Malignancy and the Haemostatic System; Introductory Remarks
The haemostatic system, with the complexity of its various components, comprises a number of activities which may play a role in tumor growth and metastasis formation. In particular, the ability of some cancer and/or leukemic cells to adhere to and cross the vascular endothelium, to induce platelet aggregation, to release procoagulant and/or fibrinolytic activities, to adhere to polymerizing fibrin and other substrates (such as collagen) could influence their invasive potential. In vitro observations on such properties of cancer and/or transformed cells have received over the past 20 years, some experimental in vivo support, although indirect. Treatment with drugs active on the haemostatic system has proved effective in reducing metastatic growth in some instances. However, both the suitability of the models used and the mode of action of the drugs employed have been questioned. As a paradigmatic example, the mechanism where by warfarin reduces metastasis formation in a number of experimental models is still a matter of discussion. Finally the shift from experimental work to possible clinical application presents a number of difficultures. Nevertheless, some preliminary information is available which could orient future efforts in this puzzling field.Supported by CNR (Italy) and NIH, NCI (USA).