Effect of high-dose progestogen on hemostatic properties of blood in patients with endometrial cancer.

Fifteen cases of endometrial cancer were administered daily doses of 600 mg of MPA after surgery to prevent the recurrence of cancer. The initiation times of coagulation (time necessary for fibrin network formation) were measured with a highly sensitive damped oscillation rheometer and compared with those of 15 control patients who were not administered MPA. Biochemical studies of blood coagulation and fibrinolysis were also done. The initiation times of coagulation were 19.0+/-1.8 minutes (min mean +/- standard deviation) after 3-6 months and 16.0+/-2.0 min after 9-12 months of MPA administration, both times being significantly shorter compared with the controls (24.0+/-2.5 min). Hematocrit values, platelet counts and fibrinogen levels were similar between the two groups. Activated partial thromboplastin time (APTT) was significantly decreased and antithrombin III activity (AT III), thrombin-antithrombin complex (TAT), plasminogen level, plasmin-alpha(2) plasmin inhibitor complex level (PIC) and the fibrin degradation product level (FDP) were significantly increased in the MPA group compared with the control group. Accelerated coagulation of blood was definitely induced by high-dose MPA but antithrombin and fibrinolytic activities were also induced, and, thus, thromboembolic complications were prevented.