Bicalutamide 150 mg as secondary hormonal therapy for castration-resistant prostate cancer

This study was aimed to evaluate the effect and tolerability of bicalutamide 150 mg therapy in patients with castration-resistant prostate cancer (CRPC). A total of 48 patients with histologically confirmed prostate cancer were included. They had been treated with continuous maximal androgen blockade therapy, but their serum prostate-specific antigen (PSA) increased after initial hormonal therapy. Patients were given bicalutamide (150 mg per day). Serum PSA testing was performed every 3 months. The response was defined according to PSA decline from baseline: PSA decline a parts per thousand yen85 % as complete response, a parts per thousand yen50 % but < 85 % as partial response, and < 50 % as failure. Response duration was defined as the time from PSA response until PSA increased a parts per thousand yen25 % or a parts per thousand yen2 ng/mL from the nadir. The potential predictive factors (Gleason score, clinical stage and serum PSA) were investigated. The time of follow-up was 3-30 months. A PSA decline a parts per thousand yen50 % was observed in 37 of 48 patients including 18 a parts per thousand yen 50 % but < 85 % and 19 a parts per thousand yen 85 % responders. The median response duration was 12 months for partial responders and 20 months for complete responders. Patients with lower Gleason score, lower serum PSA and using flutamide as first-line nonsteroidal antiandrogen achieved more benefits. Moreover, bicalutamide 150 mg therapy was well tolerated. Bicalutamide 150 mg therapy was an appropriate therapeutic method for patients of CRPC, especially for those with lower Gleason score, lower serum PSA and using flutamide as first-line nonsteroidal antiandrogen.