Long-term androgen deprivation therapy improves survival in prostate cancer patients presenting with prostate-specific antigen levels > 20 ng/mL.

Purpose: To assess the benefit of androgen deprivation (AD) and its optimal duration in patients with prostate cancer treated with external beam radiotherapy, who present with prostate-specific antigen levels > 20 ng/mL.

Methods And Materials: A total of 307 patients treated with external beam radiotherapy, AD, and presenting with a PSA level > 20 ng/mL were identified from the Prostate Cancer Outcomes Initiative database of the British Columbia Cancer Agency. Androgen deprivation was defined as short term (ST-AD, < 12 months) or long term (LT-AD, > or = 12 months).