title: Obesity at diagnosis is associated with inferior outcomes in hormone receptor-positive operable breast cancer.
abstract: BACKGROUND
  Obesity has been associated with inferior outcomes in operable breast cancer, but the relation between body mass index (BMI) and outcomes by breast cancer subtype has not been previously evaluated.
  
  
  METHODS
  The authors evaluated the relation between BMI and outcomes in 3 adjuvant trials coordinated by the Eastern Cooperative Oncology Group that included chemotherapy regimens with doxorubicin and cyclophosphamide, including E1199, E5188, and E3189. Results are expressed as hazard ratios (HRs) from Cox proportional hazards models (HR >1 indicates a worse outcome). All P values are 2-sided.
  
  
  RESULTS
  When evaluated as a continuous variable in trial E1199, increasing BMI within the obese (BMI, ≥ 30 kg/m(2)) and overweight (BMI, 25-29.9 kg/m(2)) ranges was associated with inferior outcomes in hormone receptor-positive, human epidermal growth receptor 2 (HER-2)/neu-negative disease for disease-free survival (DFS; P = .0006) and overall survival (OS; P = .0007), but not in HER-2/neu-overexpressing or triple-negative disease. When evaluated as a categorical variable, obesity was associated with inferior DFS (HR, 1.24; 95% confidence interval [CI], 1.06-1.46; P = .0008) and OS (HR, 1.37; 95% CI, 1.13-1.67; P = .002) in hormone receptor-positive disease, but not other subtypes. In a model including obesity, disease subtype, and their interaction, the interaction term was significant for OS (P = .02) and showed a strong trend for DFS (P = .07). Similar results were found in 2 other trials (E5188, E3189).
  
  
  CONCLUSIONS
  In a clinical trial population that excluded patients with significant comorbidities, obesity was associated with inferior outcomes specifically in patients with hormone receptor-positive operable breast cancer treated with standard chemohormonal therapy.
authors.affiliation: Albert Einstein College of Medicine, Montefiore Medical Center, Bronx, New York, USA. jsparano@montefiore.org
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Sparano
authors.forename: Molin
authors.initials: M
authors.lastname: Wang
authors.forename: Fengmin
authors.initials: F
authors.lastname: Zhao
authors.forename: Vered
authors.initials: V
authors.lastname: Stearns
authors.forename: Silvana
authors.initials: S
authors.lastname: Martino
authors.forename: Jennifer A
authors.initials: JA
authors.lastname: Ligibel
authors.forename: Edith A
authors.initials: EA
authors.lastname: Perez
authors.forename: Tom
authors.initials: T
authors.lastname: Saphner
authors.forename: Antonio C
authors.initials: AC
authors.lastname: Wolff
authors.forename: George W
authors.initials: GW
authors.lastname: Sledge
authors.forename: William C
authors.initials: WC
authors.lastname: Wood
authors.forename: John
authors.initials: J
authors.lastname: Fetting
authors.forename: Nancy E
authors.initials: NE
authors.lastname: Davidson
mesh_terms: D000328:Adult; D000368:Aged; D015992:Body Mass Index; D001943:Breast Neoplasms / Q000737:chemistry / Q000188:drug therapy / Q000401:mortality*; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008875:Middle Aged; D009765:Obesity / Q000150:complications*; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000032:analysis; D011960:Receptors, Estrogen / Q000032:analysis
chemical_list: D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; C508053:ERBB2 protein, human