Purpose: We determine the efficacy and tolerability of bicalutamide as immediate therapy, either alone or as adjuvant to treatment of curative intent, in patients with clinically localized or locally advanced prostate cancer.
Materials and methods: This international program consists of 3 ongoing, randomized, double-blind, placebo controlled clinical trials (trials 23, 24, and 25). Men with localized or locally advanced (T1-T4, Nx/N0, M0) prostate cancer were randomized to receive 150 mg. bicalutamide daily or placebo, in addition to standard care with radical prostatectomy, radiotherapy or watchful waiting. Primary end points are time to objective progression and overall survival. In this first analysis data from the trials were combined in a single overview analysis according to protocol.
Results: Data are available for 8,113 patients (4,052 randomized to bicalutamide, 4,061 to standard care alone) at a median followup of 3.0 years. Treatment with bicalutamide provided a highly significant reduction of 42% in the risk of objective progression compared with standard care alone (9.0% versus 13.8%, hazards ratio 0.58; 95% confidence interval 0.51, 0.66; p <<0.0001). The overall result was reflected in 2 of the 3 trials (trials 24 and 25) with trial 3 (trial 23) showing a nonsignificant difference at this time. Reductions in the risk of disease progression were seen across the entire patient population, irrespective of primary treatment or disease stage. Overall survival data are currently immature and longer followup will determine if there is also a survival benefit with bicalutamide. The most frequently reported side effects of bicalutamide were gynecomastia and breast pain.
Conclusions: Immediate treatment with 150 mg. bicalutamide daily, either alone or as adjuvant to treatment of curative intent, significantly reduces the risk of disease progression in patients with localized or locally advanced prostate cancer. This benefit must be balanced with the morbidity associated with long-term hormonal therapy. Followup is ongoing to determine potential survival benefits of this treatment approach.