BreastScreen SA pilot study

What happened when South Australia started telling women their breast density

For years, women attending public breast screening programs in Australia received their mammogram results with little mention of breast density, apart from in Western Australia where they were notified if they had dense breast tissue. While some countries such as the U.S.A. and Canada have been notifying women about their density status for years, Australia has approached the issue more cautiously, concerned, in part, about whether the information might cause confusion or anxiety and whether it would actually help women make better decisions.

But in South Australia, that began to change. In 2022, BreastScreen SA introduced a pilot program notifying women of their breast density category (A, B, C, or D) and then asked a key question: how did they feel about it?

The study, published June 2025 in the Australian and New Zealand Journal of Public Health, looked at the reactions of over 5,000 women who received density notifications through this new system. The results paint a mostly positive picture, though not without some complications.

The vast majority, about 90%, said they supported the idea of continuing to notify women about their density. Many felt more informed about their breast health and confident in their ability to make decisions. And crucially, the notifications didn’t scare women away from screening. Nearly everyone who responded said they still intended to return for future mammograms.

But the study also revealed a tension. Around one in ten women reported feeling anxious after receiving the information, and roughly 14% felt confused, especially those told they had dense breasts. And while breast density is known to be linked to both cancer risk and mammogram sensitivity, many women didn’t fully understand those connections. Although over 70% were aware that dense breasts make cancer detection on a mammogram more difficult, more than half did not know that breast density is not related to breast size and cannot be determined by touch or feel. Around 4 in 5 didn’t know that dense breasts increases breast cancer risk.

This raises a bigger issue, without clear explanations and guidance, a notification can become just another confusing medical message. The researchers behind the study suggest that better education, both for women and their GPs, is key to making density notification useful, not just informative.

Despite the challenges, the pilot was successful, and BreastScreen SA rolled out density notification statewide in August 2023. A number of other states have followed, with the national screening program recently updating their policy in favour of breast density notification.

Reference: Buckley, L et al. Australian and New Zealand Journal of Public Health, June 2025. https://doi.org/10.1016/j.anzjph.2025.100240