Newsletter - July 2005
The Richard Doll Building
The Million Women Study now comes to you from our splendid new offices in the Richard Doll Building at the Churchill Hospital site in Headington, Oxford. Much more space and light, as well as the benefits of closer liaison with colleagues, including Julietta Patnick of the NHS Cancer Screening Programme, who will have a research office in this building.
Next collaborators’ meeting: Wednesday May 10th 2006
The next meeting for collaborators will be held here in the Richard Doll Building on Wednesday May 10th 2006. Details and an invitation form will be sent out nearer the time.
New Publications
Two papers have recently been published from the Million Women Study: a major paper on endometrial cancer (Lancet 2005; 365:1543-51) and an assessment of the validity of the dietary questions in the first follow-up (yellow) questionnaire (Public Health Nutrition 2005;8:201-13).
Diet questions at follow up
The first follow-up questionnaire included a set of questions about diet. Dr Andrew Roddam and Million Women Study colleagues looked at how reproducible and how accurate the answers to these questions were, by comparing the same set of questions answered at different times by a subgroup of 12 000 women in the study, and by comparing the answers to questions with more precise answers from 7-day diet diaries. The diet questions were answered consistently over time and provided a reasonably good assessment of nutrients such as carbohydrate, fat, cholesterol, sugars, alcohol,fibre and vitamins. This work will help us to use diet information from the questionnaires in future analyses.
Endometrial Cancer
Analysis based on 3-4 year follow-up of over 716 000 post-menopausal women, of whom 1320 were diagnosed with incident endometrial cancer, showed that different types of hormone replacement therapy had very different effects on the risk of endometrial cancer. Compared with never users of HRT, risk was increased with use of oestrogen-only HRT (1.5 times the risk of never users) and of tibolone (1.8 times); was not changed with use of cyclic combined HRT, and was reduced (0.7 times) with use of continuous combined HRT. These effects were significantly affected by a woman’s body mass index, so that the adverse effects of oestrogen and tibolone were greatest in lean women and the beneficial effects of combined HRT greatest in obese women. The increased risk of endometrial cancer with oestrogen-only HRT is of course well known and is the reason why women with a uterus are generally prescribed combined HRT preparations. The increased risk with tibolone was not previously clear, nor were the details of the effects of combined HRT and the joint effects with body mass index.
The Million Women Study is the only large HRT study with data on both breast and endometrial cancer and it is clear that overall, the increased risk of breast cancer with combined HRT outweighs any benefit there may be from combined therapy in terms of endometrial cancer. These results therefore have major implications for clinical practice.
