Introduction: Breast density (the extent of radio-opaque tissue visible on mammography) is a long-established risk factor for both breast cancer and reduced mammographic screening sensitivity. The combined effect is that breast screening participants with higher breast density experience higher rates of interval cancers (cancers diagnosed between regular screens) and larger screen-detected cancers. Since 2025, BreastScreen Australia (BSA) has recommended notifying participants of their breast density and advising those with higher breast density to seek further risk assessment and screening advice from their general practitioner or specialist. While this addresses consumers’ ‘right to know’ and may prompt more sensitive screening for some, the broader implications for the whole population of BSA participants, downstream health services and the BSA program remain unclear.
Methods: We reviewed BSA policies and practices relating to breast density and examined potential downstream impacts on health service utilisation, patterns and costs. We also considered implications for screening participants, the BSA program and downstream health service providers.
Results: Breast density assessment is provided for approximately 75% of BSA screening episodes, across New South Wales, South Australia, Victoria and Western Australia, with around 40% of participants classified as having high breast density. Recommended actions vary across jurisdictions. There is considerable potential for inequitable access to supplemental screening, inefficient use of diagnostic services, and limited capacity for monitoring and evaluation. Current approaches diverge from key principles of the Australian Population Screening Framework, particularly regarding participant management, quality assurance, and program evaluation.
Conclusions: Current breast density advice diverts a potentially large proportion of BSA participants to less structured screening pathways, leading to out-of-pocket costs, additional demand on diagnostic breast imaging services, and inequitable access to optimal screening. Aligned with the 2023 ROSA Project recommendations, the 2025 BSA Review has recommended actions towards implementing evidence-based, standardised risk-stratified population screening pathways. These actions are now urgent.