[Coagulation inhibitors in patients with neoplasms].

Mean plasma concentrations of the main inhibitors of blood coagulation antithrombin III (AT III), protein C and protein S were determined in 149 patients with different local and disseminated malignancies. Results were compared with findings in 44 healthy subjects. No statistical significant differences for AT III, protein C and free protein S were found between patients and controls. However, total protein S showed a significant increase in the patient group (p less than 0.0003). None of the parameters analyzed showed differences according to the degree of tumoral activity nor to the tumour localization. We conclude that the main inhibitors of the blood coagulation seem not to play an important role in the pathogenesis of the hypercoagulable state in malignancy. The increased levels in total protein S would indicate endothelial synthesis in response to thrombogenic stimuli.