title: The epidemiology of triple-negative breast cancer, including race.
abstract: OBJECTIVE
  Predictors of intrinsic breast cancer subtypes, including the triple-negative (TN) subtype, are largely unknown. We evaluated whether anthropometrics, demographics, and reproductive history were associated with distinct breast cancer subtypes.
  
  
  METHODS
  Invasive breast tumors from a population-based case-control study of 476 (116 black and 360 white) Atlanta women aged 20-54, diagnosed between 1990 and 1992, were centrally reviewed and immunohistochemically analyzed for estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2); then grouped [TN (ER-PR-HER2-); ER-PR-HER2+; ER/PR+HER2+; ER/PR+HER2- (case-only reference group)]. Data were from interviews and anthropometric measurements; adjusted odds ratios (OR) and 95% confidence intervals (CI) were estimated using logistic regression, including both case-only and case-control comparisons.
  
  
  RESULTS
  From the case-only analyses and compared with the ER/PR+HER2- subtype, women with TN tumors were more likely to be obese than normal/underweight [OR = 1.89 (95% CI = 1.22, 2.92)]. Regardless of HER2 status, ER-PR- tumors were associated with black race, young age at first birth, having a recent birth, and being overweight.
  
  
  CONCLUSIONS
  Distinct breast cancer subtypes have unique sociodemographic, anthropometric and reproductive characteristics and possibly different pathways for development.
authors.affiliation: Division of Cancer Prevention and Control, National Center for Chronic Disease Prevention and Health Promotion, Centers for Disease Control and Prevention, Atlanta, GA 30341, USA. ktrivers@cdc.gov
authors.forename: Katrina F
authors.initials: KF
authors.lastname: Trivers
authors.forename: Mary Jo
authors.initials: MJ
authors.lastname: Lund
authors.forename: Peggy L
authors.initials: PL
authors.lastname: Porter
authors.forename: Jonathan M
authors.initials: JM
authors.lastname: Liff
authors.forename: Elaine W
authors.initials: EW
authors.lastname: Flagg
authors.forename: Ralph J
authors.initials: RJ
authors.lastname: Coates
authors.forename: J William
authors.initials: JW
authors.lastname: Eley