127 patients with a clinical stage T2b and T3 prostate cancer were randomized in order to undergo either a radical prostatectomy alone or a radical prostatectomy after hormonal treatment (560 mg of estramustine phosphate daily for 6 weeks) in a prospective multi-center study. The clinical or radiological evaluation of an eventual downstaging being extremely difficult, the authors compared in the 2 groups the influence on the surgical act and the number of positive surgical margins at pathological examination of the resected specimen. There was no significant difference between the 2 groups concerning the surgery (duration of the procedure, blood transfusion, degree of difficulty). For clinical T2 prostate tumors the number of positive surgical margins was significantly lower in the group that had preoperative hormonal treatment. In the group with clinical T3 prostate cancer this difference was not found. The influence of positive margins on the later development of local or systemic recurrence and on survival still has to be awaited. At this moment one could conclude that only patients with a T2 prostate cancer benefit of a preoperative hormonal treatment.