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

Department of Urology, Institute of Clinical Medicine, University of Tsukuba, Ibaraki, Japan has released some very significant survival data about a previously reported, double-blind, randomized, multicenter phase 3 trial. This trial compared combined androgen blockade (CAB) with luteinizing hormone-releasing hormone agonist (LHRH-A) with the addition of bicalutamide (casodex) 80 mg (ADT2) to LHRH-A plus a placebo monotherapy (ADT1).

The trial studied 205 men with advanced prostate cancer, which in the original report the analysis at a median follow-up of 2.4 years indicated that CAB (ADT2) significantly (P < .001) prolonged the time to progression and the time to treatment failure. In the current data release the survival data from a long-term follow-up (median, 5.2 years) was analyzed and reported.All deaths irrespective of cause and all prostate cancer-specific deaths were noted. 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 (ADT2) over LHRH-A monotherapy (ADT1) (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 two groups was not significant. The achievement of a prostate-specific antigen (PSA) nadir concentration < /=1 ng/mL was a prognostic factor for improved survival. More patients attained PSA nadir concentrations < /=1 ng/mL with CAB (ADT2) compared with patients who received LHRH-A monotherapy (ADT1) (81.4% vs 33.7%; P < .001). CAB with bicalutamide 80 mg (ADT2) offered a significant overall survival benefit compared with LHRH-A monotherapy (ADT1) without reducing tolerability in patients with locally advanced or metastatic prostate cancer. . Reference: Cancer. 2009 Jun 17. Epub, Akaza H, Hinotsu S, Usami M, Arai Y, Kanetake H, Naito S, Hirao Y, ahead of print. doi:10.1002/cncr.24395PubMed Abstract PMID:19536889In the United the typical dosage of bicalutamidem (Casodex) is 50mg not 80mg as was used in this study. Will the survival difference still exist if the dosage was 50mg? Certainly, CAB (ADT2) with a bicalutamide dosage of 80mg is far superior to ADT1. What I want to draw your attention to is the analysis that showed that a prostate-specific antigen (PSA) nadir concentration < /=1 ng/mL was a prognostic factor for improved survival.Joel T Nowak MA, MSW