Total androgen blockade versus a luteinizing hormone-releasing hormone agonist alone in men with high-risk prostate cancer treated with radiotherapy.

Purpose To assess whether short-course total androgen blockade vs. a luteinizing hormone–releasing hormone (LHRH) agonist alone affects the risk of prostate cancer–specific mortality (PCSM) in men with localized but high-risk disease treated with radiotherapy. Methods and Materials The study cohort comprised 628 men with T1–T4, N0, M0 prostate cancer with high-risk disease (prostate-specific antigen level >20 ng/mL, Gleason score ≥8, or clinical category ≥T3) treated with 45 Gy of external beam radiotherapy followed by a brachytherapy boost in addition to receiving a median of 4.3 (interquartile range [IQR], 3.6–6.4) months of hormonal blockade with an LHRH agonist plus an antiandrogen or monotherapy with an LHRH agonist. Fine and Gray's multivariable regression analysis was used to determine whether combination androgen suppression therapy (AST) vs. monotherapy affected the risk of PCSM, adjusting for treatment year, duration of AST, age, and known prognostic factors. Results After a median follow-up of 4.9 (IQR, 3.5–6.5) years, men receiving combination AST had a lower risk of PCSM than those treated with monotherapy (adjusted hazard ratio [AHR], 0.18; 95% confidence interval [CI], 0.04–0.90; p = 0.04). An increasing prostate-specific antigen level (AHR, 2.70; 95% CI, 1.64–4.45; p p = 0.004) were also associated with an increased risk of PCSM. Conclusions In men with localized but high-risk prostate cancer treated with external beam radiotherapy and brachytherapy, short-course AST with an LHRH agonist plus an antiandrogen is associated with a decreased risk of PCSM when compared with monotherapy with an LHRH agonist.