The immune system is important to control tumor development and progression. However, tumor cells and cells of the tumor microenvironment can induce immune escape mechanisms including activation of immune checkpoints such as PD-1/PD-L1. Based on this knowledge, new immune therapies including PD-1 and PD-L1 inhibition have been developed and are already recommended as standard treatment in metastatic bladder and kidney cancer patients. In addition to its role as a therapeutic target PD-L1 seems to be a prognostic parameter although data are controversial. Only little is known about signaling pathways inducing PD-L1 expression in tumor cells on one hand and about its functional role for tumor cells itself. However, the understanding of the complex biological function of PD-L1 will improve therapeutic options in urological malignancies. This review is giving an overview of the current knowledge concerning the PD-1/PD-L1 axis in urological tumors including bladder, kidney, prostate, testicular and penile cancer.
Current drug targets. 2020 Mar 26 [Epub ahead of print]
Kerstin Junker, Markus Eckstein, Michelangelo Fiorentino, Rodolfo Montironi
Department of Urology and Pediatric Urology, Saarland University . Germany., Institute of Pathology, University Hospital Erlangen . Germany., Pathological Unit, Maggiore Hospital, University of Bologna . Italy., Section of Pathological Anatomy, United Hospital, School of Medicine, Polytechnic University of the Marche Region . Italy.