A Systematic Review on Mutation Markers for Bladder Cancer Diagnosis in Urine

OBJECTIVES To systematically summarize the available evidence on urinary bladder cancer (BC) mutation markers. Gene mutations are expected to provide novel biomarkers for urinary BC diagnosis. So far, evidence on urinary BC mutation markers has not proven sufficient to be adopted by clinical guidelines. In this systematic review, diagnostic accuracy of urinary mutation analysis is separately assessed for primary BC diagnosis (BC detection) and for follow-up of BC patients (BC surveillance). METHODS A literature search (PubMed, Embase.com and Wiley/Cochrane Library) and systematic review was performed up to October 31, 2019. As studies were too heterogeneous, no quantitative analysis could be performed. RESULTS In total, 25 studies were summarized by qualitative analysis. For BC detection, diagnostic accuracy differed considerably for single mutation markers (sensitivity 1% ─ 85%, specificity 84% ─ 100%), and for marker panels (sensitivity 50% - 94%, specificity 43% - 97%). Similarly, for BC surveillance, diagnostic accuracy was highly variable for single mutation markers (sensitivity 0% ─ 85%, specificity 66% ─ 100%), and for marker panels (sensitivity 51% - 84%, specificity 66% - 96%). CONCLUSION Urinary mutation analysis showed to be a promising diagnostic tool for non-invasive BC diagnosis. Nonetheless, we observed substantial differences in diagnostic accuracy of urinary BC mutation markers among publications. To translate the data summarized in the present review to future clinical practice, heterogeneity in research design, BC population, mutation analysis technique and urinary DNA should be considered. Eventual clinical implementation of urinary BC mutation markers can only be achieved by collecting more and stronger evidence. Combining different molecular assays might overcome current shortcomings of urinary mutation analysis.