Tumor PD-L1 and VEGF Expression, and CD8 T Cell Infiltration Predict Clinical Response to Immune Checkpoint Inhibitors in Non-small Cell Lung Cancer

Background/Aim: We evaluated the efficacy of "the tumor immune microenvironment (TIME) classification" for predicting clinical response to immune checkpoint inhibitors (ICIs) in patients with non-small cell lung cancer (NSCLC). In addition, we aimed to evaluate the "modified TIME classification", which adds the vascular endothelial growth factor (VEGF) status to TIME. Materials and Methods: Programmed cell death receptor ligand-1 (PD-L1), CD8 T cell tumor-infiltrating lymphocytes (CD8+TILs) count and VEGF expression analyses were performed using immuno - histochemistry in 44 patients who had undergone ICI monotherapy. Results: Regarding TIME classification, type-I (PD-L1 high and CD8+TILs high) had a significantly higher response than the other types. Using the modified TIME classification, type-IA (PD-L1 high, CD8+TILs high, and VEGF low) had a significantly higher response than the other types. Conclusion: The modified TIME classification, which adds tumor VEGF expression to "the TIME classification", could be useful in predicting clinical response to ICI monotherapy.