Pre-treatment CD8(+) tumour-infiltrating lymphocyte density predicts distant metastasis after definitive treatment in patients with stage III/IV hypopharyngeal squamous cell carcinoma.

OBJECTIVES: Although inflammatory markers, such as the neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio and local immune markers have been shown to have prognostic utility, limited information is available regarding inflammatory and pre-existing tumour-infiltrating lymphocyte density and their association with prognosis in patients with hypopharyngeal squamous cell carcinoma. We investigated the prognostic ability of inflammatory markers and tumour-infiltrating lymphocyte density in stage III and stage IV hypopharyngeal squamous cell carcinoma patients receiving definitive treatment. DESIGN: Retrospective cohort study. SETTING: Kurume University Hospital. PARTICIPANTS: Ninety-six stage III or stage IV hypopharyngeal squamous cell carcinoma patients treated at the Kurume University Hospital between 2000 and 2014. MAIN OUTCOME MEASURES: Inflammatory markers and pre-treatment tumour-infiltrating lymphocyte density were examined from recorded haematologic data and immunohistochemical analysis. RESULTS: Multivariate analyses showed that the CD8(+) tumour-infiltrating lymphocyte density was an independent predictive factor for distant metastasis and overall survival, whereas inflammatory markers, including the neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio, were not correlated with distant metastasis or overall survival. CONCLUSIONS: Higher pre-treatment CD8(+) tumour-infiltrating lymphocyte density is a useful predictive biomarker for reduced distant metastasis and better prognosis.