Hormone replacement therapy (HRT) and breast cancer risk

1. Taking hormone replacement therapy (HRT) can increase the risk of breast cancer
2. The risk is higher with combined HRT compared to oestrogen-only HRT
3. The risk is higher the longer you take HRT
4. For many women the benefits of taking HRT will outweigh the risks
5. You can reduce your risk of breast cancer by limiting alcohol, keeping to a healthy weight and being physically active regularly

For most people the risk of developing breast cancer because of taking HRT is small.

Around 2 in every 100 breast cancers in the UK are thought to be linked to taking HRT.

The risk of breast cancer:

• Is higher with combined HRT (containing oestrogen and progestogen) than with oestrogen-only HRT
• Is higher if you take HRT for over 5 years or started taking HRT at an older age (when breast cancer risk increases naturally)

The increased risk reduces over time after you stop taking HRT.

Vaginal HRT, which contains low doses of oestrogen, does not increase the risk of breast cancer.

We don’t know for certain why HRT increases the risk of breast cancer.

Research suggests it’s due to higher levels of hormones in the body when you’re taking HRT. Some breast cancers use hormones to help them grow.

Benefits and risks

For many women the benefits of taking HRT outweigh the increased risk of breast cancer.

The main benefit of HRT is that it can relieve menopausal symptoms such as hot flushes, night sweats and vaginal dryness.

Guidance recommends HRT should be used at the lowest dose for the shortest amount of time needed to relieve symptoms.

However, HRT may not be effective for everyone.

Who to talk to

Your GP can talk to you about the different options to manage menopausal symptoms and answer your questions about HRT.  

You can find out more about the menopause and HRT on the Women’s Health Concern and Menopause Matters websites.

Alternatives to HRT

If you choose not to take or cannot take HRT, there are alternatives that may help manage some menopausal symptoms.

These include:

• Making lifestyle changes such as eating a healthy, balanced diet and being physically active
• Keeping to a healthy body weight
• Taking other non-hormonal medicines that can be prescribed for menopausal symptoms
• Cognitive behavioural therapy (CBT), a type of talking therapy
• Vitamin and herbal supplements

If you’ve had breast cancer

HRT is not usually recommended if you’ve had a diagnosis of breast cancer.

This is because there’s uncertainty about whether HRT increases the risk of breast cancer coming back.

There are alternative options for managing menopausal symptoms, such as lifestyle changes and non-hormonal medication. Vaginal oestrogen may be considered to treat vaginal dryness.

You can talk to your breast care nurse, treatment team or GP about options for managing menopausal symptoms. You can also ask to be referred to a specialist menopause clinic for support.

If you have a family history of breast cancer

If you have a family history of breast cancer, your GP or family history clinic can help you decide if HRT is right for you.

National guidance recommends you take HRT for as short a duration and as low a dose as needed.

The risk from taking HRT will differ depending on your family history and other risk factors such as your age and lifestyle.

Your genetics team can advise whether HRT is suitable if you have a moderate or high risk of developing breast cancer, or you have an altered breast cancer gene such as BRCA1 or BRCA2.