“Your doctor said you need WHAT?” People can feel a bit uneasy when a doctor mentions screening for colon cancer or rectal cancer.
But, according to the American Cancer Society, colorectal cancer is the third most common cancer in both men and women in the United States. Preventing colorectal cancer, and not just finding it early, is why doctors recommend colorectal screening tests, even though the subject may seem embarrassing to discuss.
Colorectal cancer starts in the colon or rectum, most often as a polyp, or small piece of tissue that projects from the inner wall. Screening tools can find cancer in people before symptoms show up, which is when colorectal cancer is most easily treatable. Some also can find and remove suspicious-looking polyps before they become cancerous, which may prevent colorectal cancer.
Who should be screened:
- Starting at age 50, men and women of average risk for colorectal cancer
- People with a personal or family history of colorectal cancer or pre-cancerous polyps
- People with inflammatory bowel disease
- People with certain other risk factors, including a known family history of a hereditary colorectal cancer syndrome
The American Cancer Society recommends the following screening tests:
These tests can find cancer that is already there, as well as pre-cancerous polyps:
- Colonoscopy (every ten years)
- Flexible sigmoidoscopy (every five years)*
- Double Contrast Barium Enema (every five years)*
- CT Colonography (every five years)*
These tests mainly find cancer that is already there:
- Fecal Occult Blood Test (every year)*:
- Fecal Immunochemical Test (every year)*: Also checks for blood in the stool.
- Fecal DNA test with high sensitivity (interval for screening is uncertain)*
*All positive tests should be followed up with a colonoscopy.
Which test is right for me?
How often you get screened depends on your risk for colorectal cancer, and on which screening test you use. Some of these tests are done in your home and others must be done in a clinic or hospital.
Your doctor can help you decide which test to use and how often you should be screened.
To learn more:
- American Cancer Society: Colorectal Cancer Early Detection
- National Cancer Institute: Tests to Detect Colorectal Cancer and Polyps
- U-M Cancer AnswerLine™: 1-800-865-1125
- U-M Comprehensive Cancer Center: Multidisciplinary Colorectal Cancer Clinic
- National Comprehensive Cancer Network (pdf): Colorectal Cancer Screening
- U-M Patient Education Resource Center, Colon and Rectal Cancer
- UMClinicalTrials.org: Study recruiting volunteers for colorectal cancer screening