title: Distribution of mammographic density and its influential factors among Chinese women.
abstract: BACKGROUND
  Mammographic density (MD) has not been systematically investigated among Chinese women. Breast cancer screening programmes provided detailed information on MD in a large number of asymptomatic women.
  
  
  METHODS
  In the Multi-modality Independent Screening Trial (MIST), we estimated the association between MD and its influential factors using logistic regression, adjusting for age, body mass index (BMI) and study area. Differences between Chinese and other ethnic groups with respect to MD were also explored with adjustment for age and BMI.
  
  
  RESULTS
  A total of 28 388 women aged 45 to 65 years, who had been screened by mammography, were enrolled in the study. Of these, 49.2% were categorized as having dense breasts (BI-RADS density 3 and 4) and 50.8% as fatty breasts (BI-RADS density 1 and 2). Postmenopausal status [odds ratio (OR) = 0.66; 95% confidence interval (CI): 0.62-0.70] and higher number of live births (OR = 0.56; 95% CI: 0.46-0.68) were inversely associated with MD, whereas prior benign breast disease (OR = 1.48; 95% CI: 1.40-1.56) and later age at first birth (OR = 1.17; 95% CI: 1.08-1.27) were positively associated with MD. In comparison with the data from the Breast Cancer Surveillance Consortium, we found that women in MIST were more likely to have fatty breasts than Americans (from the Breast Cancer Surveillance Consortium) in the older age group (≥50 years) but more likely to have dense breasts in the younger age group (<50 years).
  
  
  CONCLUSIONS
  This study suggests that several risk factors for breast cancer were associated with breast density in Chinese women. Information on the determinants of mammographic density may provide valuable insights into breast cancer aetiology.
authors.affiliation: Department of Epidemiology and Biostatistics and Department of Breast Imaging, Key Laboratory of Cancer Prevention and Therapy, Tianjin, Key Laboratory of Breast Cancer Prevention and Therapy, Ministry of Education, National Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China, Prevention and Cure Center of Breast Disease, Third Hospital of Nanchang, Nanchang, China, Department of Medical Image and Department of Cancer Prevention and Control, Liaoning Cancer Institute and Hospital, Shenyang, China, Center for Breast Disease, Haidian Maternal and Child Health Hospital, Beijing, China, Department of Radiology, Key Laboratory of Cancer Prevention and Therapy, Tianjin, Key Laboratory of Breast Cancer Prevention and Therapy, Ministry of Education, National Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China, Department of Health Statistics, School of Public Health, Tianjin Medical University, Tianjin, China and Chinese Anti-Cancer Association, Tianjin, China chenkexin@tijmu.edu.cn yezhaoxiang@163.com.
authors.forename: Hongji
authors.initials: H
authors.lastname: Dai
authors.affiliation: Department of Epidemiology and Biostatistics and Department of Breast Imaging, Key Laboratory of Cancer Prevention and Therapy, Tianjin, Key Laboratory of Breast Cancer Prevention and Therapy, Ministry of Education, National Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China, Prevention and Cure Center of Breast Disease, Third Hospital of Nanchang, Nanchang, China, Department of Medical Image and Department of Cancer Prevention and Control, Liaoning Cancer Institute and Hospital, Shenyang, China, Center for Breast Disease, Haidian Maternal and Child Health Hospital, Beijing, China, Department of Radiology, Key Laboratory of Cancer Prevention and Therapy, Tianjin, Key Laboratory of Breast Cancer Prevention and Therapy, Ministry of Education, National Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China, Department of Health Statistics, School of Public Health, Tianjin Medical University, Tianjin, China and Chinese Anti-Cancer Association, Tianjin, China chenkexin@tijmu.edu.cn yezhaoxiang@163.com.
authors.forename: Ye
authors.initials: Y
authors.lastname: Yan
authors.affiliation: Department of Epidemiology and Biostatistics and Department of Breast Imaging, Key Laboratory of Cancer Prevention and Therapy, Tianjin, Key Laboratory of Breast Cancer Prevention and Therapy, Ministry of Education, National Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China, Prevention and Cure Center of Breast Disease, Third Hospital of Nanchang, Nanchang, China, Department of Medical Image and Department of Cancer Prevention and Control, Liaoning Cancer Institute and Hospital, Shenyang, China, Center for Breast Disease, Haidian Maternal and Child Health Hospital, Beijing, China, Department of Radiology, Key Laboratory of Cancer Prevention and Therapy, Tianjin, Key Laboratory of Breast Cancer Prevention and Therapy, Ministry of Education, National Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China, Department of Health Statistics, School of Public Health, Tianjin Medical University, Tianjin, China and Chinese Anti-Cancer Association, Tianjin, China.
