Hormonal response recovery after long-term androgen deprivation therapy in patients with prostate cancer

Objective: The aim of this study was to evaluate hormonal recovery after cessation of androgen deprivation therapy (ADT) in a group of elderly prostate cancer patients. Materials and methods: Forty patients with locally advanced or metastatic prostate cancer, with a mean age of 71.5 years [95% confidence interval (CI) 69.1-73.9], were treated with ADT for a mean duration of 74.6 months (95% CI 59.7-89.5 months). Mean follow-up time after ADT cessation was 36.5 months (95% CI 30.6-42.3 months). Serum testosterone and luteinizing hormone (LH) were determined at 6 month intervals after ADT cessation. Results: After 18 months of follow-up, all patients had recovered normal LH levels, while 38% of patients still presented castration levels of testosterone (< 50 ng/dl). A multivariate analysis was performed to find factors related to testosterone recovery (testosterone >50 ng/dl). Neither age at start of ADT nor clinical stage reached statistical significance. Only time under ADT was correlated with testosterone recovery (p = .031). Kaplan-Meier curves were obtained. Mean time for testosterone recovery was 14.5 months (95% CI 6.5-22.6 months) in patients treated with ADT for less than 60 months compared to 29.3 months (95% CI 19.6-39.1 months) in patients treated with ADT for more than 60 months (log-rank p = .029). Conclusions: Age did not correlate with testosterone recovery in a group of elderly prostate cancer patients in whom ADT was stopped. Testosterone recovery after ADT cessation was significantly correlated with time under ADT treatment. Significant implications related to economic aspects of the dosage schedule may be considered.