Adjuvant CMF-chemotherapy and haemostasis. Effect of "classical" and "modified" adjuvant CMF-chemotherapy on blood coagulation fibrinolysis in patients with breast cancer.

Effects of "classical" and "modified" adjuvant CMF-chemotherapy on haemostasis were studied in 22 patients with breast cancer receiving cyclophosphamide (100 mg/m2 p.o.; days 1-14 or 600 mg/m2 i.v.; days 1,8), methotrexate (40 mg/m2 i.v.; days 1,8) and 5-fluorouracil (600 mg/m2 i.v.; days 1,8). Blood collection was done prior to chemotherapy on day 1 and 8. A significant decrease of protein C antigen and activity associated with cumulative effects was observed from day 1 to 8. This effect was similar with "classical" and "modified" CMF-chemotherapy but the reduction of protein C was more pronounced with the oral application of cyclophosphamide. In absence of any significant cumulative decrease of other vitamin K-dependent blood coagulation proteins (factor VII, protein S), the simultaneous decrease of protein C activity and antigen indicates a specific influence of CMF-chemotherapy on vitamin K-dependent protein C-synthesis in the liver.