A Multicenter Prospective Randomized Controlled Trial Comparing Cxbladder Triage to Cystoscopy in Patients With Microhematuria. The Safe Testing of Risk for Asymptomatic Microhematuria Trial.

Abstract

AUA guidelines for patients with microhematuria (≥3 red blood cells [RBC]/high-power field [hpf]) include cystoscopy for most over age 40 due to risk of urothelial cancer (UC). Cxbladder Triage (CxbT) is a urinary genomic test with UC negative predictive value of 99%. In this prospective randomized controlled trial, we compared cystoscopy use in a standard of care (SOC) arm vs a marker-based approach. All patients with hematuria provided urine for a CxbT. Those categorized as lower risk (LR), defined as 3 to 29 RBC/hpf and minimal smoking history (<10 pack-years) were randomized between the test group provided with the CxbT result vs the SOC control group. Negative CxbT patients were offered omission of cystoscopy with surveillance. "Not lower risk" (NLR) patients (>30 RBC/hpf or >10 pack-year smoking history) had a CxbT but otherwise SOC. Patient decision and outcomes were recorded. Of 390 eligible patients, 255 were NLR and 135 were LR randomized to CxbT informed decision or SOC. The median age was 62 years (range 18-94) and 54% were male. Overall, 63% of CxbT tests were negative. For NLR patients, 82% had cystoscopy. In the LR control group, cystoscopy was performed in 67% of SOC and 27% in the test group (relative risk 0.41 [95% CI 0.27-0.61]). Compared to cystoscopy, CxbT had 90% sensitivity, 56% specificity, and 99% negative predictive value for UC. In this prospective randomized controlled trial, use of CxbT in patients with LR hematuria resulted in 59% reduction of cystoscopy use. This clinical utility of Cxbladder Triage can reduce the burden of unnecessary cystoscopies.