title: Reproductive and Hormonal Factors Associated with Fatty or Dense Breast Patterns among Korean Women.
abstract: OBJECTIVE
  Dense breasts have been suggested as a risk factor for breast cancer, but controversy still remains. This study evaluates the association of reproductive and hormonal factors with dense breasts among Korean women.
  
  
  METHODS
  Using a cross-sectional design, 516 women were recruited and classified for breast density patterns as being either fatty or dense, using the Breast Imaging Reporting and Data System (BI-RADS) of the American College of Radiology. Univariate and multivariate logistic regression models were used for statistical analysis.
  
  
  RESULTS
  In univariate logistic regression, older age, higher body mass index, older age at menarche, and oral contraceptive use were associated with more fatty breasts. On the contrary, longer duration of education, alcohol consumption, lower parity, menopause and use of hormone replacement therapy were associated with dense breasts. After adjustment, age and body mass index were inversely associated with breast density (p-value for trend <0.01, respectively), whereas nulliparous and premenopausal status were positively associated. Compared to women who had ≥2 children, nulliparous women had an 11.8-fold increase of dense breasts (p-value for trend <0.01). Compared to postmenopausal women, premenopausal women had 2.4-fold increase of dense breasts (odds ratio, 2.42; 95% confidence interval, 1.36 to 4.32).
  
  
  CONCLUSIONS
  Young age, lower body mass index, lower parity, and premenopausal status were significantly associated with dense breasts in Korea.
authors.affiliation: Department of Medicine, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Jei-Hun
authors.initials: JH
authors.lastname: Jeon
authors.forename: Jung-Hyun
authors.initials: JH
authors.lastname: Kang
authors.forename: Yeonju
authors.initials: Y
authors.lastname: Kim
authors.forename: Hoo-Yeon
authors.initials: HY
authors.lastname: Lee
authors.forename: Kui Son
authors.initials: KS
authors.lastname: Choi
authors.forename: Jae Kwan
authors.initials: JK
authors.lastname: Jun
authors.forename: Dong-Kwan
authors.initials: DK
authors.lastname: Oh
authors.forename: Chang Yoon
authors.initials: CY
authors.lastname: Lee
authors.forename: Kyungran
authors.initials: K
authors.lastname: Ko
authors.forename: Eun-Cheol
authors.initials: EC
authors.lastname: Park