Objective: The aim of this study was to evaluate the prognosis effect of PD-L1 in combination with CD8⁺ tumor-infiltrating lymphocyte (TIL) or HIF-1α in head and neck squamous cell carcinoma (HNSCC).
Methods: A total of 63 patients who underwent surgical resection were included in this study. The level of PD-L1, CD8⁺ TIL, and HIF-1α was determined by immunohistochemical analysis. The survival of patients was evaluated by Kaplan–Meier analysis. The prognostic power of these parameters was evaluated by C-index.
Results: We observed that the survival of patients, who had a high level of PD-L1 in tumor cells, was significantly shorter than those who had a low level of PD-L1. However, the survival of patients who had a high level of PD-L1 in tumor microenvironment was significantly longer than patients with a low level of PD-L1 in tumor microenvironment. In addition, high level of CD8⁺ tumor-infiltrating lymphocyte or low level of HIF-1α level suggests a better prognosis. Moreover, we observed that PD-L1 in combination with CD8⁺ tumor-infiltrating lymphocyte and HIF-1α could significantly improve the prognostic effect of current TNM stage.
Conclusion: The results of this study suggest that the level of PD-L1, CD8⁺TIL, and HIF-1α are useful prognostic biomarkers for patients with HNSCC. Incorporating these biomarkers into current TNM stage of HNSCC improve the discriminatory capability of TNM stage.
Keywords: PD-L1, HIF-1α, CD8+TIL, HNSCC, prognosis