How I Approach Breast Cancer Survivors with Menopausal Symptoms: Partnering with Patients

Buckle up because I know this is a heavy blog, but the details are important, and this is information patients need to know in order to make an informed decision about HRT.

Menopausal breast cancer and gynecologic cancer survivors are an often forgotten group. In this post, I will discuss breast cancer survivors. In another posts, I will discuss gynecologic cancer survivors.

For patients who have a history of breast cancer, navigating menopause can feel particularly overwhelming. Many women are told they cannot use hormone replacement therapy (HRT) due to concerns about cancer recurrence, leaving them struggling with symptoms like hot flashes, night sweats, joint pain, and vaginal dryness without clear guidance on safe and effective treatment options. But what does the research really say about HRT after breast cancer?

What the Research Says

After the Women's Health Initiative (WHI) study erroneously concluded that HRT causes breast cancer, research on HRT after breast cancer has been limited. There are only two major studies on this topic: the HABITS and Stockholm trials.

HABITS Trial

The HABITS trial suggested an increased risk of local recurrence or contralateral breast cancer in women using HRT after breast cancer but did not show an increased risk of distant metastasis or death from breast cancer. Notably, the trial found no increased recurrence risk in women using estrogen alone, those with positive lymph nodes, or those with ER-negative breast cancer. The only group with an increased risk was women using tamoxifen while on HRT, though the reasons remain unclear. Additionally, many women in the study were not adhering to their assigned treatment groups, creating significant study limitations.

The HABITS trial did not require mammograms before joining the study, making it impossible to know how many of the breast cancers that occurred were present before starting the study.

Stockholm Trial

The Stockholm trial, conducted between 1997 and 2003, found no increased risk of breast cancer recurrence at 10 years in women using HRT.

Broader Research on HRT After Breast Cancer

Between 1980 and 2013, 21 studies examined HRT use in breast cancer survivors, though all had limitations. One study, LIBERATE, is often excluded because it used tibolone, a hormone medication not used in the U.S. Of the remaining 20 studies, only one showed an increased risk of recurrence, while the rest either showed no difference or a reduced risk of recurrence in women using HRT. However, no study is perfect, and we cannot draw absolute conclusions from the data available.

The Benefits of HRT

In fact, the WHI showed that women on estrogen had a decreased risk of breast cancer, and if they did develop cancer, it was less aggressive and they were less likely to die from it.

Despite the uncertainty, we must weigh the benefits of HRT, including its role in preventing heart disease, osteoporosis, and dementia. More women die from heart disease than breast cancer, yet most women who qualify for HRT do not use it due to the lingering effects of the WHI study's misinterpretations. Additionally, breast cancer treatments have improved significantly since many of these studies were conducted.

Individualized Decision-Making

When managing menopausal symptoms in breast cancer survivors, we start by exploring non-hormonal options before considering hormone therapy. Veozah is a new non-hormonal medication specifically designed to help with hot flashes, and there are many other effective treatments available that can be part of a well-rounded approach to care.

For patients on aromatase inhibitors, side effects can sometimes make treatment challenging. My goal is to help you stay on your prescribed medication, but if the side effects become unmanageable, we can discuss alternative options. One option may be switching to tamoxifen, even at a lower dose than is usually prescribed, which can still provide the benefit of hormone blockade for recurrence prevention while carrying a lower risk of blood clots and uterine cancer compared to higher doses.

Another option to consider is bazedoxifene, a combination of estrogen and a selective estrogen receptor modulator (SERM) similar to tamoxifen. This medication blocks estrogen receptors in the breast and uterus while also protecting bone density, making it a useful alternative in some cases.

We can get creative if necessary.

Vaginal Estrogen: A Safe Option

One area of agreement among experts is that vaginal estrogen is safe, even for women on aromatase inhibitors (who often have severe vaginal dryness and atrophy as a result of the medication). Studies show that while aromatase inhibitors may cause a temporary rise in systemic estrogen after vaginal estrogen use, levels return to baseline once the vaginal tissue heals.

In all breast cancer survivors, we should feel comfortable using vaginal estrogen to help with vaginal dryness, pelvic pain, and UTIs.

Testosterone as a Treatment Option

There is evidence to suggest that testosterone may balance estrogen’s stimulatory/growth effects in the breast tissue. However, some subsets of triple-negative breast cancers have testosterone receptors, so we do need to use caution. Testosterone data is limited, but it does not appear to have a negative effect on breast cancer survivors.

The Testosterone in Treating Postmenopausal Patients with Arthralgia Caused by Adjuvant Aromatase Inhibitor Treatment trial, a randomized phase III study, found that testosterone may help relieve moderate or severe joint pain associated with aromatase inhibitors.

The Safety and Efficacy of Topical Testosterone in Breast Cancer Patients Receiving Ovarian Suppression and Aromatase Inhibitor Therapy study suggests that topical testosterone seems to be safe and may be effective in improving sexual function in patients on ovarian suppression and AI.

Final Thoughts

If you are a breast cancer survivor looking for a physician who will partner with you to navigate menopause, I would be honored to support you through this journey.

While breast cancer recurrences can happen, there is no strong evidence that HRT directly causes recurrence. Rather than a blanket “no”, patients deserve comprehensive education and the opportunity to make informed decisions about their treatment options.

If you are experiencing significant side effects from an aromatase inhibitor, taking a short "medication holiday" for 2-3 months may help determine if those symptoms are truly medication-related. This is a reasonable approach under medical supervision.

For those of us who treat breast cancer survivors for menopausal symptoms, we often feel more comfortable considering HRT more than five years after diagnosis and treatment, even in cases of triple-negative breast cancer. Additionally, in younger patients who have not had their ovaries removed, ovary reactivation may occur after completing breast cancer treatment, which is an important factor to consider in symptom management.

HRT and managing menopausal symptoms after breast cancer is complicated, but it is my deepest desire to be available for patients who are looking for exactly this type of care. Patients have a right to informed consent, and I am would love to partner with them and their oncologist to help them feel more like themselves again.

Acknowledgment

Thankful for Dr. Avrum Bluming, oncologist and author of Estrogen Matters, and Dr. Corinne Menn, ObGyn and breast cancer survivor, for their education about HRT after breast cancer.

I also recommend the Menopause and Breast Cancer podcast featuring Dr. Dani Binnington for further education on this important topic.

Also, follow Dr. Eleanor Teplinski to keep up with the latest data on breast cancer.