Systemic inflammation plays a key prognostic role in patients with head and neck cancer treated with immunotherapy and is linked to CT-based body composition metrics

To investigate the prognostic significance of pretreatment inflammatory markers and their association with computed tomography (CT)-based body composition (BC) metrics in patients with recurrent and/or metastatic head and neck squamous cell cancer (HNSCC) treated with immunotherapy. This retrospective, single-center study included 49 patients with HNSCC (20.4% female; median age 66 years). Eleven inflammatory markers, including the systemic-inflammatory-response-index (SIRI=(neutrophils×monocytes)/lymphocytes), derived neutrophil-to-lymphocyte ratio (dNLR=neutrophils/(leukocytes–neutrophils) were investigated. Pretreatment thoracic CTs yielded volumes of skeletal muscle (SM), visceral adipose tissue (VAT), and bone (B). Overall survival (OS) was assessed using Kaplan-Meier and Cox regression (HR: Hazard Ratio); group comparisons: Pearson’s and Mann-Whitney U. The median OS was 17.6 months. A significantly lower HR was observed in males with positive p16-status, lower ECOG, and albumin > 3.4 g/dl. Regarding inflammation, low SIRI demonstrated the strongest HR of all inflammatory markers. In multivariate analysis, low SIRI (HR: 0.17, 95% CI: 0.05–0.57, p = 0.0041) and low albumin (HR: 0.26, 95%CI: 0.10–0.66, p = 0.0047) were identified as independent prognostic factors. Correlation analysis revealed a weak association between dNLR and neutrophil/leukocyte counts with SM/B (r=-0.39 and − 0.47) and (SM + VAT)/B (r = -0.36, -0.47) (p ≤ 0.02). Patients with low dNLR had higher SM/B (1.77 vs. 1.35) and (SM + VAT)/B (2.05 vs. 1.54) ratios than those with high dNLR (p < 0.0001). Pretreatment SIRI and serum albumin levels are strong, independent prognostic markers for survival in HNSCC patients receiving immunotherapy. While a link between systemic inflammation, mainly driven by neutrophils, and BC-parameters has been observed, its clinical relevance warrants further investigation.