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

Purpose: This study was aimed to evaluate the effect and tolerability of bicalutamide 150 mg therapy in patients with castration-resistant prostate cancer (CRPC).

Methods: 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 ≥85% as complete response, ≥50 % but <85% as partial response, and <50 % as failure. Response duration was defined as the time from PSA response until PSA increased ≥25 % or ≥2 ng/mL from the nadir. The potential predictive factors (Gleason score, clinical stage and serum PSA) were investigated.

Results: The time of follow-up was 3-30 months. A PSA decline ≥50% was observed in 37 of 48 patients including 18 ≥ 50% but <85% and 19 ≥ 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.

Conclusions: 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.