Pretreatment nutritional indices are associated with survival and T-cell exhaustion in recurrent or metastatic oral squamous cell carcinoma patients treated with immune checkpoint inhibitors: a retrospective cohort study.

Pretreatment immune dynamics and nutritional status are important predictors of survival outcomes in various malignancies. This study was performed to evaluate the relationships between survival outcomes and the pretreatment nutritional indices - Onodera's prognostic nutritional index (OPNI) and neutrophil-to-lymphocyte ratio (NLR) - in 42 patients with recurrent or metastatic oral squamous cell carcinoma (OSCC) who underwent treatment with immune checkpoint inhibitors (ICI). Additionally, the relationships between these nutritional indices and T-cell exhaustion in the peripheral blood of the patients were analysed. As a result, the Kaplan-Meier method revealed that lower OPNI was significantly associated with poorer overall survival (OS) and progression-free survival (PFS) (both P < 0.001). Likewise, the results of the multivariate analysis showed that a low OPNI was independently associated with poor 5-year OS (hazard ratio 4.36, P = 0.008) and PFS (hazard ratio 4.04, P = 0.010). Patients with a low OPNI had a significantly higher frequency of PD-1 CD8 T-cells than those with a high OPNI (P = 0.009). These findings demonstrate that pretreatment OPNI is a valuable independent prognostic indicator of OS and PFS in OSCC patients following treatment with ICI. The OPNI might reflect T-cell exhaustion in the peripheral blood of OSCC patients.