authors.forename: Peishan
authors.initials: P
authors.lastname: Wang
authors.affiliation: Department of Epidemiology and Biostatistics and Department of Breast Imaging, Key Laboratory of Cancer Prevention and Therapy, Tianjin, Key Laboratory of Breast Cancer Prevention and Therapy, Ministry of Education, National Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China, Prevention and Cure Center of Breast Disease, Third Hospital of Nanchang, Nanchang, China, Department of Medical Image and Department of Cancer Prevention and Control, Liaoning Cancer Institute and Hospital, Shenyang, China, Center for Breast Disease, Haidian Maternal and Child Health Hospital, Beijing, China, Department of Radiology, Key Laboratory of Cancer Prevention and Therapy, Tianjin, Key Laboratory of Breast Cancer Prevention and Therapy, Ministry of Education, National Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China, Department of Health Statistics, School of Public Health, Tianjin Medical University, Tianjin, China and Chinese Anti-Cancer Association, Tianjin, China.
authors.forename: Peifang
authors.initials: P
authors.lastname: Liu
authors.affiliation: Department of Epidemiology and Biostatistics and Department of Breast Imaging, Key Laboratory of Cancer Prevention and Therapy, Tianjin, Key Laboratory of Breast Cancer Prevention and Therapy, Ministry of Education, National Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China, Prevention and Cure Center of Breast Disease, Third Hospital of Nanchang, Nanchang, China, Department of Medical Image and Department of Cancer Prevention and Control, Liaoning Cancer Institute and Hospital, Shenyang, China, Center for Breast Disease, Haidian Maternal and Child Health Hospital, Beijing, China, Department of Radiology, Key Laboratory of Cancer Prevention and Therapy, Tianjin, Key Laboratory of Breast Cancer Prevention and Therapy, Ministry of Education, National Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China, Department of Health Statistics, School of Public Health, Tianjin Medical University, Tianjin, China and Chinese Anti-Cancer Association, Tianjin, China.
authors.forename: Yali
authors.initials: Y
authors.lastname: Cao
authors.affiliation: Department of Epidemiology and Biostatistics and Department of Breast Imaging, Key Laboratory of Cancer Prevention and Therapy, Tianjin, Key Laboratory of Breast Cancer Prevention and Therapy, Ministry of Education, National Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China, Prevention and Cure Center of Breast Disease, Third Hospital of Nanchang, Nanchang, China, Department of Medical Image and Department of Cancer Prevention and Control, Liaoning Cancer Institute and Hospital, Shenyang, China, Center for Breast Disease, Haidian Maternal and Child Health Hospital, Beijing, China, Department of Radiology, Key Laboratory of Cancer Prevention and Therapy, Tianjin, Key Laboratory of Breast Cancer Prevention and Therapy, Ministry of Education, National Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China, Department of Health Statistics, School of Public Health, Tianjin Medical University, Tianjin, China and Chinese Anti-Cancer Association, Tianjin, China.
authors.forename: Li
authors.initials: L
authors.lastname: Xiong
authors.affiliation: Department of Epidemiology and Biostatistics and Department of Breast Imaging, Key Laboratory of Cancer Prevention and Therapy, Tianjin, Key Laboratory of Breast Cancer Prevention and Therapy, Ministry of Education, National Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China, Prevention and Cure Center of Breast Disease, Third Hospital of Nanchang, Nanchang, China, Department of Medical Image and Department of Cancer Prevention and Control, Liaoning Cancer Institute and Hospital, Shenyang, China, Center for Breast Disease, Haidian Maternal and Child Health Hospital, Beijing, China, Department of Radiology, Key Laboratory of Cancer Prevention and Therapy, Tianjin, Key Laboratory of Breast Cancer Prevention and Therapy, Ministry of Education, National Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China, Department of Health Statistics, School of Public Health, Tianjin Medical University, Tianjin, China and Chinese Anti-Cancer Association, Tianjin, China.
