Iacovelli R, Ciccarese C, Brunelli M, et al. - Among 32 de novo metastatic castration-sensitive prostate cancer (mCSPC) patients with available diagnostic tissue, researchers evaluated programmed death-ligand 1 (PD-L1) expression in tumor cells. Tumor PD-L1 expression ≥ 1% and ≥ 5% was detected in 46.9% and 31.3% of cases, respectively. A higher incidence of Gleason score ≥ 8 was seen in PD-L1⁻ tumors vs PD-L1⁺ tumors, while a higher incidence of lymph node metastases was observed in PD-L1⁺ tumors. The PD-L1⁻ population and the PD-L1⁺ patients did not differ with regard to median overall survival. Based on the findings, the experts concluded that tumor PD-L1 expression cannot be considered a prognostic factor for de novo mCSPC. Moreover, to better define patients that might benefit from checkpoint blockade immunotherapy, its prognostic and predictive importance have to be completely studied.