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February 2024


We are grateful for your continued support for the Million Women Study. Every participant is important to us. The Million Women Study is the largest study of women’s health in the world and has been running since 1996. Between 1996 and 2001, the study recruited 1.3 million women, aged 50-64, through NHS Breast Screening Centres. Since recruitment, participants have provided information to us on their health and aspects of their lives every 3-5 years. We have also followed our participants’ health status through linkage to their NHS records on hospital admissions, deaths and cancer registration.


We are continuing to work on our programme grant, funded by Cancer Research UK, on prevention and risk stratification for cancer. As part of this work, we are investigating whether digital mammography and other routine breast screening data can provide valuable information about a woman’s subsequent risk of breast cancer.


All information about you and your health is kept private. Data from which you cannot be recognised may be shared with other research groups who are doing similar research. Researchers working on other studies can apply to access Million Women Study data, so that they can answer new research questions using data that have already been collected. The researchers must demonstrate that their work will benefit public health and they will only be provided with the information needed to answer their specific question. There is more information about this on our data access and sharing web page


A full list of publications can be found on the website but we have highlighted a number of new reports that have been published since our last newsletter.

Alcohol and cancer

Our latest research looked at alcohol and the risk of 20 different cancers. We found that alcohol intake was most strongly associated with higher risks of upper aerodigestive cancers and that alcohol worsens the adverse effect of smoking on these cancers, with ten times higher risk of aero-digestive cancers in women who are heavy smokers and heavy drinkers compared to women who have never smoked and drink 1-2 drinks per week.

Adiposity and risk of oesophageal cancer

We investigated the risk of two types of oesophageal cancer (adenocarcinoma and squamous cell carcinoma) in relation to different measures of adiposity. We found that there was robust evidence that greater body mass index (BMI) is associated with an increased risk of adenocarcinoma and a reduced risk of squamous cell carcinoma. The increased risk of adenocarcinoma is likely to be due in part to gastric reflux but further research is needed to understand the lower risk of squamous cell carcinoma.

Sleep and risk of dementia

Our research on risk factors for dementia has shown that sleeping for long periods at night is not associated with long-term dementia risk. Similarly daytime napping is not associated with long-term dementia risk. However, our data suggests that sleeping for short periods at night may lead to a small higher risk of dementia.

Cardiovascular multi-morbidity

We found that the likelihood of having two or more cardiovascular diseases was common. 16% of women in the cohort who were free from cardiovascular disease at the start of the study, now have two or more cardiovascular diseases. The majority of women with one cardiovascular disease eventually develop at least one other.


December 2022


The Million Women Study is one of the UK’s longest running health research studies. Between 1996 and 2001, the study recruited 1.3 million women, aged 50—64, through NHS Breast Screening Centres. In 2021 we reached our 25th anniversary – celebrating a quarter of a century of research into women’s health. We are grateful for the continued support from our study participants and our collaborators. Every participant is important to us. Your participation in the study has already allowed us to provide definitive evidence regarding the role of many common risk factors for cancer and other chronic diseases, and we continue to investigate known and emerging risk factors for diseases which are relevant to women in our cohort.


With great sadness, we announce that Dame Professor Valerie Beral, the founder of the Million Women Study, died peacefully on 26 August 2022. Professor Beral was a talented epidemiologist who generated much of the world’s best evidence on hormonal factors and female cancers. By combining data from relevant studies worldwide (including the Million Women Study) she provided reliable information about the health risks and benefits associated with oral contraceptive and HRT use. She also carried out research into modifiable risk factors for cardiovascular disease, fracture, and dementia. Read her obituary.


We are pleased to confirm continued funding from Cancer Research UK for our work on prevention and risk stratification for cancer. As part of this work, we are investigating whether digital mammography and other breast screening data can provide valuable information about a woman’s subsequent risk of breast cancer.


A full list of study publications can be found in the publications section of our website, but we have highlighted a number of key findings. Our research on ‘Survival after Ovarian Cancer’ revealed that even after accounting for stage, grade and tumour histology remain important predictors of survival. The findings also suggest that greater body mass index and smoking may be associated with poorer survival (Gaitskell et al, Cancer Epidemiology 2022).

From our research on social isolation and health, we have found that women who were more socially isolated were not more likely to develop heart disease or stroke than those who were less isolated, but they had a higher risk of dying from heart attack or stroke before reaching hospital (Smith et al, The Lancet Public Health 2021). 

Our research ‘Body size in early life and post-menopausal breast cancer’ showed that women who reported having greater adiposity in early life, and particularly in childhood, have a lower risk of postmenopausal breast cancer. This apparent reduction in risk was evident for all the main subtypes of breast cancer (Yang et al, BMC Cancer 2022).

Our publication “Cellular Telephone Use and the Risk of Brain Tumours: Update of the UK Million Women Study” found that neither daily mobile phone use, nor use for 10 or more years, was associated with increased risk of brain tumours overall, by brain tumour subtype or its location (Schüz et al, Journal of the National Cancer Institute 2022). During the COV ID-19 pandemic, we also took the opportunity to carry out an online survey of the impact of the pandemic on participants’ health and wellbeing. Over 44,500 women took part and we hope to make the findings available in due course. 

