Way2Cure

Health A-Z

What is familial adenomatous polyposis (FAP)?

Familial adenomatous polyposis (FAP) is a rare, hereditary condition in which a person develops numerous precancerous polyps called adenomas in the large intestine (colon and rectum).

Polyps develop in teen years or early 20s. The number of polyps varies from less than 100 to thousands, and with increasing age the polyps get larger and more problematic. Eventually, one or more of these adenomas will become cancerous.

Without treatment, patients with FAP have a nearly 100% lifetime risk of colorectal cancer. The chance of developing colorectal cancer increases with age; the average age at which people are diagnosed with cancer is 39.