A large study in the US has raised safety concerns about the long-term use of hormone replacement therapy (HRT) in postmenopausal women.

In this trial, women who were taking a particular combination of oestrogen and progestogen (for 5.2 years on average), were found to have an increased risk of heart attack, breast cancer, stroke and blood clots on the lungs. They also had a reduced risk of bowel cancer and hip fractures. Overall, however, the risks of treatment outweighed the benefits, suggesting that this particular combination of hormones should not be used long-term for preventing conditions such as heart disease or osteoporosis.

We do not know whether these results apply to women taking other preparations, such as hormone patches, gels, implants or even other (different) hormones by mouth.

In Australia, most women use HRT for short-term use (1-3 years) to treat menopausal symptoms such as hot flushes. Short-term treatment is safe and HRT may still be used for this purpose.

The new findings do not apply to women who have had a hysterectomy and are taking oestrogen only. Oestrogen, on its own, appears to cause fewer serious side effects.

Women taking combined oestrogen and progestogen for 5 years or more should discuss their particular circumstances with their doctor. Go to http://www.jeanhailes.org.au/ for more information.