title: Cancer invasion and metastasis.
abstract: Metastasis, the spread of neoplastic cells from a primary site to distant organs, is responsible for the majority of cancer deaths. Dissemination of malignant cells throughout the body and their survival to form secondary growths is a complicated process dependent on both host and tumor properties. Although a primary tumor may release many cells, only a few survive the interactions with host defense mechanisms to yield distant cancer growths. In recent years a considerable body of evidence has accumulated which suggests that the survival of these few cells is not a random event. Rather, it represents the selection of a pre-existent metastatic subpopulation of tumor cells within the parental population. Such a process has profound implications in determining approaches to therapy and to the elucidation of those tumor-cell properties which are responsible for successful metastatic spread. These implications are discussed within the framework of what is at present known about the pathogenesis of cancer metastasis.
mesh_terms: D000818:Animals; D002465:Cell Movement; D006801:Humans; D007962:Leukocytes / Q000502:physiology; D008207:Lymphatic Metastasis; D051379:Mice; D003012:Microbial Collagenase / Q000037:antagonists & inhibitors / Q000378:metabolism; D009361:Neoplasm Invasiveness; D009362:Neoplasm Metastasis; D009369:Neoplasms / Q000098:blood supply / Q000201:enzymology / Q000276:immunology; D009374:Neoplasms, Experimental / Q000378:metabolism / Q000473:pathology; D009360:Neoplastic Cells, Circulating; D051381:Rats
chemical_list: D003012:Microbial Collagenase