Lung cancer is a disease in which the cells of the lung tissues grow uncontrollably and form tumors. It is the leading cause of death from cancer among both men and women in the United States. The American Cancer Society (ACS) estimated that in 1998, at least 172,000 new cases of lung cancer were diagnosed, and that lung cancer accounted for 28% of all cancer deaths, or approximately 160,000 people. In 2002, the ACS reported that more than 150,000 Americans die from the disease every year. Only 15 percent of people with lung cancer will live five years.
Types of lung cancer
There are two kinds of lung cancers, primary and secondary. Primary lung cancer (also called adenocarcinoma) starts in the lung itself. Primary lung cancer is divided into small cell lung cancer and non-small cell lung cancer, depending on how the cells look under the microscope. Secondary lung cancer is cancer that starts somewhere else in the body (for example, the breast or colon) and spreads to the lungs.
Small cell cancer was formerly called oat cell cancer, because the cells resemble oats in their shape. About one-fourth of all lung cancers are small cell cancers. This type is a very aggressive cancer and spreads to other organs within a short time. It generally is found in people who are heavy smokers. Non-small cell cancers account for the remaining 75% of lung cancers. They can be further subdivided into three categories.
Incidence of lung cancer
Lung cancer is rare among young adults. It usually is found in people who are 50 years of age or older, with an average age at diagnosis of 60. While the incidence of the disease is decreasing among Caucasian men, it is steadily rising among African-American men, and among both Caucasian and African-American women. This change probably is due to the increase in the number of smokers in these groups. In 1987, lung cancer replaced breast cancer as the number one cancer killer among women.
Causes & symptoms
SMOKING. Tobacco smoking is the leading cause of lung cancer. Ninety percent of lung cancers can be prevented by completely giving up tobacco. Smoking marijuana cigarettes is considered yet another risk factor for cancer of the lung. These cigarettes have a higher tar content than tobacco cigarettes. In addition, they are inhaled very deeply; as a result, the smoke is held in the lungs for a longer period of time.
EXPOSURE TO ASBESTOS AND TOXIC CHEMICALS. Repeated exposure to asbestos fibers, either at home or in the workplace, also is considered a risk factor for lung cancer. Studies show that compared to the general population, asbestos workers are seven times more likely to die from lung cancer. Asbestos workers who smoke increase their risk of developing lung cancer by 50-100 times. Besides asbestos, mining industry workers who are exposed to coal products or radioactive substances, such as uranium, and workers exposed to chemicals, such as arsenic, vinyl chloride, mustard gas , and other carcinogens, also have a higher than average risk of contracting lung cancer.
ENVIRONMENTAL CONTAMINATION. High levels of a radioactive gas (radon) that cannot be seen or smelled pose a risk for lung cancer. This gas is produced by the breakdown of uranium, and does not present any problem outdoors. In the basements of some houses that are built over soil containing natural uranium deposits, however, radon may accumulate and reach dangerous levels. Having one's house inspected for the presence of radon gas when buying or renting is a good idea. Other forms of environmental pollution (e.g., auto exhaust fumes) also may slightly increase the risk of lung cancer.
In 2002, a study in the Journal of the American Medical Association (JAMA) linked for the first time long-term exposure to fine-particle air pollution to lung cancer deaths. The risk of death from lung cancer increased substantially for people living in the most heavily polluted metropolitan areas. Tiny particles from the air pollution emitted from coal-fired power plants, factories and diesel vehicles are to blame.
CHRONIC LUNG INFLAMMATION AND SCARRING . Inflammation and scar tissue sometimes are produced in the lung by diseases, such as silicosis and berylliosis, which are caused by inhalation of certain minerals, tuberculosis , and certain types of pneumonia . This scarring may increase the risk of developing lung cancer.
FAMILY HISTORY. Although the exact cause of lung cancer is not known, people with a family history of lung cancer appear to have a slightly higher risk of contracting the disease. In 2003, researchers were continuing work aimed at learning why some smokers were more susceptible to lung cancer than others. They discovered a type of DNA repair characteristic apparent in smokers who were less likely to get lung cancer. Continued work along these lines could lead to possible screening for DNA that makes some people at higher risk for lung cancer.
Lung cancers tend to spread very early, and only 15% are detected in their early stages. The chances of early detection, however, can be improved by seeking medical care at once if any of the following symptoms appear:
- a cough that does not go away
- chest pain
- shortness of breath
- persistent hoarseness
- swelling of the neck and face
- significant weight loss that is not due to dieting or vigorous exercise
- fatigue and loss of appetite
- bloody or brown-colored spit or phlegm (sputum)
- unexplained fever
- recurrent lung infections , such as bronchitis or pneumonia
However, these symptoms may be caused by diseases other than lung cancer. It is vital, however, to consult a doctor to rule out the possibility that they are the first symptoms of lung cancer.
If the lung cancer has spread to other organs, the patient may have other symptoms, such as headaches, bone fractures, pain, bleeding, or blood clots . Early detection and treatment can increase the chances of a cure for some patients. For others, it can at least prolong life.
Physical examination and initial tests
If the patient's doctor suspects lung cancer, he or she will take a detailed medical history to check all the symptoms and assess the risk factors. The assessment of the patient's medical history will be followed by a complete physical examination. The doctor will examine the patient's throat to rule out other possible causes of hoarseness or coughing, and listen to the patient's breathing and the sounds made when the patient's chest and upper back are tapped (percussed). The physical examination, however, is not conclusive.
If the doctor has reason to suspect lung cancer—particularly if the patient has a history of heavy smoking or occupational exposure to substances that are known to irritate the lungs—he or she may order a chest x ray to see if there are any masses in the lungs. Special imaging techniques, such as CT scans or MRIs, may provide more precise information about the possibility, size, shape, and location of any tumors.
A technology called spiral CT, which rotates allowing for images of the chest from all angles, can detect lung cancer when tumors are smaller than a dime. A report in 2002 said spiral CT technology could help doctors screen the population for lung cancer, but the idea of screening remains controversial. Until clinicians and insurers receive more proof the scans produce fewer false positive (a seemingly positive result or nodule that turns out not to be a cancerous mass), widespread screening won't occur. And in 2002, the cost of a spiral CT chest study to screen for lung cancer averaged about $400. However, researchers were recommending further trials to determine the effectiveness of the screening tool for future use.
In 2003, a new radiology technique emerged for staging lung cancer. By combining positron emission tomography (PET) with CT, or PET-CT, physicians could more accurately see the details of the tumorís progression (or regression after treatment) and to diagnose a lung tumor better.
Sputum analysis involves microscopic examination of the cells that are either coughed up from the lungs, or are collected through a special instrument called a bronchoscope. Sputum analyses can diagnose at least 30% of lung cancers, some of which do not show up even on chest x rays. In addition, the test can help detect cancer in its very early stages, before it spreads to other regions. The sputum test does not, however, provide any information about the location of the tumor and must be followed by other tests, such as bronchoscopy, where machines can detect cancerous cells without the need to open the chest.
Lung biopsy is the most definitive diagnostic tool for cancer. It can be performed in several different ways. The doctor can perform a bronchoscopy, which involves the insertion of a slender, lighted tube, called a bronchoscope, down the patient's throat and into the lungs. In addition to viewing the passageways of the lungs, the doctor can use the bronchoscope to obtain samples of the lung tissue. In another procedure known as a needle biopsy, the location of the tumor first is identified using a CT scan or MRI. The doctor then inserts a needle through the chest wall and collects a sample of tissue from the tumor. In the third procedure, known as surgical biopsy, the chest wall is opened up and a part of the tumor, or all of it, is removed. A doctor who specializes in the study of diseased tissue (a pathologist) examines the tumor samples to identify the cancer's type and stage.
Alternative therapies should complement conventional treatment, not replace it. Before participating in any alternative treatment programs, patients should consult their doctors concerning the appropriateness and the role of such programs in overall cancer treatment plans. 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 use of beta-carotene and vitamin A supplements in lung cancer patients is controversial. Vitamin A and beta-carotene were advocated as antioxidants with lung-protective effects that may decrease the risk of lung cancer. However, recent studies suggest that betacarotene supplements may have no demonstrated effect in smokers and no effects on nonsmokers. Therefore, use of beta-carotene supplement in lung cancer patients or as preventive measure in smokers is not recommended at the present time. However, researchers believe that patients benefit from nature's source of beta-carotene and vitamin A. Beta-carotene in food carries all the benefits, yet does not have the harmful effects controversial high-dose supplements may carry.
The effectiveness of many of the anticancer drugs used to treat lung cancer can be reduced when patients take megadoses of antioxidants. These antioxidants in patients not undergoing chemotherapy can be helpful in protecting the body against cancer. However, taken during chemotherapy, these antioxidants protect the cancer cells from being killed by chemotherapy drugs. Because high-dose supplementation of antioxidants can interfere with conventional chemotherapy treatment, patients should check with their physicians concerning dosage and recommended daily allowance (RDA) during chemotherapy or radiation therapy.
The following dietary changes may help improve a patient's quality of life, as well as boost the immune function to better fight the disease. They also may help prevent lung cancer.
- Avoiding fatty and spicy foods. A high-fat diet may be associated with increased risk of lung cancer. Also, lung cancer patients may have a hard time digesting heavy foods.
- 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. Especially helpful are the yellow and orange fruits (orange, cantaloupes) and dark green vegetables. They contain high amounts of vitamin A and carotene.
- Eating more broccoli sprouts. These young sprouts are a good source of sulforaphane, a lung cancer fighting substance.
- Eating multiple (5-6) meals per day. Small meals are easier to digest.
- Establishing a regular eating time and not eating around bedtime.
- Avoiding foods containing preservatives or artificial coloring.
- Monitoring weight and intake of adequate calories and protein.
In 2002, a report in Family Practice News said that daily consumption of a soup used in Traditional Chinese Medicine helped slow the progression of non-small cell lung cancer for patients with advanced stages of the disease. The soup consisted of herbs and vegetables containing natural ingredients that boost immunity and help fight tumors. Patients should check with their doctors and with a licensed Traditional Chine Medicine specialist for more information. The soup does not prevent or reverse the disease, but helped prolong survival for a percentage of patients in a clinical study.
A naturopath may recommend some of the following nutritional supplements to boost the patient's immune function and help fight tumor progression:
- Vitamins and minerals. Vitamins that are considered particularly beneficial to cancer patients include B-complex vitamins, especially vitamins B6, C, D, E, and K. Most important minerals are calcium, chromium, copper, iodine , molybdenum, germanium, selenium , tellurium, and zinc . Many of these vitamins and minerals are strong antioxidants or cofactors for antioxidant enzymes. However, patients should not take mega doses of these supplements without first consulting their doctors. Significant adverse or toxic effects may occur at high dosages, which is especially true for the minerals.
