Breast density notification increases levels of confusion and anxiousness among women

• Breast density notification is being rolled out across Australia, but evidence suggests that women do not feel more informed by it

• Between 25 and 40 percent of women have denser breast tissue which can make it harder for cancers to be detected through a mammogram

New research by experts at the University of Sydney shows that breast density notification is leaving some women confused and anxious about their breast health.

The notification program is designed to advise women that their breast density is a risk for developing cancer, as well as highlighting that dense breasts could prevent cancer from being observed on a mammogram.

Breast density notification is currently being rolled out across Australia, and is already mandatory in the US, but until now there has been no high-quality research into the impact of these notifications on women.

Lead author of the British Medical Journal study, Dr Brooke Nickel from the School of Public Health, said: “Breast density notification is based on the premise that giving women information will empower them to make individual choices about their health.

“In theory this is a really good thing but what we found in practice was that breast density notification made women more confused and anxious about their breast health. Women also did not feel more informed.”

Estimates suggest that between 25 and 40 percent of women have denser breast tissue which can increase the risk of developing cancer and make it harder for cancers to be detected through a mammogram.

For women with denser breasts, further screening via ultrasound, MRI and contrast-enhanced mammography has been shown to detect cancers. However, most of these additional screening methods mean out-of-pocket costs for women, and the long-term benefits in terms of mortality rates, as well as unintended adverse consequences, such as widening health inequality, are not well-evidenced.

Carrying out the research

To understand the impact of breast density notification, the researchers carried out a randomised control trial involving 2401 women across 13 BreastScreen sites in Queensland between September 2023 and July 2024.

As part of the randomised controlled trial, women identified as having dense breasts received one of three outcomes:

1. a notification of breast density in their screening results letter plus a leaflet with additional information about having denser breasts;
2. notification of breast density in the results letter plus a link to online video-based health literacy-sensitive information;
3. no notification of breast density in their results letter (control group).

Significantly, 11.5 percent and 9 percent of the two intervention groups respectively reported feeling confused after receiving a breast density notification alongside a normal screening result, compared to only 2.7 percent of women in the control group.

Levels of anxiousness among the participants about what to do regarding their breast health were also higher in the intervention groups, rising to 20.8 percent (outcome 1) and 20.5 percent (outcome 2) respectively, compared to the 18 percent of women in the control group.

Both notified groups also had significantly higher intention to talk to their GP about their screening results – 22.8 percent and 19.4 percent respectively – compared with only 12.9 percent in the control group.

Dr Nickel said: “Creating confusion and worry for women about their breast health is not a good outcome. And while it might seem positive that notified women want to seek further advice from their GP, there is currently limited evidence-based clinical pathways that GPs can offer, with most of the suggested recommendations leaving women with out-of-pocket costs.