Novel Index Based on Inflammatory Markers Correlates with Treatment Efficacy of Nivolumab for Recurrent/Metastatic Head and Neck Cancer

INTRODUCTION: Immune checkpoint inhibitors provide new treatments for patients with recurrent or metastatic (R/M) head and neck cancers. Herein, we focused on systemic inflammatory markers in peripheral blood, including blood cell fractions, albumin (Alb), and C-reactive protein, and determined their association with nivolumab treatment response. We also examined the potential application of inflammatory markers as prognostic tools. METHODS: We assessed pretreatment systemic inflammatory markers in 61 patients with R/M head and neck cancer treated with nivolumab, determining their association with treatment response using Kaplan-Meier, multivariate, and regression analyses. Using flow cytometry, we investigated circulating T-cell subsets in 36 patients with R/M head and neck cancer. Finally, we examined the correlation between each statistically analyzed parameter and peripheral circulating T-cell activation. RESULTS: Systemic inflammatory marker values were used to estimate overall survival (OS) time by performing multivariate analysis. Systemic inflammatory markers were assigned importance for each coefficient. Monocyte and lymphocyte counts strongly impacted OS. Indices dependent on white blood cell and monocyte counts, lymphocyte percentage, platelet count, Alb levels, and prognostic nutrition index were useful prognostic tools in the regression analysis. The simplest prognostic index was defined as white blood cells (103/μL) +2 × lymphocyte percentage (%) +12 × number of monocytes (103/μL) + 27 × serum Alb. A high index that was significantly associated with a better prognosis negatively correlated with CD38/CD8 and ki67/CD8 percentages. CONCLUSIONS: According to the findings of the present study, systemic inflammatory markers may help predict the prognosis, activation, and exhaustion of circulating T cells. In patients with R/M head and neck cancer treated with nivolumab, systemic inflammatory markers could provide new insights into rational strategies in cancer immunotherapy for R/M head and neck cancer.