title: Body fatness and breast cancer risk in women of African ancestry.
abstract: BACKGROUND
  Obesity has been shown to be inversely associated with breast cancer risk in premenopausal women, while increasing risk in postmenopausal women. However, the current evidence is largely based on studies in Caucasian populations. Associations in women of African ancestry (AA), who have a higher prevalence of obesity, have been evaluated in few studies and results suggest different effects.
  
  
  METHODS
  We evaluated the impact of body size, body fat distribution, and body composition on breast cancer risk among AA women (978 cases and 958 controls) participating in the Women's Circle of Health Study, a multi-site case-control study in New York City (NYC) and New Jersey (NJ). Cases were newly diagnosed with histologically confirmed ductal carcinoma in situ or invasive breast cancer, age 20-75 yrs. In NYC, cases were recruited through hospitals with the largest referral patterns for AA women and controls through random digit dialing (RDD). In NJ, cases were identified in seven counties in NJ thorough the NJ State Cancer Registry, and controls through RDD and community-based recruitment. During in-person interviews, questionnaires were administered and detailed anthropometric measurements were obtained. Body composition was assessed by bioelectrical impedance analysis.
  
  
  RESULTS
  BMI did not have a major impact on pre- or post-menopausal breast cancer, but was significantly associated with reduced risk of ER-/PR- tumors among postmenopausal women (OR: 0.37; 95% CI: 0.15-0.96 for BMI > 30 vs. BMI < 25). Furthermore, increased premenopausal breast cancer risk was found for higher waist and hip circumferences after adjusting for BMI, with ORs of 2.25 (95% CI: 1.07-4.74) and 2.91 (95% CI: 1.39-6.10), respectively, comparing the highest vs. lowest quartile. While ORs for higher fat mass and percent body fat among postmenopausal women were above one, confidence intervals included the null value.
  
  
  CONCLUSIONS
  Our study suggests that in AA women BMI is generally unrelated to breast cancer. However, higher waist and hip circumferences were associated with increased pre-menopausal breast cancer risk, while general obesity was associated with decreased risk of ER-/PR- tumors. Larger studies are needed to confirm findings and to evaluate the impact of obesity on breast cancer subtypes.
authors.affiliation: Rutgers Cancer Institute of New Jersey, Robert Wood Johnson Medical School, 195 Little Albany Street, New Brunswick, NJ, 08903, USA. elisa.bandera@rutgers.edu.
authors.forename: Elisa V
authors.initials: EV
authors.lastname: Bandera
authors.forename: Urmila
authors.initials: U
authors.lastname: Chandran
authors.forename: Gary
authors.initials: G
authors.lastname: Zirpoli
authors.forename: Zhihong
authors.initials: Z
authors.lastname: Gong
authors.forename: Susan E
authors.initials: SE
authors.lastname: McCann
authors.forename: Chi-Chen
authors.initials: CC
authors.lastname: Hong
authors.forename: Gregory
authors.initials: G
authors.lastname: Ciupak
authors.forename: Karen
authors.initials: K
authors.lastname: Pawlish
authors.forename: Christine B
authors.initials: CB
authors.lastname: Ambrosone
mesh_terms: D050154:Adiposity; D000328:Adult; D044383:Black People; D001823:Body Composition; D001943:Breast Neoplasms / Q000453:epidemiology* / Q000209:etiology*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008593:Menopause; D008875:Middle Aged; D009515:New Jersey / Q000453:epidemiology; D009519:New York City / Q000453:epidemiology; D009765:Obesity / Q000150:complications*; D012042:Registries; D012306:Risk; D012307:Risk Factors; D001741:Black or African American