Zoladex vs. Zoladex plus cyproterone acetate in the treatment of advanced prostatic cancer: A multicenter Italian study

A collaborative multicenter trial was conducted by 17 Italian groups to verify whether the so-called total androgen blockade obtained with luteinizing hormone releasing hormone (LHRH) analogs combined with antiandrogens is more effective than conventional monotherapy in the treatment of advanced prostatic cancer. A total of 328 previously untreated patients were evaluated: 163 patients received Zoladex depot alone, 3.6 mg subcutaneously every 28 days, and 165 patients received Zoladex depot plus cyproterone acetate (CPA), 200 mg/day orally. The follow-up period ranged from 41-251 weeks. Treatment was well tolerated, and side-effects in both groups mainly comprised loss of libido and erections, hot flashes and breast swelling and tenderness. There was no significant difference in objective response after 6, 12 and 24 months of treatment between the 2 groups. Median time to disease progression was comparable in both groups: 55 weeks in the Zoladex group and 54 weeks in the Zoladex plus CPA group. The time to disease progression and the survival distribution was comparable in both groups. Although there were no significant differences in the overall subjective response to both treatments, a faster improvement, with respect to pain and performance status was noted in the Zoladex plus CPA group (8 weeks) compared to Zoladex alone (12 weeks). The addition of antiandrogen, by inhibiting the initial elevation of plasma testosterone, may prevent the disease flare-up which occurs in a small number of patients during the first few days of treatment with LHRH analogs alone. These results suggest that treatment of advanced prostatic carcinoma with Zoladex is effective and safe, but the benefit of combination therapy over conventional monotherapy is slight and needs to be demonstrated by additional controlled trials with a longer follow-up.