- Other nutritional supplements may help fight cancer and support the body. They include essential fatty acids (fish or flaxseed oil), flavonoids, pancreatic enzymes (to help digest foods), hormones such as DHEA, melatonin , or phytoestrogens.
Conventional treatment for leukemia is associated with significant side effects. These adverse effects (such as nausea, vomiting , and fatigue) 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 may be helpful for patients with cancer. Patients should mix one part of pure juice with one part of water before drinking.
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.
Acupunture 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 , and other common side effects of chemotherapy and radiation.
Other alternative treatments include stress reduction, meditation, yoga, t'ai chi , and the use of guided imagery A new report in 2003 showed early results for bee venomís possible antitumor effects on lung cancer. However, further, research was needed.
Treatment for lung cancer depends on the type of cancer, its location, and its stage. Treating the cancer early is key. In 2002, researchers announced the discovery of a chromosomal region that shows the earliest genetic change in the development of lung cancer. Eventually, this discovery could lead to earlier detection, diagnosis, prevention, and treatment of lung cancer. The most commonly used modes of treatment are surgery, radiation therapy, and chemotherapy.
Surgery is not usually an option for small cell lung cancers, because they have likely spread beyond the lung by the time they are diagnosed. Because non-small cell lung cancers are less aggressive, however, surgery can be used to treat them. The surgeon will decide on the type of surgery, depending on how much of the lung is affected. Surgery may be the primary method of treatment, or radiation therapy and/or chemotherapy may be used to shrink the tumor before surgery is attempted.
There are three different types of surgical operations:
- Wedge resection. This procedure involves removing a small part of the lung.
- Lobectomy. A lobectomy is the removal of one lobe of the lung. If the cancer is limited to one part of the lung, the surgeon will perform a lobectomy.
- Pneumonectomy. A pneumonectomy is the removal of an entire lung. If the surgeon feels that removal of the entire lung is the best option for curing the cancer, a pneumonectomy will be performed.
The pain that follows surgery can be relieved by medications. A more serious side effect of surgery is the patient's increased vulnerability to bacterial and viral infections. Antibiotics, antiviral medications, and vaccines are often needed.
Radiation therapy involves the use of high-energy rays to kill cancer cells. It is used either by itself or in combination with surgery or chemotherapy. There are two types of radiation therapy treatments: external beam radiation therapy and internal (or interstitial) radiotherapy. In external radiation therapy, the radiation is delivered from a machine positioned outside the body. Internal radiation therapy uses a small pellet of radioactive materials placed inside the body in the area of the cancer.
Radiation therapy may produce such side effects as tiredness, skin rashes , upset stomach, and diarrhea. Dry or sore throats, difficulty in swallowing, and loss of hair in the treated area are all minor side effects of radiation. These may disappear either during the course of the treatment or after the treatment is over. The side effects should be discussed with the doctor.
Chemotherapy uses anticancer medications that are either given intravenously or taken by mouth (orally). These drugs enter the bloodstream and travel to all parts of the body, killing cancer cells that have spread to different organs. Chemotherapy is used as the primary treatment for cancers that have spread beyond the lung and cannot be removed by surgery. It also can be used in addition to surgery or radiation therapy.
Chemotherapy is tailored to each patient's needs. Most patients are given a combination of several different drugs. Besides killing the cancer cells, these drugs also harm normal cells. Hence, the dose has to be carefully adjusted to minimize damage to normal cells. Chemotherapy often has severe side effects, including nausea, vomiting, hair loss, anemia , weakening of the immune system, and sometimes infertility . Most of these side effects end when the treatment is over. Other medications can be given to lessen the unpleasant side effects of chemotherapy.
If the lung cancer is detected before it has had a chance to spread to other organs, and if it is treated appropriately, at least 49% of patients can survive five years or longer after the initial diagnosis. Only 15% of lung cancers, however, are found at this early stage.
Due to improvements in surgical technique and the development of new approaches to treatment, the one-year survival rate for lung cancer has improved considerably. As of 1998, approximately 40% of patients survive for at least a year after diagnosis, as opposed to 30% that survived 20 years ago. In 2003, 14% of people diagnosed with lung cancer were reported to be long-term survivors.
The best way to prevent lung cancer is to not smoke or to quit smoking if one has already started. Secondhand smoke from other people's tobacco also should be avoided when possible. In 2002, a report on the impact of cigarette smoking said that in California, decreases in smoking among residents had resulted in reduced lung cancer death rates.
Appropriate precautions should be taken when working with cancer-causing substances (carcinogens). Monitoring the diet and eating well-balanced meals that consist of whole foods, vegetables, and fruits; eliminating toxins, exercising routinely, and weight reduction; testing houses for the presence of radon gas, and removing asbestos from buildings also are useful preventive strategies.
Dollinger, Malin, Ernest H. Rosenbaum, and Greg Cable. Everyone's Guide to Cancer Therapy. Kansas City, MO: 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.
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Morra, Marion E., and Eve Potts. Choices. New York: Avon Books, 1994.
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"Annual Smoking-Attributable Mortality, Years of Potential Life Lost, and Economic Cost - United States, 1995-1999. (From the Centers for Disease Control and Prevention)." JAMA, Journal of the American Medical Association (May 8, 2002):2355-2362.
"Bee Venom Inhibits COX and PGE-2, Inducing Apoptosis of Lung Cancer Cells." Immunotherapy Weekly (July 23, 2003):11.
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Walsh, Nancy. "A Bowl of Chinese Vegetables a Day May Keep Tumors Away (Lung Cancer Pilot Study)." Family Practice News (May 1, 2002):21.
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Rosenberg, Z'ev. "Treating the Undesirable Effect of Radiation and Chemotherapy with Chinese Medicine." Oriental Chinese Journal. http://www.healthypeople.com.
Teresa G. Odle
Lung cancer is a disease in which the cells of the lung tissues grow uncontrollably and form tumors. It is the leading cause of death from cancer among both men and women in the United States. The American Cancer Society estimated that in 2004 at least 173,770 new cases of lung cancer were diagnosed, and that lung cancer will account for 28% of all cancer deaths—approximately 160,440 people.
Types of lung cancer
There are two kinds of lung cancers, primary and secondary. Primary lung cancer starts in the lung itself. Primary lung cancer is divided into small cell lung cancer and non-small cell lung cancer, depending on how the cells look under the microscope. Secondary lung cancer is cancer that starts somewhere else in the body (for example, the breast or urinary bladder) and metastasizes (spreads) to the lungs. Identifying the type of lung cancer is important because treatment varies by type. For example, small cell cancers generally are treated with surgery. On the other hand, surgery is not generally considered beneficial for non-small cell cancers; they are treated with chemotherapy.
Small cell cancer was formerly called oat cell cancer, because the cells resemble oats in their shape. About a fourth of all lung cancers are small cell cancers. This is a very aggressive cancer and spreads to other organs within a short time. It is generally diagnosed in people who are heavy smokers. Non-small cell cancers account for the remaining 75% of primary lung cancers. They can be further subdivided into three categories.
Nearly 30% of non-small cell cancers are squamous cell carcinomas. Squamous cell carcinoma is most often found near the bronchi of patients with a history of smoking. Forty percent of non-small cell cancers are adenocarcinomas, most often found in the outer region of the lung. The remaining 10% are large-cell undifferentiated carcinomas. These rapidly spreading carcinomas may be found throughout the lung.
Incidence of lung cancer
Lung cancer is rare among young adults. It is usually found in people who are 50 years of age or older, the average age at diagnosis is 60. While the incidence of the disease is decreasing among white men, it is steadily rising among African-American men, and among both white and African-American women. This change is probably due to the increase in the number of smokers in these groups. In 1987, lung cancer replaced breast cancer as the number one cancer killer among women. Lung cancer is responsible for more deaths than the combined totals for cancers of the colon, breast, and prostate.
Causes and symptoms
SMOKING. Tobacco smoking is the leading cause of lung cancer. Ninety percent of lung cancers can be prevented by giving up tobacco. Smoking marijuana cigarettes is considered yet another risk factor for cancer of the lung. These cigarettes have a higher tar content than tobacco cigarettes. In addition, they are inhaled very deeply—as a result, the carcinogens in the smoke are held in the lungs for a longer time.
EXPOSURE TO ASBESTOS AND TOXIC CHEMICALS. Exposure to asbestos fibers, either at home or in the workplace, is also considered a risk factor for lung cancer. Studies show that compared to the general population, asbestos workers are seven times more likely to die from lung cancer. Asbestos workers who smoke increase their risk of getting lung cancer by 50-100 times. Besides asbestos, mining industry workers exposed to coal products or radioactive substances such as uranium, and workers exposed to chemicals such as arsenic, vinyl chloride, mustard gas, and other carcinogens also have a higher than average risk of contracting lung cancer.
ENVIRONMENTAL CONTAMINATION. High levels of radon, a radioactive gas that cannot be seen or smelled, pose a risk for lung cancer. This gas is produced by the breakdown of uranium, and does not present any problem outdoors. In the basements of some houses that are built over soil containing natural uranium deposits, however, radon may accumulate to dangerous levels. Other forms of environmental pollution (e.g., auto exhaust fumes) may also slightly increase the risk of lung cancer.
CHRONIC LUNG INFLAMMATION AND SCARRING. Inflammation and scar tissue are sometimes produced in the lung by diseases such as silicosis and berylliosis, which are caused by inhalation of certain minerals; tuberculosis; and certain types of pneumonia. This scarring may increase the risk of developing lung cancer.
FAMILY HISTORY. Although the exact cause of lung cancer is not known, people with a family history of lung cancer appear to have a slightly higher risk of contracting the disease.
Because lung cancers tend to spread very early, only 15% are detected in their early stages. The chances of early detection, however, can be improved by seeking medical care at once if any of the following symptoms appear:
- a cough that does not go away
- chest pain
- shortness of breath
- persistent hoarseness
- swelling of the neck and face
- significant weight loss that is not due to dieting or vigorous exercise; fatigue and loss of appetite
- bloody or brown-colored phlegm (sputum)
- unexplained fever
- recurrent lung infections, such as bronchitis or pneumonia
Diseases other than lung cancer may cause these symptoms. It is vital, however, for patients to consult a physician to rule out the possibility that they are the presenting symptoms of lung cancer.
If the lung cancer has spread to other organs, the patient may have other symptoms such as headaches, bone fractures, pain, bleeding, or blood clots. Early detection and treatment can increase the chances of a cure for some patients; for others, it can at least prolong life.
Physical examination and initial tests
If lung cancer is suspected, the physician will take a detailed medical history to document the symptoms and assess the risk factors. The history is followed by a complete physical examination. The physician will examine the patient's throat to rule out other possible causes of hoarseness or coughing, and listen to the patient's breathing and the sounds made when the patient's chest and upper back are percussed (tapped). The physical examination, however, is not conclusive.
