Point Sensitivity of the Multi-target Stool DNA Test for Colorectal Cancer Screening in Individuals Ages 45-49 Years

BackgroundMost colorectal cancer (CRC) screening tests have not been rigorously studied in younger age groups. AimsTo estimate sensitivity of the multi-target stool DNA (mt-sDNA) test in patients ages 45-49 years. MethodsWe identified archived stool samples (Exact Sciences; Madison, WI) from individuals ages 45-49 years who had completed an index colonoscopy and had confirmed diagnoses of CRC or advanced precancerous lesions (APL; defined as high-grade dysplasia, >25% villous morphology, or [≥]1 cm in size [conventional adenoma or serrated lesion]). Data annotation referent to potential CRC risk factors, other than age, was limited. Stool samples were collected at least 7 days after the index colonoscopy, prior to lesion excision or treatment. Stool samples were processed and analyzed per established laboratory protocols for the mt-sDNA assay. Mt-sDNA test sensitivity for CRC, APL, and CRC+APL was estimated from the available sample set. Samples were collected from 2010-2013 (NCT01260168) and 2014-2017 (NCT02503631), with sample testing and analysis in 2019. ResultsStool samples were analyzed from 19 eligible subjects, 13 with CRC and 6 with APL. Estimated mt-sDNA test sensitivity for CRC, APL, and CRC+APL were 92%, 83%, and 89%, respectively. ConclusionsIn this small pilot study using existing archived stool samples from subjects ages 45-49 years, mt-sDNA test sensitivity was similar to previously reported estimates for individuals ages [≥]50 years. These results support the application of mt-sDNA screening to 76 average-risk patients beginning at age 45 years. Larger studies are needed to confirm and extend these findings.