Abstract
INTRODUCTION: The efficacy of conversion from a luteinizing hormone-releasing hormone agonist to an antagonist was evaluated prospectively in patients with castration-resistant prostate cancer. MATERIALS AND METHODS: From October 2012 to December 2014, 8 cases with a serum testosterone level ≥ 20 ng/dl during following androgen deprivation therapy were enrolled and received degarelix monthly. The primary end-pointgoal was to determine the effective prostate-specific antigen response rate. The secondary end-pointgoal was to assess the proportion of cases with a decrease in serum testosterone level to < 20 ng/ml. RESULTS: One patient achieved a complete response, with a prostate-specific antigen level of 0.02 ng/ml at the nadirend of the study. The effective response rate was 25.0% (2/8), and the proportion of cases with prostate-specific antigen decline was 62.5% (5/8). In 5/8 cases (5/8, 62.5%), serum testosterone levels declined to < 20 ng/dl. CONCLUSION: Switching to a luteinizing hormone-releasing hormone antagonist in patients with testosterone levels ≥ 20 ng/dl may be an option in sequential androgen deprivation therapy for some patients.