Objective: The Early Prostate Cancer (EPC) programme is evaluating the efficacy and tolerability of bicalutamide following standard care (radiotherapy, radical prostatectomy or watchful waiting) in patients with localized (T1-2, N0/Nx) or locally advanced (T3-4, any N; or any T, N + ) non-metastatic prostate cancer. Herein we report the latest findings after a median follow-up period of 7.1 years from the Scandinavian Prostate Cancer Group (SPCG)-6 study, one of three trials in the EPC programme.
Material and methods: A total of 1218 patients were randomized on a 1:1 basis to either bicalutamide 150 mg/day (n=607) or placebo (n=611) following standard care; 81.4% were followed conservatively (watchful waiting). The primary endpoints were objective progression-free survival (PFS) and overall survival (OS).
Results: In patients with localized disease there was no significant difference in PFS [hazard ratio (HR) 0.85; 95% CI 0.69-1.06; p=0.15] and a trend towards decreased OS with bicalutamide plus standard care compared with standard care alone (HR 1.23; 95% CI 0.96-1.58; p=0.11). In patients with locally advanced disease, bicalutamide significantly improved PFS, reducing the risk of progression by 53% compared with standard care alone (HR 0.47; 95% CI 0.37-0.59; p<0.001). The median time to progression was 8.8 years for bicalutamide plus standard care and 7.1 years for standard care alone. There was a significant improvement in OS with bicalutamide plus standard care, with a reduction in the risk of death of 35% versus standard care alone (HR 0.65; 95% CI 0.50-0.85; p=0.001).
Conclusion: This analysis of the SPCG-6 study showed that bicalutamide plus standard care offers significant PFS and OS benefits for patients with locally advanced disease, but not for those with localized disease.