‘Probably the most important advance in preventive medicine in the Western world for half a century’ is how John Studd, a gynaecologist at King’s College Hospital in London, describes hormone replacement therapy, or HRT. Many of his colleagues agree. ‘HRT delivers spectacular benefits,’ says John Stevenson, a consultant endocrinologist at the Wynn Institute for Metabolic Research in London. ‘Female sex hormones are incredibly good news.’
But epidemiologists are less confident that long-term treatment with analogues of human sex hormones is an unalloyed boon for women who have passed the menopause. ‘Great uncertainty attends current estimates of the size of the impact widespread use of HRT would have on health,’ contends Jonathan Reeve of the Medical Research Council’s Clinical Research Centre at Harrow. Equally cautious is Kay-Tee Khaw, professor of clinical gerontology at the University of Cambridge: ‘We urgently need to be able to quantify the overall long-term benefits and risks associated with prolonged use of current formulations of HRT.’.
Why the disagreement? One reason is that the benefits and risks quoted by HRT’s supporters come from follow-up studies of postmenopausal American women who took oestrogen more than a decade ago, and these studies are notoriously vulnerable to biases – the women who decided to take HRT were probably healthier in the first place, for instance. What’s more, the hormonal cocktails now prescribed differ significantly from the formulations commonly used in the 1960s and 70s. So there is no way of knowing, at the moment, what effect HRT really has on women’s health.
‘We have two choices,’ says Tom Meade, director of the Medical Research Council’s Epidemiology and Medical Care Unit at Northwick Park Hospital in Harrow. ‘We…
