Katherine C. Wai

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.