This year, a patient and friend of mine was diagnosed with breast cancer. She was lucky in that her cancer was diagnosed early and, after surgery and radiation, she is for all practical purposes cancer-free. However, any cancer diagnosis comes with a flurry of new information, new vocabulary, and a slew of new doctors.
For women like my friend, a breast cancer diagnosis can come just as they are in the throes of perimenopause. Many of the women diagnosed in their 40s and 50s have estrogen receptor-positive breast cancer. This means that estrogen — which is a common treatment for perimenopause and menopause symptoms — isn’t a good idea, because it can cause the cancer to grow and spread. Over the past several months, my friend and I have had conversations about how best to navigate perimenopause after breast cancer, particularly estrogen receptor-positive breast cancer.
Many of you have asked similar questions over the past several months. And at the end of my most recent conversation with my friend, I knew I wanted to share some of what we have discussed with all of you. Luckily, she was enthusiastic about that too!
I am an endocrinologist, not an oncologist, so I am not going to be talking about the benefits and risks of different treatments to prevent recurrence. Rather, I am going to focus on how those treatments might affect your experience of perimenopause, and how to talk to your oncologist about what to expect and what you might be experiencing.
Who on your team will help manage perimenopause symptoms?
Once your initial treatment is over — it might include surgery, radiation, and/or chemotherapy — the medical oncologist takes the lead. You will have a long-term relationship with them, so find a good fit. You should feel at ease asking them questions and be satisfied that those questions are answered with a level of detail you are comfortable with. It is absolutely fine to meet with more than one doctor to find the right fit.
Your medical oncologist can work with your gynecologist or endocrinologist to manage any perimenopause symptoms you may have.
Why is perimenopause different for some women with breast cancer?
Many of the treatments used to manage breast cancer and prevent recurrence affect a woman’s reproductive hormones. Some forms of chemotherapy can act directly on the ovaries and stop ovulation. In young women, under 40, periods typically resume after chemotherapy is completed. In women over 40, the effects of chemotherapy on ovulation are often permanent — meaning the chemotherapy induces menopause.
In addition to prescribing chemotherapy if it is indicated, your oncologist may also prescribe treatments that reduce the amount of estrogen your body makes or blocks the estrogen from acting on your cells. These medications are given to reduce the risk of breast cancer recurrence. Let’s take a look at how some of the most common hormonal treatments work.
Lupron
Lupron (leuprolide) is one of a group of medications called GnRH agonists. These medications act on the pituitary gland to suppress the hormones that stimulate egg maturation, ovulation, and estrogen production. Thus, they significantly reduce the production of estrogen in the ovaries. In studies of Lupron for the treatment of breast cancer, the main side effects reported were muscle and joint pain, fatigue, hot flushes, and night sweats. These are all typical symptoms of perimenopause and are likely related to the drop in estrogen.
Oophorectomy
Oophorectomy is the surgical removal of the ovaries. Because the ovaries are the main estrogen- and progesterone-producing glands in the body, this procedure effectively reduces those hormone levels to zero, which may be desirable in women with a high risk of recurrence and younger women who might otherwise require medications to suppress ovulation for an extended period of time. As with Lupron, the significant drop in estrogen levels can trigger perimenopause symptoms. As a result of low estrogen levels, the risk of osteoporosis is increased.
Tamoxifen
Tamoxifen is a selective estrogen receptor modulator. In English, that means the drug blocks estrogen activity at some estrogen receptors but not at others. It has been around for a long time (it was first approved by the FDA in 1977), and its benefits are very well understood. Because tamoxifen acts differently in different tissues, it can have fewer and less severe side effects. Many women experience hot flushes and night sweats. Tamoxifen also increases the risk for endometrial cancer and blood clots.
Aromatase inhibitors
Aromatase inhibitors, such as anastrozole and exemestane, block the enzyme aromatase from converting other hormones into estrogen. They are only helpful when women are in menopause or taking GnRH agonists. Aromatase is present in fat — fat is an endocrine organ. Other than estrogen production in the ovaries, the conversion of other hormones into estrogen by aromatase is the main source of estrogen production in the body. Similar to other hormonal treatments for breast cancer, the reduction in estrogen with aromatase inhibitors can lead to muscle and joint pain, hot flushes, night sweats, and fatigue. They also increase the risk for osteoporosis, but have a lower risk of endometrial cancer and blood clots compared with tamoxifen.
What treatments for perimenopause symptoms are safe for breast cancer survivors?
We know that low estrogen causes many of the symptoms women experience during perimenopause and that replacing estrogen effectively treats those symptoms, but for patients with a history of breast cancer, estrogen is typically not an option. In fact, doctors often intentionally keep estrogen low to reduce the risk of recurrence.
As a result, we typically focus on treating symptoms with non-hormonal medications. Medications like Veozah have been shown to effectively treat hot flushes and night sweats without increasing the risk for recurrence.
When it comes to issues related to sexual function and vaginal dryness, there is a great deal of variability regarding what different oncologists are comfortable with, depending on different patients’ histories. Based on studies like this one, some oncologists will support local estrogen for some patients.
Ultimately, managing perimenopausal symptoms in women with a history of breast cancer must be individually tailored based on her symptoms and the details of her cancer history. In my practice, my patients are most satisfied with their perimenopausal symptom management when the patient, the oncologist, and I are all communicating openly with one another about the treatment plan.
What questions might you ask about the recommended treatment?
As with all medications, the key is understanding the benefits of a hormonal treatment for breast cancer as well as the risks, and striking the right balance for the individual patient. As a result, I think the most important conversation to have with your oncologist is one that delves into the details of your specific risk for recurrence.
Doctors have access to calculators that take into account many factors, including technical details about the cells in the tumor and its size, to give an estimate of the individual’s recurrence over time with and without different hormonal treatments.
I also recommend asking what to do if you experience side effects, what the options might be if you do not tolerate the initial treatment, and how long you should try a treatment before discussing making a change.
In my experience, feeling comfortable with the plan, knowing what to expect, and understanding what plan B might look like decreases my patients’ anxiety immensely.
The bottom line
- The same medications that can treat breast cancer and reduce the risk of recurrence can also affect women’s reproductive hormone levels, leading to symptoms of perimenopause.
- Non-hormonal treatments such as Veozah can be used to safely manage symptoms, and, in some cases, vaginal estrogen may be safe.
- Open communication between the patient, the medical oncologist, and the doctor treating perimenopause symptoms — the gynecologist or endocrinologist — is critical to patient satisfaction with their perimenopause symptom management.
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