Diagnostic performance of the Bladder EpiCheck methylation test and photodynamic diagnosis-guided cystoscopy in the surveillance of high-risk non-muscle invasive bladder cancer: A single centre, prospective, blinded clinical trial.

Purpose: Currently, bladder cancer (BC) surveillance consists of periodic white light cystoscopy and urinary cytology (UC). However, both diagnostic tools have limitations. Therefore, to improve the management of recurrent BC, novel, innovative diagnostic tests are needed. The primary aim of this study was to determine the diagnostic performance of Bladder EpiCheck (BE) and photodynamic diagnosis (PDD) guided cystoscopy in the surveillance of high-risk BC. A secondary aim was to compare Bladder EpiCheck (BE) and PDD-guided cystoscopy findings with whose of UC to design a diagnostic algorithm that facilitates clinical decision making. PATIENTS AND METHODS: This was a prospective, blinded, single-arm, single-visit cohort study. All patients were under surveillance for high-risk non-muscle-invasive bladder cancer, and underwent cystoscopy with PDD and a BE test. Those who received a histological diagnosis were used as a reference population. Receiver operating characteristic curve analysis was performed to evaluate the diagnostic performance of BE, PDD-guided cystoscopy, and UC for identifying biopsy-confirmed BC lesions. The diagnostic power of the test was assessed by determining the area under the curve (AUC).

Results: Forty patients were enrolled. For BE, the AUC was 0.95, and BC recurrence was detected at a sensitivity of 100% and specificity of 90.9%. For PDD, the AUC was 0.51, with a sensitivity and specificity of 61% and 41%, respectively. BE was combined with UC to create a decision-making algorithm capable of reducing the number of follow-up cystoscopies needed.

Conclusion: BE is a very accurate diagnostic tool that has the potential to be useful in the surveillance of high-risk BC patients. Especially when combined with UC, it may be used to reduce the number of cystoscopies needed throughout follow-up. Conversely, the use of PDD as a diagnostic tool in such patients should be reconsidered. However, due to the small sample size of this study, a larger prospective clinical trial should be performed to confirm findings.