Differential Immune-Related Microenvironment Determines Programmed Cell Death Protein-1/Programmed Death-Ligand 1 Blockade Efficacy in Patients With Advanced NSCLC

Programmed death-ligand 1 (PD-L1) expression is not a completely reliable predictive marker of the efficacy of anti–programmed cell death protein-1 (PD-1)/PD-L1 therapy in patients with advanced NSCLC. Immune-related tumor microenvironment (TME) is classified into four different types based on the tumor-infiltrating lymphocyte (TIL) status and PD-L1 expression. We retrospectively reviewed patients with advanced NSCLC treated with anti–PD-1/PD-L1 therapy between 2015 and 2019. We investigated the association between the efficacy of anti–PD-1/PD-L1 therapy, the types of TME based on PD-L1 (clone: 22C3) expression, the density of CD8-positive TILs assessed by immunohistochemistry, and mutational profiles by next-generation sequencing. Overall, 228 patients were included in the analysis. The patients were classified into the following four groups: type I: PD-L1High (tumor proportion score ≥ 50%)/TILHigh (≥85/mm2; n = 73); type II: PD-L1Low (tumor proportion score < 50%)/TILLow (