Strategies for Detecting Colorectal Cancer in Patients with Inflammatory Bowel Disease: A Cochrane Systematic Review and Meta-Analysis.

Objectives: Patients with longstanding ulcerative colitis (UC) and colonic Crohn's disease (CD) have an increased risk of colorectal cancer (CRC). We assess the effectiveness of endoscopic surveillance in patients with inflammatory bowel disease (IBD) for diagnosing CRC and reducing CRC-related mortality.

Methods: MEDLINE, EMBASE, and CENTRAL were searched from inception to 19 September 2016. Randomized controlled trials (RCTs), observational cohorts, or case-control studies assessing any form of endoscopic surveillance for early CRC detection were eligible for inclusion; studies without a comparison non-surveillance group were excluded. The primary outcome was rate of CRC detection. Secondary outcomes were rate of early (Duke stage A and B) versus late (Duke stage C & D) CRC detection and rate of CRC-related death. Data were pooled using fixed or random effects models based on the degree of heterogeneity; pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using the Mantel-Haenszel method.

Results: Five observational studies evaluating 7199 IBD patients were included; no RCTs met criteria for inclusion. There are limited new studies evaluating this clinical question (last included study published 2014). There was a significantly higher rate of cancer detection in the non-surveillance group (3.2%, 135/4256) compared to the surveillance group (1.8%, 53/2895) (OR 0.58 (95% CI: 0.42-0.80), p < 0.001). In four pooled studies, there was a significantly lower rate of CRC-associated death in the surveillance group (8.5%, 15/176) compared to the non-surveillance group (22.3%, 79/354) (OR 0.36 (95% CI: 0.19-0.69), p = 0.002). In two pooled studies, there was a significantly higher rate of early-stage CRC detection in the surveillance group (15.5%, 17/110) compared to the non-surveillance group (7.7%, 9/117) (OR 5.40 (95% CI: 1.51-19.30), p = 0.009).

Conclusions: Colonoscopic surveillance in IBD is associated with a reduction in CRC development and CRC-associated death, as well as increased detection of early-stage CRC.