Mechanisms of tumor invasion and metastasis.

Metastasis is the cascade of events involved in the transition of a malignancy from a localized tumor to the establishment of a distant foci. In this review we define the known stages and the factors involved. The multiplicity of steps involved allows many opportunities for therapeutic intervention. Current research has focused on interruption of a step or a series of steps to limit the spread of cancer. With emphasis on the urologic malignancies, we outline the research thus far accomplished in the field of metastasis.