The neutrophil-to-lymphocyte ratio in salivary gland cancers treated with pembrolizumab

Background: A minority of patients with recurrent/metastatic (R/M) salivary gland cancers (SGCs) benefit from immune checkpoint inhibitors (ICIs), necessitating reliable biomarkers for ICI response prediction.Methods: Retrospective observational study of R/M SGC patients treated with pembrolizumab between 2016 and 2022, with a primary outcome of 6-month progression-free survival (PFS) and secondary outcome of 2-year overall survival (OS). Univariate and multivariable Cox proportional hazards models were employed.Results: Twenty R/M SGC patients were included. After adjustment, NLR as a continuous variable was independently associated with 6-month PFS (HR 1.30, 95% CI 1.10-1.54, p = 0.002) and 2-year OS (HR 1.33, 95% CI 1.07-1.66, p = 0.010). Similarly, NLR >= 5 was associated with higher hazards of progression at 6 months (HR 12.85, 95% CI 2.17-76.16, p = 0.005) and death at 2 years (HR 11.25, 95% CI 1.67-75.77, p = 0.013).Conclusions: Higher pretreatment NLR was independently associated with inferior 6-month PFS and 2-year OS in pembrolizumab-treated R/M SGC patients.