PURPOSE: To evaluate the optimal duration of androgen deprivation therapy (ADT) in patients with prostate cancer treated with external beam radiotherapy (EBRT), who present with PSA levels > 20 ng/mL.
METHODS AND MATERIALS: A total of 307 patients presenting with a PSA > 20 ng/ml were treated with EBRT and ADT. The cohort was divided into four groups according to the duration of ADT: Group 1 received < 6 months (n = 71), group 2 received 6-12 months (n = 80), group 3 received 12-24 months (n = 72), and group 4 received > 24 months (n = 84) of ADT. The endpoints analyzed were biochemical control (bNED), overall survival (OS) and cause-specific survival (CSS). Statistical analysis was conducted using Kaplan-Meier estimates and Cox regression models.
RESULTS: Compared to patients who received < 6 months of ADT, patients treated with 12-24 months or > 24 months of ADT experienced significantly improved bNED (p = 0.01 and p < 0.0001, respectively). Cause-specific survival with ADT durations 12-24 and > 24 months were significantly higher compared to < 6 months (p < 0.007 and 0.024, respectively). Overall survival with ADT durations > 24 months was also significantly higher compared to < 6 months (p = 0.0025).
CONCLUSIONS: The present analysis supports the hypothesis that longer durations of ADT improves bNED, CSS and OS in patients presenting with a PSA > 20 ng/ml.