If you are 50 or over or have a family history of colon cancer, you should be screened. African-Americans should be screened beginning at age 45. Colon cancer is one of the most preventable -- and curable -- types of cancer when detected early. Since the risk of colon cancer increases with age, getting screened is essential. Learn more about colon cancer, who is at risk and when you should get tested. If you have a colonoscopy scheduled or would like to learn more about what to expect during the procedure, see the video, What to Expect During a Colonoscopy.