Declining Prevalence of Post-Colonoscopy Colorectal Cancers: A Systematic Review and Meta-Analysis

Objective: The global burden of colorectal cancer (CRC) is projected to increase by 60% by 2030. Colonoscopy plays a crucial role in CRC screening, reducing incidence and mortality. However, its limitation is the occurrence of post-colonoscopy colorectal cancers (PCCRC). This meta-analysis aimed to determine the pooled prevalence of PCCRC-3y (CRCs diagnosed within 6 to 36 mo of colonoscopy) and emphasize the importance of enhancing endoscopy quality metrics to mitigate the burden of PCCRC-3y effectively. Methods: A systematic literature search through June 2024 identified single-center, multi-center, or population-based studies reporting PCCRC-3y prevalence. Pooled prevalence was estimated using methodologies recommended by the World Endoscopy Organization with a quantitative assessment of endoscopy quality measures. Results: Seventeen studies reporting on 25,504 PCCRCs were included. The pooled PCCRC-3y prevalence was 5.5% (95% CI: 4.9-6.2%). The likelihood of these cancers developing in the proximal colon was 1.9 times higher (8.7%; 95% CI: 7.8-9.8%) than in the distal colon (4.6%; 95% CI: 3.9-5.4%). The prevalence of PCCRC-3y declined significantly from 6.7% (95% CI: 5.7-7.8%) in 1992 to 2015 to 4.0% (95% CI: 2.9-5.6%) in 2005 to 2021 ( P =0.01). Additionally, several endoscopy quality indicators impacting PCCRC were identified. Conclusions: This meta-analysis found that the pooled PCCRC-3y prevalence was 4.0% (95% CI: 2.9-5.6%) from 2005 to 2021, reflecting a significant decline from previous years. Despite high heterogeneity among studies, the pooled prevalence serves as a useful benchmark for healthcare institutions in detecting and preventing CRC, as well as improving colonoscopy quality. The endoscopy quality indicators provide clear guidance for improving colonoscopy standards.