What are the Colorectal Cancer Screening Options?
Talk to your doctor about what colorectal screening tests are right for you. In 2021, the American College of Gastroenterology updated its colorectal cancer screening guideline. Important recommendations from the authors of guideline are summarized here:
One-Step Screening Test: Colonoscopy
ACG recommends colorectal cancer screening in average-risk individuals between age 45 and 75 years to reduce pre-cancerous growths called advanced adenomas, reduce colorectal cancer, and reduce death from colorectal cancer.
Colonoscopy is a one-step test that looks for growths called polyps in your entire colon (large intestine) and rectum using a colonoscope. Your doctor can both detect and remove polyps during colonoscopy and prevent colorectal cancer. Colonoscopy is the most commonly performed gastrointestinal procedure in the United States. Colonoscopy with removal of polyps offers long term protection against developing colorectal cancer or dying from it.
Two-Step Screening Tests: Stool-Based Tests
These tests detect blood or altered DNA in the stool as a first step. A positive result would lead to the second step of colonoscopy for further examination.
Fecal Immunochemical Tests (FIT) detects hidden blood in the stool. The stool FIT test is typically performed on an annual basis. A positive test requires a follow-up colonoscopy.
Multitarget Stool DNA (mtsDNA)
Multitarget stool DNA test is a non-invasive screening for colorectal cancer. It looks for abnormal DNA associated with colon cancer or precancerous polyps. This test is more sensitive than the FIT test, but your chance of getting a false positive may increase with advancing age. According to the manufacturer's recommendations, if the mtsDNA test is negative, repeat screening occurs in three years. If the mtsDNA test is positive, the second step of colonoscopy is required. (At this time the only FDA-approved mtsDNA is Cologuard.®)
Tests for Individuals Who Cannot or Will Not Have a Colonoscopy or FIT, or Are Not Candidates for Colonoscopy
CT Colonography and Colon Capsule
At this time, CT colonography and colon capsule are options for individuals unwilling or unable to undergo colonoscopy or FIT, provided that the tests are locally available and reimbursed by insurers for screening. It is important to note that both tests will still require a follow-up colonoscopy if positive.
Source: ACG Clinical Guidelines: Colorectal Cancer Screening 2021