Abstract
Angiogenesis serves a crucial role in cancer progression. Vascular endothelial growth factor (VEGF) exhibits an immunosuppressive function in patients with cancer. However, it remains unclear whether expression of VEGF in tumor tissue can predict the outcome of programmed death‑1 blockade in patients with advanced non‑small cell lung cancer (NSCLC). A training (n=32) and validation (n=76) cohort of patients with advanced NSCLC who received first‑line pembrolizumab were enrolled. Immunohistochemical staining for VEGF receptor 2 (VEGFR2) and tumor‑infiltrating lymphocytes (TILs; CD4, CD8 and FOXP3) was performed in tumor specimens of both cohorts and association with clinical outcomes was assessed. The percentages of high VEGFR2 expression were 34.3% (11/32) in training cohort and 25.0% (19/76) in validation cohort. No statistically significant difference in objective response between high and low VEGFR2 expression was observed for training (27.2 vs. 45.0%) and validation (31.2 vs. 35.7%) cohorts. The positive rate of intratumoral FOXP3 was significantly associated with high VEGFR2 expression for validation cohort, but not training cohort. In validation cohort, high VEGFR2 expression in patients with non‑adenocarcinoma (non‑AC) was significantly correlated with positive FOXP3 TILs in intratumoral and stromal sites, but not CD4 and CD8. High VEGFR2 expression in both cohorts indicated a significantly worse overall survival (OS) than low VEGFR2 expression. VEGFR2 was identified as an independent prognostic marker associated with worse OS. High VEGFR2 expression was a significant marker for predicting worse OS in patients treated with first‑line pembrolizumab, particularly in those with non‑AC.