If there is reason to suspect lung cancer—such as a history of heavy smoking or occupational exposure to substances known to irritate the lungs—the physician may order a chest x ray to see if there are any masses in the lungs. Special imaging techniques, such as PET scans (positron emission tomography ), CT (computerized axial tomography) scans or MRI (magnetic resonance imaging ) may provide more precise information about the size, shape, and location of any tumors. X ray and other imaging techniques may be performed by a radiologic technician.
Sputum analysis involves microscopic examination of the cells that are either coughed up from the lungs, or are collected through a bronchoscope. Sputum analyses can diagnose at least 30% of lung cancers, some of which do not show up even on chest x rays. In addition, this laboratory test can help detect cancer in its very early stages, before it metastasizes (spreads) to other regions. The sputum test does not, however, provide any information about the location of the tumor and must be followed by other diagnostic tests.
Lung biopsy is the definitive diagnostic tool for cancer. It can be performed in several different ways. The physician can perform a bronchoscopy, which involves the insertion of a slender, lighted tube, called a bronchoscope, down the patient's throat and into the lungs. In addition to viewing the passageways of the lungs, the physician can use the bronchoscope to obtain samples of the lung tissue. In another procedure known as a needle biopsy, the location of the tumor is first identified using a CT scan or MRI. The physician then inserts a needle through the chest wall and collects a sample of tissue from the tumor. In the third procedure, known as surgical biopsy, the chest wall is opened up and a part of the tumor, or all of it, is removed. A pathologist, a physician who specializes in the study of diseased tissue, examines the tumor samples to identify the cancer type and stage.
Patients who will undergo surgical diagnostic and treatment procedures should be encouraged to stop smoking. Patients able to stop smoking several weeks before surgical procedures have fewer postoperative complications.
Treatment for lung cancer depends on the type of cancer, its location, and its stage. Staging is a process that describes if the cancer has metastasized and the extent of its spread. Lung cancer is staged at the time of diagnosis; this is called clinical staging. It usually is staged again following surgical intervention; this is called pathologic staging. When determining a course of treatment, the patient's age, medical history, and general state of health are taken into account. The most commonly used modes of treatment are surgery, radiation therapy, and chemotherapy.
Surgery is not usually an option for small cell lung cancers, because they have usually spread beyond the lung by the time they are diagnosed. Because non-small cell lung cancers are less aggressive, however, surgery can be used to treat them. The surgeon determines the type of surgery, depending on how much of the lung is affected. Surgery may be the primary method of treatment, or radiation therapy and/or chemotherapy may be used to shrink the tumor before surgery is attempted.
Not all patients are candidates for surgery, especially the removal of an entire lung (pneumonectomy). For example, many smokers suffer from emphysema as well as lung cancer, and as a result have sharply reduced lung capacity. Spirometric testing may be performed to assess lung capacity. The forced expiratory volume in one second (FEV1) is a laboratory test that helps to determine whether patients will have adequate pulmonary function after resection.
There are three different types of surgical operations:
- Wedge resection. This procedure involves removing a small part of the lung. A wedge resection is done when the cancer is in a very small area and has not metastasized to any other chest tissues or other parts of the body.
- Lobectomy. A lobectomy is the removal of one lobe of the lung. The right lung has three lobes and the left lung has two lobes. If the cancer is limited to one part of the lung, the surgeon will perform a lobectomy.
- Pneumonectomy. A pneumonectomy is the removal of an entire lung. If the cancer cells have spread throughout the lung, and if the surgeon feels that removal of the entire lung is the best option for curing the cancer, a pneumonectomy will be performed.
Postoperative surgical nursing care includes monitoring temperature, pulse blood pressure and respiration. Fever may indicate infection; patients are vulnerable to bacterial and viral infections. Decreased breath sounds may be symptoms of pneumothorax. The pain that follows surgery can be relieved by medications. The tendency of surgical stress to weaken the patient's immune system is treatable with antibiotics, anti-viral medicines, and vaccines.
Postoperative patient teaching encourages ambulation (walking), and reinforces patient and family understanding of surgical results and necessary follow-up.
Radiotherapy involves the use of high-energy rays to kill cancer cells. It is used either by itself or in combination with surgery or chemotherapy. Radiotherapy can be used to treat all types of cancer. The amount of radiation used depends on the size and the location of the tumor. There are two types of radiotherapy treatments, external beam radiation therapy and internal (or interstitial) radiotherapy. In external radiation therapy, the radiation is delivered from a machine positioned outside the body. Internal radiotherapy uses a small pellet of radioactive materials placed inside the body in the area of the cancer.
Radiation therapy may produce such side effects as tiredness, skin rashes, upset stomach, and diarrhea. Dry or sore throats, difficulty in swallowing, and loss of hair in the treated area are all minor side effects of radiation. Some side effects diminish or disappear either during the course of the treatment or after the treatment is over.
Patient education by nurses and radiologic technicians includes measures to identify and manage side effects such as fatigue or radiodermatitis (skin condition resulting from radiotherapy).
Chemotherapy uses anti-cancer medications that are either given intravenously or taken by mouth. These drugs enter the bloodstream and travel throughout the body, killing cancer cells that have spread to different organs. Chemotherapy is used as the primary treatment for cancers that have spread beyond the lung and cannot be removed by surgery. It may also be used in addition to surgery or radiation therapy.
Chemotherapy is tailored to each patient's needs. The prescribed regimen depends on the type of cancer, the extent of its spread, and the patient's general state of health. Most patients are given a combination of several different drugs. Besides killing the cancer cells, these drugs also harm normal cells. Hence, the dose has to be carefully adjusted to minimize damage to normal cells. Chemotherapy often has severe side effects, including nausea, vomiting, hair loss, anemia, weakening of the immune system, and sometimes infertility. Most of these side effects end when the treatment is over. Other medications can be given to lessen the unpleasant side effects of chemotherapy.
Patient teaching helps patients and families to distinguish between anticipated side effects such as alopecia (hair loss), nausea, and constipation and the more serious side effects that require medical attention. Examples of side effects that can not be managed at home include bleeding, fever, and confusion or hallucinations.
If the lung cancer is detected before it has had a chance to spread to other organs, and if it is treated appropriately, at least 49% of patients can survive five years or longer after the initial diagnosis. Only 15% of lung cancers, however, are found at this early stage.
Improvements in surgical technique and the development of new approaches to treatment have markedly improved the one-year survival rate for lung cancer. Slightly more than 40% of patients survive for at least a year after diagnosis, as opposed to 30% 25 years ago. The five-year survival rate for all stages of lung cancer is 14%.
Health care team roles
Lung cancer treatment involves an multidisciplinary team of health care professionals. In addition to primary care physicians, such as a family practitioner or an internist, the treatment team may include a pulmonologist, pathologist, radiologist, and thoracic surgeon as well as specialized nurses, radiologic and laboratory technicians, respiratory therapists, and dieticians.
Before, during and after treatment, nurses and allied health professionals should inform and educate patients and families about the risks and complications of any planned diagnostic test, intervention, or treatment. Patients and families should be taught about some of the common side effects of treatment, including weight loss, malnutrition, increased risk of infection, pain, fatigue, and depression.
The best way to prevent lung cancer is never to smoke or to quit smoking if one has already started. Secondhand smoke from tobacco should be avoided. Appropriate precautions should be taken when working with carcinogens (cancer-causing substances). Promoting healthy lifestyles, testing houses for the presence of radon gas, and asbestos abatement are also useful preventive strategies.
The objectives of education are to prevent patients, especially children and adolescents, from smoking, and to encourage smokers to quit. Participation in smoking cessation programs should be encouraged and patients should be informed about the health risks of passive (secondhand) smoking. Patient education also should describe the role of environmental carcinogens such as asbestos and radon in the development of lung cancer.
Alopecia— Hair loss.
Biopsy— The surgical removal and microscopic examination of living tissue for diagnostic purposes.
Bronchoscope— A thin, flexible, lighted tube that is used to view the air passages in the lungs.
Carcinogen— Any substance capable of causing cancer.
Chemotherapy— Treatment of cancer with synthetic drugs that destroy the tumor either by inhibiting the growth of cancerous cells or by killing them.
Lobectomy— Surgical removal of an entire lobe of the lung.
Metastasize— The spread of cancer cells from a primary site to distant parts of the body.
Pathologist— A physician who specializes in the diagnosis of disease by studying cells and tissues under a microscope.
Pneumonectomy— Surgical removal of an entire lung.
Pneumothorax— Collapse of the lung.
Radiation therapy— Treatment using high energy radiation from X-ray machines, cobalt, radium, or other sources.
Sputum— Mucus or phlegm that is coughed up from the passageways of the lungs.
Stage— A term used to describe the size and extent of spread of cancer.
Wedge resection— Removal of only a small portion of a cancerous lung.
Groenwald, S.L. et al. Cancer Nursing Principles and Practice. Sudbury, MA: Jones and Bartlett Publishers, 1997, pp.1260-1287.
Murphy, Gerald P., et al. American Cancer Society Textbook of Clinical Oncology, Second Edition. Atlanta, GA: The American Cancer Society, Inc., 1995, pp.220-234.
Otto, S.E. Oncology Nursing. St. Louis, MO: Mosby, 1997, pp. 312-343.
"Pulmonary Disorders: Tumors of the Lung." In The Merck Manual of Diagnosis and Therapy, edited by Robert Berkow, et al. Rahway, NJ: Merck Research Laboratories, 2005.
American Cancer Society. 1599 Clifton Road, N.E., Atlanta, GA 30329. (800)227-2345.
Cancer Research Institute. 681 Fifth Avenue, New York, NY 10022. (800)992-2623.
National Cancer Institute (National Institutes of Health). 9000 Rockville Pike, Bethesda, MD 20892. (800)422-6237.
Lung cancer refers to uncontrolled growth of cells in the lung tissues. The uncontrolled cell growth forms neoplasms, or tumors.
Cancer can begin in the lungs, which is primary lung cancer. Secondary lung cancer begins somewhere else in the body (for example, in the breast or kidney) and metastasizes, or spreads, to the lungs. This is not actually lung cancer, but secondary cancer that is found in the lungs. The secondary cancer is named for the site where it started, even though it is treated at the site of the lungs. Primary lung cancer is divided into type by identifying it as small cell or non-small cell cancer. Non-small cell is the more common of the two forms of lung cancer. Identifying which kind of lung cancer a senior has can help the physician plan treatment and prognosis.