authors.forename: Yahong
authors.initials: Y
authors.lastname: Luo
authors.affiliation: Department of Epidemiology and Biostatistics and Department of Breast Imaging, Key Laboratory of Cancer Prevention and Therapy, Tianjin, Key Laboratory of Breast Cancer Prevention and Therapy, Ministry of Education, National Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China, Prevention and Cure Center of Breast Disease, Third Hospital of Nanchang, Nanchang, China, Department of Medical Image and Department of Cancer Prevention and Control, Liaoning Cancer Institute and Hospital, Shenyang, China, Center for Breast Disease, Haidian Maternal and Child Health Hospital, Beijing, China, Department of Radiology, Key Laboratory of Cancer Prevention and Therapy, Tianjin, Key Laboratory of Breast Cancer Prevention and Therapy, Ministry of Education, National Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China, Department of Health Statistics, School of Public Health, Tianjin Medical University, Tianjin, China and Chinese Anti-Cancer Association, Tianjin, China.
authors.forename: Tie
authors.initials: T
authors.lastname: Pan
authors.affiliation: Department of Epidemiology and Biostatistics and Department of Breast Imaging, Key Laboratory of Cancer Prevention and Therapy, Tianjin, Key Laboratory of Breast Cancer Prevention and Therapy, Ministry of Education, National Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China, Prevention and Cure Center of Breast Disease, Third Hospital of Nanchang, Nanchang, China, Department of Medical Image and Department of Cancer Prevention and Control, Liaoning Cancer Institute and Hospital, Shenyang, China, Center for Breast Disease, Haidian Maternal and Child Health Hospital, Beijing, China, Department of Radiology, Key Laboratory of Cancer Prevention and Therapy, Tianjin, Key Laboratory of Breast Cancer Prevention and Therapy, Ministry of Education, National Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China, Department of Health Statistics, School of Public Health, Tianjin Medical University, Tianjin, China and Chinese Anti-Cancer Association, Tianjin, China.
authors.forename: Xiangjun
authors.initials: X
authors.lastname: Ma
authors.affiliation: Department of Epidemiology and Biostatistics and Department of Breast Imaging, Key Laboratory of Cancer Prevention and Therapy, Tianjin, Key Laboratory of Breast Cancer Prevention and Therapy, Ministry of Education, National Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China, Prevention and Cure Center of Breast Disease, Third Hospital of Nanchang, Nanchang, China, Department of Medical Image and Department of Cancer Prevention and Control, Liaoning Cancer Institute and Hospital, Shenyang, China, Center for Breast Disease, Haidian Maternal and Child Health Hospital, Beijing, China, Department of Radiology, Key Laboratory of Cancer Prevention and Therapy, Tianjin, Key Laboratory of Breast Cancer Prevention and Therapy, Ministry of Education, National Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China, Department of Health Statistics, School of Public Health, Tianjin Medical University, Tianjin, China and Chinese Anti-Cancer Association, Tianjin, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Wang
authors.affiliation: Department of Epidemiology and Biostatistics and Department of Breast Imaging, Key Laboratory of Cancer Prevention and Therapy, Tianjin, Key Laboratory of Breast Cancer Prevention and Therapy, Ministry of Education, National Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China, Prevention and Cure Center of Breast Disease, Third Hospital of Nanchang, Nanchang, China, Department of Medical Image and Department of Cancer Prevention and Control, Liaoning Cancer Institute and Hospital, Shenyang, China, Center for Breast Disease, Haidian Maternal and Child Health Hospital, Beijing, China, Department of Radiology, Key Laboratory of Cancer Prevention and Therapy, Tianjin, Key Laboratory of Breast Cancer Prevention and Therapy, Ministry of Education, National Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China, Department of Health Statistics, School of Public Health, Tianjin Medical University, Tianjin, China and Chinese Anti-Cancer Association, Tianjin, China.
authors.forename: Zhenhua
authors.initials: Z
authors.lastname: Yang
authors.affiliation: Department of Epidemiology and Biostatistics and Department of Breast Imaging, Key Laboratory of Cancer Prevention and Therapy, Tianjin, Key Laboratory of Breast Cancer Prevention and Therapy, Ministry of Education, National Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China, Prevention and Cure Center of Breast Disease, Third Hospital of Nanchang, Nanchang, China, Department of Medical Image and Department of Cancer Prevention and Control, Liaoning Cancer Institute and Hospital, Shenyang, China, Center for Breast Disease, Haidian Maternal and Child Health Hospital, Beijing, China, Department of Radiology, Key Laboratory of Cancer Prevention and Therapy, Tianjin, Key Laboratory of Breast Cancer Prevention and Therapy, Ministry of Education, National Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China, Department of Health Statistics, School of Public Health, Tianjin Medical University, Tianjin, China and Chinese Anti-Cancer Association, Tianjin, China.
