 27,000 will be diagnosed in adults, 2,000 in children.

Causes and symptoms

Leukemia strikes both sexes and all ages. The human T-cell leukemia virus (HTLV-I), a virus with similarities to the human immunodeficiency virus (HIV), is believed to be the causative agent for some kinds of leukemias, but this has not yet been proven, and the cause of most leukemias is not known. Acute lymphoid leukemia (ALL) is more common among Caucasians than among African-Americans, while acute myeloid leukemia (AML) affects both races equally. The incidence of acute leukemia is slightly higher among men than women. People with Jewish ancestry have a higher likelihood of getting leukemia. A higher incidence of leukemia has also been observed among persons with Down syndrome and some other genetic abnormalities.

Reports in Science News cited studies that found a gene that regulates folic acid metabolism in the body to be more prevalent in acute lymphocytic leukemia (ALL) patients. Folic acid is known to be involved in the process of DNA maintenance and repair, and this gene diverts folic acid from this function. It is therefore hypothesized that this gene plays a role in the development of ALL, and that folic acid supplementation could lower the risk for developing ALL. This gene has not been found to play a part in other leukemias, such as AML.

Exposure to ionizing radiation, such as occurred in Japan after the atomic bomb explosions, has been shown to increase the risk of getting leukemia. Electromagnetic fields are suspected of being a possible cause, as are certain organic chemicals, such as benzene. Having a history of diseases that damage the bone marrow, such as aplastic anemia, or a history of cancers of the lymphatic system puts people at a high risk for developing acute leukemias. Similarly, the use of anticancer medications, immunosuppressants, and the antibiotic chloramphenicol are also considered risk factors for developing acute leukemias.

The symptoms of leukemia are generally vague and non-specific. A patient may experience all or some of the following symptoms:

  • weakness or chronic fatigue
  • fever of unknown origin, chills and flu-like symptoms
  • weight loss that is not due to dieting or exercise
  • frequent bacterial or viral infections
  • headaches
  • skin rash
  • non-specific bone pain
  • easy bruising
  • bleeding from gums or nose
  • blood in urine or stools
  • swollen and tender lymph nodes and/or spleen
  • abdominal fullness
  • night sweats
  • petechiae, or tiny red spots under the skin
  • more rarely, sores in the eyes or on the skin

Diagnosis

For a successful outcome, treatment for acute leukemia must begin as soon as possible, but there are no screening tests available. If the doctor has reason to suspect leukemia, he or she will conduct a very thorough physical examination to look for enlarged lymph nodes in the neck, underarm, and pelvic region. Swollen gums, enlarged liver or spleen, bruises, or pinpoint red rashes all over the body are some of the signs of leukemia. Urine and blood tests may be ordered to check for microscopic amounts of blood in the urine and to obtain a complete differential blood count. This count will give the numbers and percentages of the different cells found in the blood. An abnormal blood test might suggest leukemia; however, the diagnosis must be confirmed by more specific tests.

The doctor may perform a bone marrow biopsy to confirm the diagnosis of leukemia. During the biopsy, a cylindrical piece of bone and marrow is removed. The tissue is generally taken out of the hipbone. These samples are sent to the laboratory where they are examined under a microscope by a hematologist, oncologist, or pathologist. In addition to the diagnostic biopsy, another biopsy will also be performed during the treatment phase of the disease to see if the leukemia is responding to therapy.

A spinal tap (lumbar puncture) is another procedure that the doctor may order to diagnose leukemia. In this procedure, a small needle is inserted into the spinal cavity in the lower back to withdraw some cerebrospinal fluid and to look for leukemic cells.

Standard imaging tests, such as x rays, computed tomography scans (CT scans ), and magnetic resonance imaging (MRI) may be used to check whether the leukemic cells have invaded other areas of the body, such as the bones, chest, kidneys , abdomen, or brain . A gallium scan or bone scan is a test in which a radioactive chemical is injected into the body. This chemical accumulates in the areas of cancer or infection, allowing them to be viewed with a special camera.

Treatment

As noted, treatment must be begun as soon as possible. The goal of treatment is remission, or an arresting of the disease process of the leukemia. There are two phases of treatment for leukemia. The first phase is called induction therapy. As the name suggests, during this phase, the primary aim of the treatment is to reduce the number of leukemic cells as much as possible and induce a remission in the patient. Once the patient shows no obvious signs of leukemia (no leukemic cells are detected in blood tests and bone marrow biopsies), the patient is said to be in remission.

The second phase of treatment is then initiated. This is called continuation or maintenance therapy, and the goal is to kill any remaining cancer cells and to maintain the remission for as long as possible.

