Prognostic value of pre-operative peripheral inflammation markers in patients with squamous cell carcinoma of the external auditory canal

IntroductionSquamous cell carcinoma of the external auditory canal is a rare entity. Previous studies have suggested predictors for tumor recurrence. However, most of the prognostic factors were from the clinicopathological aspect.ObjectiveThis study aims to analyze the correlation between pre-operative peripheral inflammation markers and survival outcomes, in order to identify prognostic biomarkers for patients with squamous cell carcinoma of the external auditory canal.MethodsWe retrospectively analyzed patients diagnosed with squamous cell carcinoma of the external auditory canal who underwent surgery at our institute. The pre-operative circulating inflammatory markers, such as the neutrophil, lymphocyte, platelet, and monocyte counts were measured and their ratios including neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio and lymphocyte-to-monocyte ratio were calculated. The prognostic value of the measured hematologic parameters in relation to the survival outcomes was also evaluated.ResultsA total of 83 patients were included, of which 26 patients showed tumor recurrence and 57 without recurrence. Neutrophil counts and neutrophil-to-lymphocyte ratio were closely connected with tumor stage. In the patients with recurrence, neutrophil counts, neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio were elevated (p < 0.0001, p < 0.0001 and p = 0.001), while lymphocyte counts and lymphocyte-to-monocyte ratio were decreased (p = 0.013 and p = 0.016, respectively). The receiver operating curve analysis indicated that pre-operative neutrophil-to-lymphocyte ratio is a potential prognostic marker for recurrence of squamous cell carcinoma of the external auditory canal (area under curve = 0.816), and the cut-off points was 2.325.ConclusionsPre-operative neutrophil and lymphocyte counts, neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio, lymphocyte-to-monocyte are significantly correlated with tumor recurrence in patients with external auditory canal squamous cell carcinoma. Furthermore, neutrophil-to-lymphocyte ratio may be unfavorable prognostic factors of this disease.