Screening programmes play a crucial role in early breast cancer detection; they can increase the chances of survival as well as reduce disease specific mortality. Although mammography remains the best method to detect breast cancer in an early stage, its sensitivity and specificity decreases in women with radiologically dense breast tissue (Gilbert F, et al. 2015).
Breast density describes the proportion of "breast tissue" (milk glands, milk ducts and supportive tissue) compared to fat in the breast. It is determined only through a mammogram and it is different for every woman. 

If a woman has dense breast tissue, does she require additional screening tests for early detection of breast cancer?

The European guidelines for breast cancer screening and diagnosis include five recommendations on screening tailored for women with dense breast tissue, both for healthcare professionals and a synthesised version for the general public, using clear language to empower women to make informed decisions about their health.

Mammography alone detects 2-7 cancers for every 1 000 women screened. Current data suggests that ultrasound after a mammogram may detect 2-3 more cancers per 1 000 women screened, while magnetic resonance imaging may detect 10 or more per 1 000 women screened ( Berg WA, et al. 2021 ). However, both tests may increase the chances of a false positive result, which means having further tests after screening, including biopsy, that confirm it is not cancer, but women may have suffered unnecessary anxiety and distress.

To decide whether it is better to have the additional screening or have only a mammogram, women may wish to speak with their healthcare professional about these tests and how they feel about the chances of finding breast cancer or the chance of being called back for further tests.

The Joint Research Centre has also developed the Training Template for Digital Breast Cancer Screening to ensure radiologists and radiographers are competent to work in breast cancer screening services. More information and educational tools for the screening of women with dense breast tissue can be found on the websites of other organisations, such as the European Society of Radiology or DenseBreast-info.org .