PD-L1 in combination with CD8+TIL and HIF-1α are promising prognosis predictors of head and neck squamous cell carcinoma.

Abstract

e18545 Background: Currently, the tumor/node/metastasis (TNM) staging is the most widely used Head and neck squamous cell carcinoma (HNSCC) staging system. However, this classification only provides limit information for the prognosis of HNSCC. Recently, some studies suggest that the level of PD-L1 in tumor cells (TC-PD-L1) or in tumor microenvironment cells (TMC-PD-L1) is a promising biomarker for the prognosis of HNSCC patients. Therefore, in this study, we evaluated the prognostic value of TC-PD-L1, TMC-PD-L1, CD8+ TIL, HIF-1α. In addition, we investigated if incorporated these biomarkers into TNM stage could improve the prognostic value of TNM stage. Methods: A total of 63 patients who underwent surgical resection. 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 and Cox proportional hazards model. The prognostic power of these parameters was evaluated by C-index. Results: We observed that the survival of patients, who had high level of PD-L1 in tumor cells, was significantly shorter than those who had low level of PD-L1. However, the survival of patients who had high level of PD-L1 in tumor microenvironment was significantly longer than patients with 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. Conclusions: The results of this study suggest that the level of PD-L1, CD8+TIL and HIF-1α is useful prognostic biomarkers for patients with HNSCC. Incorporated these biomarkers into current TNM stage of HNSCC improve the discriminatory capability of TNM stage.