News & Stories

Autumn 2025 Participant Newsletter

A New Step in Understanding the Genetics of Breast Cancer and Women’s Health

One of the most exciting areas of our research in the Breast Cancer Now Generations Study is understanding the genetic factors that influence a woman’s risk of breast cancer and other female health conditions. This work could lead to updates or new NHS clinical guidelines, so that women at higher risk can benefit from earlier or more frequent screening, risk-reducing medication, or other preventive strategies.

Thanks to advances in DNA sequencing technology, we’re entering a new phase of research that was not possible before. Until now, studying genetics has been limited to small numbers of participants, because sequencing the DNA is expensive and complex. But we are now able to sequence the DNA of all participants in the Breast Cancer Now Generations Study who donated a blood sample for research. This is a game-changer in terms of what we can discover.

By analysing genetic information across the entire genome and comparing it with the health, lifestyle, and medical data you have provided over the years, we can:

  • Identify new genetic variants - both common and uncommon - that increase the risk of developing breast cancer and other diseases;

  • Learn more about genetic influences on other female conditions, not just breast cancer;

  • Understand how genetic and non-genetic factors combine to influence health across a woman’s life.

Currently in the NHS, detailed risk assessment is mostly offered in specialist genetics or family history clinics, usually for women with a strong family history (for example, two close relatives with breast cancer, or one diagnosed before age 40). These services are very important (see our participant stories for more about this), but most women who develop breast cancer — over 90 per cent — do not have a strong family history and are not referred to these clinics.

Our goal is to help change that, by developing and validating tools that could be used more broadly in the NHS, including in GP practices, so that all women can benefit from better risk assessment — not just those with a family history. To do this, we need to look at the genetic profiles of many women, both those who have developed breast cancer and those who haven’t.

We all have many small differences in our DNA that make us different from other people. These differences are called polymorphisms. Research over the past 15 years, from the Breast Cancer Now Generations Study and others, has shown that even in women without a family history of breast cancer, some of these polymorphisms, when combined, can significantly predict their risk. These are known as polygenic risk scores. In addition, large-scale sequencing studies are helping to identify uncommon but potentially high-risk genetic differences, which may not be picked up by current genetic tests. Together, this research is enhancing how we assess genetic risk for breast cancer — both for women with a strong family history and for those without — and supports the work of genetics and family history clinics by providing more precise tools for decision-making and care.

We can do this new research thanks to a collaboration with Regeneron, a world leading biomedical research company, that will enable us to undertake this large-scale sequencing effort. Regeneron has a great track record of successful collaborations with academic institutions in the UK, Europe, and internationally — including other research programmes at the Institute of Cancer Research, (ICR). With the ultimate goal of speeding up drug discovery and development for everyone, they are working with collaborators to enable access to more cohorts around the world. They want to better understand the nuances of human genetics and biology while maintaining a high level of transparency and collaboration with local organisations and patients. Their work has contributed to important discoveries about the genetic causes of many diseases and the development of new strategies for prevention and treatment. Visit their website https://www.regeneron.com/science/genetics-center to learn more about their work.

“Large-scale genetic sequencing studies like the Breast Cancer Now Generations Study are essential for providing accurate risk estimates, and guide care for high-risk individuals and families. Our partnership with Regeneron supports this and other ICR studies, driving breakthroughs that improve patient care.”

(Professor Clare Turnbull, NHS Consultant in Clinical Cancer Genetics at the Royal Marsden Hospital, and ICR Translational Genetics Group Leader)

The sequencing will take place in specialised secure laboratories in the United States, following all UK regulatory requirements, including data protection laws such as GDPR. Samples will be sent under a strict data sharing agreement, which clearly defines how the data can be used. Importantly, the Breast Cancer Now Generations Study team will retain full control over the use of the data. Regeneron acts as a data processor — meaning they process the samples for sequencing on our behalf — and cannot share the data with others.

“The ICR only works with data processors who meet our rigorous security and privacy standards. We have implemented stringent safeguards to ensure that any data processed in the US or other countries remains fully protected and compliant with UK data protection law”

(Amy Carnie, Head of Information Governance at ICR)

As always, your confidentiality and trust are our top priority. All data is handled securely and approved by research ethics committees and follows the protocol you consented to when joining the study, unless you notify us of any changes to your consent. This new development will allow us to make even greater use of the incredible contributions you’ve made and will help move us closer to a future where breast cancer prevention and early detection can be more personalised, equitable, and effective.

”Unlocking the information stored in the Generations Study participants’ DNA is a very exciting moment. Having a detailed picture of the role that DNA plays in breast cancer could help all women better understand their risk and know what steps they can take to reduce it.”

(Dr Simon Vincent, Chief Scientific Officer at Breast Cancer Now)

Thank you again for your ongoing support — we are truly grateful.