SYSTEMATIC REVIEW AND META-ANALYSIS: THE THREE-YEAR POST-COLONOSCOPY COLORECTAL CANCER RATE AS PER THE WEO METHODOLOGY.

Abstract

Background and aims: In 2018, the World Endoscopy Organization (WEO) introduced standardised methods for calculating post-colonoscopy colorectal cancer-3yr rates (PCCRC-3yr). This systematic review aimed to calculate the global PCCRC-3yr according to the WEO methodology, its change over time, and to measure the association between risk factors and PCCRC occurrences.

Methods: We searched five databases from inception until January 2024 for PCCRC-3yr studies that strictly adhered to the WEO methodology. The overall pooled PCCRC-3yr was calculated. For risk factors and time-trend analyses, the pooled PCCRC-3yr and odds ratio (OR) of subgroups were compared.

Results: Several studies failed to adhere to the WEO methodology. Eight studies from four Western European and two Northern American countries were included, totalling 220,106 detected-colorectal cancers (CRC) and 18,148 PCCRCs between 2002-2017. The pooled Western World PCCRC-3yr was 7.5% (95%CI 6.4%-8.7%). The PCCRC-3yr significantly (p<0.05) decreased from 7.9% (95%CI 6.6%-9.4%) in 2006 to 6.7% (95%CI 6.1%-7.3%) in 2012 (OR 0.79 (95%CI 0.72-0.87)). There were significantly higher rates for people with inflammatory bowel disease (PCCRC-3yr 29.3%, OR 6.17 (95%CI 4.73-8.06)), prior CRC (PCCRC-3yr 29.8%, OR 3.03 (95% CI 1.34-4.72)), proximal CRC (PCCRC-3yr 8.6%, OR 1.51 (95%CI 1.41-1.61), diverticular disease (PCCRC 3-yr 11.6%, OR 1.74 (95%CI 1.37-2.10)) and female sex (PCCRC-3yr 7.9%, OR 1.15 (95%CI 1.11-1.20)).

Conclusion: According to the WEO methodology, the Western World PCCRC-3yr was 7.5%. Reassuringly, this has decreased over time, but further work is required to identify the reasons for PCCRCs, especially in higher-risk groups. We devised a WEO methodology checklist to increase its adoption and standardise the categorisation of patients in future PCCRC-3yr studies.