Clinical Validation of a Multiplex Urine Biomarker Assay for Surveillance of Recurrent Bladder Cancer.
PURPOSE: More than 50% of patients with non-muscle-invasive bladder cancer experience recurrence, requiring lifelong surveillance with repeated cystoscopy. Given the invasive nature and cost of cystoscopy, accurate noninvasive tools are needed to support risk-adapted monitoring. We evaluated the ability of Oncuria-Monitor, a multiplex urine biomarker assay, to detect recurrent bladder cancer during surveillance. PATIENTS AND METHODS: Between February 2017 and August 2020, six medical centers in the United States and Japan prospectively enrolled 300 patients with a history of bladder cancer, generating 1,248 serial urine samples. Participants were divided into training and validation cohorts. At each surveillance visit over 2 years, urine samples were analyzed in a blinded manner using Oncuria-Monitor and BladderChek, alongside urine cytology. Test performance was compared with cystoscopy and histopathology-confirmed recurrence. RESULTS: Recurrent bladder cancer was identified in 31% (93/300) of participants, with 143 total recurrences during follow-up, including 90 tumors in the validation cohort. In the validation cohort, Oncuria-Monitor achieved a sensitivity of 85.6% [95% confidence interval (CI), 78.1%-92.2%] and a negative predictive value (NPV) of 93% (95% CI, 89.2%-96.4%). In comparison, BladderChek demonstrated a sensitivity of 20.0% and an NPV of 88%, whereas urine cytology showed a sensitivity of 36.9% and an NPV of 91.6%. The number needed to evaluate to detect one recurrence was 3 for both cystoscopy and Oncuria-Monitor, compared with 15 for BladderChek and 8 for cytology. CONCLUSIONS: In this large prospective longitudinal study, Oncuria-Monitor demonstrated clinically actionable performance, enabling a rule-out strategy that could safely reduce cystoscopy in approximately 25% of surveillance visits. These findings support a paradigm shift toward biomarker-guided, risk-adapted surveillance in bladder cancer that reduces unnecessary invasive procedures while maintaining oncologic safety.