Detailed analysis of inflammatory cell infiltration and the prognostic impact on nasopharyngeal carcinoma.

Abstract

One of the most striking characteristics of nasopharyngeal carcinoma (NPC) is the presence of a very abundant immune cells infiltrate containing mainly T-lymphocytes. The purpose of this study was to present our analysis providing a comprehensive characterization of antitumor inflammatory response in NPC. The densities of 9 types of inflammatory cells were assessed in 197 patients with NPC, including CD3 + T-lymphocytes, CD8 + cytotoxic T-lymphocytes, CD20 + B-lymphocytes, CD56 + natural killer (NK) cells, FOXP3 + regulatory T-lymphocytes, CD1a + immature dendritic cells, CD83 + mature dendritic cells, neutrophil elastase + neutrophils, and tryptase + mast cells. We characterized the inflammatory infiltrate in relation to clinical stage and patient survival. The expression of programmed death-1 (PD-1) on tumor-infiltrating lymphocytes (TILs) was also detected. The correlations between PD-1 expression and clinical characteristics and posttreatment outcome were analyzed. The patients with NPC with a low density of tumor-infiltrating FOXP3+, CD8 + T-lymphocytes, neutrophils, and mast cells showed a significantly longer overall survival (OS) and progression-free survival (PFS). However, patients with a high density of NK cells showed a better OS and PFS. The densities of NK cells and mast cells could be served as biomarkers for predicting recurrence or distant metastasis in patients with NPC. Moreover, PD-1 positivity predicted poor prognosis in patients with NPC. The densities of inflammatory cells are correlated with the prognosis of patients with NPC.