Cancer Chemotherapy and Pharmacology

, Volume 76, Issue 2, pp 301–306 | Cite as

Efficacy of treatment with a GnRH antagonist in prostate cancer patients previously treated with a GnRH agonist

  • Taisuke Ezaki
  • Takeo KosakaEmail author
  • Ryuichi Mizuno
  • Toshiaki Shinojima
  • Eiji Kikuchi
  • Akira Miyajima
  • Mototsugu Oya
Original Article



The efficacy of switching from a GnRH agonist to a GnRH antagonist for prostate cancer patients resistant to treatment with the GnRH agonist has not been fully characterized yet. We aimed to evaluate the efficacy of the switch to a GnRH antagonist in patients with PSA failure after hormonal therapy with a GnRH agonist.


We retrospectively examined 18 patients with prostate cancer who received androgen-deprivation therapy and who were treated with a GnRH antagonist (degarelix) after they showed an elevated PSA while on GnRH agonist therapy. We evaluated the characteristics of the patients and analyzed some clinical factors for their potential association with the patient response to the switch.


The median PSA at the switch was 7.9 (0.37–1709) ng/ml, and the median testosterone level was 0.17 (<0.08–0.81) ng/ml. Three months after the switch, the median PSA level was 11.3 (0.22–2636) ng/ml, and the median testosterone level was 0.14 (<0.08–0.23) ng/ml. The PSA decreased in six patients (33.3 %) 1 month after the switch, and in three of them it decreased by more than 50 % by 3 months after the switch. Univariate analyses revealed that the lower number of prior treatment lines for prostate cancer before the switch was associated with a favorable decrease in PSA.


Switching from GnRH agonist to GnRH antagonist therapy was effective for some prostate cancer patients with PSA failure. The small number of prior treatment lines for prostate cancer before the switch was significantly associated with a good PSA response.


GnRH antagonist Prostate cancer PSA failure Androgen-deprivation therapy 


Conflict of interest

All authors were directly or indirectly involved in the treatment of prostate cancer with the GnRH antagonist. The authors declare that there is no conflict of interest.

Ethical standard

This study was performed in accordance with the requirements and approval of the Committee for Human Ethics and Experimentation of our institution.


  1. 1.
    Choueiri TK et al (2009) Time to prostate-specific antigen nadir independently predicts overall survival in patients who have metastatic hormone-sensitive prostate cancer treated with androgen-deprivation therapy. Cancer 115(5):981–987PubMedCentralPubMedCrossRefGoogle Scholar
  2. 2.
    Lam JS et al (2006) Secondary hormonal therapy for advanced prostate cancer. J Urol 175(1):27–34PubMedCrossRefGoogle Scholar
  3. 3.
    Masson-Lecomte A et al (2013) A switch from GnRH agonist to GnRH antagonist in castration-resistant prostate cancer patients leads to a low response rate on PSA. World J Urol 31(2):339–343PubMedCrossRefGoogle Scholar
  4. 4.
    Raddin RS, Walko CM, Whang YE (2011) Response to degarelix after resistance to luteinizing hormone-releasing hormone agonist therapy for metastatic prostate cancer. Anticancer Drugs 22(3):299–302PubMedCrossRefGoogle Scholar
  5. 5.
    Scher HI et al (1999) Post-therapy serum prostate-specific antigen level and survival in patients with androgen-independent prostate cancer. J Natl Cancer Inst 91(3):244–251PubMedCrossRefGoogle Scholar
  6. 6.
    Ben-Josef E et al (1999) Hormone-refractory prostate cancer cells express functional follicle-stimulating hormone receptor (FSHR). J Urol 161(3):970–976PubMedCrossRefGoogle Scholar
  7. 7.
    Crawford ED et al (2011) A phase III extension trial with a 1-arm crossover from leuprolide to degarelix: comparison of gonadotropin-releasing hormone agonist and antagonist effect on prostate cancer. J Urol 186(3):889–897PubMedCrossRefGoogle Scholar
  8. 8.
    Suzuki H et al (2008) Alternative nonsteroidal antiandrogen therapy for advanced prostate cancer that relapsed after initial maximum androgen blockade. J Urol 180(3):921–927PubMedCrossRefGoogle Scholar
  9. 9.
    Noonan KL et al (2013) Clinical activity of abiraterone acetate in patients with metastatic castration-resistant prostate cancer progressing after enzalutamide. Ann Oncol 24(7):1802–1807PubMedCrossRefGoogle Scholar
  10. 10.
    Loriot Y et al (2013) Antitumour activity of abiraterone acetate against metastatic castration-resistant prostate cancer progressing after docetaxel and enzalutamide (MDV3100). Ann Oncol 24(7):1807–1812PubMedCrossRefGoogle Scholar
  11. 11.
    Schrader AJ et al (2014) Enzalutamide in castration-resistant prostate cancer patients progressing after docetaxel and abiraterone. Eur Urol 65(1):30–36PubMedCrossRefGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2015

Authors and Affiliations

  • Taisuke Ezaki
    • 1
  • Takeo Kosaka
    • 1
    Email author
  • Ryuichi Mizuno
    • 1
  • Toshiaki Shinojima
    • 1
  • Eiji Kikuchi
    • 1
  • Akira Miyajima
    • 1
  • Mototsugu Oya
    • 1
  1. 1.Department of UrologyKeio University School of MedicineTokyoJapan

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