Expression of clec9a in the oral cancer microenvironment. A preliminary immunohistochemical pilot study

BACKGROUND: The search for treatments to improve cancer survival has led to the emergence of immunotherapy and the study of the tumour microenvironment existing in neoplasms. This preliminary study aims to understand the clinical and pathological relationship of clec9a expression in oral cancer and to explore survival models for future studies. Material and methods: Immunohistochemical study that included 26 patients with a diagnosis of oral squamous cell carcinoma (OSCC) in mobile tongue and floor of the mouth. Clinical and histopathological variables were recorded, and the biomarkers clec9a for dendritic cells and CD8 and CD4 for lymphocytes were used. RESULTS: Clec9a was expressed in 58% of the sample. It was more common in cases with low lymphoplasmacytic infiltration and in type 2 invasion patterns. It was significantly related to CD8 expression (p=0.055 and p=0.007). No prognostic risks were evident in the survival models studied (overall survival, disease-specific survival, disease-free survival). CONCLUSIONS: CLEC9A expression is present in the OSCC microenvironment and is mainly related to the presence of CD8 lymphocytes. The relationship of its expression with survival prognosis in OSCC could not be confirmed; however, this needs to be confirmed through future studies with larger sample size. Key words:Clec9a, dendritic cells, tumor microenvironment, oral cancer, immunotherapy.