[Metastatic process]

The metastatic dissemination is one characteristic property of malignant tumors. It represents a crucial step in the progression of the disease. Multiple cellular and molecular mechanisms are involved in the dissemination of cancer cells and their proliferation at secondary sites. The metastatic process requires the transient or permanent acquisition of invasive properties mediated in part by diverse families of proteases. Numerous growth factors control the autocrine or paracrine growth of the tumor. These factors can also act as motogens and may contribute to the maintainance of the loss of the differentiated state of tumors. Angiogenesis of newly formed primary tumors is required for further growth and dissemination. Malignant cells modulate their adhesive status throughout the different steps of dissociation from the primary tumor and their intravasation and extravasation from lymph and blood vessels. Proteases, adhesion molecules, growth factors, angiogens and their cognate receptors may constitute markers to assign a metastatic phenotype and could serve as targets for the management of patients.