If you are at average risk for colorectal cancer, you have several recommended choices for screening. All have benefits and drawbacks to consider as you make your decision.
2008 Screening Guidelines
The American Cancer Society, US Multi-society Task Force on Colorectal Cancer, and the American College of Radiology jointly recommend that patients of average risk and their doctors discuss the following options for colorectal cancer screening:
Tests that Detect Adenomatous Polyps and Cancer
- Colonoscopy every 10 years.
- Double-contrast barium enema (DCBE) every five years.
- Computer tomographic colonography (CTC, virtual colonoscopy) every five years.
- Flexible sigmoidoscopy every five years (limited to detection in the rectum and descending colon).
Tests that Primarily Detect Cancer
- Annual guaiac-based fecal occult blood test (gFOBT) with high sensitivity for cancer.
- Annual fecal immunochemical test (FIT) with high test sensitivity for cancer.
- Stool DNA test with high sensitivity for cancer.
In addition, there are experimental tests that are not yet part of standard recommendations including capsule endoscopy and a blood test for colon cancer specific antigen 2 (CCSA-2).
Such tests should only be used as part of clinical trials, and patients should not put off screening waiting for them to become publicly available.
Benefits and Drawbacks of Screening Methods
Here are questions to ask your doctor about screening methods. Confused? Check out a chart comparing screening methods.
- How sensitive is the test? How likely is it to find significant adenomatous polyps or cancer?
- Does this test prevent colorectal cancer by finding precancerous lesions or it is primarily a test to detect early cancer?
- How specific is this test? How often does it have false positive results which will require further testing with colonoscopy?
- How often must this test be done?
- How expensive is the test? Does my insurance cover it?
- How intrusive is it? Does it involve entering the body with medical instruments?
- Are there risks such as bleeding, perforation of the colon, or problems with sedation?
Where Can You Go for More Information?
Joint Guidelines for Screening and Surveillance for the Early Detection of Colorectal Cancer and Adenomatous Polyps 2008 are available in CA A Cancer Journal for Clinicians, published online on March 5, 2008.
National Digestive Diseases National Clearinghouse provides patient-friendly information about screening tests including
The National Cancer Institute compares current screening methods and their effectiveness in technical detail and includes links to the studies that support each method. They also have more simply written information for patients.
The American Cancer Society has detailed information about each of the recommended screening methods, as well as comparisons of the pros and cons of the tests.