Intestinal Cancer Risk Factors

Small Intestine Cancers

Cancer of the small intestines is very rare—less than one percent of people in the United States will be diagnosed with small intestinal cancer in their lifetime.

The most common type of small intestine cancers are adenocarcinomas. Adenocarcinomas occurring in the small intestines typically develop in the duodenum, and the remaining small intestinal adenocarcinomas develop in the jejunum and ileum.

The rarity of small intestine cancers makes it difficult to study the disease. And, the known risk factors may vary depending on the type of cancer.

Risk Factors for Small Intestine Cancer

The cause of small intestine cancer is not well understood. Some diseases and inherited factors may increase your risk. The statistics show that men are slightly more likely to develop the disease than women. And close to a third of all diagnoses are made after the age of 65.

Some of the known risk factors for this type of intestinal cancer include the following:

• Age - According to the National Cancer Institute, the average age of diagnosis is 67. It seems that the risk increases with age.
• Tobacco and Alcohol - There is a lot of evidence linking cigarette smoking and alcohol abuse to many types cancer. Some research suggests that smoking and drinking may also be associated with the development of small intestine cancer.
• Gastrointestinal diseases - Certain diseases that affect the gastrointestinal (GI) tract may increase the risk of developing small intestine cancer. For example, Crohn's disease is a condition in which the immune system harms the small intestines. If you have had colon cancer, you may also be at an increased risk for small intestine adenocarcinomas, possibly because both cancers share similar risk factors. The GI diseases that affect the risk of developing small intestine cancer are:
  • Colon cancer
  • Celiac disease
  • Crohn's disease
• Inherited conditions - Although most small intestine cancers occur sporadically; that is, without a known familial link, there are some inherited conditions that may lead to a higher risk. The inherited conditions associated with small intestine adenocarcinoma are:
  • Familial adenomatous polyposis (FAP)
  • Hereditary nonpolyposis colorectal cancer (HNPCC), also called Lynch syndrome
  • Peutz-Jeghers syndrome (PJS)
  • Cystic fibrosis (CF)

Risk Factors Associated with Other Types of Intestinal Cancer

Sarcomas of the small intestines

• Gardner syndrome - Caused by a genetic defect, people with this syndrome often develop many polyps throughout the intestinal tract, specifically the colon. Although there is a greater risk for developing colon cancer, this disease is considered a risk factor for sarcomas of the small intestines.
• Lymphedema - Damage to the lymph vessels (the vessels that connect the lymph nodes) or an infection may cause lymph fluid to build up. Lymphedema is also sometimes referred to as elephantiasis.
• Chemical exposure - Certain chemicals, like vinyl chloride, dioxins, and high doses of herbicides containing phenoxyacetic acid are risk factors for certain types of sarcomas, and possibly sarcomas in the small intestines.

Gastrointestinal stromal tumors (GIST) of the small intestines

• 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 intestines and familial links are rare.

Carcinoid tumors of the small intestines

• Inherited conditions - 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 intestines that are at risk of becoming malignant.

NOTE: Anything that increases your risk of getting a disease is called a risk factor. Having a risk factor does not mean that you will get cancer. Not having risk factors does not mean that you won't get cancer. If you think you may be at risk, you should discuss it with your doctor.

Understanding your Risk Factors

You may want to talk to you doctor if a hereditary risk factor is suspected because a relative has had colon cancer, or an associated genetic syndrome. More often, small intestine cancers occur sporadically without known cause. Nonetheless, family history is an important piece of the puzzle and may lead to a better understanding of the risk factors associated with this rare disease. Diets high in fiber may reduce your risk for small intestine adenocarcinomas.

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