title: Effects of zoledronic acid and the association between its efficacy and γδT cells in postmenopausal women with breast cancer treated with preoperative hormonal therapy: a study protocol.
abstract: BACKGROUND
  Although the efficacy of zoledronic acid in postmenopausal women with breast cancer has been suggested, the underlying mechanism has not been fully clarified. Therefore, which patients may benefit from zoledronic acid and the optimal frequency of zoledronic acid administration are unclear. This study evaluates the effects of zoledronic acid on the tumor response in postmenopausal women with breast cancer and explores the relationship between its efficacy and γδ T cells.
  
  
  METHODS
  This study is an open-label, multi-institutional, single-arm, phase II clinical trial. Zoledronic acid will be administered once during preoperative hormonal therapy with letrozole for 24 weeks in postmenopausal women with Estrogen Receptor (ER)-positive , Human Epidermal Growth Factor Receptor 2 (HER2)-negative, clinical T1 or T2 N0M0 breast cancer. The primary endpoint is the objective response rate measured by MRI at 12 and 24 weeks. The secondary endpoints are the associations between the frequency of Vγ2Vδ2 T cells before the administration of zoledronic acid and the objective response, the association between the frequency of Vγ2Vδ2 T cells and the Preoperative Endocrine Prognostic Index score, and the association between the frequency of Vγ2Vδ2 T cells and Ki67 (MIB-1 index).
  
  
  CONCLUSIONS
  This study is designed to determine the add-on effect of zoledronic acid during preoperative hormonal therapy and to investigate the changes of the frequency of Vγ2Vδ2 T cells after the administration of zoledronic acid to explore the potential mechanism of zoledronic acid in breast cancer patients.
  
  
  BACKGROUND
  This trial was registered at the UMIN Clinical Trials Registry as UMIN000008701.
authors.forename: Eriko
authors.initials: E
authors.lastname: Sumi
authors.forename: Tomoharu
authors.initials: T
authors.lastname: Sugie
authors.forename: Kenichi
authors.initials: K
authors.lastname: Yoshimura
authors.forename: Harue
authors.initials: H
authors.lastname: Tada
authors.forename: Takafumi
authors.initials: T
authors.lastname: Ikeda
authors.forename: Eiji
authors.initials: E
authors.lastname: Suzuki
authors.forename: Yoshimasa
authors.initials: Y
authors.lastname: Tanaka
authors.forename: Satoshi
authors.initials: S
authors.lastname: Teramukai
authors.forename: Akira
authors.initials: A
authors.lastname: Shimizu
authors.forename: Masakazu
authors.initials: M
authors.lastname: Toi
authors.forename: Nagahiro
authors.initials: N
authors.lastname: Minato
mesh_terms: D005260:Female; D006801:Humans; D018931:Antineoplastic Agents, Hormonal / Q000627:therapeutic use; D001943:Breast Neoplasms / Q000188:drug therapy / Q000601:surgery; D004164:Diphosphonates / Q000494:pharmacology; D007093:Imidazoles / Q000494:pharmacology; D000077289:Letrozole; D009570:Nitriles / Q000627:therapeutic use; D017698:Postmenopause; D011300:Preoperative Care; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology; D014230:Triazoles / Q000627:therapeutic use; D000077211:Zoledronic Acid / Q000627:therapeutic use; D012107:Research Design; D050071:Bone Density Conservation Agents / Q000627:therapeutic use
chemical_list: D018931:Antineoplastic Agents, Hormonal; D004164:Diphosphonates; D007093:Imidazoles; D000077289:Letrozole; D009570:Nitriles; D016692:Receptors, Antigen, T-Cell, gamma-delta; D014230:Triazoles; D000077211:Zoledronic Acid; D050071:Bone Density Conservation Agents