Introduction

Colon cancer is cancer of the colon, which is the large intestine in the lower part of the digestive system. It is the third most common type of cancer and one of the leading causes of cancer death in the West.

The majority of colon cancers start as small clumps on noncancerous clusters of cells referred to as adenomatous polyps located in the colon. They often start benign, but later become cancerous. A colonoscopy is used to diagnose colon cancer.