Combined androgen blockade with bicalutamide for advanced prostate cancer: long-term follow-up of a phase 3, double-blind, randomized study for survival.

Abstract

A previously reported, double-blind, randomized, multicenter phase 3 trial in 205 patients with stage C/D prostate cancer compared combined androgen blockade (CAB) with luteinizing hormone-releasing hormone agonist (LHRH-A) plus bicalutamide 80 mg versus LHRH-A plus bicalutamide-matching placebo (LHRH-A monotherapy). The analysis at a median follow-up of 2.4 years indicated that CAB significantly (P<.001) prolonged the time to progression and the time to treatment failure. In the current report, survival data from a long-term follow-up (median, 5.2 years) were analyzed. All deaths irrespective of cause and all prostate cancer-specific deaths were recorded. The data were analyzed using Cox regression analysis and the log-rank test. At a median follow-up of 5.2 years, a significant overall survival advantage was observed in favor of CAB over LHRH-A monotherapy (Cox regression analysis: hazard ratio, 0.78; 95% confidence interval, 0.60-0.99; P=.0498; log-rank test: P=.0425). The difference in cause-specific survival between the 2 groups was not significant. The achievement of a prostate-specific antigen (PSA) nadir concentration<or=1 ng/mL was a prognostic factor for improved survival. More patients attained PSA nadir concentrations<or=1 ng/mL with CAB compared with patients who received LHRH-A monotherapy (81.4% vs 33.7%; P<.001). CAB with bicalutamide 80 mg offered a significant overall survival benefit compared with LHRH-A monotherapy without reducing tolerability in patients with locally advanced or metastatic prostate cancer.