The goal of colorectal cancer screening is to remove precancerous polyps before they develop into cancer or to diagnose a cancer in its early stages when survival is greatest. A consortium of five medical societies including surgeons and gastroenterologists, and sponsored by the United States Agency for Health Care Policy and Research, has defined separate screening protocols based on an individual’s assignment to risk categories.

How often you should be screened

• Recommended cancer screening strategies begin with patients who have a family history (first degree relative) of colorectal cancer, screening should begin at 40 years old or 10 years prior to the family member’s age at diagnosis, whichever is earlier.
• In individuals without symptoms or increased risk factors colorectal cancer screening should begin at 50 years old.
• If no precancerous polyps are found, screening colonoscopy will occur every 10 years.
• If precancerous polyps are found, screening colonoscopy will be more frequent, typically every 5 years.
• Yearly testing for blood in the stool with cards, with the more accurate fecal immunochemical testing preferred.
• Flexible sigmoidoscopy (which only examines the rectum and lower colon) every 3 to 5 years
• Barium enema every 5 years

Testing Methods

Colonoscopy

The use of colonoscopy is the superior alternative among testing options. Colonoscopy screens for cancer by examining the whole colon, and is a tool to prevent cancer by removing pre-cancerous colorectal polyps (polypectomy). For more information on colonoscopy including preparation and what you can expect from the test, please see the related NetWellness orginal feature.

Virtual Colonoscopy

At this time, there are not enough data to recommend CT scanning otherwise known as virtual colonoscopy, and it is currently not reimburse by insurance unless performed as a follow up to an incomplete colonoscopy. The colon is inflated with air through a tube in the rectum, and the patient has to undergo a CT scan. This procedure does not allow for polyp removal and can miss smaller polyps detected by endoscopic colonoscopy. 

Stool DNA Testing

This technology involves collection of a whole bowel movement. The cells that are shed from the lining of the colon are then isolated and checked for DNA mutations that are known to be associated with colon cancer and colon polyps. At present, the test is still under development and not commercially available.

Support

There are many excellent support groups and references that the patient’s physician will be happy to share.  The following websites can provide further information:

• American Cancer Society – www.cancer.org/
• National Cancer Institute – www.cancer.gov/
• American College of Gastroenterology – www.acg.gi.org/
• American Gastroenterological Association – www.gastro.org/
• American Society of Colon and Rectal Surgeons – www.fascrs.org/

The American Cancer Society can address cancer-related questions 24 hours a day at 1-800-ACS-2345. Concerns should also be addressed with a physician.

More features about colon cancer:

• Colon Cancer Overview
• About the Colon and Rectum
• Colorectal Cancer: Myths and Realities
• Risk Factors of Colon Cancer
• 5 Steps to Lowering Your Risk of Colorectal Cancer
• Symptoms, Tests, and Staging of Colon Cancer
• Screen Out Colon Cancer in Women
• Colon Cancer and African Americans
• Colon Cancer: Choosing a Doctor and What to Ask
• 20 Most Frequently Asked Questions About Colorectal Cancer

For more information:

Go to the Colon Cancer health topic.