Mast Cells as a Factor in Regulation of Breast Cancer Stromal Component Associated with Breast Cancer Aggressiveness

During the BCa progression, the role of MCs in the manifestation of the tumor development increases. A growing number of infiltrated MCs contributes to the activation of MMP and fibrillar collagen expression. These changes lead to increased remodeling of the tumor stroma, which is directly reflected in the spatial organization of the collagen matrix. The increased activity of proteases causes a decrease in the length and width of fibrils, which is explained by a decrease in the number of mature fibers and their disorganization in three-dimensional space. The obtained data allow us to assert that MCs play a key role not only in the formation of a specific immune microenvironment of BCa but also in determining the direction of changes in the tumor stroma, which promotes cancer aggressiveness.