Small intestine cancer

Definition

Cancer of the small intestine is a rare disease that results when abnormal, malignant cells divide out of control. Cancers in this location consist primarily of adeno-carcinoma, lymphoma , sarcoma, and carcinoid tumors.

Description

The small intestine is a long tube inside the abdomen divided into three sections: the duodenum, jejunum, and ileum. The function of the small intestine is to break down food and to remove proteins, carbohydrates, fats, vitamins , and minerals. Obstruction of the small intestine by cancer may impair normal passage and digestion of food and nutrients.

Adenocarcinoma

These malignancies most often start in the lining of the small intestine, most frequently occurring in the duodenum and jejunum, the sections closest to the stomach. These tumors may obstruct the bowel, causing digestive problems. Adenocarcinoma is the most common cancer of the small intestine, but only accounts for 2% of all tumors in the gastrointestinal tract and 1% of all deaths related to cancer of the gastrointestinal tract. Carcinomas of the small intestine may appear at multiple sites.

Lymphoma

This fairly uncommon cancer is typically a non-Hodgkin's type that starts in the lymph tissue of the small intestine. (The body's immune system is comprised of lymph tissue, which assists in fighting infections.) Malignant lymphoma is not often found as a solitary lesion.

Sarcoma

Sarcoma malignancies of the small intestine are usually leiomyosarcoma . They most often occur in the smooth muscle lining of the ileum, the last section of the small intestine. Liposarcoma and angiosarcoma occur more rarely in the small intestine.

Carcinoid tumors

Carcinoid tumors are most often found in the ileum. In approximately 50% of cases, they appear in multiples.

Demographics

Approximately 50% of small intestine cancers are adneocarcinomas; 20% are lymphomas; 20% are carcinoid; and about 10% are sarcomas .

Causes and symptoms

The causes of this cancer are not known, but factors that contribute to its development include exposure to carcinogens such as chemicals, radiation, and viruses. In addition, smoking and a poor diet may contribute to the incidence of small intestine cancer. The incidence of cancer is higher in obese individuals.

Often cancer of the small intestine does not initially produce any symptoms. Gastrointestinal bleeding is perhaps the most common symptom. A doctor should be consulted if any of these symptoms are present:

• involuntary weight loss
• a lump in the abdominal region
• blood in the stool
• pain or cramping in the abdominal region

Diagnosis

Evaluation begins by taking a patient's medical history and conducting a physical examination. If a patient experiences symptoms, a doctor may suggest the following tests:

• Upper gastrointestinal x ray/ upper GI series :To allow the stomach to be seen easier on an x ray , the patient drinks a liquid called barium. This test can be conducted in either a doctor's office or a radiology department at a hospital.
• CT scan (computed tomography ): A computerized x ray that takes a picture of the abdomen.
• MRI scan (magnetic resonance imaging ): A imaging technique that uses magnetic waves to take a picture of the abdomen.
• Ultrasound: An imaging technique that uses sound waves to locate tumors.
• Endoscopy: An endoscope is a thin, lighted tube which is placed down the throat to reach the first section of the small intestine (duodenum). During this procedure, the doctor may take a biopsy , in which a small piece of tissue is removed for examination of cancereous cells under a microscope.

If small intestine cancer is evident, more tests will be conducted to determine if cancer has spread to other parts of the body.

Treatment team

Cancer treatment often requires a team of specialists and may include a surgeon, medical oncologist, radiation oncologist, nurse, physical therapist, occupational therapist, dietitian, and or a social worker.

Clinical staging, treatments, and prognosis

As with many other types of cancer, malignancies of the small intestine can be classified as localized, regional spread, or distant spread.

• Localized: The cancer has not spread beyond the wall of the organ it developed in.
• Regional spread: The cancer has spread from the organ it started in to other tissues such as muscle, fat, ligaments, or lymph nodes.
• Distant spread: The cancer has spread to tissues or organs outside of where it originated such as the liver, bones, or lungs.

