Hemostatic effects of high-dose megestrol acetate therapy in patients withadvanced gynecological cancer

Effects of high-dose megestrol acetate on blood coagulation and fibrinolysi s were investigated in patients with gynecological (n = 13) and breast (n = 10) cancer. Patients received either 160 mg or 320 mg/day megestrol acetat e orally. Blood sampling was performed prior to and after months 1, 3 and 6 of treatment. Pretreatment values of global clotting times, fibrinogen, fa ctor VII, thrombin-antithrombin IH complex, anticoagulation, fibrinolysis a nd antifibrinolysis were found to be within the reference range. Elevated p lasma levels were demonstrated for prothrombin fragments 1 and 2, fibrin de gradation products and the plasmin-antiplasmin complex. We demonstrated a s ignificant 20-30% reduction of factor VII until the 3rd month of therapy. N o further effects were seen within the remaining 3 months of treatment. For the other analyzed parameters of hemostasis, no significant influence of h igh-dose progestin treatment was found. Furthermore, we observed no clinica lly relevant differences between the two dosages, Our results do not provid e any evidence that there is a thrombogenic effect of high-dosage megestrol acetate with 160 mg or 320 mg per day amongst patients with advanced gynec ological malignancies. The observed incidence of thrombosis might be the co nsequence of other risk factors such as tumor-induced hypercoagulability, s imultaneous chemotherapy or other individual thrombosis risk factors.