title: Impact of body mass index on the efficacy of endocrine therapy in premenopausal patients with breast cancer: an analysis of the prospective ABCSG-12 trial.
abstract: OBJECTIVE
  Aromatase inhibitors are effective as endocrine treatment for patients with hormone receptor-positive breast cancer. According to the hypothesis that overweight patients have higher levels of aromatase enzyme availability, we investigated the influence of body mass index (BMI) on the efficacy of adjuvant endocrine therapy in premenopausal patients in a retrospective analysis of the Austrian Breast and Colorectal Cancer Study Group (ABCSG) 12 trial.
  
  
  METHODS
  ABCSG-12 examined the efficacy of ovarian suppression using goserelin (3.6 mg subcutaneously every 28 days) in combination with anastrozole or tamoxifen with or without zoledronic acid (4 mg intravenously every 6 months) in premenopausal women with endocrine-responsive breast cancer. BMI was calculated using the prospectively collected data on patients' height and weight at study entry. BMI categories have been differentiated according to the WHO definition.
  
  
  RESULTS
  Overweight patients treated with anastrozole had a 60% increase in the risk of disease recurrence (hazard ratio [HR], 1.60; 95% CI, 1.06 to 2.41; P = .02) and more than a doubling in the risk of death (HR, 2.14; 95% CI, 1.17 to 3.92; P = .01) compared with normal weight patients treated with anastrozole. In the overweight group, patients treated with anastrozole had a nearly 50% increase in the risk of disease recurrence (HR, 1.49; 95% CI, 0.93 to 2.38; P = .08) and a three-fold increase in the risk of death (HR, 3.03; 95% CI, 1.35 to 6.82; P = .004) compared with patients treated with tamoxifen.
  
  
  CONCLUSIONS
  BMI significantly impacts on the efficacy of anastrozole plus goserelin in premenopausal patients with breast cancer, probably through influencing aromatase availability and/or ovarian suppression by goserelin.
authors.affiliation: Department of Surgery, Comprehensive Cancer Center Vienna, Medical University of Vienna, Waehringer Guertel 18-20, A-1090, Vienna, Austria.
authors.forename: Georg
authors.initials: G
authors.lastname: Pfeiler
authors.forename: Robert
authors.initials: R
authors.lastname: Königsberg
authors.forename: Christian
authors.initials: C
authors.lastname: Fesl
authors.forename: Brigitte
authors.initials: B
authors.lastname: Mlineritsch
authors.forename: Herbert
authors.initials: H
authors.lastname: Stoeger
authors.forename: Christian F
authors.initials: CF
authors.lastname: Singer
authors.forename: Sabine
authors.initials: S
authors.lastname: Pöstlberger
authors.forename: Guenther G
authors.initials: GG
authors.lastname: Steger
authors.forename: Michael
authors.initials: M
authors.lastname: Seifert
authors.forename: Peter
authors.initials: P
authors.lastname: Dubsky
authors.forename: Susanne
authors.initials: S
authors.lastname: Taucher
authors.forename: Hellmut
authors.initials: H
authors.lastname: Samonigg
authors.forename: Vesna
authors.initials: V
authors.lastname: Bjelic-Radisic
authors.forename: Richard
authors.initials: R
authors.lastname: Greil
authors.forename: Christian
authors.initials: C
authors.lastname: Marth
authors.forename: Michael
authors.initials: M
authors.lastname: Gnant
mesh_terms: D000328:Adult; D000077384:Anastrozole; D018931:Antineoplastic Agents, Hormonal / Q000627:therapeutic use; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D047072:Aromatase Inhibitors / Q000627:therapeutic use; D015992:Body Mass Index; D001943:Breast Neoplasms / Q000188:drug therapy*; D005260:Female; D017273:Goserelin / Q000008:administration & dosage*; D006801:Humans; D008875:Middle Aged; D009570:Nitriles / Q000008:administration & dosage*; D017697:Premenopause; D011446:Prospective Studies; D012008:Recurrence; D012189:Retrospective Studies; D012306:Risk; D013629:Tamoxifen / Q000494:pharmacology; D016896:Treatment Outcome; D014230:Triazoles / Q000008:administration & dosage*
chemical_list: D018931:Antineoplastic Agents, Hormonal; D047072:Aromatase Inhibitors; D009570:Nitriles; D014230:Triazoles; D013629:Tamoxifen; D017273:Goserelin; D000077384:Anastrozole