Chemotherapy

Chemotherapy is the use of drugs to kill cancer cells. It is usually the treatment of choice in leukemia, and is used to relieve symptoms and achieve long-term remission of the disease. Generally, combination chemotherapy, in which multiple drugs are used, is more efficient than using a single drug for the treatment. Some drugs may be administered intravenously through a vein in the arm; others may be given by mouth in the form of pills. If the cancer cells have invaded the brain, then chemotherapeutic drugs may be put into the fluid that surrounds the brain through a needle in the brain or back.

This is known as intrathecal chemotherapy. Because leukemia cells can spread to all the organs via the blood stream and the lymphatic vessels, surgery is not considered an option for treating leukemias.

Radiation

Radiation therapy, which involves the use of x rays or other high-energy rays to kill cancer cells and shrink tumors, may be used in some cases. For acute leukemias, the source of radiation is usually outside the body (external radiation therapy). If the leukemic cells have spread to the brain, radiation therapy can be given to the brain.

Bone marrow transplantation

Bone marrow transplantation is a process in which the patient's diseased bone marrow is replaced with healthy marrow. There are two ways of doing a bone marrow transplant. In an allogeneic bone marrow transplant, healthy marrow is taken from a donor whose tissue is either the same as or very closely resembles the patient's tissues. The donor may be a twin, a brother or sister (sibling), or a person who is not related at all. First, the patient's bone marrow is destroyed with very high doses of chemotherapy and radiation therapy. Healthy marrow from the donor is then given to the patient through a needle in a vein to replace the destroyed marrow.


KEY TERMS


Antibodies —Proteins made by the B lymphocytes in response to the presence in the body of infectious agents, such as bacteria or viruses.

Biopsy —The surgical removal and microscopic examination of living tissue for diagnostic purposes.

Chemotherapy —Treatment with drugs that act against cancer.

Computerized tomography (CT) scan —A series of x rays put together by a computer in order to form detailed pictures of areas inside the body.

Cytokines —Chemicals made by the cells that act on other cells to stimulate or inhibit their function. Cytokines that stimulate growth are called growth factors.

Immunotherapy —Treatment of cancer by stimulating the body's immune defense system.

Lumbar puncture —A procedure in which the doctor inserts a small needle into the spinal cavity in the lower back to withdraw some spinal fluid for testing. Also known as a spinal tap.

Magnetic resonance imaging (MRI) —A medical procedure using a magnet linked to a computer to picture areas inside the body.

Maturation —The process by which stem cells transform from immature cells without a specific function into a particular type of blood cell with defined functions.

Radiation therapy —Treatment using high-energy radiation from x-ray machines, cobalt, radium, or other sources.

Remission —A disappearance of a disease as a result of treatment. Complete remission means that all disease is gone. Partial remission means that the disease is significantly improved by treatment, but residual traces of the disease are still present.


In the second type of bone marrow transplant, called an autologous bone marrow transplant, some of the patient's own marrow is taken out and treated with a combination of anticancer drugs to kill all the abnormal cells. This marrow is then frozen to preserve it. The marrow remaining in the patient's body is destroyed with high-dose chemotherapy and radiation therapy. The marrow that was frozen is then thawed and given back to the patient through a needle in a vein. This type of bone marrow transplant is currently being investigated in clinical trials.

Biological therapy or immunotherapy is a mode of treatment in which the body's own immune system is harnessed to fight the cancer. Interferon is a biological therapy that is increasingly being used. Substances that are routinely made by the immune system (such as growth factors, hormones, and disease-fighting proteins) are either synthetically made in a laboratory or their effectiveness is boosted and they are then put back into the patient's body. This treatment mode is also being investigated in clinical trials all over the country at major cancer centers.

Prognosis

Like all cancers, the prognosis for leukemia depends on the patient's age and general health. According to statistics, more than 60% of the patients with leukemia survive for at least a year after diagnosis. Acute myelocytic leukemia (AML) has a poorer prognosis rate than acute lymphocytic leukemias (ALL) and the chronic leukemias. In the last 15 to 20 years, the five-year survival rate for patients with ALL has increased from 38% to 57%.

Interestingly enough, since most childhood leukemias are of the ALL type, chemotherapy has been highly successful in their treatment. This is because chemotherapeutic drugs are most effective against actively growing cells. Due to the new combinations of anti-cancer drugs being used, the survival rates among children with ALL have improved dramatically. Ninety-five percent of all childhood ALL patients will enter remission, and 60–75% will remain in remission after five years, depending upon the type. T-cell ALL is considered cureable in half of all cases, while B-cell ALL is rarely, if ever cureable. The worst prognosis is for non-typable ALL, whose victims are usually below one year of age.

