Colon Cancer Causes Most colorectal cancers arise from adenomatous polyps. Such polyps are comprised of excess numbers of both normal and abnormal appearing cells in the glands covering the inner wall of the colon. Over time, these abnormal growths enlarge and ultimately degenerate to become adenocarcinomas.
People with certain genetic abnormalities develop what are known as familial adenomatous polyposis syndromes. Such people have a greater-than-normal risk of colorectal cancer