Related Experiment Video
Updated: Aug 15, 2026
06:18
An In Vivo Estrogen Deficiency Mouse Model for Screening Exogenous Estrogen Treatments of Cardiovascular Dysfunction After Menopause
Published on: August 13, 2019
Menopausal Estrogen Therapy and Risk of Breast Cancer
Andrew M Kaunitz1, Jason D Wright
1Department of Obstetrics & Gynecology, University of Florida College of Medicine-Jacksonville, Jacksonville, Florida; and the Department of Obstetrics & Gynecology, Tufts School of Medicine, Boston, Massachusetts.
Obstetrics and Gynecology
|August 13, 2026
Summary
Estrogen-only therapy may reduce breast cancer risk in women post-hysterectomy. Further research is needed, but current evidence suggests potential benefits for high-risk individuals.
Area of Science:
- Oncology
- Endocrinology
- Gynecology
Background:
- Menopausal hormone therapy (MHT) use is common among postmenopausal women.
- Estrogen-only therapy is prescribed for women who have undergone hysterectomy.
- Breast cancer risk is a significant concern for many women, particularly those with genetic predispositions like BRCA mutations.
Purpose of the Study:
- To review current evidence on the effect of estrogen-only therapy on breast cancer risk in women who have had a hysterectomy.
- To inform clinical decision-making regarding MHT for women at risk of breast cancer.
Main Methods:
- Meta-analysis of 10 randomized trials involving 14,282 participants at population risk.
- Matched prospective cohort study of 676 patients with BRCA mutations and intact breasts.
Main Results:
- Meta-analysis showed estrogen therapy was associated with a reduced risk of breast cancer (RR 0.77; 95% CI, 0.65-0.91).
- BRCA mutation carriers using estrogen alone had a lower 15-year cumulative incidence of breast cancer (24.3%) compared to non-users (47.3%).
Conclusions:
- Estrogen-only therapy may decrease breast cancer risk in women post-hysterectomy, including those with BRCA mutations.
- Shared decision-making is crucial for counseling women at risk about MHT, considering various health risks and benefits.
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