Cancers occur when the cells in the body that control growth and division malfunction. Many types of cells make up the lungs; one of these types is epithelial cells, which line the lung's airways and help produce mucus. Non-small cell lung cancer arises from epithelial cells. It looks and behaves differently from small cell lung cancer, which generally spreads faster than non-small cell lung cancer. Within each of these two types, there are specific cancers that have been identified. For example, small cell lung cancer includes the more common small cell carcinoma, as well as a mixed cell and combined cell carcinoma. Non-small cell lung cancer has three sub-types that are described based on the cell makeup, shape, and size of the tumor. These are squamous cell carcinoma, adenocarcinoma, and large-cell (undifferentiated) carcinoma. Adenocarcinoma is the most common of the three non-small cell cancer types, at about 40%. It arises mostly from cells in the outer part of the lung. Squamous cell cancer makes up about 25 to 30% of non-small cell lung cancer. It forms from cells in the middle of the lungs, near the bronchi, or large air tubes. Large-cell lung cancers make up about 10-15% of all non-small cell cancers.
Usually, lung cancers take years to develop and often are not found until they are in more advanced stages. An exception is large cell cancers, which can develop anywhere in the lung and grow and spread quickly.
The American Cancer Society estimated that for 2008, there would be 215,020 new lung cancer cases diagnosed in the United States. Of those, about 114,690 were anticipated to be men and 100,330 were anticipated to be women. Estimated deaths in 2008 from lung cancer were anticipated to be 161,840, with about 90,810 of the deaths occurring in men and 71,030 occurring in women.
Worldwide, lung cancer is the most common cancer in men. Of all lung cancer patients, 90% either smoke cigarettes or have smoked. This precondition applies across lung cancer types. Male smokers are about 23 more times as likely to develop lung cancer than nonsmokers. The most common form of lung cancer to develop in people who have never smoked and in those younger than age 45 is adenocarcinoma.
Causes and symptoms
Smoking cigarettes is the primary cause of almost all lung cancers. Smoking marijhuana also increases risk for lung cancer. Exposure to certain toxic fibers or chemicals may increase a person's risk for lung cancer, whether the exposure is at home or at work. Those who work around asbestos are seven times more likely to die from lung cancer, and asbestos workers who smoke increase their risk as much as 50 to 100 times those who do not smoke and are not exposed to asbestos. People who work in certain mining industries and around certain chemicals also are at higher risk. The radioactive gas radon cannot be seen or smelled but poses a risk for lung cancer if it accumulates to dangerous levels.
Some people can develop lung cancer as a result of chronic inflammation and scarring in the lungs that occur from certain diseases. Tuberculosis and pneumonia are examples of diseases that cause scarring and inflammation. In 2004, researchers identified a chromosome that makes people more susceptible to lung cancer and that is inherited in families. Research on genetics in lung cancer continued as of 2008.
Lung cancers may spread early, so only about 15% are detected in early stages, while a patient shows few or no signs. Often, earlier-stage cancers are detected when a person goes to a physician for some other reason, such as to check for heart disease , and a spot is discovered on the lung. The spot normally is seen on a chest x ray or CT scan image. More often, lung cancer is discovered only after the tumor becomes so large that it takes up valuable lung space, causing breathing problems , or it pushes against nearby structures, which can cause pain or discomfort, as well as other symptoms. A lung tumor may cause fluid to collect in the lungs, which also causes difficulty breathing. The following symptoms may indicate another problem or condition but may mean lung cancer is present and should be a sign to see a physician:
- coughing that does not go away
- coughing up blood or brown-colored spit (sputum)
- shortness of breath
- wheezing that comes on suddenly
- chest pain
- recurring infections in the chest, such as pneumonia
- weight loss and loss of appetite
If lung cancer has spread to other organs, a senior may have other symptoms such as headaches , bone pain or fractures, bleeding, or blood clots .
Diagnosis of lung cancer begins with a detailed medical history and physical examination. The physician will listen to the patient's breathing for sounds made when breathing or when the chest is tapped. The throat may be examined to rule out other possible causes of hoarseness or coughing. A physical examination alone is not enough to diagnose lung cancer, but it can determine the next steps.
If the physician suspects lung cancer because of a history of smoking and physical symptoms, several tests maybe ordered to try to find the causes of the symptoms or to confirm a suspicion of lung cancer. A final lung cancer diagnosis only can be made with a biopsy, which is a sampling of tissue from the tumor. Often, the first test ordered is a chest x ray. A radiologist will examine the x ray and look for a nodule. The radiologist will note if the nodule has signs that make it appear cancerous. Other imaging examinations can show more features and details of masses in the lungs. CT scans , positron emission tomography (PET) scans, and magnetic resonance imaging (MRI) may provide better detail about the size, shape, and location of tumors.
A physician may order other examinations to help decide if symptoms may be caused by something other than lung cancer. For example, a positive tuberculosis skin test can rule out lung cancer but diagnose tuberculosis. Some tests may help determine extent of disease or possible spread to other organs. Examinations a physician may order in diagnosis of lung cancer include bronchoscopy , complete blood count , electrocardiogram, pulmonary function tests, and imaging examinations of other parts of the body such as the brain and bones to see if the lung cancer has spread.
The final lung cancer diagnosis is based on a biopsy. A small amount of fluid or tissue will be examined under a microscope by a pathologist. Several types of biopsy options are available for diagnosing lung cancer, depending on the patient's situation. If the patient is coughing up phlegm or sputum, some of the mucus may contain cancerous cells. Sometimes, sputum analysis diagnoses cancer earlier than other types of tests. But the findings will have to be followed by other diagnostic tests to gather information about the location of the tumor.
The tissue sample for lung biopsy often is obtained through bronchoscopy. In this procedure, a slender, lighted tube is placed down the patient's throat into the lungs. It allows the physician to see the passageways of the lungs and to use the scope to obtain samples of lung tissue. The patient may receive mild anesthesia. The procedure usually is performed by a surgeon or a pulmonologist. Tissue for biopsy also may be obtained during surgery to remove a mass. A fine needle aspiration biopsy is the use of a thin needle to aspirate, or suck, fluid directly out of the mass. It is usually performed by an interventional radiologist, who uses CT scanning or fluoroscopy to guide the way to the mass. Any biopsy sample provided to a pathologist is examined to determine if the cells are cancerous. The pathologist also may use the information from the cells' appearance under the microscope to determine if they are small cell lung cancer or non-small cell lung cancer.
The treatment a physician recommends for lung cancer depends on the type of cancer, its location, and the stage. Treatment may involve radiation therapy, chemotherapy , surgery, or some combination of treatments. For example, many patients with early stages of non-small cell lung cancer have surgery to remove the mass, sometimes after use of chemotherapy or radiation therapy to shrink the size of the mass.
Use of surgery depends on the patient's age, overall health, and location of the tumor. For example, a physician may need to ask for a spirometry examination prior to scheduling surgery to check lung function or certain cardiac tests to check the heart's function. The surgeon will determine the type of surgery, depending on how much of the lung is affected. Surgery usually is not an option for patients who have small cell lung cancer. These cancers often have spread beyond the lungs by the time they are diagnosed. Surgery also is not the best option even for some patients with non-small cell cancer, particularly if the entire lung is to be removed, a procedure called pneumonectomy. For example, many seniors who smoke have emphysema or COPD as well as lung cancer. Because they already have reduced lung capacity, they probably are not candidates for surgery.
The surgeon has several options available in addition to complete removal of the lung. In 2007, the American College of Chest Physicians updated its guidelines concerning diagnosis and management of lung cancer. These recommendations help physicians decide the best treatment for patients based on clinical research. One recommendation is that patients who are candidates for surgery not be denied resection, or removal of all or part of the lung, based solely on their age. A lobectomy removes only the affected lobe of the lung, leaving the remaining healthy parts of the organ. A surgeon also may surgically remove lymph nodes in the area to check them for presence of cancer. Presence of cancer in the lymph nodes is a sign that the cancer may have spread to distant organs.
Complications of surgery may include infection and pain, as well as pneumothorax. Pneumothorax is collapse of the lung due to injury, gas in the lung, or puncture of the chest wall.
Radiation therapy is the careful use of high-energy x rays to kill cancer cells. Several types of external beam radiation therapy may be used. New methods help to carefully target the tumor and protect surrounding healthy tissue. An internal method of radiation therapy called brachytherapy places radioactive material in or near the tumor. Radiation therapy may be used before or after surgery or as the only treatment. It also may be used as palliative treatment to ease pain and discomfort.
Side effects of radiation therapy may include skin irritation, difficulty swallowing, and fatigue. Some patients notice temporary shortness of breath from radiation therapy to the lung. Each patient's side effects are different.
Anticancer medicines may be given intravenously or taken by mouth. This treatment is called chemotherapy. The drugs enter the bloodstream and travel throughout the body, killing cancer cells that have spread to distant organs. Chemotherapy may be used in addition to surgery or radiation therapy and often is given to patients whose cancer has spread beyond the lung area.
Chemotherapy drugs are always changing as new ones are developed to target specific types of cancer. Each patient's particular drugs are carefully considered for the individual situation and to try to minimize damage to normal cells in the body. Side effects of chemotherapy for lung cancer may include nausea, vomiting, hair loss, anemia , and a weakened immune system .
All lung cancer patients who smoke are encouraged to stop smoking as part of their treatment.
QUESTIONS TO ASK YOUR DOCTOR
- What type and stage of lung cancer do I have?
- What treatment options are available?
- What are side effects I can expect from the treatment?
- What is my prognosis?
Patients who have metastasis , or spread of the lung cancer to other organs, may receive chemotherapy to attack all cancer cells in the body or radiation therapy targeted to the cells in the affected organ. Some patients have advanced disease that is not curable and receive radiation therapy or other therapies that are considered palliative care. Palliative care is given to a patient to provide pain relief and comfort only, not to attempt to cure. When a palliative care is needed, difficult decisions have to be made by the physicians, patients, and patients' families. A hospice physician or hospice staff can help coordinate palliative care and other needed services.
Seniors who have trouble breathing should eat several small meals a day instead of a few large meals. A full stomach can push against the diaphragm and make breathing more difficult. Certain cancer treatments may cause dietetic concerns for people with lung cancer. After surgery, patients may have to follow a surgeon's instructions while recovering, but usually only for a short period of time. Radiation therapy may cause swallowing problems , so people treated with radiation may have to choose softer foods that are easily chewed and swallowed. It is important for them to eat foods that are nutritious and easy on digestion to help ease the stomach if nausea arises from chemotherapy. Eating nutritious foods such as whole grains, fruits, and vegetables, is preferred to foods high in fats and sugars. Some seniors may have to use supplemental nutrition products. Drinking plenty of fluids and getting lots of rest help ease fatigue.
Some patients try complementary or alternative therapies to reduce stress or symptoms caused by other treatments. These patients should talk with their medical oncologists or other physicians about their
desire to use these therapies, since they may interfere with conventional treatment. Some patients who have lung cancer receive rehabilitative therapy to improve their breathing. Help also may be provided in learning how to properly exercise . If the cancer diagnosis is causing an emotional burden, some patients, survivors, and families may receive mental health therapy or participate in support groups.
