Colorectal Neoplasia Detection in Individuals With Positive Multitarget Stool DNA Tests: Data From the New Hampshire Colonoscopy Registry

Background: The US Preventive Services Task Force (USPSTF) includes multitarget stool DNA (mt-sDNA) testing as a colorectal cancer (CRC) screening option in average-risk individuals, but data on colonoscopy outcomes after positive mt-sDNA tests in community settings are needed.

Aim: The aim of this study was to investigate colonoscopy outcomes and quality following positive mt-sDNA in the population-based New Hampshire Colonoscopy Registry.

Methods: We compared colonoscopy outcomes and quality between age-matched, sex-matched, and risk-matched patients from 30 endoscopy practices with and without a preceding positive mt-sDNA test. Main outcomes were colonoscopy findings of CRC, advanced noncancerous neoplasia, nonadvanced neoplasia, or normal examination. Quality measures included withdrawal time, bowel preparation quality, examination completion, and percentage of average-risk individuals with normal colonoscopies receiving a USPSTF-recommended 10 year rescreening interval.

Results: Individuals with positive mt-sDNA tests (N=306, average age 67.0 y; 61.8% female) were significantly more likely than colonoscopy-only patients (N=918, 66.2 y; 61.8% female) to have CRC (1.3% vs. 0.4%) or advanced noncancerous neoplasia (27.1% vs. 8.2%) (P<0.0001). Neoplasia was found in 68.0% of patients having colonoscopy after a positive mt-sDNA test, (positive predictive value, was 68.0%), versus 42.3% of patients with colonoscopy only (P<0.0001). No significant differences in colonoscopy quality measures were observed between cohorts.

Conclusions: Colonoscopy after a positive mt-sDNA test was more frequently associated with CRC and colorectal neoplasia than colonoscopy alone. Positive mt-sDNA tests can enrich the proportion of colonoscopies with clinically relevant findings. Follow-up recommendations suggest that endoscopists do not inappropriately shorten rescreening intervals in mt-sDNA-positive patients with normal colonoscopy. These findings support the clinical utility of mt-sDNA for CRC screening in community practice.