title: Combined conjugated esterified estrogen plus methyltestosterone supplementation and risk of breast cancer in postmenopausal women.
abstract: OBJECTIVE
  Testosterone supplementation is being prescribed increasingly to treat symptoms of hormone deficiency in pre- and postmenopausal women; however, studies of the association of testosterone therapy, alone or in combination with estrogen, with risk of breast cancer are limited. The current study assessed the association of combination conjugated esterified estrogen and methyltestosterone (CEE+MT) use and breast cancer risk in postmenopausal women in the Women's Health Initiative (WHI).
  
  
  METHODS
  At Year 3 of follow-up, women in the WHI observational study (N=71,964) provided information on CEE+MT use in the past two years, duration of use, and the brand name of the product. In addition, in each of years 4-8, women were asked whether they had used CEE+MT in the previous year. After 10 years of follow-up, 2832 incident breast cancer cases were identified. Cox proportional hazards models were used to estimate hazard ratios (HR) and 95% confidence intervals (95% CI) for the association of CEE+MT use (irrespective of use of other hormones) and of exclusive CEE+MT use in relation to breast cancer risk.
  
  
  RESULTS
  Neither CEE+MT use nor exclusive use of CEE+MT was associated with risk: multivariable-adjusted HR 1.06, 95% CI 0.82-1.36 and HR 1.22, 95% CI 0.78-1.92, respectively. Among women with a natural menopause, the HR for exclusive use was 1.32 (95% CI 0.68-2.55). There was no indication of an association when repeated measures of CEE+MT use were included in a time-dependent covariates analysis.
  
  
  CONCLUSIONS
  The present study, the largest prospective study to date, did not show a significant association of CEE+MT supplementation and risk of breast cancer.
authors.affiliation: Department of Epidemiology and Population Health, Albert Einstein College of Medicine, Bronx, NY, United States. Electronic address: geoffrey.kabat@einstein.yu.edu.
authors.forename: Geoffrey C
authors.initials: GC
authors.lastname: Kabat
authors.affiliation: Department of Epidemiology and Population Health, Albert Einstein College of Medicine, Bronx, NY, United States.
authors.forename: Victor
authors.initials: V
authors.lastname: Kamensky
authors.affiliation: Department of Epidemiology and Population Health, Albert Einstein College of Medicine, Bronx, NY, United States.
authors.forename: Moonseong
authors.initials: M
authors.lastname: Heo
authors.affiliation: Department of Medicine, Arizona Cancer Center, Tucson, AZ, United States.
authors.forename: Jennifer W
authors.initials: JW
authors.lastname: Bea
authors.affiliation: Department of Preventive Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States.
authors.forename: Lifang
authors.initials: L
authors.lastname: Hou
authors.affiliation: Department of Preventive Medicine, School of Medicine, State University of New York at Stony Brook, Stony Brook, NY, United States.
authors.forename: Dorothy S
authors.initials: DS
authors.lastname: Lane
authors.affiliation: Departments of Epidemiology and Medicine, Brown University, Providence, RI, United States.
authors.forename: Simin
authors.initials: S
authors.lastname: Liu
authors.affiliation: Department of Public Health Sciences, School of Medicine, University of California at Davis, Davis, CA, United States.
authors.forename: LiHong
authors.initials: L
authors.lastname: Qi
authors.affiliation: Karmanos Cancer Institute, Detroit, MI, United States.
authors.forename: Michael S
authors.initials: MS
authors.lastname: Simon
authors.affiliation: Department of Social and Preventive Medicine, School of Public Health and Health Professions, University at Buffalo, Buffalo, NY, United States.
authors.forename: Jean
authors.initials: J
authors.lastname: Wactawski-Wende
authors.affiliation: Department of Epidemiology and Population Health, Albert Einstein College of Medicine, Bronx, NY, United States.
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Rohan
mesh_terms: D000367:Age Factors; D000368:Aged; D000428:Alcohol Drinking; D015992:Body Mass Index; D001943:Breast Neoplasms / Q000209:etiology*; D003276:Contraceptives, Oral / Q000627:therapeutic use; D004522:Educational Status; D015914:Estrogen Replacement Therapy / Q000379:methods*; D004966:Estrogens, Conjugated (USP) / Q000627:therapeutic use*; D042724:Estrogens, Esterified (USP) / Q000627:therapeutic use*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007182:Income / Q000706:statistics & numerical data; D008327:Mammography / Q000706:statistics & numerical data; D008423:Maternal Age; D008777:Methyltestosterone / Q000627:therapeutic use*; D008875:Middle Aged; D011159:Population Surveillance; D017698:Postmenopause; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012307:Risk Factors; D012907:Smoking; D044465:White People / Q000706:statistics & numerical data
chemical_list: D003276:Contraceptives, Oral; D004966:Estrogens, Conjugated (USP); D042724:Estrogens, Esterified (USP); D008777:Methyltestosterone
keywords: Androgens; Breast cancer; Conjugated esterified estrogen plus methyltestosterone supplementation; Postmenopausal women