[The antiandrogen withdrawal syndrome: decrease in prostate specific antigen serum levels after withdrawal of antiandrogens].

Combined androgen blockade using surgical or medical (luteinizing hormone-releasing hormone agonist) castration in association with anti-androgen has become the primary therapy in patients with metastatic prostate cancer. Patients undergoing combined androgen blockade will progress within 18-30 months after initial hormonal therapy. When progression occurs following combined androgen blockade, the non-steroid anti-androgen should be subsequently withdrawn. Several recent reports have been published on the paradoxical effect of anti-androgen withdrawal. Eight (22.9%) of 35 patients showed a decline in PSA levels following flutamide withdrawal. The mean time to progression following combined androgen blockade was 26 month and the mean duration of response to flutamide withdrawal was 4.1 months.