Figure 2.

Histopathological examination reveals that prostate cancer is associated with diverse immune cell infiltrates and that, in the cancer context, epithelial cells coexist with extracellular matrix components and nonneoplastic cell types, including fibroblasts and endothelial cells, which collectively form the tumour stroma. Evidence supports the concept that tumour stromal cells are not merely a scaffold, but rather they influence growth, survival, and invasiveness of cancer cells, dynamically contributing to the tumour microenvironment. The interactions between epithelium and the surrounding stroma are required to maintain organ function and provide proliferative and migratory restraints that define anatomical and positional information, mediated by several growth factors, cytokines, chemokines, and extracellular matrix components. When cancer develops, transformed cells lose these constraints while stroma adapts and coevolves to support the “function” of the tumour.