Warning over risks of HRT prompts urgent inquiry

The Government has ordered an urgent investigation into an American study that highlighted the risks of hormone replacement therapy.

Downing Street said independent advisers had been asked to examine the findings of the five-year study, which was abandoned when scientists found the risks of the therapy outweighed its benefits.

Researchers in the United States – where HRT doses differ to those in Britain – said it increased the risk of breast cancer by 26 per cent, heart attacks and other coronary events by 29 per cent, and strokes by 41 per cent.

Benefits included a 37 per cent reduction in bowel cancer, and hip fracture rates were reduced by a third.

Lord Hunt of Kings Heath, a Health minister, has asked the Committee on the Safety of Medicines to examine the study, published in the Journal of the American Medical Association.

Tony Blair's spokesman said the committee would report back to ministers after considering any further implications of the Women's Health Initiative study – run by the US National Heart, Lung and Blood Institute – and updating its advice as necessary.

The Royal College of Obstetricians and Gynaecologists insisted that women taking HRT should not be alarmed. Peter Bowen-Simpkins, representing the college, said the figures were based on relative not absolute risks. He said: "When you look at the cardiovascular rates, there was an increase from 30 to 37 cases per 10,000, which is 0.07 per cent increased risk overall. The risk is very, very small indeed. We always explain to patients about these risks and they are very, very small risks in absolute numbers."

He advised women who were concerned to speak to their GP but felt most were already well informed about what they were using. "The research is very similar to what we already knew," he said. "The cancer rates haven't altered our opinions at all and, in fact, look better than we had thought, but patients must weigh up the risks with any benefits."

One proponent of HRT, the former MP Teresa Gorman, warned women not to be scared by the "shock horror report". She said: "A five-year study is not a long study. It's absolute nonsense to scare women off this kind of treatment.

"My message to women is don't stop taking the tablets. There's massive evidence that the quality of life for women is much, much greater when they are accessing this treatment," said the former MP for Billericay, who is over 70.

"It's something with a proven track record and that's what matters to me and that's what should matter to other women," she added.

A spokeswoman said the Medicines Control Agency and the committee explained that doctors were informed of the risk of breast cancer in an article three months ago.

She said: "Product information is also already being updated to warn prescribers and patients that the risk of breast cancer in association with combined oestrogen/progestogen HRT may be increased relative to oestrogen only therapy."

The doctor who led the research, Jacque Rossouw, also tried to calm fears yesterday by insisting: "It's not an urgent alert situation. There's no emergency here."

But he added: "In the longer term, if you use hormone replacement therapy for several years, you are not likely to gain health – you are likely to lose health."