The role of tumour-associated tissue eosinophilia as a prognostic indicator in head and neck squamous cell carcinoma

Background: Eosinophils are bone marrow-derived granulocytes known to have an imperative role in tissue inflammation. The mechanism of tumour-associated tissue eosinophilia (TATE) in head and neck cancers is however not well understood, and its role as a prognosticator is under evaluation. The aim of this study was to evaluate the association of TATE with factors associated with head and neck cancer and to assess its role as a prognostic marker in such patients. Results: 102 males and 24 females comprised the study population, and 34.9% of which were in the age group of 41 to 50 years. Amongst these 126 patients, most (37.3%) presented in stage III followed by stage IV (28.6%). 29.4% had well-differentiated SCC, 55.6% had moderately differentiated SCC, and 15% were diagnosed with poorly differentiated SCC. 42.8% had TATE grade II, followed by grade III (29.4%) and grade I (27.8%). Correlation studies showed that factors significantly associated with TATE were age, site and tumour differentiation. While 45.7% poorly differentiated tumours showed grade I eosinophilia, 51.4% of well-differentiated tumours had grade III TATE. Conclusions: TATE showed a highly significant association with tumour differentiation, suggestive of eosinophils partaking a tumouricidal role. This association may be utilised as a convenient early prognosticator for head and neck cancers and should be made a regular feature of biopsy reports. Furthermore, it may be utilised in planning and adopting appropriate treatment modalities in malignancies predicted to have an aggressive course.