Interactions of cancer cells with the microvasculature during metastasis.

Metastasis of cancer via the bloodstream is a major factor in the diagnosis, treatment, and prognosis of patients with cancer. Key events in hematogenous metastasis occur in the microvasculature. This is a brief, selective review of some interactions involving cancer cells and the microvasculature in pathological sequence, specifically: 1) intravasation of cancer cells; 2) the arrest of circulating cancer in the microvasculature; 3) cancer cell trauma associated with arrest; 4) microvascular trauma; 5) the inflammatory and 6) coagulative responses associated with arrest; and 7) the fate of arrested cancer cells. The evidence shows that in addition to providing routes for cancer cell dissemination and arrest sites for cancer cell emboli, the microvasculature, through a series of complex interactions with cancer cells, controls the efficiency of and acts as a rate regulator for the metastatic process.