Impact of physician compliance with colonoscopy surveillance guidelines on interval colorectal cancer

Background and Aims: Interval colorectal cancer (iCRC) incidence is the criterion standard benchmark for measuring the effectiveness of colonoscopy. Colonoscopy surveillance guidelines are designed to minimize iCRC cases. Our aims were to describe characteristics of iCRC patients and to assess whether development of iCRC is related to colonoscopy surveillance guideline intervals. Methods: We performed a retrospective cohort study of postcolonoscopy iCRC cases in a large healthcare system. Guideline-based colonoscopy intervals were calculated based on the 2012 U.S. Multi-Society Task Force for Colorectal Cancer colonoscopy surveillance guidelines. Backward stepwise linear regression was used to determine predictors of iCRC before guideline-recommended follow-up intervals. Results: We identified 245 iCRC cases (mean age, 69.4 years; 56.3% male) out of 5345 colon cancers evaluated for a prevalence of 4.60%. On index colonoscopy, 75.1% had an adequate preparation, 93.0% reached the cecum, and 52.5% had polyps. iCRC developed before the guideline-recommended interval in 59.1% of patients (94/159). Independent predictive factors of this finding were inadequate preparation (OR, .012; 95% CI, .003-.06; P < .0001) and >= 3 polyps on index colonoscopy (OR, .2; 95% CI, .078-.52; P = .0009). An endoscopist-recommended follow-up interval past the guideline-recommended interval was seen in 23.9% of cases (38/159). Most (34/38, 89.5%) of these iCRCs had inadequate preparation and were diagnosed after the guideline-based follow-up interval. Conclusions: Current colonoscopy surveillance guidelines may be inadequate to prevent many iCRC cases. Physician noncompliance with guideline-based surveillance intervals may increase in iCRC cases, especially in patients with an initially inadequate bowel preparation.