authors.forename: Xueou
authors.initials: X
authors.lastname: Liu
authors.affiliation: Department of Epidemiology and Biostatistics and Department of Breast Imaging, Key Laboratory of Cancer Prevention and Therapy, Tianjin, Key Laboratory of Breast Cancer Prevention and Therapy, Ministry of Education, National Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China, Prevention and Cure Center of Breast Disease, Third Hospital of Nanchang, Nanchang, China, Department of Medical Image and Department of Cancer Prevention and Control, Liaoning Cancer Institute and Hospital, Shenyang, China, Center for Breast Disease, Haidian Maternal and Child Health Hospital, Beijing, China, Department of Radiology, Key Laboratory of Cancer Prevention and Therapy, Tianjin, Key Laboratory of Breast Cancer Prevention and Therapy, Ministry of Education, National Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China, Department of Health Statistics, School of Public Health, Tianjin Medical University, Tianjin, China and Chinese Anti-Cancer Association, Tianjin, China.
authors.forename: Chuan
authors.initials: C
authors.lastname: Chen
authors.affiliation: Department of Epidemiology and Biostatistics and Department of Breast Imaging, Key Laboratory of Cancer Prevention and Therapy, Tianjin, Key Laboratory of Breast Cancer Prevention and Therapy, Ministry of Education, National Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China, Prevention and Cure Center of Breast Disease, Third Hospital of Nanchang, Nanchang, China, Department of Medical Image and Department of Cancer Prevention and Control, Liaoning Cancer Institute and Hospital, Shenyang, China, Center for Breast Disease, Haidian Maternal and Child Health Hospital, Beijing, China, Department of Radiology, Key Laboratory of Cancer Prevention and Therapy, Tianjin, Key Laboratory of Breast Cancer Prevention and Therapy, Ministry of Education, National Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China, Department of Health Statistics, School of Public Health, Tianjin Medical University, Tianjin, China and Chinese Anti-Cancer Association, Tianjin, China.
authors.forename: Yubei
authors.initials: Y
authors.lastname: Huang
authors.affiliation: Department of Epidemiology and Biostatistics and Department of Breast Imaging, Key Laboratory of Cancer Prevention and Therapy, Tianjin, Key Laboratory of Breast Cancer Prevention and Therapy, Ministry of Education, National Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China, Prevention and Cure Center of Breast Disease, Third Hospital of Nanchang, Nanchang, China, Department of Medical Image and Department of Cancer Prevention and Control, Liaoning Cancer Institute and Hospital, Shenyang, China, Center for Breast Disease, Haidian Maternal and Child Health Hospital, Beijing, China, Department of Radiology, Key Laboratory of Cancer Prevention and Therapy, Tianjin, Key Laboratory of Breast Cancer Prevention and Therapy, Ministry of Education, National Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China, Department of Health Statistics, School of Public Health, Tianjin Medical University, Tianjin, China and Chinese Anti-Cancer Association, Tianjin, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Epidemiology and Biostatistics and Department of Breast Imaging, Key Laboratory of Cancer Prevention and Therapy, Tianjin, Key Laboratory of Breast Cancer Prevention and Therapy, Ministry of Education, National Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China, Prevention and Cure Center of Breast Disease, Third Hospital of Nanchang, Nanchang, China, Department of Medical Image and Department of Cancer Prevention and Control, Liaoning Cancer Institute and Hospital, Shenyang, China, Center for Breast Disease, Haidian Maternal and Child Health Hospital, Beijing, China, Department of Radiology, Key Laboratory of Cancer Prevention and Therapy, Tianjin, Key Laboratory of Breast Cancer Prevention and Therapy, Ministry of Education, National Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China, Department of Health Statistics, School of Public Health, Tianjin Medical University, Tianjin, China and Chinese Anti-Cancer Association, Tianjin, China.