Lymph node —Small oval-shaped filters in the lymphatic system that trap bacteria and other unwanted particles to ensure they are removed from the body.
Metastasis —The spread of cancer cells from the primary site to distant parts of the body.
Neoplasm —The growth of tissue that does not serve any function in the body, also called a tumor.
Palliative —Treatment that is given to relieve symptoms rather than to cure disease.
Sputum —The mucus or phlegm that is coughed up from the lung's passageways.
Prognosis for lung cancer depends on the type and stage of disease. Generally, prognosis for lung cancer is poor, but it improves if the cancer is found early. Treatment advances have improved survival so that the overall five-year survival rate for lung cancer has risen to about 16%. However, this is an average. Patients with Stage I disease have much higher survival rates, whereas patients with advanced stage inoperable disease have extremely low survival rates.
The best prevention for lung cancer is to avoid cigarette smoking. Never smoking at all or quitting smoking greatly reduces risk of the disease. Avoiding secondhand smoke also helps. If individuals work or live around known cancer-causing substances, they should take proper precautions.
If seniors have surgery for lung cancer, they may require close attention for several days following their discharge from the hospital . During radiation therapy or chemotherapy for lung cancer, side effects change and often add to medical and comfort needs. It is important for caregivers to communicate with patients and with medical caregivers to ask questions and offer observations that will add to appropriate and comprehensive care for seniors with lung cancer. Caregivers must be willing to be open to discussing difficult end-of-life issues if they arise. Hospice care may be the choice for seniors who have incurable lung cancer and want only pain relief and comfort in the final weeks or months of life. It also is important for caregivers to seek help, such as respite care, when they feel overwhelmed by caring for loved ones with lung cancer.
American Cancer Society. Cancer Facts & Figures, 2008. Atlanta: American Cancer Society, 2008.
Minna, John D. “Neoplasms of the Lung.” In Harrison's Internal Medicine. New York: The McGraw-Hill Companies, 2005.
Alberts, W. Michael. “Diagnosis and Management of Lung Cancer: Executive Summary: ACCP Evidence-based Clinical Practice Guidelines.” Chest (September, 2007):1S–19S.
People Living with Cancer, American Society of Clinical Oncology, 19000 Duke Street, Suite 200., Alexandria, VA, 22314, (703) 519-2997, (888) 651-3038, (703) 299-1014, [email protected], www.plwc.org.
Teresa G. Odle
Carcinoid Tumors, Lung
Carcinoid tumors, lung
Lung carcinoid tumors are rare malignant growths that develop from cells that help regulate the flow of air and blood through the lungs. These growths are also known as neuroendocrine lung tumors, pulmonary carcinoids, and lung carcinoids.
These cancers account for 1% to 3% of all lung tumors. Most lung carcinoids measure between slightly less than 1/4" (0.63 cm) and slightly more than 3/4" (1.9 cm). These tumors usually develop in the right lung.
Doctors classify lung carcinoids according to what tumor cells look like under a microscope, and where in the lung the tumor is located. Typical lung carcinoids occur about nine times as often as atypical tumors. They grow slowly and rarely spread beyond the lungs. Atypical lung carcinoids grow somewhat faster than typical tumors and are more likely to spread to other organs. In their most invasive form, atypical lung carcinoids look and behave like small-cell lung cancers.
About 80% of lung carcinoids are central carcinoids. Located in the walls of the large airways in the center of the lungs, where the neuroendocrine cells that form them are most concentrated, these tumors are almost always typical tumors. Carcinoids that develop in the narrower airways, close to the edges of the lungs, are called peripheral carcinoids. Most are typical tumors.
Lung carcinoids usually develop between the ages of 45 and 55. These tumors are equally common in men and women and rarely affect children.
Causes and symptoms
Lung carcinoids are not caused by smoking or by exposure to chemicals at work or in the environment. Doctors believe that central carcinoids develop from glands beneath the surface of the large air passages. Lung biopsies performed to diagnose or treat other conditions sometimes reveal microscopic clusters of neuroendocrine cells. These carcinoid tumorlets look like tiny peripheral carcinoids. They are most common when disease has caused scar tissue to form in the lungs, and may grow to be carcinoid tumors.
Patients who have peripheral or small central carcinoids don't usually show symptoms, but some patients who have central carcinoids cough, wheeze, or cough up blood (hemoptysis ).
A large carcinoid that blocks part or all of an airway can cause post-obstructive pneumonia . Doctors may not consider the possibility of a carcinoid until antibiotics fail to cure this lung infection.
About 10% to 20% of lung carcinoids produce hormone-like substances that release into the bloodstream. These substances can cause symptoms such as Cushing's syndrome , acromegaly, or hypercalcemia . They may also cause carcinoid syndrome, which is a constellation of symptoms including facial flushing, abdominal cramps, diarrhea , and breathlessness, among others.
A thorough physical examination will detect symptoms of syndrome health problems associated with these tumors. If a patient has one or more symptoms that suggest the presence of a lung carcinoid, the doctor will inquire about:
- chest pain
- blood-tinged sputum
- pneumonia not cured by antibiotics
- recent weight gain
- facial flushing
The doctor will use one or more methods to determine whether the patient has a lung tumor. Lung carcinoids that do not cause symptoms usually show up on chest x rays taken during a routine physical or as a result of other health problems.
Chest x rays cannot detect tumors that are very small or hidden by other organs in the chest. A doctor who suspects a lung carcinoid may order additional imaging studies in order to make a more detailed search.
About 75% of lung carcinoids can be seen through a long, lighted tube called a bronchoscope. Doctors also use CT scans, octreoscans, or MIBG (metaiodobenzyl-guanidine) scans to locate lung carcinoids and determine how far they have spread. CT scans provide a detailed view of the lungs. Octreoscans and MIBG scans trace the path of radioactive substances that are attracted to lung carcinoids.
Also called indium-111-labeled DTPA-octreotide scintigraphy, octreoscan involves injecting a small amount of a radioactive hormone-like substance into the patient's vein. Carcinoid tumors attract this substance, and a special camera locates tumors by pinpointing the area where the radioactive material accumulates.
Doctors perform MIBG scans by attaching radioactive iodine to a chemical absorbed by carcinoid tumors. This compound is injected into the patient's bloodstream, drawn to carcinoid tumor cells, and tracked by a special scanner.
Although diagnostic procedures can indicate that a patient might have a lung carcinoid, biopsy is the only way to confirm the diagnosis. Doctors use several different techniques to remove samples of these tumors.
To obtain a sample of a tumor in one of the large airways, the doctor uses a bronchoscope to examine the lining of these organs. When a tumor is located, the doctor manipulates pincers or tongs (biopsy forceps) through the bronchoscope to remove a small sample of tissue. The patient leaves the hospital a few hours after undergoing this outpatient procedure. If serious bleeding occurs, the doctor narrows or seals the blood vessels by injecting drugs or aiming a laser beam.
A doctor who performs a bronchoscopic biopsy may also wipe a tiny brush over the surface of the tumor. Tumor cells extracted in this way (brushing sample) are examined under a microscope. A brushing sample can add useful information to the results of bronchoscopic biopsy.
Doctors often use needle biopsy to obtain samples of tumors that are not close to the large airways. Guided by a computed tomography scan (CT scan) image, a long needle is passed between the ribs and into the lung to remove a small piece of the tumor. Because carcinoid tumors are usually small, localization using a needle biopsy may be difficult or impossible.
If neither bronchoscopic biopsy nor needle biopsy yields enough tissue to identify the tumor type, the doctor may open the patient's chest (thoracotomy ) to remove a tissue sample. A doctor who feels certain that a tumor is a carcinoid may perform a thoracotomy and remove the entire tumor without having taken a biopsy sample.
Lung carcinoids are treated by thoracic and cardiothoracic surgeons.
Clinical staging, treatments, and prognosis
Once lung carcinoids have been diagnosed, more tests are done to find out if the cancer has spread from the lung to other parts of the body (staging). A doctor needs to know the stage to plan treatment. Doctors stage lung carcinoids the same way they stage non-small cell lung cancers:
- Stage 0: Cancer is only found in a local area and only in a few layers of cells. It has not grown through the top lining of the lung.
- Stage I: The cancer is only in the lung, and normal tissue is around it.
- Stage II: Cancer has spread to nearby lymph nodes.
- Stage III: Cancer has spread to the chest wall or diaphragm near the lung; or the cancer has spread to the lymph nodes in the area that separates the two lungs (mediastinum); or to the lymph nodes on the other side of the chest or in the neck. Stage III is further divided into stage IIIA (usually can be operated on) and stage IIIB (usually cannot be operated on).
- Stage IV: Cancer has spread to other parts of the body.
Treatment of lung carcinoids
Doctors consider tumor size and location, and whether the patient has additional lung problems or serious disease affecting any other organ, in order to determine the most appropriate treatment for lung carcinoids.
Removing the tumor (surgical resection) is the treatment of choice for these cancers because most lung carcinoids:
- can be cured by surgery alone
- do not respond to chemotherapy or radiation
- must be removed in order to prevent airway obstruction and other complications of tumor growth
If the tumor is located in a large airway, the surgeon may remove the tumor and normal tissue above and below it, then sew together the remaining lung tissue. This procedure is a sleeve resection.
If tumor size or location makes sleeve resection impossible, the surgeon removes the affected lobe of the lung (lobectomy ). In rare cases, the surgeon removes the entire right or left lung (pneumonectomy ).
Surgeons use lobectomy to remove peripheral carcinoids located at the edges of the lungs farthest from the large airways. If the tumor is very small, the surgeon may remove it and a wedge-shaped piece of lung tissue surrounding it (wedge resection).
Surgeons who remove lung carcinoids usually remove some of the lymph nodes near the lungs because:
- About 10% of typical carcinoids and 30% to 50% of atypical carcinoids have spread to lymph nodes by the time the disease is diagnosed.
- Not removing lymph nodes might increase the risk of cancer spreading to other organs.
- Surgery alone cannot cure lung carcinoids that have spread to other organs.
- Examining lymph nodes can indicate the likelihood that cancer will recur.
Surgeons who remove lung carcinoids try to preserve the patient's lung function by removing the smallest possible amount of normal lung tissue.
A patient who has severe emphysema, chronic bronchitis, heart disease, or other medical problems may not be able to withstand the stress of surgery to cure lung carcinoids or to cope with breathing difficulties resulting from removal of normal lung tissue.
Doctors use a bronchoscope and a laser to burn away (vaporize) most of the tumor in a patient who is too ill to withstand surgery. These palliative treatments can relieve most symptoms associated with lung carcinoids, but cannot cure the disease. They are often supplemented by radiation administered externally or directly into the air passages (intrabronchial radiation).
