Basic Information About Colorectal Cancer

Cancer is a disease in which cells in the body grow out of control. When cancer starts in the colon or rectum, it is called colorectal cancer. Sometimes it is called colon cancer, for short.

Of cancers that affect both men and women, colorectal cancer is the second leading cancer killer in the United States, but it doesn’t have to be. Colorectal cancer screening saves lives. Screening can find precancerous polyps—abnormal growths in the colon or rectum—that can be removed before they turn into cancer. Screening also helps find colorectal cancer at an early stage, when treatment works best. About nine out of every 10 people whose colorectal cancers are found early and treated appropriately are still alive five years later.

If you are 45 years old or older, get screened now. If you think you may be at increased risk for colorectal cancer, speak with your doctor about when to begin screening, which test is right for you, and how often to get tested.

Medical illustration of the colon and rectum
Colorectal cancer is cancer that occurs in the colon or rectum. Sometimes it is called colon cancer, for short.
Photo of two women walking outdoors
Your risk of getting colorectal cancer increases as you get older, and there are other risk factors.
Photo of a man and a woman making a salad
The most effective way to reduce your risk of colorectal cancer is by having regular colorectal cancer screening tests beginning at age 45.
Photo of a man who has stomach pain
Colorectal cancer doesn't always cause symptoms, especially at first. See a list of possible symptoms.
Photo of a man looking at a tablet
Screening tests can find precancerous polyps, so that they can be removed before they turn into cancer. Screening tests can also find colorectal cancer early, when treatment works best.
Photo of a woman asking her doctor a question
Several screening tests can be used to find polyps or colorectal cancer. The benefits and risks of these screening methods vary. Discuss with your doctor which test is best for you.
Page last reviewed: February 8, 2021