The Immune Infiltrate in Prostate, Bladder and Testicular Tumors: An Old Friend for New Challenges

In genito-urinary tumors immunotherapy has been administered for a long time: Calmette-Guèrin Bacillus as adjuvant treatment in high risk patients with non muscle invasive urothelial bladder cancer and interleukin-2 and interferon-α in metastatic kidney cancer. The vaccine Sipuleucel-T has been approved by United States Food and Drug Administration for the treatment of castration resistant prostate cancer patients with asymptomatic or minimally symptomatic disease, given the 22% reduction of mortality risk in this group. Recently immunotherapeutic agents targeting inhibitory immune checkpoint molecules lead to improved outcomes and lasting anti-tumor effects in a variety of hematological and solid malignancies, including urogenital tumors. The benefit from these treatments has been observed only in a proportion of subjects, raising a need in optimizing patients' selection for immune checkpoint blockade. The composition and activity of a pre-existing immune infiltrate may aid in identifying ideal candidates to immunotherapy, with possible implications for the clinical management of neoplastic diseases from earlier to later stages.