Do We Know What Causes Small Intestine Adenocarcinoma?

Very little is known about the causes of small intestine adenocarcinoma. In fact, many experts wonder why it’s so rare. The small intestine is the longest structure in the gastrointestinal tract, yet it has only 2% or less of the adenocarcinomas.

Scientists have recognized some DNA changes in the small intestine adenocarcinoma cells that are probably responsible for their increased growth and abnormal spread. Many of these tumors show specific genetic abnormalities. But what causes these changes is not yet known.

One cause of these cancers is thought to be problems repairing DNA, the large molecule that contains our genetic material. Certain genes control substances called enzymes that are responsible for repairing DNA when it makes mistakes when reproducing itself. Some have compared this to a spell checker on a computer. Without these spell checker enzymes, mistakes are not corrected and genetic mutations or changes are allowed to persist. These changes may produce abnormal substances that lead to cancer formation.

A second theory is that mutations take place naturally with aging and that some of these will lead to cancer formation.

The American Cancer Society medical and editorial content team
Our team is made up of doctors and master's-prepared nurses with deep knowledge of cancer care as well as journalists, editors, and translators with extensive experience in medical writing.

Last Medical Review: April 30, 2014 Last Revised: February 9, 2016

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