Incidence of breast cancer in Australian women

In 2016, 1 in 8 women in Australia are at risk of being diagnosed with breast cancer before the age of 85.

How does Australia compare with the rest of the world?

Globally, rates of breast cancer are highest in Europe, North America and Australia, and lowest in Africa and Asia. They tend to be higher in countries and continents with the highest levels of human development. The incidence rate in Australia — the number of new cases of breast cancer diagnosed per 100,000 women – is one of the highest in the world.

Global incidence of breast cancer in 2012

Survival rates from breast cancer in Australian women

In 2008–2012, the relative 5-year survival (a benchmark for successful treatment) for Australian women diagnosed with breast cancer was 90%, compared to women of the same age in the general population.

How does Australia compare with the rest of the world?

While incidence rates are high, mortality rates from breast cancer are lower in more highly developed countries and continents. This is due to improved detection and earlier diagnosis, and more effective treatments. The relative mortality rate in Australia — the number of deaths due to breast cancer divided by the number of cases – is one of the lowest in the world.

Relative global mortality from breast cancer in 2012

Breast cancer incidence increases with age

In 2012, more than two-thirds of breast cancers diagnosed in Australia were in women aged 40–69 and one quarter in women aged 70 and over.

In 2016, it is expected that the incidence rate will increase with age until age group 65–69, and then decrease for age group 70–79. The incidence rate may increase again for individuals aged 80+, due to the small overall size of the age group.

 

Breast cancer risk increases with age

Relative incidence of new cases of breast cancer in Australian women in 2012 by age group Data source: Australian Government (2012) Breast Cancer in Australia: an overview

Early detection of breast cancer

In Australia, a program called BreastScreen Australia organises mammographic screening to detect unsuspected breast cancers. Women aged 50–69 are invited to participate in mammograms every two years, due to their relatively high incidence of breast cancer. Women aged 40 and above are also eligible.

The national breast screening program was established in 1991. In 2009–2010, 55% of women aged 50–69 participated in this program.

Detecting breast cancer early increases the chance of survival. Women of all ages are encouraged to be on the lookout for any changes in their breasts, and if this occurs, consult their GP promptly.

Risk factors for breast cancer

The causes of breast cancer are not completely understood, however certain risk factors have been identified. It is important to note that women with one or more of these risk factors will not necessarily develop breast cancer, nor do women who develop breast cancer always have one or more risk factors. Breast cancer risk factors include:

  • Increasing age
  • Family history of breast cancer
  • Breast conditions:
    • a previous breast cancer increases the risk of developing a second breast cancer
    • dense breast tissue
  • Lifestyle factors such as:
    • alcohol consumption
    • overweight and obesity in postmenopausal women
  • Hormonal factors:
    • early menarche (first period)
    • late menopause
    • the use of a combined hormone replacement therapy and/or use of an oral contraceptive pill within the past ten years
  • Child-bearing history: women who have had no children, or who had their first child at the age of over 30

Protective factors for breast cancer

Some factors have been identified that may reduce the risk of breast cancer. They include:

  • Childbirth before age 30
  • Increasing number of children
  • Breastfeeding for at least 12 months (this can be with more than one child)
  • Physical activity: regular exercise can help prevent breast cancer

References
Australian Institute of Health and Welfare (2012): Breast cancer in Australia: an overview
Australian Institute of Health and Welfare (2016). Australian Cancer Incidence and Mortality (ACIM) books: breast cancer.
Cancer Australia (2012): Report to the nation breast cancer 2012
Ferlay, J. et al. (2015). Cancer incidence and mortality worldwide: Sources, methods and major patterns in GLOBOCAN 2012. Int. J. Cancer, 136, E359-E386.
World Cancer Report 2014. Edited by Bernard W. Stewart and Christopher P. Wild. International Agency for Research on Cancer (World Health Organisation).

Related links
https://canceraustralia.gov.au/affected-cancer/cancer-types/breast-cancer/breast-cancer-statistics