It’s a common misconception that menopausal hormone therapy (MHT) causes breast cancer. But this misconception and others about MHT could be standing between you and relief.

You might’ve heard that menopausal hormone therapy (MHT) is closely tied to breast cancer. But that’s not the whole story.

Learn the facts about this relationship and how to make an informed decision for yourself.

A note on wording

A previous term for MHT was hormone replacement therapy. The new name, MHT, more accurately reflects that menopause is a natural process rather than an illness.

Your menopause transition may involve common symptoms, such as hot flashes, night sweats (collectively known as vasomotor symptoms), and vaginal dryness.

How long you’ll experience these symptoms varies. For some people, they may continue into postmenopause. The intensity of these symptoms will also vary for everyone.

Whether you classify your symptoms as severe or not, MHT is an effective treatment — and one of the most effective at that — to manage symptoms of menopause.

But there are some facts to know about why it’s been linked to breast cancer before you decide if it’s for you.

Past research has labeled MHT as “clearly” associated with an increased risk of breast cancer, and this label has almost become synonymous with MHT since the publication of a 2006 study.

This study is just one example of many that are part of the ongoing debate over the safety of MHT.

Many experts have reacted to this particular study and others similar in nature, citing their findings as overstating the risks of breast cancer.

Your risk will also depend on:

These are three important considerations for when you and your doctor are discussing using MHT. They’re related to the following misconceptions:

All forms of menopausal hormone therapy have the same breast cancer risk

ET, in particular, is associated with lower breast cancer risk compared to EPT. It may even lower breast cancer occurrence and death, but more research is needed to support this finding.

Menopausal hormone therapy always significantly increases breast cancer risk

Your risk for breast cancer is determined on a case-by-case basis, not from the results of any one study. Individual risk is often small, too.

A 2023 research review suggests a small increase in breast cancer — 1 in 1,000 women per year — for EPT from animal-obtained estrogen.

All people face the same risk when using menopausal hormone therapy

Your family history (since breast cancer has a genetic component), your age at menopause onset, and duration of use all influence your risk profile.

If you’re considering MHT, your doctor will provide a personalized risk assessment rather than a blanket recommendation against MHT.

Since the release of the 2006 study’s weak findings, more research has been and is being conducted to strengthen this area of knowledge, especially in doses and duration of MHT usage.

A 2019 studyTrusted Source of 58 past studies, which included 143,887 postmenopausal women with invasive breast cancer and 424,972 who didn’t develop it, aimed to do just that.

While its results continue to support that the risk of breast cancer is higher for people who use MHT than those who don’t, there’s more to it. It also found that risk:

  • increases with duration of use, particularly beyond 5 years
  • is higher for EPT than ET
  • is very low for less than 1 year of use
  • didn’t significantly differ between the main estrogenic constituents (synthetic versus bioidentical estrogen) or by administration (transdermal or oral)
  • is very low for topical vaginal estrogen formulations
  • profile is more favorable for starting closer to menopause onset (within 5 years), which ranges between ages 45 and 55 yearsTrusted Source on average

It’s important to note that some data from the study are from older observational studies of formulations and doses of MHT that doctors no longer recommend.

But for a study of long-term effects, some older data are necessary.

This means that the findings aren’t generalizable to modern MHT regimens and younger women.

Despite the associated adverse risk of breast cancer, the relief that MHT can provide in the short term from your symptoms may outweigh it.

Ultimately, the decision is up to you and your doctor’s recommendations based on your personal risk. If you choose to try MHT, continuing with regular screenings for breast cancer is important.

Benefits of MHT

Risks of MHT

The relationship between breast cancer and menopausal hormone therapy is a complicated one.

But this topic is riddled with misconceptions about the degree of breast cancer risk, who’s at risk, and the therapies that may cause it. Current research aims to correct these.

Consider speaking with your doctor about an individualized risk assessment. They may just tell you that the benefits outweigh the risks in your case.

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