authors.forename: Yaogang
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Epidemiology and Biostatistics and Department of Breast Imaging, Key Laboratory of Cancer Prevention and Therapy, Tianjin, Key Laboratory of Breast Cancer Prevention and Therapy, Ministry of Education, National Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China, Prevention and Cure Center of Breast Disease, Third Hospital of Nanchang, Nanchang, China, Department of Medical Image and Department of Cancer Prevention and Control, Liaoning Cancer Institute and Hospital, Shenyang, China, Center for Breast Disease, Haidian Maternal and Child Health Hospital, Beijing, China, Department of Radiology, Key Laboratory of Cancer Prevention and Therapy, Tianjin, Key Laboratory of Breast Cancer Prevention and Therapy, Ministry of Education, National Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China, Department of Health Statistics, School of Public Health, Tianjin Medical University, Tianjin, China and Chinese Anti-Cancer Association, Tianjin, ChinaDepartment of Epidemiology and Biostatistics and Department of Breast Imaging, Key Laboratory of Cancer Prevention and Therapy, Tianjin, Key Laboratory of Breast Cancer Prevention and Therapy, Ministry of Education, National Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China, Prevention and Cure Center of Breast Disease, Third Hospital of Nanchang, Nanchang, China, Department of Medical Image and Department of Cancer Prevention and Control, Liaoning Cancer Institute and Hospital, Shenyang, China, Center for Breast Disease, Haidian Maternal and Child Health Hospital, Beijing, China, Department of Radiology, Key Laboratory of Cancer Prevention and Therapy, Tianjin, Key Laboratory of Breast Cancer Prevention and Therapy, Ministry of Education, National Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tian
authors.forename: Xishan
authors.initials: X
authors.lastname: Hao
authors.affiliation: Department of Epidemiology and Biostatistics and Department of Breast Imaging, Key Laboratory of Cancer Prevention and Therapy, Tianjin, Key Laboratory of Breast Cancer Prevention and Therapy, Ministry of Education, National Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China, Prevention and Cure Center of Breast Disease, Third Hospital of Nanchang, Nanchang, China, Department of Medical Image and Department of Cancer Prevention and Control, Liaoning Cancer Institute and Hospital, Shenyang, China, Center for Breast Disease, Haidian Maternal and Child Health Hospital, Beijing, China, Department of Radiology, Key Laboratory of Cancer Prevention and Therapy, Tianjin, Key Laboratory of Breast Cancer Prevention and Therapy, Ministry of Education, National Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China, Department of Health Statistics, School of Public Health, Tianjin Medical University, Tianjin, China and Chinese Anti-Cancer Association, Tianjin, China chenkexin@tijmu.edu.cn yezhaoxiang@163.com.
authors.forename: Zhaoxiang
authors.initials: Z
authors.lastname: Ye
authors.affiliation: Department of Epidemiology and Biostatistics and Department of Breast Imaging, Key Laboratory of Cancer Prevention and Therapy, Tianjin, Key Laboratory of Breast Cancer Prevention and Therapy, Ministry of Education, National Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China, Prevention and Cure Center of Breast Disease, Third Hospital of Nanchang, Nanchang, China, Department of Medical Image and Department of Cancer Prevention and Control, Liaoning Cancer Institute and Hospital, Shenyang, China, Center for Breast Disease, Haidian Maternal and Child Health Hospital, Beijing, China, Department of Radiology, Key Laboratory of Cancer Prevention and Therapy, Tianjin, Key Laboratory of Breast Cancer Prevention and Therapy, Ministry of Education, National Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China, Department of Health Statistics, School of Public Health, Tianjin Medical University, Tianjin, China and Chinese Anti-Cancer Association, Tianjin, China chenkexin@tijmu.edu.cn yezhaoxiang@163.com.
authors.forename: Kexin
authors.initials: K
authors.lastname: Chen
mesh_terms: D000368:Aged; D044466:Asian People / Q000706:statistics & numerical data*; D000071060:Breast Density; D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000453:epidemiology; D002681:China / Q000453:epidemiology; D055088:Early Detection of Cancer; D005260:Female; D006801:Humans; D016015:Logistic Models; D042361:Mammary Glands, Human / Q000002:abnormalities*; D008875:Middle Aged; D016017:Odds Ratio; D010298:Parity; D017698:Postmenopause; D011859:Radiography
keywords: Mammography; breast density; ethnicity; hormone; reproduction