Chromoendoscopy versus autofluorescence imaging for neoplasia detection in patients with longstanding ulcerative colitis (FIND-UC): an international, multicentre, randomised controlled trial.

Background Patients with longstanding ulcerative colitis (UC) undergo regular dysplasia surveillance because of increased colorectal cancer risk. Previous studies demonstrated that autofluorescence imaging (AFI) and chromoendoscopy (CE) increased dysplasia detection. The aim of this study was to determine whether AFI should be further studied as an alternative method for dysplasia surveillance in patients with longstanding UC. Methods In this prospective international, randomised trial, 210 patients undergoing colonoscopy surveillance for longstanding UC were randomised between 1 August 2013 and 10 March 2017 for inspection with either AFI or CE (105:105). Randomisation was minimised for a previous history of dysplasia and a previous history of primary sclerosing cholangitis. The main outcome was the relative dysplasia detection rate calculated by the ratio of AFI versus CE. This relative dysplasia detection rate was determined for the proportion of UC patients in which at least one dysplastic lesion was detected and for the mean number of dysplastic lesions per patient. The relative dysplasia detection rate needed to be above 0·67 for both outcomes to support performing a subsequent large non-inferiority trial, using an 80% confidence interval. Analysis was performed per protocol. The trial is registered at Netherlands Trial Register (NTR4062). Findings AFI detected dysplasia in 13 (12·4%) patients, compared to 20 patients (19·1%) with CE. The relative dysplasia detection rate of CE versus AFI for the proportion of UC patients with at least one dysplastic lesion was 0·65 (80% CI; 0·43-0·99). The mean number of detected dysplastic lesions per patient was 0·13 for AFI compared to 0·37 for CE (relative dysplasia detection rate 0·36, 80% CI; 0·21-0·61). Two patients experienced an adverse event (intraprocedural mild bleeding = 1, abdominal pain = 1) in the AFI-arm and three patients (intraprocedural mild bleeding = 2, perforation = 1) in the CE-arm. Interpretation In this randomised study comparing AFI with CE for dysplasia surveillance in patients with longstanding UC, AFI did not meet criteria for proceeding to a large non-inferiority trial. Therefore, current AFI technology should not be further investigated as an alternative dysplasia surveillance method.