A national audit of 1724 post-colonoscopy colorectal cancers: understanding causes and consequences

Abstract

Background Post-colonoscopy colorectal cancer (PCCRC) represents a potential missed opportunity to diagnose or prevent colorectal cancer (CRC). This study aimed to create a standardized, nationwide audit system to determine why PCCRCs occur and to generate evidence to aid prevention.

Methods PCCRCs occurring 6–48 months after colonoscopy were identified from English national datasets and uploaded to a secure portal. The portal contained case review forms based on World Endoscopy Organization (WEO) recommendations for PCCRC review. National Health Service colonoscopy providers (n = 126) were asked to review ≤ 25 PCCRCs. The data were analyzed to determine the characteristics of and reasons for PCCRC.

Results Of 2859 PCCRCs, 1724 (60.3 %) were reviewed. Colonoscopies were mostly performed for symptoms (59.2 %) or surveillance (26.5 %). PCCRCs were more common at the hepatic and splenic flexures and transverse colon compared with detected CRCs. PCCRC WEO categorizations were: possible missed lesion, examination adequate 68 %; possible missed lesion, examination inadequate 18 %; detected lesion, not resected 9 %; and likely incompletely resected lesion 5 %. Overall, 69.0 % of PCCRCs were avoidable and 44.2 % led to harm, including premature death in 8.0 %. Non-procedural reasons contributed to 27.1 % of PCCRCs: patient factors 10.2 %; clinical decision making 9.5 %; and administrative factors 7.4 %.

Conclusions This is the largest detailed PCCRC review to date. The majority of PCCRCs were avoidable and caused significant harm. This study clarifies the causes of diagnostic delays and highlights high-risk patients and areas of the colon, and suggests what needs to be done to reduce PCCRC in the future.

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