Hormone replacement therapy (HRT) and breast cancer risk

Does HRT cause breast cancer?

HRT can increase the risk of breast cancer however the increased risk is small and will depend on the type of HRT and how long it is taken.

What is HRT?

HRT is a treatment to help with menopausal symptoms. It increases the level of hormones in the body that naturally reduce during the menopause (when periods stop). For some women, HRT can vastly improve quality of life, and the risks of taking it needs to be balanced against the benefits.

Why does HRT increase breast cancer risk?

It’s not fully understood why HRT increases the risk of breast cancer, but research suggests that this is due to the higher levels of oestrogen. Some (although not all) breast cancers can use oestrogen to help them to grow.

There are some factors that can influence the risk of breast cancer.

• How long you take HRT for. The longer you use HRT, the greater the risk 
• The type of HRT you are taking. Breast cancer risk is greater with combined HRT (which contains oestrogen and progestogen) than with oestrogen-only HRT

Should I take HRT if I have a family history of breast cancer?

If you have inherited the altered breast cancer genes BRCA1 or 2, speak to your family history or genetics specialist before using HRT.

Making the decision to take HRT

Talking to your GP, practice nurse or gynaecologist is a good place to start and will depend on what side effects of the menopause you are experiencing and how they are affecting your everyday life.