Intestinal Cancer

Overview

As with most cancers, intestinal cancer develops when defective or mutated cells grow out of control and form a tumor. Intestinal cancer, also called small intestine cancer or small bowel cancer, usually starts in the lining of the small intestine and may spread to other parts of the body. Most cases of intestinal cancer develop in the duodenum, or upper part of the organ.

The main types of small intestine cancer include:

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• Adenocarcinomas, the most common type of small intestine cancer, usually develop in the cells that line the walls of the small intestine. Often, this type of cancer will develop out of small benign (noncancerous) growths called polyps.

• Sarcoma is a type of intestinal cancer that develops in the connective tissue of the small intestine.

• Gastrointestinal stromal tumors are variants of soft tissue sarcoma.

• Carcinoid tumors form in the lining of the intestines and are often are slow-growing.

• Lymphomas are an immune system disease that may originate in the intestines.

Symptoms

Some common symptoms of cancer that develops in the small intestines include:

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• Abdominal pain

• Unexplained weight loss

• Weakness or fatigue (sometimes a result of anemia)

• Bloody or tarry stools (from bleeding tumors)

• A noticeable lump in the abdomen

Causes

Inherited condition: Although most small intestine cancers occur without a known hereditary link, there are some inherited conditions that may lead to a higher risk. The inherited conditions associated specifically with small intestine adenocarcinoma are:

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• Familial adenomatous polyposis (FAP)

• Hereditary nonpolyposis colorectal cancer (HNPCC), also called Lynch syndrome

• Peutz-Jeghers syndrome (PJS)

• Cystic fibrosis (CF)

• People with either multiple endocrine neoplasia, type I (MEN1) or defects in the gene NF1 (type 1 neurofibromatosis) may develop benign tumors in the small intestine that are at risk of becoming malignant carcinoid tumors.

• Gardner syndrome: Caused by a genetic defect. People with this syndrome often develop many polyps throughout the GI tract, particularly in the colon. Although there is a greater risk for developing colon cancer, this disease is considered a risk factor for sarcomas of the small intestine.

• Von Recklinghausen's disease: Neurofibromatosis, an inherited gene mutation, may lead to GISTs. However, there usually is no known cause for GISTs of the small intestine and hereditary links are rare.

• Tobacco and alcohol use: Lots of evidence links cigarette smoking and alcohol abuse to many types cancer. Some research suggests that smoking and drinking may also be associated with small intestine cancer.

• Diet: Eating a high-fat diet may be a small intestine risk factor.

• Chemical exposure: Certain chemicals, like vinyl chloride, dioxins and high doses of herbicides containing phenoxyacetic acid, are considered intestinal cancer risk factors for certain types of sarcomas, possibly including sarcomas in the small intestine. NDMA in Zantac has also been linked to cancer.