Diagnostic accuracy, clinical utility and influence on decision-making of a methylation urine biomarker test in the surveillance of non-muscle-invasive bladder cancer

Objectives: To investigate prospectively the clinical utility and influence on decision-making of Bladder EpiCheck™, a non-invasive urine test, in the surveillance of non-muscle-invasive bladder cancer (NMIBC). Materials and Methods: Urine samples from 440 patients undergoing surveillance for NMIBC were prospectively collected at five centres and evaluated using the Bladder EpiCheck test (NCT02647112). A multivariable nomogram and decision-curve analysis (DCA) were used to evaluate the impact of Bladder EpiCheck on decision-making when used in routine clinical practice. The test was designed to exclude recurrent disease. Results: Data from 357 patients were available for analysis. The test had a specificity of 88% (95% confidence interval [CI] 84–91), a negative predictive value (NPV) of 94.4% (95% CI 91–97) for the detection of any cancer and an NPV of 99.3% for the detection of high-grade cancer. In multivariable analysis, positive Bladder EpiCheck results were independently associated with any and high-grade disease recurrence (odds ratio [OR] 18.1, 95% CI 8.7–40.2; P < 0.001 and OR 78.3, 95% CI 19.2–547; P < 0.001). The addition of Bladder EpiCheck to standard variables improved its predictive ability for any and high-grade disease recurrence by a difference of 16% and 22%, respectively (area under the curve 85.9% and 96.1% for any and high-grade cancer, respectively). DCA showed an improvement in the net benefit relative to cystoscopy over a large threshold of probability, resulting in a significant reduction in unnecessary investigations. These results were similar in subgroups assessing the impact of specific clinical features. Conclusions: Bladder EpiCheck is a robust high-performing diagnostic test in patients with NMIBC undergoing surveillance that can potentially reduce the number of unnecessary investigations.