title: Clinical endocrinological evaluation of the gonadal axis (testosterone, LH and FSH) in prostate cancer patients switched from a GnRH antagonist to a LHRH agonist.
abstract: OBJECTIVE
  To investigate the levels of testosterone, luteinizing hormone (LH), follicle-stimulating hormone (FSH), and prostate-specific antigen (PSA) in prostate cancer patients before and after the switch from degarelix to leuprolide treatments.
  
  
  METHODS
  We enrolled 40 treatment-naïve prostate cancer patients who were treated initially with degarelix and were later switched to leuprolide. The subjects were divided into three groups depending on when they were switched to leuprolide: the 3-month group (3m; switched after 84 days, n=10), the 2-month group (2m; 56 days, n=10), and the 1-month group (1m; 28 days, n=20). Patient symptoms and hormone levels were measured after switching therapy. The castration level was defined as a serum testosterone level ≤50 ng/dl.
  
  
  RESULTS
  Thirty-nine subjects (97.5%) achieved castration levels of testosterone (11±5.8 ng/dl) 2 weeks after degarelix was first administered, and the characteristics of these patients were investigated. Testosterone levels increased and exceeded the castration level in one subject each of the 3m (142 ng/dl), 2m (72 ng/dl), and 1m groups (63 ng/dl). All subjects achieved the castration level by day 5. In contrast to testosterone levels, the LH and FSH surge on day 2 was significantly higher in the 1m group than in the other groups. The clinical symptoms were not exacerbated before or after switching in any patients.
  
  
  CONCLUSIONS
  A testosterone surge was observed in 8.3 % of the study patients; however, it was very short-lived and mild. LH and FSH levels were significantly higher 1 month after administration compared with 2 or 3 months after degarelix administration.
authors.affiliation: Department of Urology, Gunma University Graduate School of Medicine, 3-39-22 Showa-machi, Maebashi 371-8511 Gunma, Japan.
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Miyazawa
authors.affiliation: Department of Urology, Gunma University Graduate School of Medicine, 3-39-22 Showa-machi, Maebashi 371-8511 Gunma, Japan.
authors.forename: Haruo
authors.initials: H
authors.lastname: Kato
authors.affiliation: Department of Urology, Gunma University Graduate School of Medicine, 3-39-22 Showa-machi, Maebashi 371-8511 Gunma, Japan.
authors.forename: Seiji
authors.initials: S
authors.lastname: Arai
authors.affiliation: Department of Urology, Gunma University Graduate School of Medicine, 3-39-22 Showa-machi, Maebashi 371-8511 Gunma, Japan.
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Furuya
authors.affiliation: Department of Urology, Gunma University Graduate School of Medicine, 3-39-22 Showa-machi, Maebashi 371-8511 Gunma, Japan.
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Sekine
authors.affiliation: Department of Urology, Gunma University Graduate School of Medicine, 3-39-22 Showa-machi, Maebashi 371-8511 Gunma, Japan.
authors.forename: Masashi
authors.initials: M
authors.lastname: Nomura
authors.affiliation: Department of Urology, Gunma University Graduate School of Medicine, 3-39-22 Showa-machi, Maebashi 371-8511 Gunma, Japan.
authors.forename: Hidekazu
authors.initials: H
authors.lastname: Koike
authors.affiliation: Department of Urology, Gunma University Graduate School of Medicine, 3-39-22 Showa-machi, Maebashi 371-8511 Gunma, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Matsui
authors.affiliation: Department of Urology, Gunma University Graduate School of Medicine, 3-39-22 Showa-machi, Maebashi 371-8511 Gunma, Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Shibata
authors.affiliation: Department of Urology, Gunma University Graduate School of Medicine, 3-39-22 Showa-machi, Maebashi 371-8511 Gunma, Japan.
authors.forename: Kazuto
authors.initials: K
authors.lastname: Ito
authors.affiliation: Department of Urology, Gunma University Graduate School of Medicine, 3-39-22 Showa-machi, Maebashi 371-8511 Gunma, Japan.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Suzuki
keywords: GnRH-antagonist; LHRH-agonist; Prostate cancer; Testosterone