HRT doubles danger of breast cancer says study

Women taking the most common form of hormone replacement therapy in Britain are twice as likely to develop breast cancer, the world's largest study on the treatment's risks has concluded.

An extra 2000 British women a year are developing the disease because of HRT, researchers have warned.

The results have prompted New Zealand authorities to consider whether medical advice for women using HRT drugs should be reviewed. The risks associated with the combined oestrogen-progestogen HRT are far higher than previously thought and begin much earlier than doctors had assumed.

Tens of thousands of New Zealand women take some form of combined HRT therapy.

Breast cancer is the biggest killer of women in Britain, with 1000 deaths a month from the disease.

In New Zealand, about 2000 women are diagnosed with breast cancer each year and about 600 die from it.

This week, the British Government's Committee on Safety of Medicines sent emails and faxes telling all National Health Service doctors and other health professionals of the new findings, published in the Lancet.

The advice stops short of telling doctors to take women off combined HRT.

Dr Mary Armitage, chairwoman of the committee's steering group on HRT, said for most women the benefits outweighed the risks for short-term use.

Long-term, however, women needed to discuss other options with their doctors, she said.



NZ Health Ministry spokesman Dr Stewart Jessamine said the British study would be considered at the meeting of the Medicines Adverse Reactions Committee next month to see if advice needed to be changed.

Guidelines released last September recommended that HRT therapy be limited to the early stages of menopause, and only if the symptoms were disruptive to the woman's quality of life.



The research in the Lancet involved more than a million women, making it the world's largest study on HRT and breast cancer.

Smaller studies have suggested that women on combined HRT are 26 per cent more likely than others to develop breast cancer.

But the Million Women study, as it is called, concluded that combined HRT users are 100 per cent more likely to get the disease.

It is already known that oestrogen-only HRT preparations, less popular than combined products, carry a 30 per cent higher risk of breast cancer.

The risk for both types begins within a year of starting an HRT course, and increases in proportion to the duration on the treatment.

* Two medical studies published in the New England Journal of Medicine this week found that giving older women hormones does not protect them from heart disease.

One study found it increased the risk of a heart attack by 81 per cent in the first year.

- INDEPENDENT, Additional reporting: Rebecca Walsh