Breast cancer treatment, menopause and bone health can intersect at a time of life already full of change. For someone diagnosed with breast cancer during a period of age-related hormonal changes, symptoms can seem to compound. Changes in estrogen can affect your treatment plan, bone health and quality of life. In this blog, we walk through changes you may experience, and how to prepare for them with questions and awareness, so your doctor can help you manage any symptoms and protect your bones and long-term health.
What’s happening with hormones during perimenopause and menopause
There’s a transition period leading up to menopause called perimenopause. During that time, hormone levels like estrogen can rise and fall in an imbalanced way. Periods can become irregular, and some people experience symptoms like hot flashes, night sweats, sleep issues or mood changes and vaginal dryness. Generally, you’re considered to have hit menopause when you’ve gone one year without a menstrual period. Thereafter, the ovaries make much less estrogen and progesterone.
The experience of menopause is not the same for everyone. One person may experience mild symptoms, but they may be much more severe or life-disrupting for another.
It’s important to be aware that some breast cancer treatments can affect your natural hormonal timeline and disrupt the way the ovaries work – lowering estrogen levels or causing symptoms that look or feel like menopause, even at times inducing menopause early, which can be especially common in women over the age of 40. In fact, studies have found that treatment-induced menopause can make the symptoms feel more abrupt or severe at first compared to naturally occurring menopause, especially in the case of vasomotor symptoms like hot flashes and night sweats.
Certain treatments accelerate the natural process of menopause or mimic it somewhat abruptly. Chemotherapy can damage the ovaries, which can cause periods to stop or become irregular. Ovarian suppression uses surgery or drug therapy to prevent the ovaries from making estrogen. Additionally, hormone therapies can cause ongoing symptoms common in menopause like hot flashes or vaginal dryness even if the ovaries remain active.
So, if you’re already in your 40s or 50s when breast cancer treatment starts, it can often be unclear if a symptom is related to natural menopause, the treatment or both.
Menopausal status can influence breast cancer treatment
While overall breast cancer treatment is determined mainly based on tumor characteristics (like hormone receptor status, HER2 status and stage), your menopausal status can play a specific role in what hormone therapy is recommended to you – particularly for those with hormone receptor-positive (HR+) breast cancer.
HR+ breast cancer cells have receptors on them that cause them to grow when hormones like estrogen or progesterone are present. Hormone therapies treat breast cancer by interfering with this process, but the specific medication depends on whether or not your ovaries are still making estrogen. For example, tamoxifen can be used before or after menopause because it blocks estrogen from reaching cancer cells. Another type of medication called aromatase inhibitors (AI) can be prescribed after menopause, but they work differently by lowering estrogen production outside of the ovaries. Because of this, postmenopausal people can take an AI on its own whereas premenopausal women need to pair an AI with ovarian suppression to stop the ovaries from making estrogen too.
Breast cancer hormone therapy and menopausal hormone therapy (MHT) are not the same thing
While these therapies sound alike, they’re in fact used for opposite reasons. Breast cancer hormone therapy treats breast cancer. Hormone therapy in the case of breast cancer means blocking or lowering hormone levels since they can fuel cancer growth whereas menopausal hormone therapy (MHT) is used to supplement or add hormones back into the body to help relieve menopausal symptoms. This is important because MHT can increase the risk of recurrence for women with a history of breast cancer. That doesn’t mean though that they should simply deal with menopausal symptoms.
Symptoms related to hormone fluctuations can seriously impact quality of life. Nonhormonal options and other strategies exist. Talk with your health care team about them. Together, you can make a decision about what’s right for you.
Estrogen also plays a role in bone health
In addition to its involvement in things like pregnancy, mood and development – estrogen plays a key role in keeping your bones strong. When estrogen levels fall around menopause, bone loss can happen more quickly, and some breast cancer treatments can even compound it.
Aromatase inhibitors (AIs), for example, increase the risk of osteoporosis and bone fractures. A review of research studies found that women taking AIs had a 35% higher fracture risk than those taking tamoxifen. The tricky thing is that you can’t really notice or feel bone loss happening. They gradually weaken, and for some people a fracture can be the first sign that there’s a problem. This is why discussing bone health with your doctor is important to do before problems develop – not after.
Bone-health assessments can help identify bone loss early, decide a monitoring plan and provide options that may help lower fracture risk. A DEXA (or DXA) scan is a quick, low-dose X-ray that measures bone density to get a snapshot of how strong your bones are at the time of the scan. It’s common for people starting AIs to get these scans before treatment begins and to monitor your bone density over time.
There are proactive ways to protect your bones
- Ask about your bone health early: If your treatment lowers estrogen or you’re at a higher risk for bone loss, be sure to ask questions. Bone density medications (also called bone-modifying agents) may be recommended. The conversation may change over time especially if treatment changes or you shift from perimenopause to menopause.
- Move your bones, not just your muscles: Weight-bearing exercises are especially helpful. This means exercise that supports your own body weight against gravity – think walking, stair climbing, yoga or dancing. Exercise that involves using your own body weight, resistance training and weight-lifting all help preserve your muscles and the bones that support them. These help maintain bone strength, and working on balance is also useful to help reduce falls where fractures often occur. Be sure to discuss with your doctor what exercise is safe and best for you.
- Keep your calcium and vitamin D in mind: Calcium supports bone strength, and vitamin D helps calcium get absorbed. You can seek out calcium rich foods like dairy products, dark leafy greens and foods fortified with it. Vitamin D is in fatty fish and other fortified foods, and it can also be taken as a supplement as needed, especially in months with less sun. Talk with your doctor about recommended supplements that can support your health.
Protecting your bone health during breast cancer treatment also means thinking about the years after treatment.
Midlife and breast cancer treatment can come with a lot of change all at once. You don’t have to siphon different concerns to different doctors or sources of support. Bring up the whole picture from menopausal symptoms to your treatment, bone health and quality of life. Ask how they fit together. Understanding how these changes connect can help you work with your care team to make decisions that support not only the period of your treatment but also how you feel and function through midlife and thereafter.
Content covered in the Know More Educational Series may be an emerging area in research or technology. Talk with your doctor about what is right for you.
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