The Antiandrogen Withdrawal Syndrome

Objective To evaluate the response to antiandrogen withdrawal in patients with advanced prostate cancer treated with combined androgen blockade. Methods Twenty four cases of advanced prostate cancer (10 in stage C and 14 in stage D) were retrospectively studied. All the patients were treated with combined androgen blockade (bilateral orchiectomy and flutamide). After initial response to hormone therapy for 7 to 36 months, flutamide was discontinued because of deterioration of the disease. Serum prostate specific antigen (PSA) levels were checked every 2 to 4 weeks and symptoms observed. Results The results following withdrawal of flutamide were as follows: 8 patients showed a decline in PSA (mean 74.8%), of whom 6 cases had the PSA decline greater than 50%. Clinical symptoms improved in 4 cases. The nodules of the prostate were smaller than before in cases. The mean duration of response was 4.3 months.Conclusion In patients with hormone refractory advanced prostate cancer after initial combined androgen blockade therapy, a trial of "antiandrogen withdrawal" is a reasonable choice of therapeutic maneuver.