Combination therapy with flutamide and castration (orchiectomy or LHRH agonist): the minimal endocrine therapy in both untreated and previously treated patients.

Patients (154) with clinical stage D2 prostate cancer with no previous endocrine therapy or chemotherapy received the combination therapy with the pure antiandrogen Flutamide and the LHRH agonist [D-Trp6]LHRH ethylamide for an average of 22 months (3-49 months). The objective response to the treatment was assessed according to the criteria of the US NPCP. There was a 6.3-fold increase (29.2 vs 4.6%) in the percentage of patients who achieved a complete response as compared to the results achieved in five recent studies limited to removal (orchiectomy) or blockade (DES or Leuprolide) of testicular androgens. Only 4.5% of patients did not respond to the combination therapy as compared to an average of 18% by standard therapy. The duration of response is also significantly increased in the patients who received the combination therapy. The death rate was decreased by approximately 2-fold between 2 and 3 yr of treatment. The marked (6.3-fold) improvement in the rate of complete objective responses coupled with the 4-fold decrease in the number of non-responders, the increased duration of the positive responses and the 2-fold decrease in the death rate at 2-3 yr of treatment are obtained with the combination therapy using Flutamide and castration with no or minimal secondary effects.