Effects of estrogen, orchidectomy, and cyproterone acetate on tissue fibrinolysis in patients with carcinoma of the prostate.

Twenty-six patients with carcinoma of the prostate were allocated to treatment by subcapsular orchidectomy, estrogen administration, or cyproterone acetate administration. Tissue fibrinolytic activity in skin biopsy specimens was estimated by a histochemical method before treatment was initiated and 2 and 8 weeks later. Orchidectomy caused no significant changes in the fibrinolytic activity. During estrogen therapy the fibrinolytic activity in skin was significantly reduced at 8 weeks. In the group given cyproterone acetate the activity was significantly increased at 8 weeks. In the group given cyproterone acetate the activity was significantly increased at 8 weeks. The reduction in fibrinolytic activity in skin could contribute to the increased risk of thromboembolism during estrogen treatment of patients with cancer of the prostate.