Endometrial cancer (EC) is the most common gynaecological tumour in developed countries, and its incidence is increasing in part due to the prevalence of obesity and its related hormone dysregulation. As described in this chapter, the tumour microenvironment plays a principal role in unopposed oestrogen stimulation promoting tumour cell proliferation. Factors and cytokines secreted by the different cell types defining the reactive tumour stroma also determine the invasive abilities of the tumour cells. Cancer-associated fibroblasts and tumour-associated macrophages actively participate through SDF-1, TGF-b or HGF to promote epithelial-to-mesenchymal transition or to generate an appropriate tumour niche. Likewise, endothelial cells facilitate lymph node and vascular infiltration through VEGF. Finally, the possibility to balance the immunosuppressive phenotypes in advanced endometrial cancer through the tumour microenvironment will probably represent a main therapeutic strategy in the near future.
Keywords: Activated stroma; Carcinoma-associated fibroblasts; Endometrial cancer; Endothelial cells; Epithelial-mesenchymal transition; Extracellular matrix; Hormone-regulated tissue; Immune checkpoint inhibitors; Myometrial invasion; Oestrogen receptors; Pericytes; Tumour microenvironment; Tumour-associated macrophages; Tumour-derived growth factors; Tumour-infiltrating lymphocytes.