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The risk estimates of breast cancer associated with hormone replacement therapy (HRT) found in the Million Women Study were amongst the highest reported in the literature. Nevertheless, the press release which accompanied its publication1 in August 2003 was uncompromising and made no attempt to place the results in the perspective of a large volume of earlier work. Amongst other claims, it stated that 'For every 1000 postmenopausal women who begin 10 years of HRT use at the age of 50, there will be five extra cases of breast cancer amongst users of oestrogen-only HRT and 19 amongst users of oestrogen-progestagen combinations. So combined HRT causes four times as many extra cancers as oestrogen only. The study also found that current users have a 22% increased risk of death from breast cancer. . .'. The principal investigator (Professor Valerie Beral) was quoted as saying that 'We estimate that over the past decade use of HRT by UK women aged 50-64 has resulted in an extra 20000 breast cancers . . .'. It is not surprising that the subsequent coverage in the general press had a profound and immediate effect on the confidence of both women and doctors in hormone replacement therapy. The licensing authorities were quick to take action. Indeed, on the day the paper was published, the Chairman of the UK Committee on Safety of Medicines (Professor Gordon Duff) wrote to all health professionals in the UK2. In his letter, he said that 'The Committee on Safety of Medicines (CSM) and its expert working group (EWG) on HRT have reviewed (the MWS) study. The key points are: The previously described small increase in risk of breast cancer with oestrogen-only products has been confirmed. The increased risk of breast cancer in association with use of combined . . . HRT is substantially higher than with oestrogen only therapy. . .. An increase in the risk of breast cancer becomes apparent within 1-2 years of starting treatment, irrespective of the type of HRT used. The risk . . . begins to decline when HRT is stopped and by 5 years reaches the same level as in women who have never taken HRT. No mention was made of the fact that the principal investigator for MWS and a memher of its Steering Committee were both members of the Expert Working Group of the CSM.