Patients with ulcerative colitis have an increased risk of colorectal cancer. We sought to assess the comparative efficacy of standard white-light endoscopy (SDWLE) or high-definition white-light endoscopy (HDWLE) versus dye-based chromoendoscopy through a meta-analysis and rate the quality of evidence using the GRADE (Grading of Recommendations Assessment, Development, and Evaluation) system.

A systematic review of the literature in PubMed, EMBASE, and Web of Science was performed in April 2018. The primary outcome was the number of patients in whom dysplasia was identified using a per patient analysis in randomized controlled trials (RCT) and analyzed separately for non-RCTs. Analysis was performed using RevMan 5.3 reporting random-effects risk ratios.

Of the 27,904 studies identified, 10 studies were included 6 of which were RCTs (3 SDWLE and 3 HDWLE). Seventeen percent (84/494) of patients were noted to have dysplasia using chromoendoscopy compared with 11% (55/496) with white-light endoscopy (relative risk [RR] 1.50; 95% confidence interval [CI], 1.08-2.10). When analyzed separately, chromoendoscopy (n = 249) was more effective at identifying dysplasia than SDWLE (n = 248) (RR, 2.12; 95% CI, 1.15-3.91), but chromoendoscopy (n = 245) was not more effective compared with HDWLE (n = 248) (RR, 1.36; 95% CI, 0.84-2.18). The quality of evidence was moderate. In non-RCTs, dysplasia was identified in 16% (114/698) of patients with chromoendoscopy compared with 6% (62/1069) with white-light endoscopy (RR, 3.41; 95% CI, 2.13-5.47). Chromoendoscopy (n = 58) was more effective than SDWLE (n = 141) for identification of dysplasia (RR, 3.52; 95% CI, 1.38-8.99), and chromoendoscopy (n = 113) was also more effective than HDWLE (n = 257) (RR, 3.15; 95% CI, 1.62-6.13). The quality of the evidence was very low.

Based on this meta-analysis, non-RCTs demonstrate a benefit of chromoendoscopy over SDWLE and HDWLE, whereas RCTs only show a small benefit of chromoendoscopy over SDWLE, but not over HDWLE.