title: Clinical Effect of Switching from a Luteinizing Hormone-Releasing Hormone Agonist to an Antagonist in Patients with Castration-Resistant Prostate Cancer and Serum Testosterone Level ≥ 20 ng/dl.
abstract: BACKGROUND
  The efficacy of conversion from a luteinizing hormone-releasing hormone agonist to an antagonist was evaluated prospectively in patients with castration-resistant prostate cancer.
  
  
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Department of Urology, Aichi Cancer Center Hospital, Nagoya, Japan.
authors.forename: Norihito
authors.initials: N
authors.lastname: Soga
authors.affiliation: Department of Urology, Aichi Cancer Center Hospital, Nagoya, Japan.
authors.forename: Takumi
authors.initials: T
authors.lastname: Kageyama
authors.affiliation: Department of Urology, Aichi Cancer Center Hospital, Nagoya, Japan.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Ogura
authors.affiliation: Department of Clinical Epidemiology and Biostatistics Graduate School of Medicine, Osaka University, Suita, Japan.
authors.forename: Tomomi
authors.initials: T
authors.lastname: Yamada
authors.affiliation: Department of Urology, Aichi Cancer Center Hospital, Nagoya, Japan.
authors.forename: Norio
authors.initials: N
authors.lastname: Hayashi
keywords: Castration-resistant; Degarelix; Luteinizing hormone-releasing hormone; Prostatic neoplasms; Testosterone