Frequently asked questions about breast screening

Routine screening (imaging people without any signs or symptoms) is offered to people who are the most likely to have breast cancer. The two biggest risk factors for breast cancer are being a woman and getting older, with over 80% of breast cancers occurring in women over 50. 

Younger women are less likely to develop cancer, but also are more likely to have dense breasts, which makes mammography a less reliable way of finding cancer. These factors – the lower relative risk level and effectiveness of mammography – mean that mammographic screening for women under 50 is not currently recommended.  

Women who are over 70 are not automatically invited to screening because they are more likely to be ‘over diagnosed’. For example they are more likely to have an early cancer found and treated that would have not caused any harm in their lifetime. However, they can self-refer into screening every 3 years if they choose.

There is less evidence that the benefits of breast screening outweigh the risks in women outside the current age range, but research is ongoing. The Age X extension trial is looking at expanding screening to women aged 47-73 and is due to report findings in 2027. If screening is shown to be effective in women outside the current age group, we will push for the screening offer to be expanded as quickly as possible. 

Women who are at an increased risk of developing breast cancer, due to a significant family history or genetic risk, should already be offered screening from a younger age and more regularly. Women at an increased risk are categorised as moderate, high or very-high risk, and should be offered screening based on which group they’re in.

The frequency of screening is based on the balance of benefits provided by screening more often compared to the risks more frequent screening would present, as well as considering the sustainability and cost of the programme.  

It’s estimated that around 3 out of every 1,000 women who do get screened will develop cancer between screenings, which is called an ‘interval cancer’. This is why we encourage everyone to still regularly check themselves for any signs of breast cancer between screenings. 

While screening more often would likely reduce the number of interval cancers that occur, it would also increase the harms associated with screening. For example, more regular screening would increase women’s radiation exposure, result in more follow up tests for women who do not have a cancer but need them to rule it out, and risk more over diagnosis.

The UK National Screening Committee (UK NSC) is responsible for reviewing the evidence and making recommendations around what health conditions should be screened for, and who should be eligible. Health ministers in the UK are then responsible for deciding whether and how UK NSC recommendations are put into practice.  

The UK NSC make screening recommendations based on specific criteria, looking at the disease, the population it affects, and the possible tests. The goal of screening is to reduce the harm caused by a condition through finding and treating it earlier.

We agree that screening recommendations must be evidence-based and carefully consider the benefits and risks. As a leading funder of breast cancer research, we understand the importance of designing services and support based on the best evidence available. We review and carefully consider all new evidence to decide whether we believe a change to screening should be made.    

We welcomed the UK NSC’s decision to set up a specific breast screening working group. The group reviews the large amount of evidence coming out on breast screening, with the eventual aim to “move us beyond ‘one-size-fits-all’ screening”.

Yes. We want to see changes in the way women who are at an increased risk of breast cancer are offered screening. We would like to see the UK NSC act faster and with more transparency to determine how women with dense breasts can be screened more effectively. 

Currently, at-risk screening is not consistently delivered through the national screening programme across the UK for women at all levels of increased risk, with each nation taking a different approach.

For example, in England, at-risk screening for moderate and high-risk women is not provided through the national programme. As a result, access varies a lot. In 2024 we collected data from a freedom of information request. We found that of the 64 breast clinics in England that  offered screening to moderate and high-risk women, only 4 offered at-risk screening in line with guidance. Most clinics offered less than what was recommended.

Screening that is delivered through the national Breast Screening Programme (which in England is only very-high risk screening) is subject to national oversight and quality standards. That’s why we want to see all at-risk screening delivered through the national programme. So all women have consistent access to the screening that’s right for them.

Standard mammography is less effective at finding breast cancers in women with dense breasts, which reduces their chances of getting diagnosed early through mammography. 

Looking at the most recent evidence, the UK NSC recently concluded that the current screening offer is insufficient for women with dense breasts, and that other types of imaging could find more cancers in this group. But they feel more evidence is still needed to make a recommendation.

We believe women with dense breasts should get additional imaging to ensure they are screened effectively. We want the committee to prioritise gathering the evidence needed to decide what additional imaging should be offered, so they have the same opportunity to be diagnosed early. This should be considered an urgent matter for the UK NSC, and the process needs to be completed, and a recommendation made as quickly as possible.

Ongoing research is looking how women could be offered different screening, based on their individual level of risk (referred to as risk-stratified screening). This could involve offering some women screening more frequently and from a younger age if they are found to be at higher risk. But it could also involve offering less screening to women at lower risk. These risk assessments take into account family history and genetics, but also other risks like lifestyle factors that can impact the risk of someone developing breast cancer.  

We support the goal to move towards risk-based screening and have funded studies looking at the benefits and risks of introducing it. We continue to monitor emerging evidence on risk-stratified screening to inform our position on this issue. We're undertaking work to understand the barriers to introducing a risk-stratified approach in practice, so we can develop solutions that would enable a successful rollout.  

We want the UK NSC breast screening working group to share their findings and the evidence gaps they’ve identified around risk-stratified screening and set out timelines for the next stages of work. We want them to commit to working with the NHS and clinical experts to prepare screening programmes for the introduction of a risk-based screening.