LAUSR

BACKGROUND & AIMS Dye-based pancolonic chromoendoscopy is recommended for colorectal cancer surveillance in patients with Lynch syndrome. However, there is scarce evidence to support its superiority to high-definition white-light endoscopy. We performed a prospective study assess whether in the hands of high detecting colonoscopists, high-definition, white-light endoscopy is non-inferior to pancolonic chromoendoscopy for detection of adenomas in patients with Lynch syndrome. METHODS We conducted a parallel controlled study, from July 2016 through January 2018 at 14 centers in Spain of adults with pathogenic germline variants in mismatch repair genes (60% women; mean age, 47±14 years-old) under surveillance. Patients were randomly assigned to groups that underwent high-definition white-light endoscopy (n=128) or pancolonic chromoendoscopy (n=128) evaluations by 24 colonoscopists who specialized in detection of colorectal lesions in high-risk patients for colorectal cancer. Adenoma detection rates (defined as the proportion of patients with at least 1 adenoma) were compared between groups, with a non-inferiority margin (relative difference) of 15%. RESULTS We found an important overlap of confidence intervals and no significant difference in adenoma detection rates by pancolonic chromoendoscopy (34.4%; 95% CI, 26.4%-43.3%) vs white-light endoscopy (28.1%; 95% CI, 21.1%-36.4%; P=.28). However, pancolonic chromoendoscopy detected serrated lesions in a significantly higher proportion of patients (37.5%; 95% CI, 29.5-46.1) than white-light endoscopy (23.4%; 95% CI, 16.9-31.4; P=.01). However, there were no significant differences between groups in proportions of patients found to have serrated lesions of 5 mm or larger (9.4% vs 7.0%; P=.49), of proximal location (11.7% vs 10.2% P=.68), or sessile serrated lesions (3.9% vs 5.5%; P=.55) respectively. Total procedure and withdrawal times with pancolonic chromoendoscopy (30.7±12.8 min and 18.3±7.6 min, respectively) were significantly longer than with white-light endoscopy (22.4±8.7 min and 13.5±5.6 min; P<.001). CONCLUSIONS In a randomized parallel trial, we found that for Lynch syndrome surveillance, high-definition white-light endoscopy is not inferior to pancolonic chromoendoscopy if performed by experienced and dedicated endoscopists. CLINICALTRIALS. GOV NO NCT02951390.