[Breast carcinomas and the extracellular matrix]

This paper underlines the interrelations between tumoral cells and the extra-cellular matrix in breast cancers with possible applications for the diagnosis and the prognosis. In mammary carcinomas, the first step of tumoral invasion is characterized by the loss of basement membrane components, particularly type IV collagen and laminin. Immunohistochemical detection of these disruptions of basement membrane is easy and useful for the diagnosis of "in situ" or microinvasive carcinomas. Laminin seems also to facilitate the adhesion of cancer cells to type IV collagen, and the dosage of its fragment P1 in the blood serum may be a good marker for the follow up of the patients. Stromal reaction involves many intricate macromolecules of the extra-cellular matrix. Types I and III collagens are often present in non colloid carcinomas. Rate, turn over of elastin and its prognostic value are still debated. Elastosis is related to well differentiated carcinomas and the presence of estrogen receptors. The stroma of the colloid form of breast cancer is rich in proteoglycans. Malignant and stromal cells, through the intermediary of cytokines, can synthesize these macromolecules. Hyaluronic acid and chondroitin sulfate are abundant in mammary carcinomas and form a favorable substrate for the growth and the migration of malignant cells. However, proteases decrease and limit their action. The presence of fibronectin, principally in the stroma, is difficult to interpret but fibronectin seems to play a role in tumoral retraction.