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It’s no exaggeration to say that we’re on the verge of a menopause care revolution in this country. Two decades after the infamous Women’s Health Initiative (WHI) study broadly (and misleadingly) linked hormone therapy (HT) to breast cancer, better science and increased advocacy for midlife women’s health have transformed the treatment landscape.
But there’s a huge group of women who are unfairly excluded from HT: breast cancer survivors. Prevailing dogma dictates that once you’ve had this disease, you can’t ever take HT, because those hormones will make the cancer come back. (Women with a history of hormonal cancers, like ovarian and uterine cancer, are told the same thing.) But this guidance is based in fear, not solid science—and it’s gatekeeping the relief and protection of HT from more than 4 million breast cancer survivors in the U.S.
To be clear: Hormones your body naturally makes don’t cause cancer on their own. Yes, they may feed a cancer that already exists, which is why hormone withdrawal medications are often part of cancer treatment. But they can’t magically make cancer show up.
This isn’t wishful thinking. The data we have now provides more nuance and assurances about the safety of modern HT formulations. Vaginal estrogen, which is used to help with dryness and other symptoms of genitourinary syndrome of menopause (GSM), has been proven time and time again to be safe and effective—which is why the FDA ruled in 2025 that these medications no longer needed a scary “black box” warning label.
When it comes to systemic HT after breast cancer, there have only been a few human trials post-WHI. At first glance, the news doesn’t seem good. The Hormonal Replacement Therapy After Breast Cancer—Is It Safe? (HABITS) trial, which came out right after the WHI, examined how safe it was for women who had survived breast cancer to take HT. It was stopped early after more women on HT seemed to develop breast cancer. But there’s a caveat: The study didn’t require a mammogram to rule out existing breast cancer before participants entered the trial, so it’s hard to say whether any new cases of breast cancer were actually “new” or had already been present. The study also used synthetic progestins, not the oral micronized progesterone that’s the standard of care today, making its findings less relevant for the modern woman.
Then there was the Stockholm trial, which followed hundreds of Swedish breast cancer survivors in the late ’90s and early 2000s. Like HABITS, it wanted to see if HT was linked to breast cancer recurrence among survivors. Unlike HABITS, it was designed to limit the amount of progestins women took. And that seemingly made a difference, because after 4.1 and 10.8 years of follow-up, there was no difference in the number of new breast cancer cases between women taking systemic HT and the control group.
A few other studies have looked into the issue over the years, but they don’t always drill down into what kind of hormones women are taking. And as we’ve learned from newer studies, the type and amount of progestin used in HT really makes a difference in breast cancer risk. Not all breast cancers are created equal, either: triple-negative, HER2-positive or -negative, and ductal carcinoma in situ all operate differently in how they grow and spread, and they’re treated differently. (While there is limited data on the safety of HT for women with hormonal cancers like ovarian and uterine, what we do know should guide us to make the best decisions we can now, rather than wait for studies that may never come.)
The good news is we’ve done an incredible job at treating breast cancer. The five-year relative survival rate is nearly 92 percent, although that number differs depending on the specific type of cancer and when it was diagnosed. Now, it’s time to consider survivors’ quality of life after cancer. These women, like all other women, are going to get hot flashes, they’re going to suffer bone loss, they’re going to have brain fog, night sweats, vaginal dryness, recurrent urinary tract infections, and libido changes. Don’t they deserve protection against osteoporosis and GSM? Don’t they deserve to have the best possible life after enduring the ravages of cancer treatment? Don’t they deserve a choice in how to care for their bodies?
It’s long past time for us to move away from the blanket ban against HT for breast cancer survivors—a position that’s starting to emerge in new papers and cancer treatment organizations, but is taking way too long to hit mainstream care. Patients deserve to have an individualized conversation with their doctors. Together, they’d factor in the patient’s cancer history (including what type she had and how long ago she had it) and her specific potential risk of recurrence. Then they’d unpack her current menopause symptoms and goals. A doctor can then lay out both the lifestyle things that can help her feel better—diet, sleep, exercise, cutting back on alcohol, stress management, and nonhormonal treatments—as well as what hormonal options could help, too.
Not everyone will be a candidate for HT. Some women might have a uniquely high risk of recurrence, or had a cancer that is super responsive to hormones. Some women may decide hormones aren’t right for them. But survivors deserve to at least have an evidence-based discussion with their doctor.
How is it even possible to change a cancer paradigm? Our road map is prostate cancer treatment. When I was training as a urologist 20 years ago, I was taught that testosterone caused prostate cancer, and that patients who survived could never have testosterone again. Sound familiar? But better data and an intentional shift toward prioritizing men’s quality of life radically transformed our perspective. Now, many men are able to take testosterone therapy after prostate cancer to support their sexual and functional health. We can change this dogma with breast cancer, too—when we decide education, autonomy, and individual risk-benefit decision-making are better than fear.
At the end of the day, we have to care about women’s quality of life as much as we care about men’s. Why are we okay with letting breast cancer survivors suffer when there isn’t really the data there to justify it? The benefits of this treatment are so clear. (In fact, we need to have a better discussion about the risks of not taking HT after menopause.) And we can no longer justify gatekeeping it from a group of women who have endured so much already.
Kelly Casperson, MD, is a board-certified urologist, midlife health expert, and author of the books The Menopause Moment and You Are Not Broken. She also hosts the podcast You Are Not Broken and is a critical thinker in the women’s empowerment space.
