Research and optimisation of breast screening

Evidence for extending the age of eligibility  

The appropriate age bracket to offer breast screening is often debated, as there is limited evidence on the benefits and harms of screening before the age of 50 and after the age of 70. Before any changes to the current eligible age range, any evidence would be assessed by the UK National Screening Committee (UK NSC).  

A UK trial has demonstrated that beginning screening at 39-41 years results in a slight reduction in breast cancer mortality, with little increase in overdiagnosis¹

.​ Authors suggest that further analysis of other trials might help clarify the long-term effects of early screening.  

The Cancer Research UK supported AgeX trial is in progress and will assess the mortality benefit of inviting women aged 47-49 and 71-73 to breast screening. The trial is due to end in 2026.

Risk stratified screening evidence

Risk assessment of various factors, such as breast density and family history, could identify people at a higher or lower risk of breast cancer. 

Individuals with a high risk of developing breast cancer could be offered screening more frequently or with a different screening method. Additionally, individuals with a low risk of breast cancer could have longer screening intervals.  

Risk stratification has the potential to improve service efficiencies, reduce screening harms and facilitate earlier detection of cancer²

.​ Studies suggest that risk stratification is likely to be cost-effective and acceptable to the public³.​ However, public engagement would be required to address concerns around high risk scores and any reduction in screening frequency for people classified as low risk.

My Personalised Breast Screening (MyPeBS) is an ongoing randomised trial of risk stratified breast screening across six countries, including the UK. The results are expected to provide evidence for whether risk stratified screening is an effective and feasible method to improve the detection of breast cancer. The study is due to complete in 2027.

Further research may support NHS adoption of risk stratification. Gaps include how to structure a risk stratified programme, the best tools to use for risk assessment and the impact of a programme on health inequalities. 

Proactive identification of women at a high risk of developing breast cancer

Studies show that proactively offering risk assessment enables accurate and increased identification of women, particularly those younger than the current eligible screening age, at increased risk of breast cancer. These women may be eligible for additional breast screening and surveillance.  

Training and resource to support primary care professionals is important to support their role in breast cancer risk assessment⁴

⁵⁶⁷.​​ Information on how primary care should manage people with an increased risk of breast cancer is on our overview of breast screening page. 

There are evidence gaps around how applicable the available risk assessment tools are across diverse populations. Engagement strategies will also be required to support informed uptake and avoid exacerbating health inequalities 

Evidence for supplementary screening based on breast density

Breasts are made up of fatty and ‘dense’ tissue. People with more dense tissue have an increased risk of developing breast cancer and having cancer missed during routine screening, as the dense tissue can mask tumours. Younger women (under 49) and those with a lower Body Mass Index (less than 25kg/m²) are more likely to have dense breasts.​

Supplementary screening, using an alternative technique to mammography, may support earlier cancer diagnosis in women with dense breasts⁸

⁹.​ The BRAID trial will compare usual care to supplementary screening for women with dense breasts using three different techniques, to identify which is the most effective.  

Further research is required to identify a reliable, automated method of measuring breast density that is feasible to implement into breast screening programmes. In addition, there is an evidence gap around the acceptability of supplementary screening among people with dense breasts.    

Artificial intelligence (AI) in breast screening

Several AI-based tools have been developed to optimise mammography, ultrasound, and MRI imaging. Applications include:  

• Improving speed of image acquisition and/or quality of images. 

• Detecting regions of interest for review by a radiologist.  

• Acting as an image reader alongside a radiologist. 

• Identifying exams most likely to reveal cancer for high-priority review.  

• Classification of ambiguous lesions. 

While evidence gaps around AI performance exist, research suggests these tools could bring clinical benefits by improving cancer detection rates, sensitivity and specificity, and reducing false negatives and unnecessary biopsies. They may also deliver organisational benefits through improved efficiency, especially in low-resource areas. Further research is required around implementation barriers to application in breast screening, such as programme costs, IT requirements, and acceptance among patients and practitioners¹⁰

¹¹. ​

Read more about breast screening