BreastCheck is for women aged 50 to 69, whether you have dense breasts or not. It’s for women who have no symptoms of breast cancer.
Breast density and cancer risk
Dense breasts are common. About half of all women have dense breasts. Breast density is non-fatty breast tissue and is one of the risk factors for breast cancer. The advice for all women, whether you have dense breasts or not, is to be breast aware and talk to your GP if you have any concerns.
BreastCheck and breast density information
We invite women for free screening mammograms – a breast x-ray. Our aim is to find breast cancer at an early stage and to provide access to treatment.
While density is visible on mammography, we do not measure or record breast density information on screening mammograms. It’s not part of the screening process and we do not use it to guide our screening decisions. This is the same in most population-based screening programmes across Europe and globally.
Could this change?
We don’t know. Changes to population-based screening programmes in Ireland, including incorporating breast density into breast screening, must first be evaluated by the National Screening Advisory Committee (NSAC), an independent committee. This involves the assessment of evidence, including the benefits to women and to public health, the harms associated with any change such as unnecessary tests and anxiety for women, and the cost-effectiveness of the proposed change.
Submissions have been made to NSAC proposing a standardised breast density notification for all BreastCheck screening participants. NSAC has asked the Health Information and Quality Authority to examine the evidence for this proposal. When this review is completed, NSAC will make its recommendation to the Minister for Health and the Department of Health, and the government will make a decision. When recommendations are accepted, we begin planning for implementation.
Best practice guidance
Reporting of breast density would mean that we must provide clear guidance to women and their GPs on what action to take with this health information. At the moment the international screening guidance is to take no action regarding density. We do not give this health information as there is no onward testing or treatment pathway recommended.
We take our best practice guidance from the European Commission Initiative on Breast Cancer (ECIBC) Guidelines Development Group (GDG) - a group of experts in all aspects of screening. This EU body does not recommend doing additional tests such as MRI or ultrasound for women with dense breast tissue in organised population-based breast screening programmes. This is because there is limited evidence that further tests for women with dense breasts leads to improved outcomes. More research is needed.
Any new tests being added into population-based screening programmes must be assessed using a set of principles for screening (Wilson and Jungner). This means reviewing the evidence for making the change and considering the practical implications of sending many women for extra tests. We do this to make sure the new tests do more good than harm, and lead to better health outcomes overall.
For now, mammography is the recommended screening test for population-based breast cancer screening, including BreastCheck.
Mammograms and breast density
Dense breast tissue appears white on a mammogram. Cancer also appears white on a mammogram. This can make it more difficult to find breast cancer because high levels of breast density can lower the sensitivity of mammography to detect it.
Mammograms are still effective for breast cancer screening if you have dense breasts. In 2008, we became the world’s first national breast screening programme to fully adopt modern digital mammography which has substantially improved breast cancer detection rates even when density is present.
Screening will not find all cases of breast cancer. We tell women about the symptoms of breast cancer because some women will still develop breast cancer even if they go for regular screening. These are called interval cancers and happen in every screening programme in the world. Our interval cancer rate is low and within international standards.
BreastCheck and cancer detection
We know from research that BreastCheck saves lives. Over the past 25 years, we have contributed to a reduction in the number of deaths from breast cancer, with data showing a 40% reduction in breast cancer deaths in the screened population between 2000 and 2019.
Our breast cancer detection rate is high compared to screening programmes in other European countries. This means that our screening programme is doing what it was set up to do – find breast cancer at an early stage when it can be easier to treat.
Women with dense breasts who are diagnosed with breast cancer have similar treatment success rates as women who do not have dense breasts. The stage at diagnosis, cancer type, and biological characteristics of a tumour are more important in determining outcomes than breast density information. Modern treatments work just as well no matter what your breast density is.
Future developments
We’ll continue to look at the best evidence available to improve screening outcomes for women. As technology improves and more data and research become available, approaches to breast cancer screening may evolve, including for women with dense breasts.
BreastCheck recently received re-certification from the European Reference Organisation (EUREF) for Quality Assured Breast Screening and Diagnostic Services. Women who choose screening can be confident in this external reassurance that we continue to deliver the highest standards in breast cancer screening in Ireland.
Coming for breast screening every time you’re invited is the best way to find and treat breast cancer early.