From the Guidelines
Cologuard is the best alternative to colonoscopy for colorectal cancer screening for average-risk individuals, as it is a non-invasive stool DNA test that can be done at home and needs to be repeated every 3 years if results are negative. According to the U.S. Multi-Society Task Force on Colorectal Cancer 1, Cologuard, also known as FIT-DNA, is a recommended screening test for average-risk individuals who refuse colonoscopy and FIT. The task force recommends CT colonography every 5 years or FIT-DNA every 3 years as alternative screening options.
Other good alternatives include:
- The fecal immunochemical test (FIT), which detects hidden blood in stool and should be done annually 1
- CT colonography (virtual colonoscopy), which requires bowel preparation but no sedation and is done every 5 years 1
- Flexible sigmoidoscopy, which examines only the lower part of the colon, can be performed every 5-10 years 1
It's essential to note that any positive result from these alternative tests will require a follow-up diagnostic colonoscopy. These alternatives are particularly suitable for people who cannot or will not undergo colonoscopy, though colonoscopy remains the gold standard as it can both detect and remove precancerous polyps in a single procedure. The U.S. Preventive Services Task Force also recommends discussing with your healthcare provider which option is best for you based on your personal risk factors, preferences, and insurance coverage 1.
From the Research
Alternatives to Colonoscopy for Colorectal Cancer Screening
- The US Preventive Services Task Force recommends several screening strategies, including high-sensitivity guaiac fecal occult blood test (HSgFOBT), fecal immunochemical test (FIT), multi-target stool DNA (mt-sDNA) test, computed tomographic (CT) colonography, flexible sigmoidoscopy, and traditional colonoscopy 2.
- Stool-based DNA screening, such as Cologuard, is a noninvasive alternative for CRC screening that can identify early-stage CRCs and adenomatous polyps in routine clinical practice 3.
- A study found that a positive mt-sDNA test is associated with a higher risk for finding any neoplasia on colonoscopy compared with positive FIT, and particularly associated with higher prevalence of clinically relevant serrated polyps compared with positive FIT 4.
Effectiveness of Multitarget Stool DNA Testing
- A retrospective review of patients referred for colonoscopy after a positive Cologuard test found that the positive predictive value (PPV) for colorectal cancer was 1.3% and for precancerous lesions plus colorectal cancer was 7.7% 5.
- The study concluded that multitarget stool DNA testing carries an unacceptably low PPV to be utilized as a screening test for colorectal cancer 5.
- However, another study found that fecal DNA testing, including mt-sDNA, has a higher sensitivity for detection of CRC and advanced adenomas compared to FIT, but lower specificity 6.
Considerations for Screening Strategies
- Factors to consider when choosing a screening strategy include the invasiveness of the test, test performance, screening interval, accessibility, and cost 2.
- Health systems should have a programmatic approach to CRC screening, which may include evidence-based strategies such as patient education, provider education, mailed screening outreach, and/or patient navigation, to maximize screening participation 2.
- Noninvasive CRC screening strategies, such as fecal DNA testing, have the potential to significantly increase national screening rates due to their noninvasive nature and convenience for patients 6.