Short- vs long-term androgen suppression plus external beam radiation therapy and survival in men of advanced age with node-negative high-risk adenocarcinoma of the prostate.

BACKGROUND: The study evaluated whether the use of 3 years as compared with 6 months of androgen suppression therapy (AST) combined with external beam radiation therapy (RT) in the treatment of high-risk prostate cancer was associated with prolonged survival in advanced age men.
METHODS: A pooled analysis of 311 men enrolled in 3 prospective randomized trials between 1987 and 2000 who received 6 months or 3 years of AST and RT for locally advanced or high-grade localized adenocarcinoma of the prostate comprised the study cohort. Cox regression multivariable analysis was performed adjusting for known prognostic factors to determine whether the treatment received was associated with time to death after randomization. The median age and follow-up was 70 and 5.9 years, respectively, during which 82 (26%) deaths occurred.
RESULTS: Treatment received was not significantly associated with survival time after randomization (adjusted hazard ratio [AHR]: 1.1; 95% confidence interval [CI]: 0.7, 1.8; P = .70), whereas age at randomization (AHR: 1.05; 95% CI: 1.01, 1.09; P = .02) was. The presence of Gleason score 8 to 10 cancers approached significance (AHR: 1.6; 95% CI: 0.9, 2.6; P = .09).
CONCLUSIONS: After adjusting for known prognostic factors, the treatment of node-negative, high-risk prostate cancer using 3 years as compared with 6 months of AST with RT was not associated with prolonged survival in men of advanced age. The European Organization for Research and Treatment of Cancer randomized trial will help answer whether unknown confounding factors affected the results of the study. (c) 2007 American Cancer Society