DefinitionColon, or colorectal, cancer is cancer that starts in the large intestine (colon) or the rectum (end of the colon).Other types of cancer can affect the colon, such as lymphoma, carcinoid tumors, melanoma, and sarcomas. These are rare. In this article, use of the term "colon cancer" refers to colon carcinoma only.Alternative NamesColorectal cancer; Cancer - colon; Rectal cancer; Cancer-rectum; Adenocarcinoma- colon; Colon -adenocarcinomaCauses, incidence, and risk factorsAccording to the American Cancer Society, colorectal cancer is one of the leading causes of cancer-related deaths in the United States. However, early diagnosis often leads to a complete cure.Almost all colon cancer starts in glands in the lining of the colon and rectum. When most people and when doctors talk abou