General mechanisms of metastasis.

In the present article, the steps involved in the process of tumor metastasis are discussed. Several events are required for malignant cells to leave the primary tumor and proliferate at a distant site: vessel formation (angiogenesis), cell attachment, invasion (matrix degradation, cell motility), and cell proliferation. Molecular mechanisms underlying each of these steps are described. Based on blocking these processes, new anti-metastasis therapies are being developed.