To maximize the benefits of the study for scientific research we welcome applications from bona-fide researchers for controlled access to pseudonymised study data for high-quality medical and health research. See our updated data access policy, which fulfils Research Councils’ UK requirements.


march 2021

We are grateful for the continued support of all our collaborators and study participants. We are pleased to announce continued funding from Cancer Research UK.


Over 40,000 participants completed our online questionnaire on the impact of the Coronavirus pandemic on themselves and their families. We are aware that for many of our participants and their families, this has been a particularly challenging year. We are immensely grateful to all those participants who have filled out the questionnaire online and to all those who filled out our latest postal questionnaire.

participant panel

The first meeting of the Million Women Study Participant Panel was held in Oxford in October 2019. The panel members had a tour of the Cancer Epidemiology Unit and then discussed various aspects of the study and future plans. The next meeting of the panel will be held online in April 2021.

study progress

Physical activity reduces risk of lower limb and hip fractures
Using data from postmenopausal women in good health, we showed that women who did physical activities such as walking, yoga, participation in sports club activities, and gardening, reduced their risk of lower limb and hip fractures. Gardening was also associated with a lower risk of upper limb fractures but cycling had a higher risk.
Armstrong et al, Journal of Bone and Mineral Research 2020.

HRT and breast cancer
The Million Women Study team gathered data from 58 studies around the world, world, including the Million Women Study, to provide definitive evidence on the long term effects of taking HRT on the risk of breast cancer. Compared with women who had never taken HRT, women who started taking HRT after menopause had a significantly increased risk of invasive breast cancer. The longer women took HRT, the greater the risk. In women who stopped taking HRT, their risks of breast cancer were lower but remained elevated more than 10 years after stopping. Collaborative Group on Hormonal Factors in Breast Cancer, Lancet 2019.

Risk factors for dementia
We have published two reports on risk factors for dementia. Using nearly 20 years of data on participants, we found that obesity in middle-age increases the risk of dementia later in life, but also that engaging in physical and cognitive activities may not be effective in reducing the risk of dementia.
Floud et al, Neurology 2020; Floud et al, Lancet Public Health 2021.

Lack of sleep does not increase risk of breast cancer
Short sleep has been thought to increase risk of breast cancer through the effect of the circadian system on hormone production. This study was the largest prospective study to investigate this and showed that there was no association between sleep duration and breast cancer risk.
Wong et al, Sleep 2019.

For more of our recent papers, please visit the publications section of this website.

Please be reminded that participants in The Million Women Study are free to withdraw from the study at any time. Full details of how to do this, as well as details of how we use your data, are given on the opt out options webpage and in our privacy policy or you can contact us by e-mail or telephone.  


july 2019

save the date:friday september 13th 2019

For our next collaborators’ meeting, here in Oxford. As before, this will be a joint Million Women Study/AgeX breast screening trial meeting. Invitations to follow.

new postal questionnaire

Another postal re-survey questionnaire is currently being mailed out, twenty years after study recruitment. We are still getting a wonderful response from participants. Data collected repeatedly over many years is immensely valuable, especially now when supplemented by our online questionnaires.

branching out: participant interviews

One of the study Principal Investigators, social science epidemiologist Dr Sarah Floud, is piloting a new part of the study, interviewing women about their life experiences around retirement from paid work. The aim is to help assess the possibilities for health and lifestyle changes - and barriers to change.

...and a new particiPant panel

Sarah is also setting up a new Participant Panel to help us as we further develop the study. The first meeting is planned for the autumn.

diet and breast cancer - few associations

The very large size of the study meant that we could look systematically at a wide range of foods, nutrients and dietary patterns- and we found that most were not related to breast cancer risk. By far the strongest link was an increased risk with increasing consumption of alcohol – as we had already found. Higher intakes of fruit and fibre were weakly associated with lower breast cancer risk, but these links may not be causal.
Key et al, 2018, Int J Epidemiology.

cancer risk in women breastfed as children - possible link with bowel cancer

Women in the study who were breastfed as infants were about 20% more likely to develop bowel (colorectal) cancer and bowel polyps in adulthood- but there were no differences in risk for breast cancer or for 6 other cancers. These are novel findings which we hope may lead to further understanding of how bowel cancer develops.
Yang et al, 2019, Eur J Epidemiology.

Smoking is associated with risk of interval, but not screen-detected, bowel cancers

Using linked Million Women Study and NHS bowel cancer screening data, we compared risk factors for cancers found by screening with those diagnosed in the interval between screens. Smoking was associated only with interval cancer risk- a finding which fits with other evidence that different types of bowel tumour have different risk factors, and are not all equally well picked up on screening.
Blanks et al, 2019, Int. J Cancer.

Thank you to all our participants, friends and collaborators for your continued support

For more of our recent papers, please visit the publications section of our website.

If you have any comments or suggestions, please email us on:


older newsletters

January 2018
December 2016 December 2015 October 2014 October 2013
August 2011 June 2009 December 2007 October 2006 July 2005
November 2004 January 2004 February 2003 October 2002 August 2001
February 2001 July 2000 November 1999 February 1999 June 1998
February 1998 March 1997