Clinical significance of tumor-associated immune cells in patients with oral squamous cell carcinoma.

ABSTRACT

BACKGROUND: The expression of PD-L1 in tumor cells and infiltration of tumor-associated immune cells (TAICs) might reflect the tumor biology of head and neck cancer. We aimed to characterize their prognostic roles in oral squamous cell carcinomas (OSCCs). METHODS: We enrolled 103 OSCC patients who underwent definitive surgery. Immune expression levels of PD-L1, PD-1, CD3, CD4, CD8, and CD68 were assessed in surgically resected specimens. We evaluated the effects of immune marker expression and localization on survival outcomes. RESULTS: Multivariate analysis results adjusted by the pathological stage, resection margin, and extracapsular extension showed that a high number of PD-1+ TAICs and intratumoral CD68+ TAICs were independent positive and negative prognostic markers (hazard ratio 0.20 and 4.15, respectively; P = .02 and .01, respectively). CONCLUSION: PD-1+ TAICs in the tumor microenvironment and CD68+ TAICs in the intratumoral area could act as novel biomarkers for predicting overall survival outcomes in OSCC patients.