Effect of postmenopausal hormonal replacement therapy on mammographic density and parenchymal pattern

Radiology. 1995 Aug;196(2):433-7. doi: 10.1148/radiology.196.2.7617857.


Purpose: To measure changes and predictors of change in mammograms obtained in postmenopausal women undergoing continuous combined hormonal replacement therapy (HRT).

Materials and methods: Mammograms of 41 postmenopausal women obtained before and 1 year after the initiation of HRT were evaluated blindly according to the quantitative density percentage method and the Wolfe classification system.

Results: Mammographic densities increased compared with baseline values in 73% of subjects (mean increase, 6.7%; 95% confidence interval, 2.5%, 11.0%; P = .003). A shift in Wolfe classification from lower to greater parenchymal density was noted in 24% of subjects (P = .016). Multivariate analysis results indicated that the lower the tissue density percentage before treatment, the greater the increase in density percentage after treatment.

Conclusion: An increase in mammographic density was demonstrated in most subjects undergoing continuous combined HRT and was most pronounced in subjects with a lower baseline density percentage.

Publication types

  • Clinical Trial
  • Comparative Study
  • Randomized Controlled Trial

MeSH terms

  • Breast / anatomy & histology
  • Breast / drug effects*
  • Breast Neoplasms / diagnostic imaging*
  • Breast Neoplasms / epidemiology
  • Breast Neoplasms / etiology
  • Estrogen Replacement Therapy* / adverse effects
  • Estrogens, Conjugated (USP) / administration & dosage
  • Estrogens, Conjugated (USP) / pharmacology
  • Female
  • Humans
  • Mammography / statistics & numerical data
  • Medroxyprogesterone Acetate / administration & dosage
  • Medroxyprogesterone Acetate / pharmacology
  • Middle Aged
  • Multivariate Analysis
  • Risk Factors


  • Estrogens, Conjugated (USP)
  • Medroxyprogesterone Acetate