Prognostic value of programmed death-ligand 1 status in Japanese patients with renal cell carcinoma.

Programmed death-ligand 1 (PD-L1) positivity is associated with poor prognosis in renal cell carcinoma (RCC). Because the prognostic impact and effect of confounding factors are less known, we investigated the prognostic significance of PD-L1 expression in Japanese patients with recurrent/metastatic RCC who started systemic therapy in 2010–2015. This multicenter, retrospective study recruited patients from 29 Japanese study sites who had prior systemic therapy for RCC (November 2018 to April 2019) and stored formalin-fixed paraffin-embedded primary lesion samples. The primary outcome was overall survival (OS) by PD-L1 expression. Secondary outcomes included OS in subgroups and duration of first- and second-line therapies by PD-L1 expression. OS distributions were estimated using Kaplan–Meier methodology. PD-L1 expression (on immune cells [IC] ≥ 1%) was observed in 315/770 (40.9%) patients. PD-L1 positivity was more prevalent in patients with poor risk per both Memorial Sloan Kettering Cancer Center [MSKCC] and International Metastatic RCC Database Consortium, and high-risk pathological features (higher clinical stage, nuclear grade and sarcomatoid features). Median OS for PD-L1–positive patients was 30.9 months (95% CI 25.5–35.7) versus 37.5 months (95% CI 34.0–42.6) for PD-L1–negative patients (HR 1.04 [90% CI 0.89–1.22, p = 0.65]; stratified by MSKCC risk and liver metastases). Propensity score weight (PSW)-adjusted OS was similar between PD-L1–positive and –negative patients (median 34.4 versus 31.5 months; estimated PSW-adjusted HR 0.986). This study suggests PD-L1 status was not an independent prognostic factor in recurrent/metastatic RCC during the study period because PD-L1 positivity was associated with poor prognostic factors, especially MSKCC risk status.