Results from the Million Women Study, together with those of the WHI trial from the USA, have influenced national policy, including recent recommendations on the prescribing and use of hormone replacement therapy from the Royal College of Obstetricians and Gynaecologists and from the Commission on Human Medicines.
At these centres, women received a study questionnaire with their invitation, which they were asked to complete and return at the time of screening.
Around 70% of those attending the programme returned questionnaires and agreed to take part in the study, over 1 in 4 women in the UK in the target age group.
A reanalysis refuting the initial conclusion that HRT increased the risk of breast cancer, was published in a 2012 paper in the Journal of Family Planning and Reproductive Health Care.
The paper's authors, led by Samuel Shapiro of the University of Cape Town, claimed that the study had not in fact establish a causal relationship between HRT and breast cancer, and that the original analysis had been flawed.
[7][8] It is well known that post-menopausal women who have not had a hysterectomy are at increased risk of cancer of the endometrium (the lining of the womb) if they take estrogen-only HRT.
[11][12][13] Results from the Million Women Study, together with those from other studies such as the Women’s Health Initiative trial from the USA,[14] have influenced national policy, including recent recommendations on the prescribing and use of hormone replacement therapy from the Royal College of Obstetricians and Gynaecologists and from the Commission on Human Medicines.
Public awareness of the study and its findings has led to significant behavioural changes,[15] predominately resulting in the swift decline of HRT prescriptions throughout Europe and the US from 2003.