BACKGROUND: Colon cancer is cancer of the large intestine, colon, and the lower part of the digestive system.* Rectal cancer is cancer of the last several inches of the colon.* Together they are often referred to as colorectal cancer.* Most cases of colon cancer begin as small, noncancerous, clumps of cells called adenomatous polyps.* Overtime some of these polyps become colon cancers. For this ...