Colon cancer is a malignant tumor that arises from the cells that line the colon. The majority of cancers develop from precancerous polyps called adenomas. If colon polyps are detected early and removed, many cases of colon cancer can be prevented. Risk factors that increase the risk of colon cancer include eating a diet high in red meat, physical inactivity, smoking, heavy alcohol use, obesity, family history of colon cancer or polyps, and personal history of inflammatory bowel disease (ulcerative colitis or Crohn's disease). Being age 50 or older increases colon cancer risk. Certain genetic mutations confer susceptibility to colon cancer. African Americans and Ashkenazi Jews have a greater risk for colon cancer compared to other ethnic groups. Colon cancer is curable when it is found and treated early.