Expression of programmed death-ligand 1 and hypoxia-inducible factor-1a proteins in endometrial carcinoma

Background: Programmed death-ligand 1 (PD-L1) and hypoxia-inducible factor-1a (HIF-1a) proteins mediate major alterations of tumor microenvironment including generation of immunosuppressive microenvironment and tumor hypoxia, respectively. These alterations play a crucial role in carcinogenesis and tumor progression. Aims: The present study was designed to investigate the correlation between the expression of PD-L1 and HIF-1a proteins and the clinicopathologic variables in endometrial carcinoma. Materials and Methods: Tumor tissue sections from 95 endometrial carcinomas were evaluated for PD-L1 and HIF-1a immunohistochemical protein expression. Statistical Analysis Used: The statistical analyses were performed using Chi-square and Fisher's exact tests when appropriate. Two-sided P < 0.05 was considered statistically significant. Results: PD-L1 and HIF-1a expression were detected in 48.4% and 68.4% of endometrial carcinomas, respectively. PD-L1 expression was significantly associated with lymph node metastasis (P = 0.027). HIF-1a expression was significantly associated with tumor grade, depth of myometrial invasion, and lymph node metastasis (P = 0.014, 0.012, and 0.046, respectively). A significant positive correlation was detected between PD-L1 and HIF-1a immunoexpression (P = 0.015). Conclusions: PD-L1 and HIF-1a proteins are promising potential prognostic biomarkers in endometrial carcinomas since their overexpression is associated with clinicopathologic variables of advanced disease. A potential role of HIF-1a in upregulation of PD-L1 expression is suggested based on the finding of positive correlation between PD-L1 and HIF-1a expression in endometrial carcinoma. These findings point to a potential role of biomarkers inhibitors in controlling endometrial cancer progression.