Newsletter - February 1998
Million Women Study meeting: May 20th, in Oxford
A meeting for collaborators will take place on the 20th of May 1998, at St Catherine’s College in Oxford. There will be talks about HRT and breast cancer as well as an update on the progress of the study, with time for discussion of any issues participants would like to raise. An invitation to attend this meeting is included with this newsletter- We hope you can come.
Collaborative paper confirms HRT and breast cancer link
The largest ever analysis of the relationship between HRT and breast cancer was published in the Lancet on the 11th of October and confirmed the previously suspected link between HRT and breast cancer. A copy of that report is enclosed. The study was a collaboration which pooled over 90% of the world-wide studies of HRT and breast cancer, and was based on evidence from 52,705 women with breast cancer and 108,411 women without breast cancer. It showed that women who are currently taking HRT have a 2.3% increase in their risk of breast cancer with every year of use, but that the effect is reduced as soon as HRT is stopped and has largely, if not wholly disappeared after about 5 years. The breast cancers in women taking HRT were found to be less advanced than those found in women not taking HRT.
While this study has answered many questions about the relationship between HRT and breast cancer, many important questions remain. Most of the studies in the collaborative group report were on oestrogen-only types of HRT (such as Premarin), whereas the majority of women in the UK are using combined oestrogen and progestagen HRT (such as Prempak C and Trisequens). As yet there is not enough information on these types of HRT to know their effect on breast cancer risk. The Million Women Study should more than triple the total world-wide evidence on combined types of HRT and should also help to clarify why the cancers in women taking HRT are less advanced than those in women not taking HRT. It will also be able to provide much needed information on how HRT affects breast screening itself.
Progress: Recruitment continues, Scotland comes on board.
The Million Women Study questionnaire is now being sent out by over 55 breast screening centres and the study has received ethical approval from over 120 ethics committees nation-wide. There are now many centres in Scotland participating, with East Scotland, South West, South East, North and North East Scotland all taking part. Thanks to centres throughout the UK, over 280,000 questionnaires have been received in Oxford and the study is on target to recruit 1,000,000 women over the next 3 years. The study is now recruiting over 30,000 women per month, one of the fastest rates of recruitment of any study, anywhere in the world.
Pilot study results published
The results of the pilot studies prior to the Million Women Study were published in this month’s issue of the Journal of Epidemiology and Community Health (1998;52(2):116-119). The pilot studies involved over 6000 women and showed that the study questionnaire did not affect subsequent breast screening attendance. A reprint of this article is included with this newsletter. Thank you to the participating centres.
