title: Associations of hormone-related factors with breast cancer risk according to hormone receptor status among white and African American women.
abstract: BACKGROUND
  Causes of racial disparities in breast cancer incidence and mortality between white and African American women remain unclear. This study evaluated associations of menstrual and reproductive factors with breast cancer risk by race and cancer subtypes.
  
  
  METHODS
  Included in the study were 1866 breast cancer cases and 2306 controls recruited in the Nashville Breast Health Study, a population-based case-control study. Multivariable logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs).
  
  
  RESULTS
  African American women were more likely to have estrogen receptor-negative (ER(-)), progesterone receptor-negative (PR(-)), and triple-negative (ER(-)PR(-)HER2(-)) breast cancer than white women. Age at menarche (≥ 14 years) and multiparity (≥ 3 live births) were inversely associated with ER(+) tumors only, whereas late age at first live birth (> 30 years) and nulliparity were associated with elevated risk; such associations were predominantly seen in white women (OR = 0.70, 95% CI = 0.55-0.88; OR = 0.72, 95% CI = 0.56-0.92; OR = 1.42, 95% CI = 1.13-1.79; OR = 1.32, 95% CI = 1.06-1.63, respectively). Age at menopause between 47 and 51 years was associated with elevated risk of ER(-) tumors in both white and African American women. Among women who had natural menopause, positive association between ever-use of hormone replacement therapy and breast cancer risk was seen in white women only (OR = 1.39, 95% CI = 1.03-1.87).
  
  
  CONCLUSIONS
  This study suggests that certain hormone-related factors are differentially associated with risk of breast cancer subtypes, and these associations also differ by race.
authors: Division of Epidemiology, Department of Medicine, Vanderbilt Epidemiology Center, Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, TN.
authors: Yong
authors: Y
authors: Cui
authors: Division of Epidemiology, Department of Medicine, Vanderbilt Epidemiology Center, Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, TN.
authors: Sandra L
authors: SL
authors: Deming-Halverson
authors: Division of Epidemiology, Department of Medicine, Vanderbilt Epidemiology Center, Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, TN.
authors: Martha J
authors: MJ
authors: Shrubsole
authors: Division of Epidemiology, Department of Medicine, Vanderbilt Epidemiology Center, Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, TN.
authors: Alicia
authors: A
authors: Beeghly-Fadiel
authors: Vanderbilt Institute of Clinical Translational Research, Vanderbilt University School of Medicine, Nashville, TN.
authors: Alecia M
authors: AM
authors: Fair
authors: Meharry/Vanderbilt Cancer Partnership, Nashville General Hospital, Nashville, TN.
authors: Maureen
authors: M
authors: Sanderson
authors: Division of Epidemiology, Department of Medicine, Vanderbilt Epidemiology Center, Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, TN.
authors: Xiao-Ou
authors: XO
authors: Shu
authors: Division of Surgical Oncology and Endocrine Surgery, Department of Surgery, Vanderbilt University School of Medicine, Nashville, TN.
authors: Mark C
authors: MC
authors: Kelley
authors: Division of Epidemiology, Department of Medicine, Vanderbilt Epidemiology Center, Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, TN. Electronic address: wei.zheng@vanderbilt.edu.
authors: Wei
authors: W
authors: Zheng
mesh_terms: D000328:Adult; D001741:Black or African American / Q000706:statistics & numerical data*; D000368:Aged; D014408:Biomarkers, Tumor / Q000378:metabolism; D001943:Breast Neoplasms / Q000209:etiology / Q000378:metabolism* / Q000473:pathology*; D016022:Case-Control Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008593:Menopause; D008875:Middle Aged; D060787:Neoplasm Grading; D009367:Neoplasm Staging; D011379:Prognosis; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism*; D011960:Receptors, Estrogen / Q000378:metabolism*; D011980:Receptors, Progesterone / Q000378:metabolism*; D012307:Risk Factors; D044465:White People / Q000706:statistics & numerical data*
chemical_list: D014408:Biomarkers, Tumor; D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; C508053:ERBB2 protein, human
keywords: Epidemiology; Estrogen receptor; Hormone receptor status; Race; Risk factors