Urinary Analysis of <i>FGFR3</i> and <i>TERT</i> Gene Mutations Enhances Performance of Cxbladder Tests and Improves Patient Risk Stratification.

Abstract

Cxbladder tests are urinary biomarker tests for detection of urothelial carcinoma. We developed enhanced Cxbladder tests that incorporate DNA analysis of 6 single nucleotide polymorphisms for the <i>FGFR3</i> and <i>TERT</i> genes, in addition to the current 5 mRNA biomarkers and clinical risk factors. Two multicenter, prospective studies were undertaken in: (1) U.S. patients with gross hematuria aged ≥18 years and (2) Singaporean patients with gross hematuria or microhematuria aged >21 years. All patients provided a midstream urine sample and underwent cystoscopy. Samples were retrospectively analyzed using enhanced Cxbladder-Triage (risk stratifies patients), enhanced Cxbladder-Detect (risk stratifies patients and detects positive patients), and the combination enhanced Cxbladder-Triage × Cxbladder-Detect. In the pooled cohort (N=804; gross hematuria: n=484, microhematuria: n=320), enhanced Cxbladder-Detect had a sensitivity of 97% (95% CI 89%-100%), specificity of 90% (95% CI 88%-92%), and negative predictive value of 99.7% (95% CI 99%-100%) for detection of urothelial carcinoma. Overall, 83% of patients were enhanced Cxbladder-Detect-negative (ie, needed no further work-up). Of 133 enhanced Cxbladder-Detect-positive patients, 59 had a confirmed tumor, of which 19 were low-grade noninvasive papillary carcinoma or papillary urothelial neoplasm of low malignant potential. In total, 40 tumors were high-grade Ta, T1-T4, Tis, including concomitant carcinoma in situ. Of the 74 patients with normal cystoscopy, 41 were positive by single nucleotide polymorphism analysis. Enhanced Cxbladder-Triage and enhanced Cxbladder-Detect had significantly better specificity than the first-generation Cxbladder tests (<i>P</i> < .001). This study in ethnically diverse patients with hematuria showed the analytical validity of the enhanced Cxbladder tests.