We compared the clinical efficacy and safety of Buserelin treatment versus orchiectomy in 29 patients with newly diagnosed advanced prostatic cancer. There was no significant difference between the two treatment modalities in 1) reduction of plasma testosterone to below 100 ng/dl after 8 weeks, 2) objective clinical response rates in patients with stage D2 carcinoma, 3) induction of complete remission in patients with stages C and D1 carcinoma, or 4) relapse rates and death rates in patients with stage D2 carcinoma. After scoring stage D2 disease according to our aggressiveness analysis system, we found that patients with less aggressive neoplasms displayed a qualitatively better response and more prolonged remission. These data and the absence of estrogenic effects confirm Buserelin as a favorable alternative to orchiectomy in the treatment of prostatic cancer. Additionally, the study demonstrates the importance of considering the heterogeneity of the aggressiveness of stage D2 disease in assessing the benefits of clinical trials in prostatic carcinoma.