The addition of bicalutamide 150 mg to radiotherapy significantly improves overall survival in men with locally advanced prostate cancer.

PURPOSE

Castration therapy adjuvant to radiotherapy can significantly improve overall survival compared with radiotherapy alone in patients with locally advanced prostate cancer. Although many of the adverse effects of castration therapy are manageable, they can have a detrimental effect on quality of life. Here we evaluate the efficacy and tolerability of the non-castration-based therapy bicalutamide ('Casodex') 150 mg adjuvant to radiotherapy in patients with T1-4, M0, any n prostate cancer.

METHODS

The subset of patients within the early prostate cancer (EPC) program who received radiotherapy with curative intent (n = 1,370) were included in the analysis. These patients were randomized to receive oral bicalutamide 150 mg once daily (n = 699) or placebo (n = 671).

RESULTS

The median follow-up for patients included in this analysis was 7.2 years. In patients with locally advanced disease (n = 305), bicalutamide adjuvant to radiotherapy significantly improved: progression-free survival (PFS), reducing the risk of objective progression by 44% compared with radiotherapy alone [hazard ratio (HR) 0.56; 95% confidence interval (CI) 0.40, 0.78; P < 0.001). Prostate-specific antigen (PSA)-PFS, reducing the risk of PSA progression by 59% compared with radiotherapy alone (HR 0.41; 95% CI 0.30, 0.55; P < 0.001). Overall survival, reducing the risk of death by 35% compared with radiotherapy alone (HR 0.65; 95% CI 0.44, 0.95; P = 0.03). This significant overall survival benefit for bicalutamide was driven by a lower risk of prostate cancer-related deaths (16.1 vs 24.3%, respectively). There was no significant difference in PFS or overall survival in patients with localized disease (n = 1,065).

CONCLUSIONS

In patients with locally advanced disease, bicalutamide 150 mg adjuvant to radiotherapy demonstrates significant clinical benefits in terms of overall survival, PFS and PSA-PFS compared with radiotherapy alone. The overall survival benefit in these patients is consistent with prior studies evaluating castration-based therapies adjuvant to radiotherapy (Bolla et al. in Lancet 360:103-108, 2002; Pilepich et al. in Int J Radiat Oncol Biol Phys 61:1285-1290, 2005). In addition, the clinical benefit of bicalutamide 150 mg in locally advanced patients, but not in those with localized disease, is consistent with the overall results from the EPC program (McLeod et al. BJU Int 97:247-254, 2006). Given the quality-of-life advantages of bicalutamide relative to castration, bicalutamide 150 mg adjuvant to radiotherapy is an attractive alternative for men with locally advanced prostate cancer.