Menopause Hormone Therapy Does Not Raise Your Risk of Breast Cancer. Here’s Why This Myth Persists

Roughly one-third of a woman’s life is spent in menopause, and the transition can often include life-disrupting symptoms such as hot flashes, night sweats, insomnia, and mental health issues. 

For women suffering from menopause symptoms, hormone therapy (HT) is the most effective way to provide relief. And while once a commonly prescribed treatment in the United States, hormone therapy became a controversial subject seemingly overnight in 2002, after one study in the Women’s Health Initiative (WHI) linked the therapy to health risks for women, in particular an increased risk of breast cancer. 

What we know now: Menopause hormone therapy does not increase the risk of breast cancer. And a new report, “Tis But a Scratch: a critical review of the Women’s Health Initiative evidence associating menopausal hormone therapy with the risk of breast cancer,” published in the journal Menopause, aims to set the record straight. “A generation of women has been deprived of HT largely as a result of this widely publicized misinterpretation of the data,” the authors write.

While hormone therapy, like all medications, carries risks, it has been proven to also have a positive impact on cardiovascular health, as well as improving bone density and reducing the risk of osteoporosis. But despite its benefits, the stigma around hormone therapy still lingers decades later.

To break down the benefits of hormone therapy and explain what went wrong in the WHI, we spoke with OBGYN and menopause specialist, Corinne Menn, a medical advisor and prescribing physician at Alloy. (Don’t miss her two-part recap on Instagram of “Tis But a Scratch,” what she refers to as “one of the most important journal articles to be published in the last 20 years on menopausal hormone therapy.”)

What the Women’s Health Initiative (WHI) Got Wrong

Flow: The WHI (2002) reported that hormone therapy is the most effective treatment for vasomotor symptoms, and any small negative findings that they saw in much older, often unhealthy women simply don’t apply to perimenopausal women or younger menopausal women. Even with all that included in the report, there was so much fear and confusion surrounding the findings that we saw a dramatic drop in women taking hormone therapy.  Why do you think that is?

Dr. Corinne Menn: There is one main reason why there is so much fear and confusion around estrogen, hormone therapy and menopause and this is how the WHI reported and misinterpreted their own findings in 2002 when they halted the study. First, the WHI findings were announced in a highly unusual and unprecedented way — with a highly publicized press conference done prior to the actual publication of their findings, prior to a peer review of the data, and before doctors could read the article. 

The WHI reported statistically insignificant results and portrayed them as being meaningful. They misinterpreted their own data and made highly misleading claims that never applied to the vast majority of women in menopause who seek to use hormone therapy. There was also a strange reluctance for the WHI to highlight the many significant positive findings. The media loves ‘bad news’ and ran with highly inaccurate and misleading headlines, rather than facts. And women’s health has suffered ever since.

The Health Benefits of Menopause Hormone Therapy

Flow: In the years following the WHI, dozens of studies have shown that there are many health benefits of hormone therapy. Can you recap what some of those benefits are?

Related story 3 Lifestyle Changes You Can Make Right Now To Reduce Perimenopause Symptoms

Dr. Corinne Menn: These are the most important facts that we know from the WHI as well as decades of peer reviewed studies:

Why Age Matters

Flow: One of the major critiques of the WHI is that they studied the use of hormone therapy primarily in older women, as opposed to including a more even distribution of women from premenopausal to post-menopausal age. Is age and the time a woman enters menopause important to the benefits of hormone therapy?

Dr. Corinne Menn: Yes, this is one of the most important points I want women to understand, that the average age of women in the WHI were older and less healthy than most women seeking care for bothersome menopause symptoms. The WHI and many other landmark studies have demonstrated that there is a window of opportunity where the tissues, bones, and blood vessels are healthier, where we can prevent many chronic disease states from starting.  

The time frame is in the first 10 years of entering menopause where the benefits are clear and far outweigh any rare risks. The ideal time to start would be when you start having symptoms, as early as the perimenopause or at the time of menopause, which the average is 51. It is also important to note that if you go through menopause a bit later, at say 54, then your “window” is 10-years from then, but the sooner the better. In addition, routine discontinuation after age 60 for arbitrary reasons in women who are otherwise doing well is not supported by ACOG or The Menopause Society, and the 10-year ideal starting window is not the same as duration of therapy.”

Menopause Hormone Therapy Does Not Increase Your Breast Cancer Risk

Flow: The WHI reported that for women taking estrogen plus progesterone saw an increased risk of breast cancer, but that is refuted by their own data. Can you unpack that?

Dr. Corinne Menn: “Yes, hopefully by now the word is out that there were two arms of the study. In one arm, women without a uterus took estrogen alone, and the data has always clearly shown that there was a significant 23 percent decreased risk of breast cancer, and a 40 percent reduction in death from breast cancer. 

The other arm was women who still had their uterus and they were given a combination of estrogen and progestogen. This is where the WHI reporting failed to be transparent and clear. They reported a small increase in breast cancer risk in these women, in addition to one additional case for every 1,000 women per year, but with no increase in breast cancer mortality. But even this conclusion has been highly criticized and disputed. The WHI failed to disclose they were reporting results that were not statistically significant, and they misinterpreted their own data. In fact, on further examination, it is very clear that in women who never used hormone therapy in the past, who started estrogen and progestogen, had no increased risk of breast cancer or dying of breast cancer, even women with a family history of breast cancer.”

For Most Women, the Benefits of Hormone Therapy Outweigh the Risks

Flow: Knowing what we now know about hormone therapy, what are your recommendations as an OBGYN for women who may be scared of the WHI findings?

Dr. Corinne Menn: For the vast majority of women, initiating hormone therapy early in menopause, ideally within the first 10 years, the benefits far outweigh any rare risks. Hormone therapy does not cause breast cancer or raise your risk of getting breast cancer. We have many FDA approved, safe hormone therapy options, in various formulations and doses, including oral and non-oral options like patches, gels, sprays, and rings. The goal of therapy is to treat symptoms while minimizing any side effects, and you should choose the dose and formulation that is best for you.

“I also want to remind women that the genitourinary syndrome of menopause ( GSM) affects most women at some point in menopause with symptoms of vaginal dryness, painful sex, decreased lubrication, urinary urgency, and frequency and increased risk for UTIs.  While systemic hormone therapy can help, local vaginal hormone options are the gold standard to preventing and treating GSM and can vastly improve women’s sexual and urinary health. They are safe to be used on their own or with hormone therapy and are very safe, yet widely underutilized.

I also want women to know that many doctors are misinformed and not educated in the care of menopausal women, including their OB-GYNS. They can look for a provider certified by The Menopause Society. If you are not getting the help you need, keep pushing and asking for it — you are worth it.”