Orchidectomy versus oestrogen for prostatic cancer: cardiovascular effects

One hundred consecutive patients aged up to 75 with newly diagnosed cancer of the prostate suitable for hormonal treatment were included in a controlled study of the cardiovascular effects of oestrogen versus orchidectomy. In all cases pre-existing cardiovascular morbidity was excluded. Of the 100 patients, 91 were strictly randomised to receive either oestrogen (n = 47) or orchidectomy (n = 44) and 9 (6 given oestrogen, 3 orchidectomy) either chose their own treatment (five cases) or had it selected for them by the urologist (four). Oestrogen was given in the lowest recommended dosage in Sweden--namely, as 160 mg polyestradiol phosphate intramuscularly every month for the first three months, then 80 mg monthly, plus ethinyloestradiol 1 mg by mouth daily for the first two weeks, then 150 micrograms daily. At entry to the study the two treatment groups showed no difference in demographic characteristics or conventional risk factors for cardiovascular disease. During the first year, however, 13 (25%) of the patients given oestrogen suffered major cardiovascular events as compared with none of the patients after orchidectomy. Patients in the oestrogen treatment group who did not have minor signs of atherosclerosis at entry to the study suffered a similar incidence of cardiovascular complications to those who did have these signs at entry. The substantially increased risk of cardiovascular complications in patients given oestrogen for prostatic cancer warrants careful consideration when choosing treatment for this disorder.