title: Obesity and risk of recurrence or death after adjuvant endocrine therapy with letrozole or tamoxifen in the breast international group 1-98 trial.
abstract: OBJECTIVE
  To examine the association of baseline body mass index (BMI) with the risk of recurrence or death in postmenopausal women with early-stage breast cancer receiving adjuvant tamoxifen or letrozole in the Breast International Group (BIG) 1-98 trial at 8.7 years of median follow-up.
  
  
  METHODS
  This report analyzes 4,760 patients with breast cancer randomly assigned to 5 years of monotherapy with letrozole or tamoxifen in the BIG 1-98 trial with available information on BMI at randomization. Multivariable Cox modeling assessed the association of BMI with disease-free survival, overall survival (OS), breast cancer-free interval, and distant recurrence-free interval and tested for treatment-by-BMI interaction. Median follow-up was 8.7 years.
  
  
  RESULTS
  Seventeen percent of patients have died. Obese patients (BMI ≥ 30 kg/m(2)) had slightly poorer OS (hazard ratio [HR] = 1.19; 95% CI, 0.99 to 1.44) than patients with normal BMI (< 25 kg/m(2)), whereas no trend in OS was observed in overweight (BMI 25 to < 30 kg/m(2)) versus normal-weight patients (HR = 1.02; 95% CI, 0.86 to 1.20). Treatment-by-BMI interactions were not statistically significant. The HRs for OS comparing obese versus normal BMI were HR = 1.22 (95% CI, 0.93 to 1.60) and HR = 1.18 (95% CI, 0.91 to 1.52) in the letrozole and tamoxifen groups, respectively.
  
  
  CONCLUSIONS
  There was no evidence that the benefit of letrozole over tamoxifen differed according to patients' BMI.
authors.affiliation: Department of Oncology (ME), Odense University Hospital, Institute of Clinical Research, University of Southern Denmark, Odense, Denmark. mew@dadlnet.dk
authors.forename: Marianne
authors.initials: M
authors.lastname: Ewertz
authors.forename: Kathryn P
authors.initials: KP
authors.lastname: Gray
authors.forename: Meredith M
authors.initials: MM
authors.lastname: Regan
authors.forename: Bent
authors.initials: B
authors.lastname: Ejlertsen
authors.forename: Karen N
authors.initials: KN
authors.lastname: Price
authors.forename: Beat
authors.initials: B
authors.lastname: Thürlimann
authors.forename: Hervé
authors.initials: H
authors.lastname: Bonnefoi
authors.forename: John F
authors.initials: JF
authors.lastname: Forbes
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Paridaens
authors.forename: Manuela
authors.initials: M
authors.lastname: Rabaglio
authors.forename: Richard D
authors.initials: RD
authors.lastname: Gelber
authors.forename: Marco
authors.initials: M
authors.lastname: Colleoni
authors.forename: István
authors.initials: I
authors.lastname: Láng
authors.forename: Ian E
authors.initials: IE
authors.lastname: Smith
authors.forename: Alan S
authors.initials: AS
authors.lastname: Coates
authors.forename: Aron
authors.initials: A
authors.lastname: Goldhirsch
authors.forename: Henning T
authors.initials: HT
authors.lastname: Mouridsen
mesh_terms: D000328:Adult; D000368:Aged; D018931:Antineoplastic Agents, Hormonal / Q000627:therapeutic use*; D047072:Aromatase Inhibitors / Q000627:therapeutic use; D015992:Body Mass Index; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000401:mortality* / Q000601:surgery; D017024:Chemotherapy, Adjuvant; D018572:Disease-Free Survival; D020847:Estrogen Receptor Modulators / Q000627:therapeutic use; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D053208:Kaplan-Meier Estimate; D000077289:Letrozole; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000209:etiology*; D009570:Nitriles / Q000627:therapeutic use*; D009765:Obesity / Q000150:complications*; D016017:Odds Ratio; D011237:Predictive Value of Tests; D011379:Prognosis; D016016:Proportional Hazards Models; D018570:Risk Assessment; D012307:Risk Factors; D013629:Tamoxifen / Q000627:therapeutic use*; D016896:Treatment Outcome; D014230:Triazoles / Q000627:therapeutic use*
chemical_list: D018931:Antineoplastic Agents, Hormonal; D047072:Aromatase Inhibitors; D020847:Estrogen Receptor Modulators; D009570:Nitriles; D014230:Triazoles; D013629:Tamoxifen; D000077289:Letrozole