The aim of liquid biopsies is to obtain tumor information via the molecular interrogation of liquid samples, including blood and urine. As a minimally invasive procedure, liquid biopsies have attracted attention. A series of studies have reported associations of biomarkers such as circulating tumor DNA, cell-free DNA and extracellular vesicles with urological cancers, especially prostate cancer (PCa), and demonstrated the promising potential of liquid biopsies. In this review, we summarize recent clinical translational studies of liquid biopsies in PCa and other urological cancers, including bladder cancer and renal cell carcinoma. The number of translational studies was limited, and most of the studies focused on PCa. Biomarkers isolated from blood by different detection methods could be applied in clinical practice to predict prognosis and treatment response in advanced PCa. The other applications in urological cancers identified in previous studies remain to be explored further. Current studies are limited due to the lack of ideal standard detection methods for biomarkers. In the future, with advances in methodology, more translational studies will be conducted to identify potential applications of liquid biopsies in urological cancers.
