Colorectal cancer is one of the most preventable cancers, but one-third of adults are not getting screened as recommended.

Published: October 18, 2022 | Updated: January 31, 2023

Colorectal cancer is the fourth-leading cancer killer of adults in the U.S. It also is one of the most preventable cancers and very treatable when caught early. By understanding when to get your screening, along with your personal risk factors, you can learn how to reduce your risk.

Prevention is key

Routine screenings are the first line of defense against colorectal cancer because they can find and remove polyps as well as detect colorectal cancer early — when it’s highly treatable.

At age 45, everyone should be screened for polyps or cancer in one of the following ways:

• Flexible sigmoidoscopy every five years or 
• Colonoscopy every 10 years or CT colonography (virtual colonoscopy) every five years

If sigmoidoscopy or CT colonography are positive, a colonoscopy should be done.

There also are some simpler options that test only for cancer (not polyps):

• Guaiac-based fecal occult blood test (gFOBT) every year or 
• Fecal immunochemical test (FIT) every year or
• Stool DNA test every three years (Cologuard)

If any of these tests are positive, a colonoscopy should be done. With gFOBT or FIT, at least two tests should be done; one test done by a doctor is not adequate.

Are you at risk?

There is no single cause of colon cancer. Most colon cancers begin as noncancerous (benign) polyps, which can develop slowly into cancer.

You may be at greater risk for developing colon cancer if:

• You have a history of Crohn’s disease, ulcerative colitis or chronic inflammatory bowel disease.
• You have a personal or family history of colon cancer or precancerous polyps.
• You are over age 45.
• You are a smoker.
• You are a heavy alcohol user.
• You have inherited genetic syndromes such as familial adenomatous polyposis or hereditary nonpolyposis (Lynch syndrome).