Treatment options for small intestine cancer most often include surgery, and possibly radiation therapy , chemotherapy , and/or biological therapy. Cancer of the small intestine is treatable and sometimes curable depending on the histology. Removing the cancer through surgery is the most common treatment. If the tumor is large, a small portion may be removed if resection of the small intestine is possible. For larger tumors, surgery requires removing a greater amount of the surrounding normal intestinal tissue, in addition to some surrounding blood vessels and lymph nodes.

Radiation therapy kills cancer cells and reduces the size of tumors through the use of high-energy x rays. Radiation therapy may come from an external source using a machine or an internal source. Internal-based therapy involves the use of radioisotopes to administer radiation through thin plastic tubes to the area of the body where cancer cells are found. Side effects of radiation therapy include:

• fatigue
• loss of appetite (anorexia )
• nausea and vomiting
• Diarrhea
• gas
• bloating
• mild temporary, sunburn-like skin changes
• difficulty tolerating milk products

Chemotherapy kills cancer cells with drugs taken orally or by injection in a vein or muscle. It is referred to as a systemic treatment due to fact that it travels through the bloodstream and kills cancer cells outside the small intestine. Adjuvant chemotherapy may be given following surgery to ensure all cancer cells are killed. Some side effects of chemotherapy are:

• nausea and vomiting
• loss of appetite
• temporary hair loss (alopecia )
• mouth sores
• fatigue, as a result of a low red blood cell count
• higher likelihood of infection or bleeding due to low white blood cell counts and low blood platelets, respectively

Radiation and chemotherapy are seldom beneficial in small intestinal cancers.

Utilizing the body's immune system, biological therapy stimulates the body to combat cancer. Natural materials from the body or other laboratory-produced agents are designed to boost, guide, or restore the body's ability to fight disease.

Treatment options for small interstine cancers are based on the type of cells found—adenocarcinoma, lymphoma, sarcoma, or carcinoid tumor—rather than the clinical staging system.

Treatment of adenocarcinoma of the small intestine may consist of:

• surgical removal of the tumor
• If the cancer cannot be removed by resection of the small intestine, surgery may be performed to bypass the cancer to allow food to travel through the intestine.
• symptom relief with radiation therapy
• chemotherapy or biological therapy in a clinical trial setting
• a clinical trial involving radiation and drug therapy (with or without chemotherapy) to elicit greater sensitivity to radiation using radiosensitizers

Treatment of lymphoma of the small intestine may consist of:

• surgical removal of the cancer and lymph nodes in close proximity to it
• Surgery accompanied by radiation therapy or adjuvant chemotherapy. If the disease is localized to the bowel wall, then surgical resection alone or combined chemotherapy should be considered. If the disease has extended to the regional lymph nodes, then surgical resection and combination chemotherapy is suggested at the time of diagnosis.
• For extensive lymphoma or lymphoma that cannot be removed surgically, chemotherapy with or without additional radiation therapy is frequently used to reduce the risk of recurrence.

Treatment of leiomyosarcoma of the small intestine may consist of:

• surgical removal of the cancer
• When cancer cannot be removed by resection, surgical bypass of the tumor is recommended to allow food to pass.
• radiation therapy
• For unresectable metastatic disease, surgery, radiation therapy, or chemotherapy is suggested in order to alleviate symptoms.
• For unresectable primary or metastatic disease, a clinical trial evaluating the benefits of new anticancer drugs (chemotherapy) and biological therapy.

For recurrent small intestine cancer, treatment may consist of the following measures, if the cancer has returned to one area of the body only:

• surgical removal of the cancer
• symptom relief using chemotherapy or radiation therapy
• a clinical trial using radiation and drug therapy (with or without chemotherapy) to elicit greater sensitivity to radiation using radiosensitizers

For recurrent metastatic adenocarcinoma or leiomyosarcoma, there is no standard effective chemotherapy treatment. Patients should be regarded as candidates for clinical studies assessing new anticancer drugs or biological agents.

For carcinoid tumors at least than 1 cm in size, surgical removal of the tumor and surrounding tissue is possible. Carcinoid tumors often grow and spread slowly, therefore, approximately half are found at an early or localized stage. By the time of sugery, 80% of the tumors over 2 cm in diameter have metastasized locally or to the liver.

