Editorial: Identifying novel biomarkers in bladder cancer

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Editorial on the Research Topic Identifying novel biomarkers in bladder cancerUrothelial carcinoma (UC) of the bladder is the tenth most diagnosed cancer worldwide and represents a significant cause of morbidity and mortality (1).UC is a heterogeneous disease with significant differences in management and prognosis for nonmuscle invasive and muscle invasive stages (2).The increased knowledge regarding molecular changes associated with development and growth of bladder cancer has accelerated research into the disease (3).Methodological developments have contributed to a better understanding of the biology and heterogeneity of UC.This new understanding has also led to the development of new biomarkers and approaches for targeted therapy (4).Cystoscopy and cytology are still mentioned as gold standard for the detection and surveillance of bladder cancer with unequal combined overall sensitivity and specificity.However, they have only limited sensitivity in detecting small lesions of the urinary tract and flat lesions such as carcinoma in situ that are thus particularly challenging.For such cases urine cytology is still the most used non-invasive test detecting bladder cancer during followup.Despite its high specificity of approximately 86%, the limitation lies in low sensitivity of only 50% (5), especially for low-grade tumors (6, 7).With the absence of reliable cost-effective urinary biomarkers, the confirmation of suspected carcinomas of the urinary tract and the subsequent life-long surveillance for relapse is nowadays still undertaken by cystoscopically examinations, which represents significant costs for healthcare systems (8).There is a wide range of potential clinical uses for markers.Molecular markers could improve detection of disease in hematuria patients, improve surveillance for NMIBC, detect residual disease after therapy, predict response to treatment, select patients for more aggressive treatment and identify patients for targeted therapies.Markers can evaluate urine, serum, plasma and can identify alterations in proteins, DNA, RNA, epigenetic changes, cellular changes and be individual or panels.Most importantly, markers need validation and evaluation of clinical benefit.Studies comparing different rapid tests to the gold standard, urine cytology based on the Paris system for reporting (9) and integrating clinical parameters such as haematuria, ECOG performance score, smoking behavior and others (10) are needed ( 11).An incomplete understanding of tumor biology and responsiveness to current therapy strategies has led to numerous studies focusing on differentiating molecular subtypes of bladder Frontiers in Oncology frontiersin.