title: Use of hormone therapy and isoflavones and mammographic density in Spain.
abstract: The use of some forms of hormone therapy (HT) is associated with an increase in mammographic density-a major risk factor for breast cancer. The role of isoflavones, however, is unclear. Here, we quantify the prevalence of HT and isoflavone use among postmenopausal Spanish women, determine associated risk factors, and explore the relationship between these therapies and mammographic density.
  
  
  
  This cross-sectional study included 2,754 postmenopausal women who underwent breast cancer screening in seven geographical areas. Mammographic density was evaluated using Boyd's semiquantitative scale. Multinomial logistic regression models were adjusted to assess risk factors associated with both therapies. Ordinal regression models were fitted to study the association between HT and isoflavone consumption with mammographic density.
  
  
  
  The prevalence of ever-use of HT was 12%, whereas that of the current use was 2.3%. Isoflavone lifetime prevalence was 3.7%, and current use was 1.7%. The most common HT types were tibolone and estrogens. Surgical menopause, oral contraceptive use, educational level, population density, and years since menopause were positively associated with HT, whereas body mass index and parity were inversely associated. Mammographic density was not associated with current or past HT use. However, women who reported having consumed isoflavones in the past and those who started their use after menopause had a higher mammographic density when compared with never-users (odds ratio 1.98, 95% CI 1.21-3.25, P = 0.007; and odds ratio 1.60, 95% CI 1.01-2.53, P = 0.045 respectively).
  
  
  
  Our results show a low prevalence of HT and isoflavone use in postmenopausal Spanish women. In this population, HT use was not associated with mammographic density, whereas some categories of isoflavone users had higher density.
authors.affiliation: 1Cancer and Environmental Epidemiology Unit, National Center for Epidemiology, Carlos III Institute of Health, Madrid, Spain 2Department of Preventive Medicine, HM Hospitals, Madrid, Spain 3Consortium for Biomedical Research in Epidemiology and Public Health (CIBER Epidemiología y Salud Pública, CIBERESP, Spain 4Cancer Epidemiology Research Group, Oncology and Hematology Area, IIS Puerta de Hierro (IDIPHIM), Madrid, Spain 5Castile-León Breast Cancer Screening Programme, General Directorate Public Health SACYL, Burgos, Castile-León, Spain 6Balearic Islands Breast Cancer Screening Programme, Health Promotion for Women and Childhood, General Directorate Public Health and Participation, Regional Authority of Health and Consumer Affairs, Balearic Islands, Palma de Mellorca, Spain 7Galicia Breast Cancer Screening Programme, Regional Authority of Health, Galicia Regional Government, Corunna, Spain 8Aragon Breast Cancer Screening Programme, Health Service of Aragon, Zaragoza, Spain 9Cancer Prevention and Control Unit, Catalan Institute of Oncology (ICO), Barcelona, Spain 10Valencia Breast Cancer Screening Programme, General Directorate Public Health, Valencia, Spain 11FISABIO, Valencia, Spain 12Navarra Breast Cancer Screening Programme, Public Health Institute, Pamplona, Spain.
authors.forename: Beatriz
authors.initials: B
authors.lastname: Isidoro
authors.forename: Virginia
authors.initials: V
authors.lastname: Lope
authors.forename: Denis
authors.initials: D
authors.lastname: Whelan
authors.forename: Carmen
authors.initials: C
authors.lastname: Pedraz
authors.forename: Carmen
authors.initials: C
authors.lastname: Sánchez-Contador
authors.forename: Carmen
authors.initials: C
authors.lastname: Santamariña
authors.forename: Pilar
authors.initials: P
authors.lastname: Moreo
authors.forename: Carmen
authors.initials: C
authors.lastname: Vidal
authors.forename: Dolores
authors.initials: D
authors.lastname: Salas-Trejo
authors.forename: María
authors.initials: M
authors.lastname: Ederra
authors.forename: Nuria
authors.initials: N
authors.lastname: Aragonés
authors.forename: Beatriz
authors.initials: B
authors.lastname: Pérez-Gómez
authors.forename: Marina
authors.initials: M
authors.lastname: Pollán
mesh_terms: D000368:Aged; D000071060:Breast Density / Q000187:drug effects*; D001943:Breast Neoplasms / Q000000981:diagnostic imaging / Q000209:etiology; D003430:Cross-Sectional Studies; D055088:Early Detection of Cancer / Q000379:methods; D015914:Estrogen Replacement Therapy / Q000009:adverse effects*; D004967:Estrogens / Q000009:adverse effects; D005260:Female; D006801:Humans; D007529:Isoflavones / Q000009:adverse effects*; D008327:Mammography / Q000379:methods*; D008875:Middle Aged; D009652:Norpregnenes / Q000009:adverse effects; D017698:Postmenopause / Q000187:drug effects*; D013030:Spain
chemical_list: D004967:Estrogens; D007529:Isoflavones; D009652:Norpregnenes; C027385:tibolone