A colon polyp is a small clump of cells that forms on the lining of the colon. Most colon polyps are harmless. But over time, some colon polyps can develop into colon cancer, which is often fatal when found in its later stages.
Anyone can develop colon polyps. You're at higher risk if you're 50 or older, are overweight or a smoker, or have a personal or family history of colon polyps or colon cancer.
Colon polyps often don't cause symptoms. It's important to have regular screening tests, such as colonoscopy, because colon polyps found in the early stages can usually be removed safely and completely. The best prevention for colon cancer is regular screening for polyps.
There are several types of colon polyps, including:
- Adenomatous. About two-thirds of all polyps are adenomatous. Only a small percentage of them actually become cancerous. But nearly all malignant polyps are adenomatous.
- Serrated. Depending on their size and location in the colon, serrated polyps may become cancerous. Small serrated polyps in the lower colon, also known as hyperplastic polyps, are rarely malignant. Larger serrated polyps — which are typically flat (sessile), difficult to detect and located in the upper colon — are precancerous.
- Inflammatory. These polyps may follow a bout of ulcerative colitis or Crohn's disease of the colon. Although the polyps themselves are not a significant threat, having ulcerative colitis or Crohn's disease of the colon increases your overall risk of colon cancer.