Health care team roles

In most cases, a diagnosis of leukemia is made in a physician's office, a general medical clinic, or emergency room by a primary care practitioner. Children and adolescents with leukemia are likely to be diagnosed by their primary care physician, or pediatrician. However, oncologists, or physicians that specialize in the diagnosis and treatment of cancer are also often involved. Hematologists, physicians that specialize in the diagnosis and treatment of disorders of the blood and the organs that produce blood cells, may become involved through consultation. A pathologist, or physician who specializes in studying tissue and cell samples, often to assist other physicians in reaching the correct diagnosis, also may be consulted.

Both registered nurses and licensed practical nurses provide direct care to leukemia patients in general hospitals, homes, or other healthcare facilities. Good supportive nursing care and observation are necessary to:

  • Prevent or monitor for the infections to which leukemia patients are so susceptible.
  • Monitor for anemia and bleeding.
  • Assist in treatments such as chemotherapy, radiation, bone-marrow transplantation, or in giving blood transfusions.
  • Monitor vital signs.
  • Provide teaching regarding the prevention of infection, the normal course of leukemia, including the fatigue so many patients feel, the signs and symptoms of anemia, and good dental care (both leukemia and chemotherapy are apt to cause sensitivity in the mouth, vulnerability to infection and bleeding).

Clinical laboratory scientists draw blood samples that are ordered by the physician to monitor the leukemia from the outset, during treatment, and also during remission. Radiologic technologists take x rays to visualize and monitor parts of the body that may be affected by the leukemia.

Prevention

Most cancers can be prevented by changes in lifestyle or diet, which will reduce the risk factors. However, in leukemias, there are no such known risk factors. Therefore, at the present time, no way is known to prevent leukemias from developing. People who are at an increased risk for developing leukemia because of proven exposure to ionizing radiation or exposure to the toxic liquid benzene, and people with Down syndrome, should undergo periodic medical checkups.

Resources

BOOKS

Beers, Mark H., et al., eds. Merck Manual of Diagnosis and Therapy. 17th ed. Rahway, NJ: Merck & Co., 1999.

Keene, Nancy, and Linda Lamb, eds. Childhood Leukemia: A Guide for Families, Friends and Caregivers. Cambridge, MA: O'Reilly & Associates, 1999.

Lackritz, Barbara. Adult Leukemia: A Comprehensive Guide for Patients and Families. Cambridge, MA: O'Reilly & Associates, 2001.

Murphy, Gerald P. Informed Decisions: The Complete Book of Cancer Diagnosis, Treatment and Recovery. Atlanta, GA: American Cancer Society, 1997.

PERIODICALS

Seppa, N. "Genetic Variants May Ease Leukemia Risk." Science News 156 (November 6,1999): 293.

ORGANIZATIONS

American Cancer Society. 1599 Clifton Road, N.E., Atlanta, Georgia 30329. (800) 227-2345. <http://www.cancer.org>.

Cancer Research Institute. 681 Fifth Avenue, New York, N.Y. 10022. (800) 992-2623. <http://www.cancerresearch.org>.

National Cancer Institute. 9000 Rockville Pike, Building 31, Room 10A16, Bethesda, Maryland, 20892. (800) 422-6237. <http://wwwicic.nci.nih.gov>.

Leukemia Society of America, Inc. 600 Third Avenue, New York, NY 10016. (800) 955-4572. <http://www.leukemia.org>.

OTHER

University of Pennsylvania Cancer Center. Oncolink. <http://cancer.med.upenn.edu>.

Joan M. Schonbeck

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"Leukemias, Acute." Gale Encyclopedia of Nursing and Allied Health. . Encyclopedia.com. 13 Sep. 2018 <http://www.encyclopedia.com>.

"Leukemias, Acute." Gale Encyclopedia of Nursing and Allied Health. . Encyclopedia.com. (September 13, 2018). http://www.encyclopedia.com/medicine/encyclopedias-almanacs-transcripts-and-maps/leukemias-acute-2

"Leukemias, Acute." Gale Encyclopedia of Nursing and Allied Health. . Retrieved September 13, 2018 from Encyclopedia.com: http://www.encyclopedia.com/medicine/encyclopedias-almanacs-transcripts-and-maps/leukemias-acute-2

Learn more about citation styles

Citation styles

Encyclopedia.com gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, Encyclopedia.com cannot guarantee each citation it generates. Therefore, it’s best to use Encyclopedia.com citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

http://www.mla.org/style

The Chicago Manual of Style

http://www.chicagomanualofstyle.org/tools_citationguide.html

American Psychological Association

http://apastyle.apa.org/

Notes:
  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most Encyclopedia.com content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.