The criteria given to GPs to refer women at risk of breast cancer for further action miss nearly all under-50s who go on to develop the disease within a decade, analysis suggests.
The University of Cambridge analysis suggests the NICE criteria miss up to 95% of women at higher risk of developing the disease. This means they are not being referred for further tests or specialist care.
In England, women at a higher risk of the disease are referred by their GP for further assessment and specialist care.
The referrals rely on family history, as well as criteria set by the National Institute for Health and Care Excellence (Nice).
Researchers analysed data from 1,258 women under 50 who took part in the Breast Cancer Now Generations Study between 2004 and 2011.
Using a new risk assessment system, experts identified eight times as many women in the age group who developed breast cancer.
The tool, known as Boadicea, looked at factors such as family history, reproductive history, lifestyle and genetics.
The analysis, published in the British Journal of Cancer, suggests that using the Boadicea model for all women under 50 would lead to 26.5% being classed as above-population level risk and referred for further assessment.
This includes almost 35% of women under 50 who develop breast cancer within a decade.
Meanwhile, researchers found the current NICE criteria would result in 1.4% of women being referred for tests, including 4.4% who go on to develop breast cancer.
Dr Simon Vincent, chief scientific officer at Breast Cancer Now, which supported the study, said: "Finding new ways to identify women at increased risk could help to prevent some breast cancers or detect them earlier, when treatment is more likely to be successful."
The disease is one of the leading causes of death in women under 50 in the UK.
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Professor Montserrat Garcia-Closas, of the Institute of Cancer Research, London, cautioned that "there will be a balance to strike".
"Ultimately, it will be a trade-off between the practical, resource, and cost implications of data collection and risk assessment, and the potential benefits and harms associated with accurate and inaccurate classification of women."
Dr Sowmiya Moorthie, senior strategic evidence manager at Cancer Research UK, which funded the study, warned that: "The current UK approach, which relies on women under 50 self-presenting, misses many women with a higher risk of breast cancer who could benefit from targeted support and guidance on how to manage their risk."
A NICE spokesperson welcomed the study findings and recognised the potential of different models which may improve identification rates in the future.
While the institute said it was "committed" to reviewing and considering all new evidence, it said that "the current evidence does not warrant a change to our existing familial breast cancer guideline at this time".
(c) Sky News 2026: Women under 50 at risk of breast cancer are not being referred - study
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