Fecal Hemoglobin-Guided Precision Postpolypectomy Surveillance Within the Current Framework: A Four-Million-Participant Fecal Immunochemical Test–Based Screening Study

BACKGROUND & AIMS: Defining precision postpolypectomy surveillance intervals is essential to optimize the balance between colonoscopy resource use and colorectal cancer (CRC) risk reduction within population-based fecal immunochemical test (FIT) screening programs. We sought to develop fecal hemoglobin (f-Hb) concentration-guided surveillance intervals and integrate them into the existing surveillance framework. METHODS: Between 2010 and 2015, 3,929,387 individuals participated in FIT screening, of whom 89,771 participants aged 50 to 74 years with f-Hb ≥20 μg Hb/g and complete colonoscopy after polypectomy were enrolled and monitored through 2018 for ascertaining incident CRCs. CRC risks across different f-Hb concentrations were estimated using an accelerated failure time model, and surveillance intervals were proportionally adjusted-shortened at higher f-Hb and extended at lower levels. We compared pragmatic, precision-oriented surveillance intervals with current guidelines to evaluate the extent of colonoscopy reduction without compromising CRC risk. RESULTS: There were 89,771 postpolypectomy individuals stratified as high-risk (49.5%) and low-risk (50.5%) groups based on the United States surveillance guideline. During a mean 5.5-year follow-up, CRC incidence was 2.8/1000 person-years (95% confidence interval, 2.7-3.0), increasing stepwise from 2.2/1000 person-years at 20 to 49 μg/g to 4.0/1000 person-years at ≥450 μg/g. Hypothetical f-Hb-guided surveillance intervals were lengthened for low-risk individuals with low f-Hb and shortened for those with elevated f-Hb within both risk categories. If adopting this precision approach, colonoscopy demand could be reduced by 9.8% vs current United States guidelines, while maintaining comparable CRC risk. CONCLUSIONS: Precision surveillance intervals guided by f-Hb can complement current guideline-based strategies by optimizing colonoscopy resource use while preserving the benefits of FIT-based CRC screening programs.