Urinary Biomarkers in the Evaluation of Primary Hematuria: A Systematic Review and Meta-Analysis

INTRODUCTION: Urinary biomarkers are entering the clinical landscape as a non-invasive method to evaluate patients for bladder cancer, however it is currently predominantly used in the surveillance setting. The use of biomarkers in the setting of primary hematuria is not widespread despite initial promising results. This study comprehensively reviews the literature on the diagnostic performance of FDA-approved biomarkers in the evaluation of primary hematuria. METHODS: According to the Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) statement, MEDLINE, EMBASE, ScienceDirect, Cochrane Libraries, HTA database, Google Scholar and Web of Science were searched up to June 2017 for studies assessing the diagnostic accuracy of FDA-approved urinary biomarkers amongst patients presenting with primary hematuria. The quality of included studies was assessed using the QUADAS-2 tool. RESULTS: Fourteen studies met the pre-specified eligibility criteria and were included for analysis. The biomarkers assessed in these studies were AssureMDx, Bladder tumor antigen, CxBladder, NMP22, UroVysion and uCyt+. Across these four biomarkers, the sensitivity ranged from 0.67 to 0.95, and specificity from 0.68 to 0.93, respectively. There was significant heterogeneity between the included studies. Limited head-to-head comparison with urine cytology demonstrated that in general, the biomarkers have superior sensitivity but inferior specificity. Overall, the quality of evidence was graded as moderate primarily because of inadequate blinding. CONCLUSION: The current diagnostic performance of biomarkers are inadequate to replace cystoscopy in the primary hematuria setting. However, AssureMDx in particular may have a role as a triage test for cystoscopy but further prospective data is required to validate these findings. Given the current evidence, the use of these markers as an adjunct to cystoscopy for the evaluation of hematuria should be considered investigational.