Metabolomics and Bladder Cancer: Current State and Future Perspectives

Introduction: Bladder cancer is the ninth common tumor worldwide and the most common malignant carcinoma of urinary system with an increasing incidence. Despite the high frequency and mortality associated with this carcinoma, little has evolved recently regarding the diagnosis and management of this type of tumor. In fact, cystoscopy and cytology are still standards for bladder cancer detection. The development of less invasive and more reliable diagnostic techniques of bladder cancer than cystoscopy and cytology is critical. In this sense, metabolomics has recently emerged as a promising technique for the diagnosis and orientation of oncological diseases. Evidence Acquisition: We searched PubMed, Medline and Web of Science for studies about metabolomics and bladder cancer published before October 2017. We performed a review of the literature, trying to clarify what is already known about the application of metabolomics in bladder cancer and what are the future prospects. Evidence Synthesis: The spectral acquisition is made using predominantly two analytic platforms: nuclear magnetic resonance and mass spectrometry. Regarding to bladder cancer, several metabolites were associated with the presence of bladder cancer, leading to the creation of a metabolomic profile capable of distinguishing between bladder cancer patients and control. Besides the diagnosis, the metabolomic has also been studied to stratify bladder cancer according to its aggressiveness. In this sense there are studies that used metabolomic analysis to distinguish between low-grade and high-grade bladder cancer. One investigation showed that the levels of carnitine were higher in muscle-invasive bladder cancer than in nonmuscle-invasive bladder cancer, which suggests that they may be correlated with bladder cancer aggressiveness. Conclusion: Biomarkers detected by metabolomics give an insight into cancer biology and tapped properly this can lead to new strategies for bladder cancer diagnosis and new drugs discovery.