Primary orchiectomy versus estrogen therapy in advanced prostatic cancer--a randomized study: results after 7 to 10 years of followup. Of 163 new consecutively diagnosed cases of advanced (T3-4 M0 or T04M1) prostatic cancer 13 had contraindications for estrogen treatment, and the remainder were randomized to orchiectomy (76) or to estrogen treatment (74), consisting of 150 micrograms ethinyl estradiol daily and 80 mg. polyestradiol monthly. During the followup period of 7 to 10 years disease progression was noted in 27 patients (36%) treated with estrogen and 39 (51%) orchiectomized patients. The free of progression survival rate was significantly better (less than 0.05) among the estrogen treated patients but the over-all survival rates after orchiectomy and estrogen treatment were almost identical. A significantly higher frequency of cardiovascular side effects was noted in the estrogen group (23 cases) compared to the orchiectomy group (4 cases). Therefore, estrogen treatment in this form cannot be recommended for the palliative treatment of prostate cancer. 