The prognosis or likelihood of recovery depends on the type of cancer, the overall health of the patient, and whether the cancer has spread to other regions or is only localized in the small intestine. A cure depends on the ability to remove the cancer completely with surgery. Adenocarcinoma is most common in the duodenum, however, patient survival is less likely for individuals with cancer is in this area compared with those patients with tumors in the jejunum or ileum due to reduced rates of surgery to remove cancer. Between 1985-1995, there were 4, 995 cases of adenocarcinoma of the small intestine reported to the National Cancer Database. Of these malignancies, 55% occurred in the duodenum, 13% in the ileum, 18% in the jejunum, and 14% were in unspecified areas. The National Cancer Database reported a median survival of 19.7 months for these patients with an overall 5-year disease survival rate of 30.5%. For resectable adenocarcinoma, the National Cancer Institute reports an overall five-year survival rate of only 20%, whereas resectable leiomyosarcoma's survival rate is reported at approximately 50%. One study found the overall rate of metastatic spread of leiomyosarcoma ranged from 24-50%; this cancer most often spread to the liver. Five-year survival in 705 patients with leiomyosarcoma was reported at 28%. Surgery is the preferred treatment for smooth muscle tumors. Little benefit was found for irradiation or chemotherapy, or for these therapies combined. Patients over 75 years of age have a significantly poorer survival rate than younger people. In addition, patients with poorly differentiated tumors have a poorer prognosis than those with moderately or well-differentiated tumors. Survival rate decreases with progression of disease by stage: localized 47.6%; regional 31%; distant 5.2%.

Alternative and complementary therapies

Bovine and shark cartilage is currently being explored in clinical trials for antitumor properties, but as of mid-2001 there is not enough evidence to warrant its use. Some popular herbs that are purported to have therapeutic effects in cancer treatment include echinacea, garlic, ginseng, and ginger. Laboratory studies have shown that echinacea has the potential to control the growth of cancerous cells, but more studies are needed to confirm efficacy in humans. In addition, dosage and toxicity levels still need to be established. Some studies suggest that diets high in garlic reduce the risk of stomach, esophageal, and colon cancers. There is still debate regarding the best form of garlic to take—whole raw garlic or garlic in tablet form; aged or fresh garlic; garlic with odor or "deodorized" garlic. Ginger is often recommended for its beneficial effects on the digestive system, but evidence has not confirmed efficacy in cancer treatment. Ginseng in excessive amounts can be very toxic, causing vomiting, bleeding, and death. Patients should not take herbal remedies without consulting their physicians, particularly if they intend to combine the herbs with prescription drugs. Herb and drug combinations can sometimes result in toxic interactions.

Coping with cancer treatment

Pain is a common problem for people with some types of cancer, especially when the cancer grows and presses against other organs and nerves. Pain may also be a side effect of treatment. However, pain can generally be relieved or reduced with prescription medicines or over-the-counter drugs as recommended by the doctor. Other ways to reduce pain, such as relaxation exercises, may also be useful. It is important for patients to report pain to their doctors, so that steps can be taken to help relieve it.

Depression may affect approximately 15-25% of cancer patients, particularly if the prognosis for recovery is poor. A number of antidepressant medications are available from physicians to alleviate feelings of depression. Counseling with a psychologist or psychiatrist also may help patients deal with depression.

Clinical trials

As of 2001, Glivec (STI-571 or imatinib mesylate ) is in clinical trials for treatment of gastrointestinal stromal tumors, as well as for leukemia and glioblastoma, a type of brain tumor. An open trial (GIST trial SWOGS0033) led by Southwest Oncology Group will test those individuals with metastatic or recurrent disease using two doses of the drug.

Clinical trials may be suitable for patients suffering from small intestine cancer. The principal investigator should be contacted regarding participation in appropriate trials. For information about cancer trials, patients can visit the National Cancer Institute web site at <http://cancertrials.nci.nih.gov>.

