Validation of an mRNA-based Urine Test for the Detection of Bladder Cancer in Patients with Haematuria.

ABSTRACT

BACKGROUND: In patients with haematuria, a fast, noninvasive test with high sensitivity (SN) and negative predictive value (NPV), which is able to detect or exclude bladder cancer (BC), is needed. A newly developed urine assay, Xpert Bladder Cancer Detection (Xpert), measures five mRNA targets (ABL1, CRH, IGF2, UPK1B, and ANXA10) that are frequently overexpressed in BC. OBJECTIVE: To validate the performance of Xpert in patients with haematuria. DESIGN, SETTING, AND PARTICIPANTS: Voided precystoscopy urine specimens were prospectively collected at 22 sites from patients without prior BC undergoing cystoscopy for haematuria. Xpert, cytology, and UroVysion procedures were performed. Technical validation was performed and specificity (SP) was determined in patients without BC. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Test characteristics were calculated based on cystoscopy and histology results, and compared between Xpert, cytology, and UroVysion. RESULTS AND LIMITATIONS: We included 828 patients (mean age 64.5 yr, 467 males, 401 never smoked). Xpert had an SN of 78% (95% confidence interval [CI] 66-87) overall and 90% (95% CI 76-96) for high-grade (HG) tumours. The NPV was 98% (95% CI 97-99) overall. The SP was 84% (95% CI 81-86). In patients with microhaematuria, only one HG patient was missed (NPV 99%). Xpert had higher SN and NPV than cytology and UroVysion. Cytology had the highest SP (97%). In a separate SP study, Xpert had an SP of 89% in patients with benign prostate hypertrophy and 92% in prostate cancer patients. CONCLUSIONS: Xpert is an easy-to-use, noninvasive test with improved SN and NPV compared with cytology and UroVysion, representing a promising tool for identifying haematuric patients with a low likelihood of BC who might not need to undergo cystoscopy. PATIENT SUMMARY: Xpert is an easy-to-perform urine test with good performance compared with standard urine tests. It should help identify (micro)haematuria patients with a very low likelihood to have bladder cancer.