P0256 - What’s in a Name? The Global Burden of Postcolonoscopy Colorectal Cancer Using WEO Terminology

Nicole S. Evans, MD, MS¹, Jeffrey Lee, MD, MPH², James H. Kang, MA, BMBCh, MRCP^3
1Kaiser Permanente San Francisco, San Francisco, CA; ²Kaiser Permanente, San Francisco, CA; ³NHS, Norwich, England, United Kingdom

Introduction: Population-based screening and surveillance with colonoscopic removal of premalignant lesions reduces colorectal cancer (CRC) incidence and mortality. However, up to 9% of patients present with symptomatic cancers despite undergoing negative colonoscopies in the three years preceding diagnosis and before the next recommended examination.‘Postcolonoscopy’ CRCs (PCCRCs) are devastating for patients, providers, and healthcare systems, and have been proposed as a key performance metric for colonoscopy quality assurance programs. Previously there was no standardized definition for PCCRC and reported rates varied depending on terminology and calculation methods used. The World Endoscopy Organization (WEO) recently suggested a standardized PCCRC definition and methods to calculate its rate. Our aim was to assess PCCRC burden using WEO methods and update prevalence estimates reported in a previous meta-analysis.

Methods: A systematic literature search identified population-based studies reporting PCCRC prevalence. We estimated pooled prevalence compared with detected CRCs and investigated between-study sources of heterogeneity using subgroup and sensitivity analyses.

Results: Six population-based studies reporting on 23,018 PCCRCs were included. Pooled prevalence was 8.2% (95% CI = 7.3-9.0%) - a twofold increase compared to the previously published pooled prevalence. In subgroup analyses, proximal PCCRC prevalence was higher than distal PCCRC (10.2%, 95% CI=8.7-11.7%; vs. 6.3%, 95% CI=5.6-6.9%, p< 0.01). Using WEO methodology pooled PCCRC prevalence was 8.2% (95% CI=6.9-9.4%) and heterogeneity remained high. Six studies reported PCCRC rates over time. Three showed a decrease in PCCRC prevalence, while three showed no significant temporal changes.

Discussion: Overall PCCRC pooled prevalence was 8.2%; however, significant heterogeneity existed between studies. Time trend analyses within individual studies showed decreased or unchanged rates. Proximal PCCRC prevalence was significantly greater than distal PCCRC. Despite application of WEO methodology, comparing PCCRC rates between populations may be challenging at present due to heterogeneity related to patient selection criteria and endoscopist factors e.g. including higher risk patients (e.g. inflammatory bowel disease), endoscopist experience, or the presence of a CRC screening program. Standardization of such factors as well as PCCRC terminology may facilitate comparison of endoscopy service performance between centers.



Disclosures:


Nicole S. Evans, MD, MS¹, Jeffrey Lee, MD, MPH², James H. Kang, MA, BMBCh, MRCP³. P0256 - What’s in a Name? The Global Burden of Postcolonoscopy Colorectal Cancer Using WEO Terminology, ACG 2021 Annual Scientific Meeting Abstracts. Las Vegas, Nevada: American College of Gastroenterology.