Menopausal Hormone Therapy After Breast Cancer

Taking post-menopausal hormone therapy (PHT), also called hormone replacement therapy (HRT), to help with menopause symptoms may not be safe for women who have had breast cancer. If you are bothered by menopause symptoms, talk to your doctor about ways to get relief.

Many women have menopause symptoms such as hot flashes after treatment for breast cancer. This can happen naturally as women get older, but it can also be caused by some breast cancer treatments. Some pre-menopausal women have menopause symptoms as a result of chemotherapy or from hormone therapy drugs used to treat breast cancer (such as tamoxifen and aromatase inhibitors). Women who are past menopause might also get symptoms if they had to stop taking PHT when they were diagnosed with breast cancer.

Can I take menopausal hormone therapy after breast cancer?

When women reach menopause, some choose to take PHT, which is made up of female hormones (estrogen, sometimes along with progesterone) to help reduce menopause symptoms. But there have been concerns about women who have had breast cancer using PHT, because of the known link between estrogen levels and breast cancer growth.

A well-designed clinical trial (the HABITS study) found that breast cancer survivors taking PHT were much more likely to develop a new or recurrent breast cancer (cancer that comes back after treatment) than women who were not taking these hormones. Because of this, doctors generally do not recommend PHT if a woman was previously treated for breast cancer.

Relieving menopausal symptoms without hormone therapy

If you are having trouble with menopause symptoms, such as hot flashes, talk to your doctor about ways other than PHT to help with specific symptoms. Some women might want to try using non-hormonal medicines or other methods first to see if they help.

Losing weight

Some women find that losing weight helps with menopausal symptoms such as hot flashes.

Diet and dietary supplements

Some women find that changing the way they eat, such as eating smaller meals and avoiding ‘triggers’ (such as spicy foods) is helpful for them.

The effects of specific foods and dietary supplements on menopausal symptoms are not clear. This doesn’t mean they won’t help, but it’s important to understand that the evidence supporting their use is limited.

Phytoestrogens: These are estrogen-like substances found in certain plants, such as soy, red clover, and black cohosh. Some women take supplements containing these substances to try to help with symptoms of menopause.

Eating soy foods seems to be safe for breast cancer survivors, although it’s not clear if it can help relieve menopause symptoms. Women can get higher doses of phytoestrogens in some dietary supplements (such as soy or isoflavone supplements). However, not enough is known about these supplements to know for sure if they are safe and if they work. If you are considering taking one of these supplements, be sure to talk with your doctor first.

Exercise, relaxation techniques, and behavioral therapies

Some women find these types of approaches help them with menopausal symptoms. Although there is only limited research showing these techniques might be helpful, there’s likely to be little harm in trying them. Before starting any exercise program after being diagnosed with breast cancer, it’s important to speak with your doctor or someone on your health care team.

Some research has suggested that acupuncture might be helpful in treating hot flashes, although not all studies have found this. This might be another option to discuss with your doctor.

Non-hormone medicines for hot flashes

Drugs without hormone properties that may be helpful in treating hot flashes include:

• Certain antidepressant drugs, such as venlafaxine (Effexor), citalopram (Celexa), or paroxetine (Paxil)*
• The nerve drug gabapentin (Neurontin)
• The blood pressure drug clonidine
• Oxybutynin, a drug used to treat overactive bladder
• Fezolinetant (Veozah), a drug that targets the nervous system activity that can lead to hot flashes

*If you are taking tamoxifen, it's important to note that some antidepressants can interact with tamoxifen and could make it less effective. Ask your doctor about any possible interactions between tamoxifen and any drugs you are taking.

Treatments for vaginal dryness

Vaginal dryness and discomfort can be bothersome menopausal symptoms for some women.

Several non-hormone treatments, including vaginal moisturizers, lubricants, and gels, are available to help treat vaginal dryness. If these aren't helpful, low-dose hormonal rings, tablets, capsules, or creams that are put directly into the vagina might be helpful.

Devices that use lasers or other forms of energy to 'rejuvenate' vaginal tissue are now being studied as well, although it's not yet clear how helpful they might be. It's important to discuss the possible risks and benefits of these treatments with your doctor before deciding if one is right for you.