Guidelines issued in 2001 by the National Comprehensive Cancer Network recommend the use of radiation following surgery to remove carcinoid lung tumors, and chemotherapy and radiation following surgery to remove atypical lung carcinoids.
Injected into a vein or taken by mouth, chemotherapy drugs are also used to treat lung carcinoids that have spread to other organs, are causing severe symptoms, or have not responded to other medications. Doctors may combine two or more chemotherapy drugs or add them to other medications to relieve symptoms of lung carcinoids that have spread to other organs.
Octreotide controls wheezing, flushing, and other symptoms of carcinoid syndrome. This medication may temporarily shrink lung carcinoids but does not cure them.
Alpha-interferon can shrink some lung carcinoids that have spread to other parts of the body and relieve symptoms of carcinoid syndrome. Doctors can prescribe other medications to relieve specific symptoms.
Radiation may be an option for patients who are too frail or ill to undergo surgery but is not a very effective treatment for lung carcinoids. High doses of radiation can damage lung tissue, create scar tissue, cause breathing problems, and make the patient more susceptible to infection.
Five-year survival rates for patients with lung carcinoids are 90% to 100% for typical tumors, and 40% to 76% for atypical tumors. Ten-year survival rates are about 10% lower than five-year rates for both types of tumors. The prognosis is worse for lung carcinoids that measure 1 1/4" (3.2 cm) or larger or have spread to lymph nodes.
Some patients who have had lung carcinoids must continue to have regular x rays and blood tests to help doctors detect recurrent disease in its earliest stages. Any patient who has had a lung carcinoid should notify the doctor whenever new symptoms develop. These symptoms could be side effects of treatment or signs that the disease has recurred. A patient who has recovered from surgery should ask the doctor about an exercise routine to restore energy and reduce shortness of breath.
Researchers are currently investigating whether:
- new methods of delivering radiation can shrink lung carcinoids that have not responded to treatment
- inhaling chemotherapy drugs can shrink advanced lung carcinoids
- biological therapy can starve lung carcinoids by cutting off the flow of blood that nourishes them and stimulate patients' white blood cells to kill cancer cells
- new methods of delivering chemotherapy can kill cancer cells without harming normal cells
- new combinations of chemotherapy drugs can prevent cancer cells from multiplying
- chemotherapy drugs combined with radioactive substances can locate and kill cancer cells without harming normal cells
Information about clinical trials is available from the National Institute of Health's National Cancer Institute.
There are no known risk factors for lung carcinoids, and no methods of prevention are known.
See Also Neuroendocrine carcinomas; Bronchoscopy
"New NCCN Recommendations for Small-Cell Lung Cancer." Oncology News International 10, no. 4 (April 2001).
National Carcinoid Support Group, Inc. 6666 Odana Rd., #146, Madison, WI 53719-1012. <http://members.aol.com/thencsg/info.html>.
National Cancer Institute. CancerNet 28 May 2001 <http://cancernet.nci.nih.gov>.
"Lung Carcinoid Tumor." Lung Carcinoid Tumor Research Center. 23 May 2000. 2 April 2001. 2 July 2001 <http://www3.cancer.org>.
"Lung Tumors: A Multidisciplinary Database." Virtual Hospital. August 1999. 27 May 2001. 2 July 2001 <http://www.vh.org/Providers/Textbooks/LungTumors/TitlePage.html>.
—Hormonal disorder causing progressive enlargement of hands and feet and elongation of the face, headache, muscle pain, and visual and emotional disturbances in middle-aged men and women.
—Rare malignant disease characterized by facial flushing, abdominal cramps, diarrhea, breathlessness, and other symptoms. Affects fewer than 10% of patients with carcinoid tumor.
—Hormonal disorder characterized by a round face, mental or emotional instability, high blood pressure, weight gain, or abnormal growth of facial and body hair in women.
—Abnormal lung condition characterized by breathing problems, cough, rapid heartbeat. Later stages are characterized by restlessness, weakness, confusion, increased breathlessness, and may cause fluid to collect around the lungs (pulmonary edema) and congestive heart failure.
—Abnormally high levels of calcium in the blood, causing muscle pain and weakness and loss of appetite. Severe cases can result in kidney failure.
QUESTIONS TO ASK THE DOCTOR
- What kind of lung carcinoid do I have?
- What treatment do you recommend?
- Will this treatment cure me?
- What can I do to make this treatment more successful?
Lung cancer is an abnormal growth of cells in the lungs, usually caused by smoking cigarettes, that frequently spreads to other parts of the body and often is fatal.
for searching the Internet and other reference sources
In the 1960s, actor David McLean was hired to portray the Marlboro Man, a macho, cigarette-smoking cowboy, in television and print advertising for the tobacco company Philip Morris. McLean smoked many packs of cigarettes to get the right, ruggedly handsome look for each ad, and later he continued to receive boxes of cigarettes as gifts from the company. McLean had begun smoking at age 12, and he never was able to quit. In 1985, he began to suffer from a lung condition called emphysema* due to smoking, and in 1993, he was diagnosed with cancer of the right lung. By 1995, the cancer had spread to his brain and spine. McLean died that year at age 73.
- * emphysema
- (em-fi-ZEE-ma) is a lung condition in which the air sacs of the lungs are enlarged, which makes the lungs work less well and leads to shortness of breath.
The lungs allow people to breathe by bringing air in and out. They take in oxygen and get rid of carbon dioxide, a gas that is a waste product of the body. The lungs are two sponge-like organs in the chest. The right lung has three sections, called lobes, and the left lung has two. A lining, called the pleura (PLOOR-a), surrounds the lungs and helps protect them. Air travels into the lungs through the trachea (TRAY-kee-a) (also called the windpipe), which divides into two tubes called bronchi (BRONK-eye), which in turn divide into small branches called bronchioles (BRON-kee-oles). At the distant tips of these branches are millions of tiny air sacs called alveoli (al-VEE-o-lye), which look like little buds. These structures together make up the lungs.
Lung cancer usually starts in the lining of the bronchi. However, it can begin in any other part of the lungs. The disease takes a long time to develop. Lung tissue, like other kinds of body tissue, contains DNA. This is material that people get from their parents that contains the instructions, or genes*, for everything the cells do. Gene changes, called mutations, can cause normal cells in the lungs to do abnormal things and to form cancers. Some genes tell cells when to grow, and others tell them when to stop growing. Mutations in these genes may tell cells to grow too much, or they may fail to tell them to stop growing. In either case, the result is cells that are out of control. The cells have repair mechanisms to correct the faulty signals, but when a cell is growing very fast, errors may slip past.
- * genes
- are chemicals in the body that help determine a person’s characteristics, such as hair or eye color. They are inherited from a person’s parents and are contained in the chromosomes found in the cells of the body.
Most of the mutations that occur in lung cancer are not believed to be changes that are inherited from a persons parents. Instead, the mutations seem to occur during the persons lifetime. However, it is possible for a person to inherit a reduced ability to break down certain kinds of cancer-causing chemicals. Scientists cannot tell yet which people have these reduced abilities.
Who gets lung cancer?
In the United States, more men and women die from lung cancer than from any other kind of cancer. The American Cancer Society estimates that, every year in the United States, about 178,000 people will find out that they have lung cancer, and more than 160,000 people will die from the disease. Lung cancer is rare in people under age 40, because it takes years to develop. The number of cases increases with age, particularly after age 65.
What causes lung cancer?
Up to 90 percent of lung cancer is caused by smoking. Tobacco smoke damages cells in the lungs of smokers in ways that can lead to cancer. Although most smokers do not get lung cancer, the longer a person has been smoking, the greater the risk.
People who have worked with asbestos, a substance once widely used as an insulating material that is now banned in the workplace and in home products, also have a higher risk of getting lung cancer. Other risk factors* for the disease include cancer-causing chemicals in the workplace.
- * risk factors
- are anything that increases the chance of developing a disease.
Symptoms of lung cancer often do not appear until the disease is advanced. Many times, the cancer is discovered when a person gets a chest x-ray for an unrelated reason. When symptoms do occur, they are so general that many conditions could cause them. Possible symptoms include a cough that does not go away, chest pain, hoarseness, bloody sputum*, and shortness of breath. The only way to find out for sure whether cancer is causing these symptoms is to see a doctor.
- * sputum
- (SPYOO-tum) is mucus that is coughed up from the lungs.
If lung cancer is suspected, the doctor may perform a physical exam and a chest x-ray. The doctor also may take a sample of sputum to be examined for abnormal or cancerous cells. In addition, if a tumor* is found on the x-ray, the doctor can do a biopsy* of the lung tissue. This procedure uses special instruments to remove a small sample of abnormal tissue from the lung for examination under a microscope.
- * tumor
- (TOO-mer) usually refers to an abnormal growth of body tissue. Some tumors are cancerous, but others are not.
- * biopsy
- (BY-op-see) is the removal and examination of a sample of tissue from a living body for the purpose of diagnosis.
So Long, Joe Camel
For a long time, cigarette advertising on billboards was a familiar feature of the American landscape. One of the most famous signs was a 72-foot-high billboard in New York’s Times Square that showed Joe Camel puffing out smoke rings for 25 years.
During the 1980s, one in three billboards advertised tobacco. However, in 1999, as part of a $206 billion agreement between tobacco producers and 46 states to settle lawsuits related to smoking, cigarette makers and outdoor advertising companies removed tobacco billboards all over the United States.
First tests are done to find out how far the cancer has spread. Based on these tests, the cancer usually is assigned a Roman numeral from I to IV. This process is called staging. The smaller the number, the less the cancer has spread. In contrast, a stage IV cancer means a more serious stage of the disease. This system is used for most types of lung cancer, including the types called squamous cell cancer, large cell cancer, and adenocarcinoma. One-fourth of lung cancers are a type called small cell lung cancer. Instead of getting a Roman numeral, this type is rated either limited (not widespread) or extensive (in both lungs, for example, and spread to distant organs).
The best treatment for lung cancer depends on the type of cancer, the stage, and the person’s overall health. Treatment usually consists of a combination of surgery, chemotherapy (kee-mo-THER-a-pee), and radiation therapy.
For cancer that has not spread, surgery offers the chance of a cure by removing the diseased part of the lung. However, some tumors can not be removed by surgery because of their size or location, and some patients can not have surgery for other health reasons.
Chemotherapy is the use of anticancer drugs to kill cancer cells. The drugs are given into a vein in the arm or as pills. Because these drugs enter the bloodstream and can reach all areas of the body, they may be useful for treating cancer that has spread beyond the lungs. Chemotherapy can have side effects, including nausea (a feeling of wanting to throw up) and hair loss. Not everyone reacts to chemotherapy in the same way. Usually, the side effects disappear and hair begins to grow back when the treatment is over.
