Impact of time to colonoscopy after a positive FIT result on colorectal cancer outcomes: nationwide retrospective cohort study in France

Depending on the colorectal cancer (CRC) screening program, a colonoscopy should be performed within 1 to 3 months after a positive FIT result, but such a short timescale may be difficult to meet and seems trivial when most CRCs take years to develop. A nationwide retrospective cohort study in France assessed the impact of time to colonoscopy on CRC outcomes. The study included 374,113 FIT-positive individuals between 2016 and 2019, who underwent subsequent colonoscopy (86.6% compliance rate) within 24 months, with 21,616 CRCs and 122,359 advanced adenomas (AAs) diagnosed. Compared with the 2-3 months interval class, no increased risk of CRC, advanced-stage CRC, or AA was observed after 3 months up to 24 months, with adjusted ORs after 12 months of 0.93 (95% CI 0.83-1.03), 1.04 (0.85-1.25), and 0.88 (0.82-0.93), respectively. Individuals with high fecal hemoglobin concentrations (f-Hb ≥ 200 μg/g) were respectively eight, eleven, and two times more likely to have CRC, advanced-stage CRC, or AA as compared with th 30-40 μg/g class. The authors conclude that ensuring colonoscopy compliance after a positive FIT may be more important than rigid adherence to interval. The higher the f-Hb, the sooner the colonoscopy should be performed.