Anti-PD-1 Therapy is Beneficial for the Survival of Patients with Oral Squamous Cell Carcinoma

Oral squamous cell carcinoma (OSCC) is one of the most common malignant tumors of the head and neck. Programmed cell death protein 1 (PD-1), and programmed cell death 1 ligand 1 (PD-L1) are often overexpressed in OSCC patients, and their expression level is closely related to tumor prognosis. The objectives of this study were: 1) to evaluate the impact of anti-PD-1 treatment on the immune system and prognosis of OSCC patients and 2) to find possible associations between T-cell immunity and anti-PD-1 therapy.

Anti-PD-1 therapy is beneficial to the survival and prognosis of patients with OSCC, improves T-cell immunity, and enhances tumor regression.

A total of 120 patients (divided into two equal groups: "non-anti-PD1 therapy" and "anti-PD1 therapy") with pathologically diagnosed OSCC participated in the study. Fresh peripheral blood samples (1 mL) were collected 2 days before and 20 days after the treatment. Heparin was used as an anticoagulant. Kaplan-Meier curves were plotted to compare the non-anti-PD-1 therapy and anti-PD-1 therapy groups.

Based on the Spearman-rho test, we found a significant correlation between anti-PD-1 treatment and survival time (P<0.001). Univariate/multivariate Cox regression analysis revealed that anti-PD-1 therapy is a significant independent risk factor of 5-year overall survival (OS) in OSCC patients (HR: 0.110, 95% CI: 0.062-0.195, P<0.001). One-way ANOVA showed that the mean levels of IFN-γ and IL-2 and numbers of CD4+ T cells were significantly increased in the anti-PD-1 therapy group compared with the non-anti PD-1 therapy group (control). The was no change in the number of CD8+ cells between the two groups. Kaplan-Meier curve results showed that the OS of patients in the anti-PD-1 therapy group was significantly longer than that in the non-anti-PD-1 therapy group.