OBJECTIVE: Noninvasive biomarkers are used routinely in the clinical management 
of several cancers but bladder cancer detection and surveillance remains 
dependent on invasive procedures such as cystoscopy. No validated biomarker 
currently exists in routine clinical practice other than cytology. Gene-based 
testing has shown great promise for biomarker profiling and this review 
addresses the current state of biomarker research in bladder cancer.
MATERIALS AND METHODS: A comprehensive review of all published literature on 
urinary biomarkers from 1970 - 2012 was conducted in PubMed. Keywords used alone 
or in combination were bladder cancer, diagnosis, surveillance, urinary 
biomarker, molecular biomarkers, methylation, gene expression, single nucleotide 
polymorphism and microRNA. The cited references of the manuscripts included in 
the review were also screened.
RESULTS: We have reviewed various strategies currently used for gene-based 
biomarker profiling of bladder cancer. We have comprehensively summarized the 
performance of several biomarkers in the diagnosis and surveillance of bladder 
cancer. Finally we have identified biomarkers that have shown potential and now 
deserve the opportunity to be validated in the clinical setting.
CONCLUSION: Several gene-based urinary biomarkers have demonstrated promise in 
initial studies, which now need to be rigorously validated in the clinical 
setting for them to be translated into clinically useful tests in diagnosis, 
surveillance or risk-stratification of bladder cancer.