Introduction
Post-polypectomy guidelines classify individuals with polyps ≥10mm, in the absence of other high-risk features, as being at increased risk for developing colorectal cancer (CRC). Consequently, these individuals are recommended to undergo strict surveillance at three-year intervals. However, the necessity of such strict surveillance, particularly for polyps measuring between 10-20mm, remains a subject of ongoing debate. To shed light on this debate, this study aims to compare the risk of post-colonoscopy colorectal cancer (PCCRC) between individuals with polyps ≥10mm, in the absence of other high-risk features, and individuals without polyps.
Aims & Methods
For this study, data of quality-assured baseline colonoscopies performed between 2014 and 2020 as part of the Dutch fecal immunochemical test-based CRC screening program were used. In accordance with the guidelines in place at that time, a subset of individuals with adenomas ≥10mm without high-grade dysplasia and serrated polyps ≥10mm without dysplasia were advised a 5-year surveillance interval, rather than the currently recommended 3-year interval. For these individuals, the PCCRC-risk within 5 years was assessed and compared to that of individuals without polyps at baseline colonoscopy using multilevel cox regression analysis. Additionally, the adenoma detection rate (ADR) of endoscopists was categorized into tertiles to evaluate the impact of endoscopist quality on PCCRC-risk in individuals with polyps ≥10mm without other high-risk features.
Results
Among all included individuals in the Dutch screening program with high-risk polyps (n=74.289), 79% had polyps ≥10mm and 46% had polyps measuring 10-20mm as the sole high-risk feature. In total, 21.522 individuals with ≥10mm polyps without other high-risk features who were advised a 5-year surveillance, and 68.688 individuals without polyps who were referred back to the screening program after 10 years, were included in PCCRC-risk analysis. Within 5 years, there were 21 and 108 cases of PCCRC observed in these groups, respectively. Individuals with ≥10mm polyps at baseline colonoscopy had a comparable risk of PCCRC within 5 years to those without polyps (HR 0.67; CI95% 0.42-1.07). The PCCRC-incidence was 3.07 (CI95% 1.76-4.38) per 10.000 person-years of follow-up (PYFU) in individuals with ≥10mm polyps, and 5.02 (CI 95% 4.08-5.97) per 10.000 PYFU in individuals without polyps. PCCRC incidence in individuals with polyps ≥10mm without other high-risk features was lowest when colonoscopy was performed by endoscopists with high ADR, at 0.93 per 10.000 PYFU (CI95% 0.66-2.23), compared to 5.78 (CI95% 2.64-8.93) per 10.000 PYFU in those scoped by endoscopists with low ADR (HR 5.85 CI95% 1.28-26.55).
Conclusion
PCCRC-risk within 5 years among individuals with polyps ≥10mm as the sole high-risk feature is low and comparable to that of individuals without polyps at baseline colonoscopy. Notably, the risk for individuals with ≥10mm polyps significantly reduced when colonoscopies were performed by endoscopists with high ADR. Lengthening the surveillance interval from 3 to 5 years for individuals with polyps ≥10mm as their sole high-risk feature would concern 79% of all individuals with high-risk polyps, or 46% when limited to those with 10-20mm polyps. This could ease the burden on colonoscopy capacity and allow for more cost-effective use of resources.
Disclosure
ED: Honoraria for consultancy from Olympus, Fujifilm, Ambu, InterVenn, Norgine and Exact Sciences. Speakers' fees from Olympus, Norgine, IPSEN/Mayoly, FujiFilm, Steris and Pentax. Endoscopic equipment on loan of FujiFilm.
MS: received research support from Sysmex, Sentinel, Norgine and Medtronic
All other authors (NR and JIJ, ML) have nothing to disclose.