Clinical-pathological Correlation of CD68 and CD8 in Tumor Immune Microenvironment of Salivary Gland Neoplasms

Abstract

Background: Salivary gland neoplasms represent a diverse entity of tumors in the head and neck. Tumor-associated macrophages (TAMs) and tumor-infiltrating lymphocytes (TILs) were proven to have diverse roles in the carcinogenesis of head and neck neoplasms including salivary gland tumors.Objectives: To detect and compare the expressions of CD68 and CD8 in benign and malignant salivary gland neoplasms and unveil the diagnostic ability of the markers in detecting malignancy. Besides detecting any correlation with clinical parameters, lymph node metastasis (LNM) and with each other.Methods: We measured the immunohistochemical area % of CD68, and CD8 at Intra-tumor (IT) and tumor front (TF) sites in pleomorphic adenoma (PA), mucoepidermoid carcinoma (MEC), and Adenoid cystic carcinoma (ACC). Then the data was statistically analyzed for detection of any further correlations.Results: A statistically significant increase in area % of CD68 and CD8 was observed in MEC and ACC when compared to PA. Both markers revealed accuracy in detecting malignancy with CD68 being more significantly accurate. IT CD8 area % significantly correlated with LNM. IT area % of CD68 negatively correlated with age while CD8 correlated positively with the patient's age. A statistically significant correlation between CD68 and CD8 at TF was observed.Conclusions: Both CD68 and CD8 presented accuracy in the diagnosis of malignant salivary neoplasms. CD8 may help predict nodal metastasis in malignant salivary tumors. CD68 and CD8 might be associated with age changes. A cross-talk at the TF between TAM and TIL might be present, affecting the tumor invasive potential.