Metastatic breast cancer - first national estimates

Approximately 20,800 women and 150 men are estimated to have been living with metastatic breast cancer in 2024

Using new innovative methods, the AIHW estimates that approximately 20,800 Australian women and an estimated 150 Australian men were living with metastatic breast cancer (MBC) in 2024. Initial analysis suggests that these numbers are likely to continue to increase each year.

This project has been a national collaborative effort. AIHW gratefully acknowledges the expert contributions of: Cancer Institute NSW (CINSW), Cancer Council Victoria (CCV), Cancer Alliance Queensland (CAQ), all state and territory cancer registries, the Australian Cancer Data Alliance and Breast Cancer Network Australia (BCNA).

Improving data on metastatic breast cancer: a national priority

MBC is breast cancer that has spread beyond the breast and nearby lymph nodes to other parts of the body. It is a life-limiting condition potentially requiring treatment to improve quality of life and hopefully extend survival duration, placing significant health, financial and social burden on those living with MBC.

In Australia, almost all breast cancer occurs in women, with around 99% of diagnoses in females and less than 1% in males (AIHW 2025). MBC is responsible for the vast majority of breast cancer deaths (Palmieri et al 2022), and breast cancer is the most common cause of cancer death amongst Australian women after lung cancer (AIHW 2025).

The lack of accurate data impedes the ability to improve the disease and other outcomes of people affected by breast cancer – without these estimates it is not possible to know how many people in Australia are living with metastatic breast cancer, where they live, how long before their cancer progressed and other demographic and clinical characteristics (BCNA 2023).

This work reports the first national estimate of MBC prevalence to use national linked data (cancer diagnosis, deaths, MBS and PBS) and MBC prevalence counts for three states (NSW, Victoria and Queensland) which cover a large proportion of the Australian population. Using this data, AIHW has been able to estimate national prevalence, as well as indicative estimates for each state and territory.

Several recent developments have enabled MBC prevalence in Australia to be estimated for the first time:

• the development at AIHW of the national linked cancer and treatment analysis asset (CaT-Link),
• development of a counting method and estimates for NSW by the CINSW and associated researchers (You et al (submitted)), and
• estimated MBC prevalence in Victoria and Queensland by CCV and CAQ.

Why it matters

Breast cancer is the most commonly diagnosed cancer among Australian women.  In 2025, it is estimated that more than 20,000 women will be diagnosed with breast cancer and over 3,300 women will die from the disease (AIHW 2025). While survival rates for early-stage breast cancer have improved significantly, outcomes for those with MBC remain relatively poor.

These estimates provide visibility for a growing group of people who have specific health and community service needs. Improving data on MBC will help support better clinical care, service planning, research and policy development along with the development of improved models of support for those living with MBC who often face financial and social challenges as well as the ongoing health impacts of living with cancer.

Building national cancer data capability

Australia’s cancer data system is currently fragmented. In addition, most state and territory population-based cancer registries are currently unable to record for all cases, whether a cancer has progressed to the metastatic stage. This project demonstrates how linked data from across the health system could be used to help address this gap.

The Australian Cancer Plan recognises cancer data as a critical asset for improving cancer care and patient outcomes. Along with the National Cancer Data Framework, the Plan sets a vision to improve data across the cancer control continuum to support improvements in service delivery, clinical care and research (Cancer Australia 2023). Commonwealth agencies including the Australian Institute of Health and Welfare (AIHW), Cancer Australia, and the Department of Health, Disability and Ageing are working in partnership with state and territory cancer registries and the Australian Cancer Data Alliance to enable timely, accurate and standardised data collection.

Next steps

Phase 2 of the project to produce national estimates of metastatic breast cancer prevalence will refine the estimates presented in this report through the use of soon to be available linked data. The planned linkage of cancer incidence data to the AIHW’s National Health Data Hub (NHDH) is expected to strengthen capacity and enable the production of more complete and reliable estimates and analyses for specific sub-populations (for example regional and remote populations).