Radiation therapy is the use of high-energy x-rays to kill or shrink a tumor. In lung cancer patients who are not healthy enough for surgery, radiation may be the main treatment. For other patients, radiation may be used after surgery to kill small areas of cancer cells too tiny to be seen during surgery. Radiation can make a person feel tired, and the skin in the treated area may look first sunburned, then tan. The skin eventually will return to normal.
The best way to prevent lung cancer is by not smoking. People who do not smoke should not start, and people who do smoke should quit. Because the nicotine in cigarettes is so addicting, it is not easy to quit, but it is well worth the effort. Simply switching to “low tar” or filtered cigarettes does not prevent cancer. Everyone also should avoid breathing in other people’s smoke. In addition, people can find out whether cancer-causing chemicals are used in their workplace and take steps to protect themselves.
Young People and Smoking
A study published in the Journal of the National Cancer Institute in 1999 showed that lung cancer patients who had started smoking before age 15 had twice as many DNA changes in their lung tissue as those who started after age 20. The message from this study is that smoking at a very young age may be especially likely to cause lung damage that lasts a lifetime.
Advances on the horizon
Right now, prevention seems to offer the greatest chance for fighting lung cancer. Research is continuing into ways to prevent lung cancer in people at high risk by using vitamins, foods, and medications, but the results so far have not been very helpful. Researchers also are looking into ways of detecting lung cancer earlier.
Studies of treatments for lung cancer are looking at new chemotherapy drugs or new combinations of old drugs. Treatments that help the patient’s immune system* fight lung cancer more effectively also are being tested. In addition, gene therapy* may one day be able to repair the genetic mutations that lead to lung cancer.
- * immune system
- is the body system made up of organs and cells that defend the body against infection or disease.
- * gene therapy
- is a treatment that works by altering genes.
Some people recover from lung cancer, but even in the least severe cases, only 50 percent of people with lung cancer are alive five years after their diagnosis. When all cases of lung cancer are taken together, including both most severe and least severe cases, the survival rate at five years drops to 14 percent. This is one reason that it is so important not to start smoking or to quit if a person does smoke.
Because of the low rate of cure, lung cancer patients typically have concerns about whether the cancer will come back after treatment and how long they will live. People need their lungs to breathe, so in advanced cases, as the cancer takes up more and more of the space usually occupied by air, breathing may become difficult. In addition, growth of the cancer around certain nerves may cause severe pain. Medications can relieve this pain, and patients should not hesitate to ask for them.
American Cancer Society, 1599 Clifton Road Northeast, Atlanta, GA 30329-4251. A national, nonprofit organization that provides accurate, up-to-date information about lung cancer. Telephone 800-ACS-2345 http://www.cancer.org
U.S. National Cancer Institute, Building 31, Room 10A03, 31 Center Drive, Bethesda, MD 20892-2580. This U.S. government agency offers information about lung cancer to patients and the public, and a posts a fact sheet What You Need to Know About Lung Cancer at its website. Telephone 800-4-CANCER http://rex.nci.nih.gov http://cancernet.nci.nih.gov/wyntk_pubs/index.html
Lung cancer is a malignant disease in which lung cells become abnormal, characterized by uncontrollable, unlimited growth. These cells can then invade nearby normal tissue and destroy organ structure, a process called "invasion." Lung cancer cells can also break down lung tissue structure and enter the bloodstream or lymphatic system and thus spreads to distant organs in other parts of the body, a process called metastasis. Clinically, lung cancer can be classified into two groups according to its cell types under microscopy: non-small cell lung cancer and small cell lung cancer. Non-small cell lung cancer includes cancers of three cell types: squamous cell carcinoma, adenocarcinoma, and large cell carcinoma. Small cell lung cancer, also called oat cell cancer, is a less common cancer that grows faster, and is more likely to spread to other parts of the body than non-small cell lung cancer.
Lung cancer is a highly lethal disease in the United States and worldwide. According to Parkin et al. (1999), lung cancer was the most frequent cancer in 1990, worldwide, with 1.04 million new cases (771,800 in men and 265,100 in women). It is the most common cancer in men and the fifth most frequent cancer in women. Lung cancer is the leading cause of cancer deaths worldwide, with a total of 921,000 deaths per year (692,600 in men and 228,400 in women) in 1990. In the United States, it was estimated that 169,500 new lung cancer patients (90,700 men and 78,800 women) would be diagnosed and 157,400 (90,100 men and 67,300 women) would die of lung cancer in 2001. The five-year survival rate of lung cancer is 13.7 percent in the United States, 7.8 percent in developing countries, 7 percent in Eastern Europe, 7.9 percent in China, and 6.7 percent in India.
The changes (increase or decrease) of lung cancer incidence corresponds to the alterations of prevalence of smoking in the population twenty to thirty years earlier, representing a latent period between tobacco exposure and the occurrence of lung cancer. A significant decrease in the incidence of lung and bronchus cancer in males in North America started in the late 1980s. Between 1990 and 1996 there was a 2.6 percent decline in incidence per year. Incidence rates of lung and bronchus cancer in females are stabilizing in the United States. Although the death rate from lung cancer in males is decreasing, it is increasing among females, and it has now exceeded the breast cancer death rate among females.
Tobacco smoking is a major cause of lung cancer. Over 4,000 chemical compounds have been identified in the tobacco leaf. Carcinogens in tobacco smoke can damage the cells in the lungs, which may lead to the development of lung cancer. More than fifty chemical compounds in tobacco smoke have been recognized as known or probable human carcinogens, some of which may be formed during combustion (or smoking) and some which may exist naturally in tobacco. Several groups of carcinogens in tobacco smoke are related to lung cancer, including polycyclic aromatic hydrocarbons (PAHs), aromatic amines, benzene, hydrazine, and vinyl chloride. Smoking results in damage to the bronchial and lung epithelium, which leads to lung cell proliferation and finally to lung cancer. Animal studies confirm the carcinogenic potential of tobacco smoke in tissues having smoke contact: in these studies smoke exposure leads to laryngeal tumors and pulmonary adenomas. In humans, cigarette smokers have increased levels of tobacco carcinogen DNA adducts in the lung and bronchus when compared with nonsmokers.
A very strong association between cigarette smoking and lung cancer has been consistently observed in studies done since the early 1950s. These studies have shown that cigarette smoking precedes lung cancer occurrence. It has been estimated that cigarette smokers have a ten-fold higher risk of lung cancer, in comparison with nonsmokers. With the increased number of cigarettes smoked per day, the risk is increased—heavy smokers are at greater risk of lung cancer than moderate smokers; and moderate smokers are at higher risk than light smokers and nonsmokers. The risk for individuals who smoke two or more packs per day is about twenty times that of nonsmokers, and longer smoking duration has a stronger effect on the risk of lung cancer. Beginning to smoke at an early age is also related to an increased risk, and the lung cancer risk declines with an increased duration of cessation. The percentage of reduction in risk after quitting smoking depends on the duration of exposure to smoking. The observed relationship between cigarette smoking and the risk of lung cancer is consistent with different study designs and in studies of different populations all over the world. Over eighty-five percent of deaths from lung cancer can be attributed to cigarette smoking. It is estimated that tobacco smoking accounts for over ninety percent of male lung cancer deaths and seventy-nine percent of female lung cancer deaths in the United States.
Smoking of other tobacco products, such as cigar and pipe smoking, is also associated with an increased risk of lung cancer. Like cigarette smoking, the risk of lung cancer is increased with the frequency and years of cigar and pipe smoking. Environmental tobacco smoke (ETS), also known as secondhand smoke, increases the risk of lung cancer among nonsmokers. It is estimated that ETS may lead to 3,000 new cases of lung cancer per year in nonsmokers in the United States. Other risk factors for lung cancer include race, occupational exposures (e.g., arsenic, asbestos, chromium, mustard gas, PAHs), residential radon exposure, radiation, air pollution, and nutritional factors. The host susceptibility factors for lung cancer include inheritance of different polymorphic genotypes that may interact with tobacco smoke in determining the risk of lung cancer.
Smoking cessation or lifelong abstinence from smoking offer the best opportunities to reduce lung cancer incidence and death rates. Reducing the prevalence of smoking will lead to a dramatic decrease in the incidence of lung cancer in the general population. According to the Centers for Disease Control and Prevention (CDC), cigarette smoking is the single most preventable cause of premature death in the United States. More than 400,000 people die from causes attributable to cigarette smoking each year, including 276,000 men and 142,000 women. The promotion of smoking cessation is the most cost-effective tool against lung and other smoking-related cancers and diseases.
Control of other risk factors, such as workplace exposures associated with the increased risk of lung cancer, environmental tobacco smoke, and radon exposure in residences, may also lead to a reduced risk of lung cancer. Sputum cytology and chest radiographs are not recommended for lung cancer screening because no favorable impact of the screening on lung cancer mortality has been demonstrated. Recent developments have pointed out that the molecular genetic alterations associated with progression toward lung cancer, such as p53 mutations in sputum samples, may help to identify high-risk individuals for early detection and chemoprevention.
Centers for Disease Control and Prevention (1993). "Smoking-Attributable Mortality and Years of Potential Life Lost—United States, 1990." Morbidity and Mortality Weekly Report 42(33):645–648.
Greenlee, R. T.; Hill-Harmon, M. B.; Murray, T.; and Thun, M. (2001). "Cancer Statistics, 2001." CA: A Cancer Journal for Clinicians 51:15–36.
International Agency for Research on Cancer (1986). Evaluation of the Carcinogenic Risk of Chemicals to Humans: Tobacco Smoking. IARC Monographs, Volume 38. Lyon, France: World Health Organization.
National Cancer Institute (1999). Health Effects of Exposure to Environmental Tobacco Smoking. The Report of the California Environmental Protection Agency. Smoking and Tobacco Control Monograph No. 10. Bethesda, MD: National Cancer Institute.
Parkin, D. M.; Pisani, P.; and Ferlay, J. (1999). "Estimates of the Worldwide Incidence of 25 Major Cancers in 1990." International Journal of Cancer 80: 827–841.
Pisani, P.; Parkin, D. M.; Bray F.; and Ferlay, J. (1999). "Estimates of the Worldwide Mortality from 25 Cancers in 1990." International Journal of Cancer 83:18–29.
Samet, J. M. (1995). "Lung Cancer." In Cancer Prevention and Control, eds. P. Greenwald, B. S. Kramer, and D. L. Weed. New York: Marcel Dekker.
Lung cancer is a disease in which the cells of lung tissues grow uncontrollably and form tumors. A tumor is a mass or lump of tissue made of abnormal cells.
Lung cancer is the leading cause of death from cancer among both men and women in the United States. Experts estimate that 28 percent of all cancer deaths—about 160,000—are caused by lung cancer. It is further estimated that at least 172,000 new cases of lung cancer are diagnosed each year.
