Small cell carcinoma of the lung: interaction with the blood coagulation mechanism and treatment with anticoagulants.

Studies of malignancy in experimental animal models have indicated that cause-effect relationships exist between coagulation activation and cancer progression. Evidence for coagulation activation in human malignancy together with favorable results from pilot clinical trials led to the establishment of a prospective, randomized therapeutic trial of warfarin in cancer. A statistically significant prolongation of survival was observed in patients with small cell carcinoma of the lung entered into this study. Demonstration of an initiator of coagulation activation together with coagulation factor intermediates and fibrin in situ associated with viable tumor cells in small cell carcinoma of the lung is consistent with the hypothesis that tumor-initiated thrombin formation might contribute to progression of this tumor type. These observations suggest novel experimental treatment strategies for small cell carcinoma of the lung. Warfarin anticoagulation may be of value in the treatment of certain other types of malignancy.