Systemic immune response in squamous cell carcinoma of the head and neck: a comparative concordance index analysis

The objective of this study was to investigate the prognostic role of three inflammatory markers: the neutrophil to lymphocyte ratio (NLR), the lymphocyte to monocyte ratio (LMR), and the platelet to lymphocyte ratio (PLR) as prognostic indicators in squamous cell carcinoma of the head and neck (HNSCC).

Patients with HNSCC treated with primary surgery, with or without adjuvant radiochemotherapy were enrolled. The preoperative NLR, LMR, and PLR were recorded. Confounding variables were also recorded: age, sex, BMI, comorbidities, performance status, AJCC T and N stage and HPV status. Endpoints were overall survival (OS) and event-free survival (EFS). Survival analysis was performed using Kaplan-Meier analysis, and multivariable analysis was performed using Cox proportional hazards regression. Survival models were evaluated using Harrell's concordance index (c-index).

NLR (p = 0.2413), PLR (p = 0.1593), and LMR (p = 0.0552) were not significantly associated with OS in the multivariable analysis. With regard to EFS, low LMR (HR = 2.95, 95% CI 1.54-5.65, p = 0.001), high PLR (HR = 2.68, 95% CI 1.42-5.09, p = 0.003), and high NLR (HR = 3.37, 95% CI 1.7-6.69, p < 0.001) were associated with EFS. The multivariable c-index was highest for LMR (0.762), followed by NLR (0.761) and PLR (0.739).

The LMR, PLR, and NLR were not associated with OS, but were associated with EFS in HNSCC. These markers are easily obtainable, and in the age of individualized patient care and precision medicine, they might represent further risk stratification tools for HNSCC patients.