Osteosarcoma: improved survival with anticoagulation and amputation.

A study of warfarin anticoagulation as an adjunct to amputation of osteosarcomas was undertaken after finding dramatic results in experimental systems. Anticoagulation was started 7 days preoperatively, continued during the operation, and for up to six months postoperatively. Three of 21 (14%) non-anticoagulated control patients are alive at 5-11 years. Five of 9 (56%) of the anticoagulated patients remain alive 5-8 years. The presumed mechanism of increased survival is an inhibition of fibrin deposition around circulating tumor cells, thereby preventing their adherence to capillary endothelium to initiate metastasis formation.