Angiogenic molecules and cancer metastasis.

The progressive growth of primary neoplasms and metastases depends on the development of adequate vasculature, i.e., angiogenesis. The extent of vascularization in different malignancies correlates directly with their metastatic potential and, hence, inversely with the survival of the patient. The induction of neovascularization is mediated by both tumor cells and host cells and the interaction of the two. The balance of positive and negative regulatory molecules released by tumor cells and host cells determines the biological outcome which, in the case of tumor growth, favors angiogenesis.