title: Estrogen replacement therapy in women with a history of proliferative breast disease.
abstract: BACKGROUND
  Little information is available regarding the invasive breast carcinoma risk associated with estrogen replacement therapy (ERT) in women with histories of histologically defined breast lesions.
  
  
  METHODS
  A retrospective cohort study of a consecutive series of women who underwent breast biopsies that proved to be benign between 1952-1978 was conducted. Follow-up data were obtained for 9494 women (87.6% of women eligible for follow-up). To investigate the effect of ERT on invasive breast carcinoma risk, the analysis was restricted to women with premenopausal breast disease whose follow-up extended through menopause and who did not develop premenopausal breast carcinoma. Relative risks were calculated with respect to women who took ERT but whose benign breast biopsies had neither atypical hyperplasia (AH), complex fibroadenoma (CFA), nor proliferative disease without atypia (PDWA).
  
  
  RESULTS
  During 190,845 woman-years of follow-up there were 444 confirmed cases of invasive breast carcinoma in the entire cohort. Women with a history of AH had relative risks of invasive breast carcinoma of 2.87 (95% confidence interval [95% CI], 1.3-6.3) and 2.53 (95% CI, 1.0-6.3) if they did or did not take ERT, respectively. For women with a history of CFA these risks were 1.57 (95% CI, 0.72-3.4) and 1.46 (95% CI, 0.53-4.0), respectively, whereas for women with a history of PDWA they were 1.37 (95% CI, 0.88-2.1) and 1.13 (95% CI, 0.69-1.9), respectively.
  
  
  CONCLUSIONS
  ERT does not significantly elevate the risk of invasive breast carcinoma in women with previous histologically defined benign breast disease. Therefore, ERT is not contraindicated in these women.
authors: Department of Preventive Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-2637, USA.
authors: W D
authors: WD
authors: Dupont
authors: D L
authors: DL
authors: Page
authors: F F
authors: FF
authors: Parl
authors: W D
authors: WD
authors: Plummer
authors: P A
authors: PA
authors: Schuyler
authors: M
authors: M
authors: Kasami
authors: R A
authors: RA
authors: Jensen
mesh_terms: D000328:Adult; D001941:Breast Diseases / Q000150:complications*; D001943:Breast Neoplasms / Q000139:chemically induced* / Q000209:etiology / Q000235:genetics; D015331:Cohort Studies; D015914:Estrogen Replacement Therapy / Q000009:adverse effects*; D005260:Female; D018226:Fibroadenoma / Q000150:complications; D006801:Humans; D008875:Middle Aged; D012189:Retrospective Studies; D012306:Risk; D012307:Risk Factors