Blood coagulation studies in patients with advanced carcinoma of the prostate treated with 2,6-cis-diphenylhexamethylcyclotetrasiloxane or estramustine-17-phosphate.

Two drugs, 2,6-cis-diphenylhexamethylcyclotetrasiloxane (Cisobitan) and estramustine-17-phosphate (Estracyt) were given to patients with poorly differentiated metastatic carcinoma of the prostate. The effect of the drugs on blood coagulation was investigated. Some parameters showed changes during the treatment: Antithrombin III decreased in the Estracyt treated patients to a level which might imply a thrombogenic effect. Fibrinogen decreased, whereas factor VIII showed no consistent change. Normotest changes appeared to correlate with liver damage whereas antithrombin III showed no change. Increased levels of fibrinogen degradation products and fibrinopeptide A (FPA) were more frequent in the group of deteriorating patients. However, the number of FPA analyses were too small for any definite conclusions regarding possible disseminated intravascular coagulation.