Prevention

Most people who develop cancer do not have inherited genetic abnormalities. Their genes have been damaged after birth by substances in their environment. A substance that damages deoxyribonucleic acid (DNA) in a way that can lead to cancer is called a carcinogen. Carcinogens include certain chemicals, certain types of radiation, and viruses. Asbestos is one substance that is suspected of contributing to the development of small intestinal cancer. Although the precise causes of cancer are not known, a variety of factors are known to contribute to the development of cancer including tobacco smoke, and poor dietary habits such as high-fat diet. Eating a diet rich in fruits and vegetables and low in fat may reduce the likelihood of cancer. Studies have demonstrated that individuals who were protected from cancer ate a greater variety of foods and nutrients compared to those with cancer. Several fruits, vitamins, and minerals were found particularly protective against intestinal cancer including vitamin B₆, folate, niacin, and iron. Some studies have linked eating large amounts of salt-cured, salt-pickled, and smoked foods to cancers of the digestive system. Other studies have linked stomach cancers, specifically intestinal cancer, to a lack of fruits, vegetables, and fiber in the diet. For prevention of cancer, it is important to avoid carcinogens (smoking, chemicals) and known risk factors, and to pursue a healthy lifestyle which includes moderate alcohol intake, regular exercise, a low-fat diet, and a diet rich in fruits and vegetables. Modifying genetic predispositions through risk factor reduction can also assist in prevention.

Special concerns

Due to the side effects of radiation and chemotherapy, individuals must make a deliberate effort to eat as nutritiously as possible. Those who experience pain, nausea, or diarrhea may want to discuss treatments options with their doctor to ease these side effects.

Eating well during cancer treatment means getting enough calories and protein to help prevent weight loss and maintain strength. Eating nutritiously may also help an individual feel better.

Resources

BOOKS

Coit, D.G. "Cancer of the Small Intestine." In Cancer: Princi ples and Practice of Oncology, edited by V.T. DeVita, Jr., S. Hellman, and S.A. Rosenberg. Philadelphia: Lippincott-Raven Publishers, 1997, pp. 1128-1143.

Kelsen, David, Bernard Levin, and Joel Tepper. Principles and Practice of Gastrointestinal Oncology. Philadelphia: Lippincott Williams & Wilkins Publishers, 2001.

"Small Intestine." In American Joint Committee on Cancer: AJCC Cancer Staging Manual. Philadelphia: Lippincott-Raven Publishers, 1997, pp. 77-81.

PERIODICALS

Howe, J.R., et al. "The American College of Surgeons Com mission on Cancer and the American Cancer Society. Adenocarcinoma of the Small Bowel: Review of the National Cancer Data Base, 1985-1995." Cancer 86 (1999): 2693-2706.

ORGANIZATIONS

The National Cancer Institute (NCI). For information contact the Public Inquiries Office: Building 31, Room 10A31, 31 Center Drive, MSC 2580, Betheseda, MD 20892-2580 USA. (301) 435-3848 or 1-800-4-CANCER. <http://cancer.gov/publications/> or <http://cancertrials.nci.nih.gov> or <http://cancernet.nci.nih.gov>.

National Center for Complementary and Alternative Medicine (NCCAM), 31 Center Dr., Room #5B-58, Bethesda, MD 20892-2182. (800) NIH-NCAM. Fax: (301) 495-4957. <http://nccam.nih.gov>.

Crystal Heather Kaczkowski, MSc.

KEY TERMS

Adenocarcinoma

—A cancer that starts in glandular tissue.

Angiosarcoma

—A malignant tumor that develops either from blood vessels or from lymphatic vessels.

Carcinogen

—A substance that causes cancer.

Carcinoid

—A tumor that develops from neuroendocrine cells.

Leiomyosarcoma

—A cancerous tumor of smooth (involuntary) muscle tissue.

Liposarcoma

—A cancerous tumor of fat tissue.

Lymphoma

—A cancer of the lymphatic tissue.

Malignant

—Cancerous; a tumor or growth that often destroys surrounding tissue and spreads to other parts of the body.

Metastasis

—The spread of cancer from the original site to other body parts.

Radiation therapy

—Also called radiotherapy, it uses high-energy rays to kill cancer cells.

Sarcoma

—A malignant tumor of the soft tissue including fat, muscle, nerve, joint, blood vessel, and deep skin tissues.

Staging

—Performing exams and tests to learn the extent of the cancer within the body, especially whether the disease has spread from the original site to other parts of the body.

