Clinical implications of liquid biopsies in urogenital tumors: a narrative review

Abstract

Background and Objective: Liquid biopsy is a minimally invasive method for cancer management, with diagnostic, prognostic and predictive applications, which can overcome some of the limitations of tissue biopsy. The aim of this review is to present the available literature on the clinical implications of liquid biopsy use in urogenital tumors, specifically in prostate cancers (PCs) and bladder cancers (BCs). Methods: We searched PubMed and MEDLINE up to November 2, 2021 with no language restrictions. Key Content and Findings: The use of liquid biopsy in localized or metastatic hormone sensitive PC (mHSPC) is limited, given the low yield of detection. In contrast, the utility of liquid biopsy in metastatic castrate resistant PC (mCRPC) is more widely studied, with biomarkers such as circulating tumor cells (CTCs) and androgen receptor (AR) splice variant 7 (AR-V7) playing prognostic and predictive roles, and homologous recombination repair genes guiding therapy. Standardization of these assays and validation of their benefits in guiding clinical decisions are still needed. Liquid biopsy is approved for the diagnosis and monitoring of BC, but additional evidence is required on its therapeutic role, in patient selection for adjuvant and targeted therapy. Conclusions: Liquid biopsy technics have a promising role in guiding the diagnosis, prognosis and management of prostate and bladder tumors, as compared to traditional tissue biopsy. However, they still need to be standardized and validated in larger prospective trials.