Rationale and experimental design for the VA Cooperative Study of Anticoagulation (Warfarin) in the Treatment of Cancer.

Anticoagulants have been demonstrated to reduce tumor growth in certain experimental animal systems. Inhibition of clot formation interferes with tumor growth and spread while enhancement of coagulation promotes tumor growth and spread. The fact that the coagulation mechanism is commonly activated in human malignancy together with preliminary reports of therapeutic efficacy of anticoagulants suggests that the coagulation mechanism may be of pathophysiologic significance also in the growth of human tumors. A VA Cooperative Study has been established to test the hypothesis that warfarin anticoagulation will modify the course of malignancy in man. The purpose of this paper is to present the rationale and experimental design for this study with emphasis on management of anticoagulant administration in cancer patients. This paper serves as the basis for forthcoming reports of toxicity and therapeutic efficacy of warfarin in human malignancy.