title: Failure of goserelin ovarian ablation in premenopausal women with breast cancer: two case reports.
abstract: OBJECTIVE
  We hereby report on two patients receiving goserelin due to breast cancer in whom a failure in ovarian ablation was detected. A review of the hormonal effects of LHRH analogues is performed.
  
  
  METHODS
  CASE 1: A 36-year-old female was diagnosed with breast carcinoma and treated with surgery, chemotherapy, radiotherapy, and goserelin. A 16-week gestation was detected after 17 months of uninterrumpted hormonal therapy at ablative doses. CASE 2: A 41-year-old female was diagnosed with breast carcinoma and treated with surgery, chemotherapy, radiotherapy, and tamoxifen. Goserelin was substituted for tamoxifen due to bone metastases and, 2 years later, a failure in ovarian ablation was confirmed after the reappearance of the patient's menses.
  
  
  CONCLUSIONS
  Goserelin-induced ovarian ablation may fail after the use of appropriate doses of this drug. We suggest a possible mechanism of hormone resistance induced by the long-term administration of LHRH analogues. No fetal damage was detected after goserelin exposure in the first 4 months of gestation.
authors.affiliation: Medical Oncology Department, University Hospital La Paz, Madrid, 28046, Spain.
authors.forename: A M
authors.initials: AM
authors.lastname: Jiménez-Gordo
authors.forename: B
authors.initials: B
authors.lastname: de las Heras
authors.forename: P
authors.initials: P
authors.lastname: Zamora
authors.forename: E
authors.initials: E
authors.lastname: Espinosa
authors.forename: M
authors.initials: M
authors.lastname: González-Barón
mesh_terms: D000328:Adult; D018931:Antineoplastic Agents, Hormonal / Q000494:pharmacology / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000628:therapy*; D005260:Female; D017273:Goserelin / Q000494:pharmacology / Q000627:therapeutic use*; D006801:Humans; D008597:Menstrual Cycle / Q000187:drug effects; D010053:Ovary / Q000187:drug effects*; D011247:Pregnancy; D017697:Premenopause
chemical_list: D018931:Antineoplastic Agents, Hormonal; D017273:Goserelin