Application of Omics and Systems Medicine in Bladder Cancer

Bladder cancer (BC) is the ninth most common cancer in the world. Smoking remains the main disease risk factor which is responsible for about half of the diagnosed BC cases. Although the vast majority (~75%) of BC cases are diagnosed at an early stage, the recurrence rate is reaching up to 78%. Thus, frequent monitoring is required. Since cystoscopy, the current diagnostic procedure, is highly invasive, disease monitoring is associated with increased patient incompliance and high disease-related costs. However, the limitations of the alternative diagnostic means (suboptimal accuracy of cytology and/or noninvasive markers) underscore the need for the development of novel diagnostic approaches. Apart from the diagnostic complications, the current therapeutic options for BC are also limited. The high disease heterogeneity at the molecular level presents significant challenges for biomarker translational research, as well as for drug development trials. In order to overcome the difficulties associated with the inter- and intratumor variability, the application of -omics approaches and systems medicine will greatly help to address the disease heterogeneity. The application of high-resolution -omics datasets has recently gained more popularity in several applications, such as: (i) BC disease characterization, (ii) patient stratification for therapy decision-making, and (iii) diagnostic and prognostic biomarker development. The concept of applying systems medicine to answer the above clinical questions paves a new avenue toward precision and personalized medicine. This chapter aims at providing an overview of the BC pathophysiology and main clinical needs that remain to be addressed. Along these lines, research efforts to address these clinical demands will be summarized, mainly focused on the use of state-of-the-art "OMICS" methodologies.