Harvard Health Letter

By the way, doctor: Cancer of the small intestine

Q. We hear a lot about colon cancer, and sometimes about stomach cancer, but hardly ever anything about cancer of the small intestine. Why? Is it rare?

A. The stomach is only about 10 inches long, the colon about five feet, and the small intestine, or small bowel, which connects the two, is about 20 feet. And yet you're right, cancer of the small intestine is relatively rare. The American Cancer Society estimates that about 5,000 new cases are diagnosed in the United States each year, compared to over 110,000 cases of colon cancer — 150,000 if you lump colon and rectal cancers together. Stomach cancer is less common than it used to be, but there are still over 21,000 new cases diagnosed each year.

Given the small number of cases, the risk isn't very large, but some conditions do increase the likelihood of developing small bowel cancer — chronic inflammation of the small bowel from a condition like Crohn's disease, for example. And people with celiac disease, an allergy to dietary gluten, are more prone than others to developing lymphomas of the small bowel.

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