The prognostic impact of sarcopenia and systemic inflammation in head and neck cancer patients treated with immune checkpoint inhibitors

Objective Sarcopenia and systemic inflammatory markers predict prognosis in various cancers, including head and neck cancer (HNC) treated with surgery or chemoradiotherapy. Their significance in patients receiving immune checkpoint inhibitors (ICIs), however, remains unclear. This study aims to determine whether skeletal muscle loss and systemic inflammation influence treatment response and survival in ICI-treated HNC, and whether composite indices provide prognostic value. Methods A retrospective cohort of 179 patients with histologically confirmed recurrent or metastatic (R/M) HNC who received ICI therapy between April 2017 and July 2024 was analyzed. Sarcopenia was assessed using the lumbar skeletal muscle index (LSMI), calculated from cervical CT images. Inflammatory markers such as neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and lymphocyte-to-monocyte ratio (LMR) were derived from pre-treatment blood samples. Overall survival (OS) and progression-free survival (PFS) were evaluated using Kaplan–Meier estimates, and prognostic factors were identified through Cox regression analysis. Results Among the 179 patients, 98 (54.7%) were classified as sarcopenic. These patients had significantly shorter median OS compared to non-sarcopenic patients (12.1 vs. 39.8 months; p < 0.001). Univariate analysis identified sarcopenia, BMI, NLR, and PLR as significant predictors of OS. However, multivariate Cox analysis revealed that only sarcopenia remained an independent prognostic factor for both OS (HR 1.94; 95% CI: 1.15–3.27; p = 0.013) and PFS (HR 1.92; 95% CI: 1.33–2.75; p < 0.001). Inflammatory markers and their composite indices failed to retain prognostic significance in adjusted models. Conclusion Sarcopenia independently predicts poor survival outcomes in patients with R/M HNC undergoing ICI therapy, whereas conventional inflammatory markers such as NLR, PLR, and LMR, alone or in combination with sarcopenia, lack independent prognostic value. Routine pre-treatment evaluation of skeletal muscle mass using CT imaging may offer a practical and effective tool for patient risk stratification.