Initial tumor cell arrest in animals of defined coagulative status.

Experiments were made to evaluate the potential role played by thrombogenic factors on the hematogenous arrest of circulating tumor cells in mice with demonstrable coagulopathies associated with the presence of a primary tumor, by administration of "therapeutic" doses of anticoagulants. The effects of warfarin, aspirin and heparin administration on the early arrest patterns of 125IdUrd-labelled TA3 carcinoma and Gardner lymphosarcoma cells injected intravenously into tumor-bearing mice were examined. Several hematologic parameters of carcinoma- and lymphosarcoma-bearing animals were measured prior to anticoagulation experiments and the results indicated that mice had coagulopathies similar to those found in cancer patients with disseminated intravascular coagulation syndrome, i.e., thrombocytopenia and elevated fibrinogen levels. Despite the presence of coagulation abnormalities and effective anticoagulation in recipient animals, all three agents were without effect on localization patterns of both tumor types. It was concluded that the proposed involvement of thrombogenesis in metastasis was probably not due to any role played by those clotting factors inhibited by aspirin, warfarin and heparin in early intravascular tumor cell arrest.