NHS breast screening is failing to identify 95 per cent of younger women who later develop breast cancer, according to researchers.
Breast cancer among women under 50, once considered comparatively uncommon, has risen sharply in the UK in recent decades, with cases increasing by about 1.4 per cent each year.
When the disease is detected early, before it has spread, it is highly treatable.
However, younger women are more likely to be diagnosed at a later stage, and those under 40 are almost 40 per cent more likely to die from breast cancer than women over 40.
The findings, from a troubling new study by researchers at the University of Cambridge and The Institute of Cancer Research, London, suggest that most breast cancer cases in young women are not being picked up through NHS pathways.
In England, women younger than 50 are offered further breast cancer screening and monitoring only on an individual, case-by-case basis.
A woman who is worried about her risk of breast cancer, but has no symptoms such as a lump or changes in breast tissue, can ask her GP for a referral to a breast cancer risk assessment service.
That specialist service offers guidance and screening options based on how a patient’s level of risk is assessed.
Once relatively rare, cases of breast cancer in women under 50 have rapidly increased in the UK over the past few decades
Those who are deemed high-risk of the disease can receive tailored annual scans, clinical breast exams, lifestyle advice or referrals for genetic testing.
Women at moderate risk are typically offered early annual scans and surveillance, often starting from age 40.
Those determined to be at standard risk of the disease, meanwhile, return to the routine NHS Breast Screening Programme, which automatically invites women for a breast cancer scan every three years from the ages of 50 to 71.
GPs use strict guidelines set out by UK medical regulating body the National Institute for Health and Care Excellence (NICE) to decide whether or not a woman should be referred on for this specialist breast cancer screening.
The primary decider is family history – having a close blood relative diagnosed with the disease, particularly at a young age – which has been shown to increase the risk of breast cancer.
But just one-quarter of women under 50 who go on to develop the disease have a family history of it.
As a result, researchers found, just five per cent of young women who were diagnosed with breast cancer within the next decade had been eligible for referral under current guidelines.
‘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,’ said Dr Juliet Usher-Smith, the study’s lead author and associate professor at the University of Cambridge’s Department of Public Health and Primary Care.
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How should the NHS balance early breast cancer detection in young women with the costs of wider screening?
‘The current NICE criteria used in general practice are missing up to 95 per cent 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.’
Published in the British Journal of Cancer, the new study analysed data from more than 1,000 women aged under 50 years recruited to the Breast Cancer Now Generations Study between 2004 and 2011.
Researchers assessed the number of young women who went on to develop breast cancer that were correctly identified as high-risk and referred to specialists under NICE criteria.
This was then compared to the number of women identified and referred through a rival criteria, called the BOADICEA risk model.
Rather than just focusing on family history, the BOADICEA model looked at a range of factors, including lifestyle, reproductive history, and genetic information.
While just 1.4 per cent of women who went on to develop breast cancer were caught by the NICE model, 26.5 per cent were correctly identified by the BOADICEA criteria.
The researchers wrote that they recognise that changing the criteria – offering the full BOADICEA risk assessment to all women under 50, for example – would be far more costly and lead to more referrals, many of whom will not develop breast cancer.
Said Professor Montserrat Garcia-Closas from The Institute of Cancer Research, London: ‘There will be a balance to strike: the NICE criteria are much easier to implement, but miss a large proportion of women at elevated risk.
‘But a full risk assessment including genetic testing will 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.’
Other experts raised several limitations with the study, however – including the fact that all participants monitored were white.
Dr Paul Pharoah, Professor of cancer epidemiology at Cedars-Sinai Health Sciences University called the study’s interpretation of its findings ‘misleading’.
As the NICE criteria is intended to help doctors manage referrals for women who come to them because they are worried about their family history, he said, they are irrelevant for those who do not have a family history of the disease.
‘Most women do not have a family history of breast cancer and so the guidelines are not relevant for those women,’ he said.
‘The fact that most women aged 20 to 50 who go on to develop breast cancer in the next ten years are not identified by the NICE guidelines criteria is an expected finding – 80 per cent of breast cancers in this group of women occur in women without any family history of breast cancer.
‘Similarly, most women at high-risk do not have a family history and criteria intended to help manage women who are worried about their family history will inevitably perform poorly at a different task.’
Roughly one in seven women in the UK will develop breast cancer in their lifetime, research shows.
More than 80 per cent of cases occur in women over 50 – with one-third striking women aged 70 and older.
But the number of breast cancer cases in younger women has been steadily climbing in recent years.
Women under 50 now make up one in five breast cancer cases in Britain – a 20 per cent rise from the early 1990s.
Experts have linked the rise in breast cancer cases in under-50s to a range of lifestyle factors, including rising obesity and alcohol consumption, as well as changes in reproductive patterns.
Better awareness and detection of breast cancers in younger women in recent years is also believed to have contributed to the rise in cases.