QUESTIONS TO ASK THE DOCTOR

• Is there any evidence the cancer has spread?
• What is the stage of the disease?
• What are my treatment choices?
• What new treatments are being studied?
• Would a clinical trial be appropriate for me?
• What are the expected benefits of each kind of treatment?
• What are the risks and possible side effects of each treatment?
• How often will I have treatments?
• How long will treatment last?
• Will I have to change my normal activities?
• What is the treatment likely to cost?
• Is infertility a side effect of cancer treatment? Can anything be done about it?
• What is my prognosis?

Small Intestine Biopsy

Definition

A biopsy is a diagnostic procedure in which tissue or cells are removed from a part of the body and specially prepared for examination under a microscope. When the tissue involved is part of the small intestine, the procedure is called a small-intestine (or small-bowel) biopsy.

Purpose

The small-bowel biopsy is used to diagnose and confirm disease of the intestinal mucosa (the lining of the small intestine). The test is most commonly done to test for tumors of the small bowel or malabsorption syndromes.

Precautions

Due to the slight risk of bleeding during or after this procedure, aspirin, aspirin-containing medications, nonsteroidal anti-inflammatory drugs, and anticoagulants and antiplatelet drugs should be withheld for at least five days before the test.

Description

The small intestine is approximately 21 ft (6.4m). It has three sections: the duodenum (a short, curved segment fixed to the back wall of the abdomen), the jejunum, and the ileum (two larger, coiled, and mobile segments). Some digestion occurs in the stomach, but the small intestine is mainly responsible for digestion and absorption of foods.

Malabsorption syndromes occur when certain conditions result in impaired absorption of nutrients, vitamins, or minerals from the diet by the lining of the small intestine. For example, injury to the intestinal lining can interfere with absorption, as can infections, intestinal parasites, some drugs, blockage of the lymphatic vessels, poor blood supply to the intestine, or diseases like sprue.

Malabsorption is suspected when a patient not only loses weight, but has diarrhea and nutritional deficiencies despite eating well (weight loss alone can have other causes). Laboratory tests like fecal fat, a measurement of fat in stool samples collected over 72 hours, are the most reliable tests for diagnosing fat malabsorption, but abnormalities of the small intestine itself are diagnosed by small-intestine biopsy.

Several different methods are used to detect abnormalities of the small intestine. A tissue specimen can be obtained by using an endoscope (a flexible viewing tube), or by using a thin tube with a small cutting instrument at the end. This latter procedure is ordered when specimens larger than those provided by endoscopic biopsy are needed, because it allows removal of tissue from areas beyond the reach of an endoscope.

Several similar types of capsules are used for tissue collection. In each, a mercury-weighted bag is attached to one end of the capsule, while a thin polyethylene tube about 5 ft (1.5m) long is attached to the other end. Once the bag, capsule, and tube are in place in the small bowel, suction on the tube draws the tissue into the capsule and closes it, cutting off the piece of tissue within. This is an invasive procedure, but it causes little pain and complications are rare.

A newer method of obtaining diagnostic information about the small intestine was approved by the Food and Drug Administration (FDA) in 2001. Known as the M2A Imaging System, the device was developed by a company in Atlanta, Georgia. The M2A system consists of an imaging capsule, a portable belt-pack image receiver and recorder, and a specially modified computer. The patient swallows the capsule, which is the size of a large pill. A miniature lens in the capsule transmits images through an antenna/transmitter to the belt-pack receiver, which the patient wears under ordinary clothing as he or she goes about daily activities. The belt-pack recording device is returned after seven or eight hours to the doctor, who then examines the images recorded as a digital video. The capsule itself is simply allowed to pass through the digestive tract.

Preparation requires only fasting the night before the M2A examination and taking nothing but clear liquids for two hours after swallowing the capsule. After four hours the patient can eat food without interfering with the test. As of the early 2000s, the M2A system is used to evaluate gastrointestinal bleeding from unknown causes, inflammatory bowel disease, some malabsorption syndromes, and to monitor surgical patients following small-bowel transplantation. The system has shown good results in detecting Crohn's disease undiagnosed by conventional methods.

