A Plea for the Use of Video-recorded Cystoscopy for Blinded Independent Central Review of Tumor Response in Open-label Non-muscle invasive Bladder Cancer Trials

Given that most of non-muscle invasive bladder cancer trials available in the literature share the same limitation of an open-label design, they are likely prone to detection bias. Indeed, tumor response is currently assessed by unblinded investigators, mainly via follow-up cystoscopy, which has well-known intraobserver and interobserver variability. Thus, we believe that the use of video-recorded cystoscopy for blinded independent central review of tumor response could help to minimize detection bias in open-label NMIBC trials.