NHS criteria for screening women under 50 for breast cancer are too narrow and are missing up to 95% of those at higher risk of developing the disease, researchers have warned. The current guidelines, set by the National Institute of Health and Care Excellence (Nice), focus solely on inherited genes and not other factors such as lifestyle.
The findings, published in the British Journal of Cancer by researchers from the University of Cambridge and the Institute of Cancer Research, have prompted calls for a review of the criteria used by GPs to refer women for further assessment and specialist care. Using a new risk assessment tool, the study identified eight times as many women in this age group who later developed breast cancer.
What are the risks?
Breast cancer is a leading cause of death in women under 50 in the UK and is one of the most common cancers worldwide. About one in seven women develop breast cancer in their lifetime, yet only 5-10% of cases are linked to inherited genes.
Most cases, 96%, are in women over 40, while 25% are in women over 75. Men can get breast cancer too, with about 420 new cases every year in the UK.
In England, guidance from Nice recommends GPs ask about family history if a woman is worried that she might have a higher risk of breast cancer, and sometimes if they are over 35 and using an oral contraceptive pill or considering taking hormone replacement therapy (HRT).
Hormones have been linked to a slightly increased risk of breast cancer, although larger risk factors include alcohol intake and obesity.
The study looked at how to predict breast cancer risk in younger women. It used a risk calculator called Boadicea that combines factors such as family history, lifestyle, reproductive history and genetic information to give a risk score.
If all women under 50 were to have this done, researchers estimate about a quarter (26.5%) would be categorised as at above-average risk and referred for further assessment. This would include a third of women under 50 (34.8%) who develop breast cancer within 10 years.
By comparison, the current Nice criteria would result in 1.4% of women under 50 being referred for further assessment, which would include just 4.4% of those women who develop breast cancer.
A main reason for the disparity, the researchers say, is because three-quarters of women (73%) under 50 who develop breast cancer within a decade have no family history of breast cancer - the key criterion in the Nice guidelines.
The second source also said the current criteria miss up to 95% of women aged under 50 with a higher-than-average risk of breast cancer, and 95% of women who go on to develop the disease within 10 years.
Why are the findings prompting concern?
The findings raise questions about whether relying mainly on family history is enough to identify younger women who could benefit from earlier testing or preventive treatment. The researchers said spotting those at the highest risk earlier would give doctors a better chance at treating or even preventing breast cancer.
Dr Juliet Usher-Smith said the NHS should review the criteria in the light of the findings, but acknowledged that referring more people would add to workloads and could cause some women unnecessary checks and anxiety.
"Any changes must be accessible and equitable, taking into consideration the anxiety that extra referrals might cause for women."
Dr Sowmiya Moorthie, from the charity Cancer Research UK which funded the work, said: "Any changes must be accessible and equitable, taking into consideration the anxiety that extra referrals might cause for women."
"We need to get better at identifying women at highest risk of breast cancer so that we can intervene early, when there are more options for treating, or even preventing, their disease."
"The current Nice criteria used in general practice are missing up to 95% of women under 50 who will go on to develop breast cancer. It’s time to look again at these criteria in the light of our findings."
Prof Montserrat García-Closas of the ICR said there would be a balance to strike. She said the Nice criteria are much easier to implement, but miss a large proportion of women at elevated risk, while a full risk assessment including genetic testing would place a heavy burden on resources.
"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."
What do doctors and charities say?
Dr Simon Vincent, chief scientific officer at Breast Cancer Now, which supported the study, said new ways to identify women at increased risk could help prevent some breast cancers or detect them earlier, when treatment was more likely to be successful.
"These findings highlight the limitations of Nice’s current referral criteria, and so this research must now be carefully considered as part of the current review of its family history guidelines.
However, it’s equally important that any changes come with the needed investment in family history services, so they can be implemented effectively and fairly across the NHS."
A Nice spokesperson said: "Nice welcomes the findings of this study and recognises the potential of multifactorial risk models in improving the identification of women at increased risk of breast cancer in the future.
"However, the current evidence does not warrant a change to our existing familial breast cancer guideline at this time. Nice remains committed to reviewing new evidence and will consider further updates as more data on feasibility and clinical outcomes become available."
What happens next?
The NHS breast cancer screening programme is regularly evaluated by the UK National Screening Committee. The researchers and campaigners involved in the study say the findings should be considered as part of Nice’s current review of its family history guidelines.
All women are encouraged to know what looks and feels normal or usual for them and to see a doctor if they notice any changes.
Key Facts
- The study was published in the British Journal of Cancer.
- Researchers from the University of Cambridge and the Institute of Cancer Research said current Nice criteria may miss up to 95% of women under 50 who develop breast cancer within 10 years.
- The Boadicea tool assesses family history, lifestyle, reproductive history and genetics.
- Nice said the current evidence does not warrant an immediate change to its guidance.
