Systematic review and meta-analysis: the global three-year post-colonoscopy colorectal cancer rate as per WEO methodology

Introduction Colorectal cancer (CRC) occurring after a negative colonoscopy is called a post-colonoscopy colorectal cancer (PCCRC). Until recently, it has been difficult to compare global performance due to different methods used to define PCCRC rates. In 2018, the World Endoscopy Organization (WEO) standardised the methodology to calculate unadjusted PCCRC-3yr rates (PCCRC-3yr). The PCCRC-3yr is a textquotedblleftfalse-negativetextquotedblright rate of CRC diagnosed by colonoscopy.A recent systematic review investigated PCCRC-3yr rates but included studies outside the WEO’s methodology. Therefore, the true global prevalence of PCCRC as per the WEO methodology remains unknown.Methods We searched six databases for studies calculating the PCCRC-3yr rate using the WEO methodology. We performed a systematic review and meta-analysis to calculate the global PCCRC prevalence, change in prevalence over time and associated characteristics.Results Our search identified 4 studies reporting 13,791 cases of PCCRC. The pooled PCCRC prevalence is 7.595.6-8.4 with high heterogeneity observed (I2 = 98 plt;0.001)(Figure 1).Compared to the combined baseline year category of 2011-12, the odds of PCCRC occurrence were significantly higher in 2008 textendash 2010 (OR 1.12 (95.01textendash1.24), p=0.03) and 2004 textendash 2007 (OR 1.19, 95.06-1.33, p=0.03) for three studies combined with high heterogeneity.Patients with inflammatory bowel diseases (IBD) had a pooled PCCRC-3yr rate of 29.3951.3 textendash 38.1, 6-times the odds than those without (OR 6.17, 95.06-1.33) based on three studies combined with high heterogeneity. The pooled PCCRC-3yr rate in the right colon (two studies) was 8.695.3 textendash 8.8, 50OR 1.51, 95.41-1.61).Conclusions The global pooled PCCRC prevalence was 7.5 the results show a reduction in the PCCRC-3yr rate over time. We also identified that IBD patients have over 6 times higher odds than those without for developing a PCCRC.Abstract P169 Figure 1 Forest plot of overall PCCRC-3yr rates for colonoscopies performed between 2004-2012