title: Concurrent Gonadotropin-Releasing Hormone Agonist Administration with Chemotherapy Improves Neoadjuvant Chemotherapy Responses in Young Premenopausal Breast Cancer Patients.
abstract: OBJECTIVE
  This study aimed to determine the oncologic efficacy of gonadotropin-releasing hormone (GnRH) agonist treatment concurrent with chemotherapy in a neoadjuvant setting.
  
  
  METHODS
  A retrospective analysis was performed on 332 cases of invasive breast cancer in patients who were <40 years old at diagnosis and received GnRH agonists concurrent with neoadjuvant chemotherapy (GnRH agonist group) or neoadjuvant chemotherapy alone (neochemotherapy-alone group) from December 2010 to September 2014. Pathologic complete response rates (pCR) and Ki-67 changes were evaluated between the two groups.
  
  
  RESULTS
  Median age was 32±3.9 and 36±3.0 years in the GnRH agonist group and neochemotherapy-alone group, respectively (p<0.001). After adjustment for tumor size, grade, lymph node metastasis, hormone receptor (HR) status, and chemotherapy regimen, the GnRH agonist group exhibited a higher pCR rate with an odds ratio (OR) of 2.98 (95% confidence interval [CI], 1.37-6.34) and a greater decrease in Ki-67 expression after treatment (p=0.05) than the neochemotherapy-alone group. For HR-negative tumors, the GnRH agonist group showed a higher pCR rate (multivariate OR, 3.50; 95% CI, 1.37-8.95) and a greater decrease in Ki-67 expression (p=0.047). For HR-positive breast cancer, the pCR rate, change in Ki-67 index, and clinical response were higher, and preoperative endocrine prognostic index scores were lower, in the GnRH agonist group, but these did not reach statistical significance.
  
  
  CONCLUSIONS
  Concurrent administration of GnRH agonists during neoadjuvant chemotherapy improved pCR rates and suppressed Ki-67 expression, especially in HR-negative tumors.
authors.affiliation: Division of Breast and Endocrine Surgery, Department of Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Hee Jeong
authors.initials: HJ
authors.lastname: Kim
authors.affiliation: Division of Breast and Endocrine Surgery, Department of Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Tae-In
authors.initials: TI
authors.lastname: Yoon
authors.affiliation: Department of Obstetrics and Gynecology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Hee Dong
authors.initials: HD
authors.lastname: Chae
authors.affiliation: Department of Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Jeong Eun
authors.initials: JE
authors.lastname: Kim
authors.affiliation: Department of Radiology, Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Eun Young
authors.initials: EY
authors.lastname: Chae
authors.affiliation: Division of Breast and Endocrine Surgery, Department of Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Jong Han
authors.initials: JH
authors.lastname: Yu
authors.affiliation: Division of Breast and Endocrine Surgery, Department of Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Guiyun
authors.initials: G
authors.lastname: Sohn
authors.affiliation: Division of Breast and Endocrine Surgery, Department of Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Beom Seok
authors.initials: BS
authors.lastname: Ko
authors.affiliation: Division of Breast and Endocrine Surgery, Department of Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Jong Won
authors.initials: JW
authors.lastname: Lee
authors.affiliation: Division of Breast and Endocrine Surgery, Department of Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Byung Ho
authors.initials: BH
authors.lastname: Son
authors.affiliation: Division of Breast and Endocrine Surgery, Department of Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Sei Hyun
authors.initials: SH
authors.lastname: Ahn
keywords: Breast neoplasms; Drug therapy; Gonadotropin-releasing hormone agonist