6-Month Androgen Suppression Plus Radiation Therapy vs Radiation Therapy Alone for Patients With Clinically Localized Prostate Cancer: A Randomized Controlled Trial

Abstract

CONTEXT: Survival benefit in the management of high-grade clinically localized prostate cancer has been shown for 70 Gy radiation therapy combined with 3 years of androgen suppression therapy (AST), but long-term AST is associated with many adverse events. OBJECTIVE: To assess the survival benefit of 3-dimensional conformal radiation therapy (3D-CRT) alone or in combination with 6 months of AST in patients with clinically localized prostate cancer. DESIGN, SETTING, AND PATIENTS: A prospective randomized controlled trial of 206 patients with clinically localized prostate cancer who were randomized to receive 70 Gy 3D-CRT alone (n = 104) or in combination with 6 months of AST (n = 102) from December 1, 1995, to April 15, 2001. Eligible patients included those with a prostate-specific antigen (PSA) of at least 10 ng/mL, a Gleason score of at least 7, or radiographic evidence of extraprostatic disease. MAIN OUTCOME MEASURES: Time to PSA failure (PSA >1.0 ng/mL and increasing >0.2 ng/mL on 2 consecutive visits) and overall survival. RESULTS: After a median follow-up of 4.52 years, patients randomized to receive 3D-CRT plus AST had a significantly higher survival (P =.04), lower prostate cancer-specific mortality (P =.02), and higher survival free of salvage AST (P =.002). Kaplan-Meier estimates of 5-year survival rates were 88% (95% confidence interval [CI], 80%-95%) in the 3D-CRT plus AST group vs 78% (95% CI, 68%-88%) in the 3D-CRT group. Rates of survival free of salvage AST at 5 years were 82% (95% CI, 73%-90%) in the 3D-CRT plus AST group vs 57% (95% CI, 46%-69%) in the 3D-CRT group. CONCLUSION: The addition of 6 months of AST to 70 Gy 3D-CRT confers an overall survival benefit for patients with clinically localized prostate cancer.