While menopause has existed for a long time, there’s been a recent surge in attention toward it, particularly in what’s being referred to as the “menopause moment.” This has sparked a national dialogue about the topic.
One treatment option, known as menopausal hormone therapy, can help alleviate various troublesome symptoms like hot flashes, and for some, it can enhance overall quality of life. Additionally, it may offer benefits for heart health and bone density.
However, following findings from the Women’s Health Initiative—an extensive study that identified a heightened risk of breast cancer linked to hormone therapy—there was a notable decline in prescriptions. This created a climate of fear surrounding hormone therapy among both providers and patients.
Over time, criticisms and inconsistencies related to the study’s results have led to a reevaluation of the data. Moreover, the Food and Drug Administration has started to eliminate stringent warnings associated with hormone therapy for menopause, as of late 2025.
This raises questions for the one in eight women expected to face a breast cancer diagnosis at some point in their lives.
The FDA’s adjustments point to a gray area when it comes to determining who might gain from menopausal hormone therapy and which specific formulations pose the least risk. From my perspective as a gynecologist with a focus on breast cancer care, these new guidelines highlight the necessity of personalized treatment—especially for breast cancer survivors, who have historically been advised against hormone therapy.
Menopause and breast cancer survivors
In the United States, breast cancer is the most frequently diagnosed cancer among women. Notably, incidences of breast cancer are rising among women under 50, showing a yearly increase of 1.4% from 2012 to 2021.
Survivors might face menopausal symptoms related to their natural age or as side effects of their cancer treatments. For younger patients, breast cancer therapies could push them into menopause either temporarily or permanently by affecting ovarian function, and sometimes, ovaries are removed due to increased ovarian cancer risk.
These changes can limit the body’s hormone production, such as estrogen, consequently raising the risk of cardiovascular issues and osteoporosis for young breast cancer survivors.
Menopausal hormone therapy has the potential to reduce health risks encountered by these survivors. Research indicates estrogen-based therapies can lower overall mortality rates in younger patients and improve quality of life. They’re particularly effective in treating hot flashes, one of the more unpleasant symptoms of menopause.
There’s a considerable subset of breast cancer survivors who could reap the benefits of menopausal hormone therapy. however, healthcare practitioners often shy away from this treatment due to the belief it might heighten the chances of recurrence for these patients.
And yet, the associated research is mixed.
Deconstructing the data
Much of the anxiety around menopausal hormone therapy can be traced back to the Women’s Health Initiative. Critics have pointed out its limitations over the years.
Specifically, while it indeed found an increased breast cancer risk for participants using hormone therapy, that risk was identified among older individuals aged 50 to 79. This led to the “timing hypothesis,” suggesting that certain demographics might experience more advantage and less risk from hormone therapy based on age.
Results also varied by the type of treatment formulation used. The most widely administered version of progesterone today is considered safer than what was used in the Women’s Health Initiative. While using estrogen with progesterone raised breast cancer risk, those taking estrogen alone didn’t demonstrate the same increased risk.
Additionally, the Women’s Health Initiative didn’t specifically explore the impact of menopausal hormone therapy on breast cancer risk in survivors.
Deconstructing even more data
Another pivotal study known as “Hormone Replacement Therapy After Breast Cancer – Is It Safe?” (HABITS) investigated the safety of hormone therapy for those with a breast cancer history. It was halted early in 2003, revealing that 26 out of 219 women receiving hormone therapy developed breast cancer, compared to only 8 out of 215 women who did not.
Similar to the Women’s Health Initiative, the HABITS study drew attention for suggesting that hormone therapy posed significant risks for breast cancer survivors.
Still, researchers later challenged findings from the HABITS study, voicing concerns about the treatment formulations used. Furthermore, the breast cancer characteristics for some participants were not disclosed, potentially skewing the results.
A follow-up ten years later showed no substantial difference in breast cancer recurrence between those who had or had not received hormone therapy. Likewise, neither the HABITS nor the Stockholm trials indicated elevated mortality rates linked to hormone therapy in these survivors.
The initial increase in recurrences noted in HABITS could have been linked to higher progesterone exposure. Ultimately, due to the premature termination of these studies, no definitive conclusions can be drawn.
Conflicting research
Many additional studies have produced varying outcomes.
A smaller clinical trial found that breast cancer survivors with estrogen-negative tumors, who were treated with estrogen alone for five years, did not show significant increases in breast cancer risk.
Conversely, a meta-analysis including data from four clinical trials demonstrated a notable rise in recurrence risk for hormone receptor-positive survivors treated with both estrogen and progesterone, but no comparable increase for those with hormone-negative tumors.
Moreover, over twenty studies over recent decades have reported no significant uptick in new breast cancer activity, recurrences, or fatalities among survivors who utilized hormone therapy. Some of this research even indicated a potentially lower risk of breast cancer linked to particular hormone therapy formulations.
However, these findings have not garnered as much attention as the major trials like the Women’s Health Initiative and HABITS, which are seen as the gold standards in research despite their limitations and the contradictory results seen in smaller studies.
Personalized care for breast cancer survivors
The removal of stringent warnings for hormone therapy doesn’t translate to automatic safety or suitability for every patient, regardless of age. Rather, it opens up the floor for discussions between patients and healthcare providers about individual eligibility and risks.
Research suggests various risk factors could influence breast cancer risk, though their interactions remain somewhat unclear. Factors like age, breast cancer subtype, and hormone therapy formulation might each play distinct roles.
Considering these complexities, a nuanced risk-benefit analysis and collaborative decision-making regarding treatment could provide a more practical and comprehensive approach to determining if and when breast cancer survivors should consider hormone therapy.
The concept of precision medicine—which focuses on tailoring treatments to individual patient needs—has increasingly become central in healthcare. I believe that the adjustment in warnings around hormone therapy presents a vital opportunity to advance personalized and holistic care for breast cancer survivors.
