The prognostic value of systemic inflammatory markers is a growing area of interest in the field of oncology. Several studies posit that systemic inflammation may contribute to tumor growth, regeneration, and metastasis. Neutrophil/lymphocyte ratio is a known index of inflammation that has been associated poor prognosis in non-head and neck solid tumors. In this study, we sought to investigate the value of this metric in predicting survival in a national cohort of head and neck cancer patients in the United States.
In this retrospective cohort study, we identified patients with head and neck squamous cell carcinoma using national Veterans Affairs data. Neutrophil/lymphocyte (N/L) ratios were calculated from complete blood counts measured in the 6 months prior to the date of cancer diagnosis and grouped into quartiles. Variables likely to impact overall survival in cancer patients, including primary cancer site, stage, tobacco/alcohol use, and comorbidity burden were collected. We compared overall survival using cox proportional hazards models with adjustment for these covariates. Ongoing analyses will investigate the prognostic value utilizing primary sites, stage, and treatment subgroups.
The primary cohort consisted of 15,159 subjects of which 99% were male. Approximately, 81.1% of the cohort was white race, with an average age of 64 years old at the time of diagnosis. Nearly 61% of the patients were current smokers and 49% currently alcohol drinkers. Pharyngeal and laryngeal subsites were the most common, making up 41.6% and 38.6% of primary sites, respectively. After accounting for patient demographics, primary site, stage, and tobacco/alcohol use, we found an increased risk of death from any cause associated with increasing N/L ratio quartile (all quartiles p<0.05 compared to reference quartile). Patients with N/L ratios in the top quartile had an 80% increased risk of all-cause mortality compared to the lowest quartile (Hazard ratio 1.8; 95% confidence interval: 1.7-1.9; P < 0.001).
Elevated N/L ratio prior to cancer diagnosis confers a poor prognosis. In further analyses, we plan to elicit site, stage, and treatment specific risks associated with this inflammatory marker.