Inflammation Tumor Microenvironment and Mast Cells in Breast Cancer

The tumor microenvironment consists of fibroblasts, endothelial and immune cells, and extracellular matrix and envelops the cancer. Mast cells are associated with angiogenesis, immunomodulation of the stroma, and tissue remodeling in cancers. In different tumors, it may have antitumor or potentiating effects in relation to the tumor microenvironment. Immune cells in breast cancer stroma form the inflammatory microenvironment that shapes cancer behavior. Samples taken from 85 female patients who underwent mastectomy due to breast cancer between 2017 and 2020 were evaluated retrospectively. Immunohistochemical staining was performed on the basis of hematoxylin-eosin stained slides. Mast cell density was assessed using the hot-spot method, counting in three high-density areas. Both peritumoral and intratumoral densities were recorded separately, and average counts were calculated from the three fields. CD117 was counted at three high magnifications (400x), and intratumoral and peritumoral cells were distinguished. The presence of intratumoral fibrosis and lymphocytes was scored . Peritumoral mast cell count was found to be below average in ER-negative cases and in cases with high metastatic lymph node count. An inverse relationship was observed between lobular carcinoma and intratumoral mast cell density. In addition, there was a significant inverse relationship between intratumoral mast cell density and increased tumor size. Cases with below average intratumoral mast cell count were significantly associated with ER negativity, high Ki67 proliferation index, , luminal group cases and absence of fibrosis. Low mast cell count in tumors was found to be associated with poor prognostic parameters.