Lung cancer is rare among children and young adults. It is usually found in people older than fifty. The average age at diagnosis is sixty. There are two kinds of lung cancer, primary and secondary. Primary lung cancer starts in the lungs. Secondary lung cancer starts somewhere else in the body; cancer cells then spread to the lungs and start a new infection. When cancer cells travel from one area of the body to another it is called metastasis (pronounced muh-TASS-tuh-siss). When this happens, a cancer is said to have metastasized (pronounced muh-TASS-tuh-sized).
By far the major cause of lung cancer is tobacco smoking. Ninety percent of all cases of lung cancer are thought to be caused by smoking. Other factors that may lead to lung cancer include:
- Exposure to asbestos and toxic chemicals. Asbestos is a naturally occurring mineral that was once used widely in many applications. For example, home and office insulation was once made of asbestos. Scientists now know that asbestos fibers can cause lung cancer. Studies show that people who work with asbestos are seven times more likely to die of lung cancer. A variety of other chemicals can also cause lung cancer, including arsenic, compounds of chromium and nickel, mustard gas, vinyl chloride, and emissions from coke ovens.
- Radon gas. Radon is a gas given off by radioactive materials. A radioactive material is a substance that gives off radiation and turns into a new substance. Radon gas is often formed in rocks that contain radioactive materials. It escapes from those rocks and gets into the air. It is often found in the basements of homes, office buildings, and factories built over such rocks. A person who smokes and is exposed to radon gas has the highest risk for lung cancer.
- Lung disorders. The lungs can be damaged by a variety of diseases and disorders. Among these are tuberculosis (see tuberculosis entry), pneumonia (see pneumonia entry), silicosis (pronounced sil-i-KO-siss), and berylliosis (pronounced buh-ril-ee-O-suhs). The last two diseases are caused by inhaling certain minerals. These diseases and disorders can scar lung tissue. Such scarring may later develop into tumors.
- Family history. People with relatives who have had lung cancer are at slightly higher risk for contracting (getting) lung cancer.
The most common symptoms of lung cancer include:
- A cough that does not go away
- Chest pain
- Shortness of breath
- Persistent hoarseness
- Swelling of the neck and face
- Significant weight loss that cannot be explained by other factors
- Fatigue and loss of appetite
- Bloody or brown-colored sputum
- Unexplained fever
- Recurrent lung infections, such as bronchitis (see bronchitis entry) or pneumonia
The first step in diagnosing lung cancer is a medical history and a physical examination. An important part of the medical history involves questions about smoking. A patient who smokes is at high risk for lung cancer.
Lung Cancer: Words to Know
- A disease of the lungs caused by inhaling small particles of the element beryllium.
- A procedure in which a small sample of tissue is removed and then studied under a microscope.
- A method of treating cancer using certain chemicals that can kill cancer cells.
- The process by which cancer cells travel from one area of the body to another.
- Primary lung cancer:
- Cancer that starts in the lungs.
- Radiation therapy:
- The use of high-energy radiation to treat cancer.
- A radioactive gas that occurs naturally and is often found in the lower levels of buildings.
- Secondary lung cancer:
- Cancer that starts somewhere else in the body and then spreads to the lungs.
- A disease of the lungs caused by inhaling fine particles of sand.
- Material that is coughed up from the passageways of the lungs.
- A mass or lump of tissue made of abnormal cells.
The primary purpose of the physical examination is to rule out other disorders with similar symptoms. For example, many respiratory problems can cause hoarseness and coughing. The doctor needs to be certain that none of these problems is responsible for the patient's symptoms.
Imaging techniques may also be used. A chest X ray may show the presence of unusual masses in the lungs. A computed tomography (CT) scan or magnetic resonance imaging (MRI) test may provide further information about the size, shape, and location of any tumors.
Sputum analysis may be ordered to study materials coughed up by the patient. This test can detect at least 30 percent of all lung cancers. An important feature of a sputum test is that it can detect cancer in its earliest stages.
The most conclusive test for lung cancer is a lung biopsy. A biopsy is a procedure in which a small sample of tissue is removed. The sample is then studied under a microscope. Cancer cells can be identified under a microscope because of their distinctive appearance.
Treatment of lung cancer depends on the type of cancer, its location, and its stage of development. The patient's age, general health, and medical history are also taken into account. The three most common forms of treatment are surgery, radiation, and chemotherapy.
Some types of lung cancer cannot be treated surgically. For example, surgery is not an option if the cancer has already metastasized. The type of surgery performed depends on how far the cancer has spread. If it is still limited to one area of the lung, only that area is removed. In many cases, however, the cancer has already spread to other parts of the lung. The next most aggressive step is to remove one lobe of the lung. The right lung has three lobes, and the left lung has two. The lungs can continue to function if one lobe is removed. The most drastic surgery involves the removal of the whole lung, followed by a lung transplantation. This procedure is used only when cancer has spread throughout the entire lung.
Radiation is also used to treat lung cancer. Radiation involves the use of high-energy rays to kill cancer cells. In most cases, the radiation comes from radioactive materials. Radioactive materials are substances that give off high-energy radiation, similar to X rays. The radiation can be given either externally or internally. If it is given externally, the radioactive source is placed above the patient's body in the area of the cancer. Radiation from the source penetrates the body and destroys cancer cells. Radiation can also be given internally by implanting the source directly in the patient's body.
Radiation can also be used prior to surgery. In this case, the purpose of the radiation treatment is to shrink the tumor. Radiation may also be given following surgery. The purpose in this case is to destroy any cancer cells that may remain after the surgery.
Chemotherapy is the use of chemicals that kill cancer cells. These chemicals can be given either orally (by mouth) or intravenously (into the bloodstream). Chemotherapy is often used when cancer has spread beyond the lungs. The chemicals spread throughout the patient's body and attack cancer cells wherever they occur. As with radiation, chemotherapy may be given either before or after surgery.
Both radiation and chemotherapy have a number of unpleasant side effects. Radiation may cause tiredness, skin rashes, upset stomach, diarrhea, sore throat, difficulty swallowing, and loss of hair. Chemotherapy also causes nausea, vomiting, hair loss, anemia (general weakness due to low blood count; see anemias entry), and weakening of the immune system.
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 better breathing and stronger chest muscles. 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.
The prognosis for lung cancer depends very much on how early the condition is discovered. If it is treated in its earliest stages, about half of all patients survive at least five years after initial diagnosis. The problem is that only 15 percent of lung cancers are found in an early stage. Overall, the five-year survival rate for all forms of lung cancer is 14 percent.
In the vast majority of cases, lung cancer is relatively easy to prevent. People who do not smoke or who stop smoking are at very low risk for contracting the disease. Some authorities suspect that secondhand smoke may also pose a threat for lung cancer. Secondhand smoke is smoke that a person breathes in from another person's cigarette, cigar, or pipe.
Other ways to prevent lung cancer are to avoid contact with chemicals that can cause the disease (such as asbestos) and to have one's home checked for radon gas. Home test kits for radon are available. They are easy to use and can tell in a matter of minutes whether radon is present in a building.
FOR MORE INFORMATION
Morra, Marion E., and Eve Potts. Choices. New York: Avon Books, 1994.
Cancer Research Institute. 681 Fifth Avenue, New York, NY 10022. (800) 992–2623. http://www.cancerresearch.org.
National Cancer Institute. 31 Center Drive, Bethesda, MD 20892–2580. (800) 4–CANCER. http://www.nci.nih.gov.
National Coalition for Cancer Survivorship. 1010 Wayne Avenue, 5th Floor, Silver Springs, MD 20910. (301) 650–8868.
lung cancer,cancer that originates in the tissues of the lungs. Lung cancer is the leading cause of cancer death in the United States in both men and women. Like other cancers, lung cancer occurs after repeated insults to the genetic material of the cell. By far the most common source of these insults is tobacco smoke, which is responsible for about 85% of U.S. lung cancer deaths (see smoking). The incidence of lung cancer in other countries follows their smoking patterns. Some other carcinogens known to cause lung cancer are found in the workplace. These include bischloromethyl ether and chloromethyl ether in chemical workers, arsenic in copper smelting, and asbestos in shipbuilders and other asbestos workers. Radon poses a risk to uranium and fluorspar miners and may pose a risk in some private residences as well. African Americans have a higher incidence of lung cancer than European Americans, even after adjusting for smoking.
Types of Lung Cancer
Lung cancers are classified according to the type of cell present in the tumor. The majority are referred to as non–small cell carcinomas. These include squamous cell or epidermoid carcinomas (the most common type worldwide), adenocarcinomas, and large cell carcinomas. Small cell carcinoma (which includes the subtypes oat cell and intermediate) comprises approximately 20% to 25% of lung cancers; it often has metastasized by the time it is detected. Lung cancer most commonly spreads to the brain, bone, liver, or bone marrow.
The primary symptoms of lung cancer are cough, shortness of breath, hoarseness, blood in the sputum, and pain. In some types, the cancer cells themselves produce hormones or other substances that can create an imbalance and result in various symptoms. Metastatic lung cancer also can cause symptoms that result from its effect on the organ to which the cancer has spread.
Diagnosis and Treatment
Diagnosis of lung cancer may be made by physical examination, chest X rays, bronchoscopy (see bronchoscope), or percutaneous needle biopsy (insertion of a fine needle through the skin and into the lung to obtain tissue for study). In many cases definitive diagnosis is made after surgical specimens have been evaluated. Evaluation of suspected sites of metastasis may involve CAT scans or magnetic resonance imaging (MRI). A special CAT-scanning technique (helical low-dose CAT-scanning) has also been used for initial diagnosis because it can detect small tumors before they have spread.
Lung cancer is staged according to its location, size, cell type, and spread. This staging plus the state of health of the patient are used to determine treatment.
Treatment typically consists of surgical excision of the tumor alone or in combination with either external-beam radiation therapy or chemotherapy using one or more anticancer drugs. Photodynamic therapy is sometimes used if the cancer is still localized. In this therapy a substance that makes cells more sensitive to light is injected into the body. When it has passed out of most of the tissues, but remains in the cancer cells, the cancer is destroyed by a beam of laser light.
Not starting to smoke or ceasing to smoke is by far the most effective lung cancer preventive. The risk of lung cancer in ex-smokers begins to decline about five years after quitting, and after 15 to 20 years their risk is 80% less than that of smokers. The reduction in cigarette smoking since the 1964 report of the Surgeon General's Advisory Committee on Health began to be translated into a decrease in the incidence of lung cancer in the 1990s; this decrease averaged more than 1% per year from 1990 to 1995. The preventive role of dietary antioxidants is under study.
See D. N. Carney, ed., Lung Cancer (1995). See also publications of the National Cancer Institute and the American Cancer Society.