Evaluation of URO17® to improve non-invasive detection of bladder cancer

Background : The gold standard for detecting bladder cancer is cystoscopy with biopsy or transurethral resection confirming histologic diagnosis. URO17® employs a chromogenically labeled monoclonal antibody to keratin 17 (k17), an intermediate filament cytoskeleton molecule associated with bladder, pancreatic, and cervical cancers. Preliminary studies evaluating k17 demonstrated a high sensitivity and specificity for the detection of bladder cancer, supporting the need for further study. Objective To evaluate the sensitivity and specificity of URO17. Methods This is a cross-sectional study of participants undergoing urologic procedures between July 6, 2018 and July 17, 2019 at a single institution. Patients undergoing cystectomy, endoscopic bladder and/or upper tract procedure for probable urothelial carcinoma comprised cases; patients undergoing urologic procedures for other reasons comprised the control group (i.e. prostatectomy, nephrectomy, etc.). Voided urine samples were at the time of procedure; a minority of participants underwent multiple resections in the study period, thus, as many as three urine samples were taken from any given participant. Samples were distributed for blinded testing with URO17. Sensitivity and specificity were calculated. Results In 152 participants and 167 samples, URO17 demonstrated an overall sensitivity of 90% and 92% and a specificity of 88% and 87%, respectively. In 76 participants and 91 samples from patients with suspected urothelial carcinoma, the sensitivity was 90% and 92%, and the specificity was 50% and 54%, respectively. No controls demonstrated a positive URO17 result, and URO17 superseded urine cytology detection of low-grade and high-grade Ta. False positive results were associated with inflamed tissue or urothelial atypia on histology; the large majority had a history of intravesical therapy. Conclusion Limitations include cross-sectional design and convenience sampling. URO17 may improve sensitivity of urine cytology in the detection of urothelial cancer, though further study is required to refine the application of this biomarker in clinical practice.