UK HRT study 'should continue'

Millions of women take HRT worldwide

Research into hormone replacement therapy should continue in the UK even though a similar trial in the US was stopped early, medical experts have said.

Five thousand women have already been recruited to take part in a £20m study in the UK.

I hope very much that the women currently in the trial will wish to stay in it and that many more women will join in the future

Professor Rory Collins

By the time it ends in 2012, 16,000 will have taken part.

The aim of the study, led by researchers from the Medical Research Council, is to discover whether HRT lowers or increases the risk of developing diseases sch as breast cancer, osteoporosis, heart problems and dementia.

It was announced last week that a similar study into the long term effects of HRT was ended early in the US after it produced evidence of a significant increased risk of breast cancer and heart disease.

However, although the increased risk was large in percentage terms, the number of extra cases of disease was actually very small.

In addition, the type of HRT under scrutiny in the US study is not available in the UK.

Closely monitored

US findings

HRT increased the risk of:

strokes by 41%

heart attacks by 29%

breast cancer by 26%

The UK research is known as the Wisdom (Women's International Study of Long Duration Oestrogen after Menopause) trial.

It will also involve 6,000 women from Australia and New Zealand.

The study, which will involve more than 400 GP practices, is being overseen by two independent committees, the Data Monitoring and Ethics Committee (DMEC) and the Trial Steering Committee (TSC).

After considering the implications of the American study, the TSC has recommended that, as long as women volunteering for the trial were fully informed of all the known risks and benefits of HRT, the Wisdom trial should continue.

US findings

Among 10,000 women taking HRT there would be:

Eight extra strokes a year

Seven extra cases of heart disease

Eight extra breast cancer

The committee said there were no strong ethical or scientific reasons to stop the trial and that there were still important questions about the balance of risks and benefits from taking HRT long-term that have not yet been answered.

It said the increased numbers of breast cancer cases seen with HRT in the American study represented a relatively low risk.

The advice will be considered next week by the Medical Research Council's governing body, which will decide on the future of the trial.

Important questions

TSC chairman Professor Rory Collins said: "GPs and patients already involved in the trial were sent letters yesterday advising them of the recommendation to continue and the reasons for doing so.

"The Wisdom study aims to answer important questions about the long-term risk and benefits of taking HRT and the results of the study could provide important information for generations of women to come.

"It's vital that women already involved in the study are informed of all the known risks and benefits associated with taking HRT.

"Until revised information has been prepared, and the MRC Council has made a decision, further women will not be recruited into the trial.

"But I hope very much that the women currently in the trial will wish to stay in it and that many more women will join in the future."

The trial is funded by the Medical Research Council, the Department of Health, the British Heart Foundation and other organisations.

It is looking at HRT which combines oestrogen and progestogen as well as that which contains oestrogen only.

The study began recruiting in 1999 and involves more than 400 general practices throughout the UK.