The molecular characterization of biomarkers will be fundamental for personalized medicine. New therapeutic targets have been identified in urological tumors (mainly in prostate cancer) and are currently being investigated in clinical trials. Tissue biopsies are associated with high costs, morbidity of the biopsy sample, and only allow analysis of a point-shaped part of the tumor. The liquid biopsy of circulating tumor cells (CTCs) and cell-free DNA (cfDNA) are noninvasive ways to detect specific changes in the tumor. There are still a few challenges to overcome, e. g., the stability and origin of the CTCs and cfDNA. The detection methods are not yet standardized which makes quality management more difficult. The main applications of liquid biopsy have led to a boom in the field of molecular diagnostics, which does not always have to do with the extended understanding of the individual analytes, but much more on the better sensitivity of the technologies. Despite the tremendous progress made in recent years in the field of liquid biopsy, this has not led to clinical implementation. There is still a lack of validated treatment guidelines in which the results of liquid biopsies can be integrated.
Keywords: Biomarkers; Circulating tumor cell; Personalizing therapy; Urooncology.