Small-intestine biopsy procedure

After application of a topical anesthetic to the back of the patient's throat, the capsule and the tube are introduced, and the patient is asked to swallow as the tube is advanced. The patient is then placed on the right side and the instrument tip is advanced another 20 in (51cm) or so. The tube's position is checked by fluoroscopy or by instilling air through the tube and listening with a stethoscope for air to enter the stomach.

The tube is advanced 2-4 in (5.1-10 cm)at a time to pass the capsule through the stomach outlet (pylorus). When fluoroscopy confirms that the capsule has passed the pylorus, small samples of small intestine tissue are obtained by the instrument's cutting edge, after which the instrument and tube are withdrawn. The entire procedure may be completed in minutes.

Preparation

This procedure requires tissue specimens from the small intestine through means of a tube inserted into the stomach through the mouth. The patient is to withhold food and fluids for at least eight hours before the test.

Aftercare

The patient should not have anything to eat or drink until the topical anesthetic wears off (usually about one to two hours). If intravenous sedatives were administered during the procedure, the patient should not drive for the remainder of the day. Complications from this procedure are uncommon, but can occur. The patient is to note any abdominal pain or bleeding and report either immediately to the doctor.

Risks

Complications from this procedure are rare, but can include bleeding (hemorrhage), bacterial infection with fever and pain, and bowel puncture (perforation). The patient should immediately report any abdominal pain or bleeding to the physician in charge. Biopsy is contraindicated in uncooperative patients, those taking aspirin or anticoagulants, and in those with uncontrolled bleeding disorders.

Normal results

Normal results are no abnormalities seen on gross examination of the specimen(s) or under the microscope after tissue preparation.

Abnormal results

Small-intestine tissue exhibiting abnormalities may indicate Whipple's disease, a malabsorption disease; lymphoma, a group of cancers; and parasitic infections like giardiasis, strongyloidiasis, and coccidiosis. When biopsy indicates celiac sprue (a malabsorption disorder), infectious gastroenteritis (inflammation of the gastrointestinal tract), folate and B₁₂ deficiency, or malnutrition, confirmation studies are needed for conclusive diagnosis.

Resources

BOOKS

Beers, Mark H., MD, and Robert Berkow, MD., editors. "Malabsorption Syndromes." Section 3, Chapter 30 In The Merck Manual of Diagnosis and Therapy. Whitehouse Station, NJ: Merck Research Laboratories, 2004.

Beers, Mark H., MD, and Robert Berkow, MD., editors. "Small-Bowel Tumors." Section 3, Chapter 34 In The Merck Manual of Diagnosis and Therapy. Whitehouse Station, NJ: Merck Research Laboratories, 2004.

PERIODICALS

Adler, Douglas J., MD, and Christopher J. Gostout, MD. "Wireless Capsule Endoscopy." Hospital Physician May 2003: 17-22.

Ge, Z. Z., Y. B. Hu, and S. D. Xiao. "Capsule Endoscopy in Diagnosis of Small Bowel Crohn's Disease." World Journal of Gastroenterology 10 (May 1, 2004): 1349-1352.

Thompson, B. F., L. C. Fry, C. D. Wells, et al. "The Spectrum of GI Strongyloidiasis: An Endoscopic-Pathologic Study." Gastrointestinal Endoscopy 59 (June 2004): 906-910.

KEY TERMS

Sprue— A disorder of impaired absorption of nutrients from the diet by the small intestine (malabsorption), resulting in malnutrition. Two forms of sprue exist: tropical sprue, which occurs mainly in tropical regions; and celiac sprue, which occurs more widely and is due to sensitivity to the wheat protein gluten.

Whipple's disease— A disorder of impaired absorption of nutrients by the small intestine. Symptoms include diarrhea, abdominal pain, progressive weight loss, joint pain, swollen lymph nodes, abnormal skin pigmentation, anemia, and fever. The precise cause is unknown, but it is probably due to an unidentified bacterial infection.

Wireless capsule endoscopy— A newer method of examining the small bowel by means of a capsule swallowed by the patient. The capsule contains a miniaturized lens and an antenna that transmits information to a belt-pack recorder worn by the patient during the day.