Association of PD-L1 expression on immune cells with survival of patients with nonmetastatic head and neck cancer

A systematic review and meta-analysis of 17 cohort studies (3190 patients) investigated the association of PD-L1 expression on immune cells and tumor cells with survival of patients with nonmetastatic head and neck squamous cell carcinoma. High PD-L1 expression on immune cells was associated with improved OS (pooled aHR 0.39; 95% CI 0.25-0.59) and disease-specific survival (0,52;0.38-0.72). There was no association of composite PD-L1 expression on immune and tumor cells with OS, or of PD-L1 expressed on tumor cells only with OS. The authors conclude that PD-L1 expression on immune cells may serve as a new prognostic biomarker in patients with nonmetastatic HNSCC.