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Updated: Jun 29, 2026

An Ex vivo Model to Study Hormone Action in the Human Breast
Published on: January 8, 2015
Effects of pre- and postmenopausal use of exogenous hormones on receptor content in normal human breast tissue: a
Gunilla Hallberg1, Ingemar Persson, Tord Naessén
1Department of Women's and Children's Health, Uppsala University, Uppsala, Sweden. gunilla.hallberg@akademiska.se
Objective:
To examine the effects of exposure to endogenous and exogenous hormones on estrogen receptor-alpha (ERalpha) and progesterone receptor (PR) levels in normal human breast tissue.
Methods:
In a randomized study of women scheduled for mammary reduction plasty (n = 81), ERalpha and PR content in breast parenchyma was analyzed in premenopausal (n = 49) and postmenopausal (n = 16) women. Premenopausal women were randomized to surgery in the follicular or luteal phase of the menstrual cycle or after oral contraceptive treatment for 2 months. Postmenopausal women were randomized to sequential or estrogen-only therapy for 2 months prior to surgery.
Results:
ERalpha content was higher in parous than in nulliparous (p = 0.009) premenopausal women and displayed a positive association with age (r(s) = 0.51, p = 0.0002). Compared with premenopausal women in the follicular phase, postmenopausal women had higher ERalpha content (p = 0.040) whereas premenopausal women on oral contraception had lower ERalpha (p = 0.048) and PR (p = 0.007) content. Smokers had lower PR content than non-smokers (p = 0.02).
Conclusion:
In the present study ERalpha content was higher in parous than in non-parous women and associated with premenopausal age. Short-term oral contraceptives yielded lower ERalpha and PR contents. Postmenopausal estrogen/progestogen combined therapy yielded lower PR content than estrogen-only therapy.
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