Research on menopausal hormone therapy will continue, as will the ongoing debate about benefits versus risks. At this point, HRT—whether in the form of combination HRT or estrogen-only HRT—is not recommended for women who have been diagnosed with breast cancer. There isn’t enough data to know if it is safe in women at high risk of breast cancer, but it’s probably not a good idea.
Women who are diagnosed with hormone receptor-negative (HR-) breast cancer sometimes wonder whether HRT could be okay for them, since the cancer cells don’t appear to have receptors for the growth signals coming from hormones. In reality, though, even HR- cancers can contain some hormone receptor-positive cells (HR+)—and vice versa. And hormone receptor status actually can change over time. So you can’t use your hormone receptor status as an indicator of whether or not HRT is safe for you. Many studies of HRT and breast cancer risk didn’t differentiate between HR+ and HR- cancers, and that may explain some of the variations in results.
Ultimately, you need to make decisions about HRT in partnership with your oncologist, gynecologist, and primary care doctor. Be informed about what is known and not known regarding HRT, and weigh the risks and benefits. For most women with breast cancer or at higher than average risk of breast cancer, the risks outweigh the benefits. If you do choose to use HRT, realize that:
- HRT may interact with or negatively affect your breast cancer therapy.
- It’s best to use the lowest dose needed to provide relief, for the shortest period of time.
- It’s important to periodically re-evaluate whether you still need to be on HRT, because symptoms such as hot flashes often do pass with time, and you will likely find yourself no longer needing HRT.
Also, HRT should be a “treatment of last resort” after trying other strategies discussed in this Menopausal Symptoms section, such as healthy lifestyle changes, stress reduction, and non-hormonal medications. Often this involves trying different solutions in combination before hitting on what works for you. One size definitely does not fit all!
“It’s normal for women to look for a simple answer and a simple solution -- but unfortunately, when it comes to hormones and breast cancer risk, it’s complicated. There are things that the medical world knows, and things that we don’t know about how hormones work. What’s important is this: Understand the issues, the risks and benefits, and make an informed decision based on what we know now. For most women with breast cancer, the risks outweigh the benefits, but this has to be a decision made between you, your physician and your oncologist.”-- Marisa Weiss, M.D., chief medical officer, Breastcancer.org