Study Suggests Hysterectomy and Oophorectomy Linked to Reduced Breast Cancer Risk

Can Surgery Lower Breast Cancer Risk?

For decades, the relationship between hysterectomy (removal of the uterus), oophorectomy (removal of the ovaries), and breast cancer risk has been debated. Now, a sweeping meta-analysis published in the Archives of Gynecology and Obstetrics provides some clear new insights—backed by data from nearly six million women.

What Did the Study Look At?

Researchers analyzed 12 high-quality studies (nine cohort, three case-control), covering over 5.8 million women from several countries. They compared women who had undergone hysterectomy and/or oophorectomy to those who hadn’t, calculating the risk of developing breast cancer.

Key Findings: Surgery and Risk Reduction

Both hysterectomy and oophorectomy were linked to a 16% reduction in breast cancer risk (HR 0.84).

Hysterectomy alone dropped breast cancer risk by 13% (HR 0.87).

Bilateral oophorectomy (removal of both ovaries) reduced risk by 19% (HR 0.81).

Unilateral oophorectomy (removal of one ovary) did not significantly affect risk.

Hormone therapy after bilateral oophorectomy provided a 20% additional risk reduction, while not using hormone therapy showed no significant benefit.

Timing matters: Bilateral oophorectomy before menopause reduced breast cancer risk by 13%. The same procedure after menopause had no significant effect.

Why Does This Happen?

The researchers suggest that the risk reduction may be due to lower estrogen and progesterone levels after these surgeries—two hormones closely tied to breast cancer development. However, findings varied based on age, hormone therapy use, and whether one or both ovaries were removed.

Should These Surgeries Be Done for Prevention?

While the results are compelling, the authors caution that surgery decisions should always be based on individual medical needs—not just risk reduction. More research is needed to fully understand the biological mechanisms and to guide clinical recommendations.

Key Takeaways:

Hysterectomy and especially bilateral oophorectomy are linked to lower breast cancer risk.

The protective effect is strongest when both ovaries are removed before menopause—especially with hormone therapy.

Unilateral oophorectomy and postmenopausal surgery have little or no impact on breast cancer risk.

Surgery decisions should be highly personalized and not based solely on cancer risk.

Further research is needed to clarify long-term effects and biological mechanisms.

Citation:

Wang B, Wang M, Xu H, Liu Y, Kang T, Cao Y. Association between hysterectomy, oophorectomy, and risk of breast cancer: a meta-analysis. Archives of Gynecology and Obstetrics. 2025;312:2031–2042. doi:10.1007/s00404-025-08179-0