Blood-Based Biomarkers for Bladder Cancer Diagnosis and Prognosis

Blood-based biomarkers comprise a number of different analytes including extracellular vesicles, proteins, circulating cells, and circulating nucleic acids. Due to the minimally invasive nature of blood sampling, these biomarkers allow for longitudinal testing, thereby enabling repeated monitoring of the patient’s disease over time. This constitutes a unique opportunity for early intervention and monitoring of tumor evolution during the disease course, ultimately providing the possibility to change treatment regimen. Hence, blood-based biomarkers have a great potential in risk stratification, detection of minimal residual disease and relapse as well as for monitoring and guidance of treatment. In this chapter we describe different types of blood-based biomarkers with a special focus on circulating tumor cells and circulating tumor DNA, as these have shown the most promising results for clinical implementation and may prove to be valuable clinical tools following clinical trial validation.