Timing of Androgen Deprivation Therapy and its Impact on Survival After Radical Prostatectomy: A Matched Cohort Study

Abstract

We assessed the impact of the timing of androgen deprivation on disease progression after radical prostatectomy for patients with localized prostate cancer. We evaluated all patients who underwent radical prostatectomy between 1990 and 1999. Patients with pathological lymph node negative disease who received androgen deprivation therapy were then separated into 5 groups for analysis based on the time of hormone therapy initiation: 1--adjuvant androgen deprivation, 2--androgen deprivation therapy started at a postoperative prostate specific antigen of 0.4 ng/ml or greater, 3--at prostate specific antigen 1.0 or greater, 4--at prostate specific antigen 2.0 or greater and 5--at systemic progression. The first 4 groups were matched by clinical and pathological features to control groups who did not receive androgen deprivation after surgery using a nested, matched cohort design. Median followup for the entire cohort was 10 years. Clinical end points included systemic progression-free survival and cancer specific survival. After matching clinicopathological variables adjuvant androgen deprivation therapy was associated with improved 10-year systemic progression-free survival (95% vs 90%, p <0.001) and 10-year cancer specific survival (98% vs 95%, p = 0.009), although overall survival for these patients remained unchanged (84% vs 83%, p = 0.427). In contrast, we found that men who started hormonal therapy at a postoperative prostate specific antigen of 0.4 or greater, 1.0 or 2.0 did not have improved systemic progression-free or cancer specific survival. Adjuvant hormonal therapy modestly improves cancer specific survival and systemic progression-free survival after prostatectomy. The benefit of hormone therapy is lost when androgen deprivation is delivered at the time of prostate specific antigen recurrence or systemic progression.