Imma Perfetto
Cosmos science journalist
A recent analysis of global breast cancer rates has found that, while Australia and New Zealand substantially decreased the disease’s mortality rate over the past decade, the countries’ breast cancer incidence rates were the highest in the world in 2022.
For every 100,000 women living in Australia and New Zealand, 100.3 cases of breast cancer were diagnosed.
“There are various reasons for this,” says Nehmat Houssami, the National Breast Cancer Foundation chair in breast cancer prevention and professor of public health at the University of Sydney, who was not involved in the research.
“[They are] related to the population structure (e.g. ageing) and risk factor profile.”
According to Houssami, breast cancer risk factors that women may be less aware of include alcohol consumption, low physical activity, and post-menopausal obesity.
“We need to improve support for women to reduce these potentially modifiable risk factors.”
The report, which is published in the journal Nature Medicine, found that 1 in 20 women globally are diagnosed with breast cancer and 1 in 70 are likely to die from the disease in their lifetime.
“However, this burden is not spread equally across countries and regions,” says Houssami.
“There are large variations in incidence rates and more concerning are the disparities in breast cancer mortality.”
The study analysed data from 185 countries and found that mortality rates decreased in 29 countries with very high Human Development Index (HDI) scores. 7 of which are meeting the Global Breast Cancer Initiative goal of at least a 2.5% decrease each year.
Australia and New Zealand’s decreases in mortality rate of 2.1% per year are on the way to meeting this goal.
HDI is a metric used to measure a country’s overall quality of life by considering factors like life expectancy, education levels, and standard of living.
However, regions with lower HDI disproportionately had the highest mortality rates, with 26.8 deaths for every 100,000 women in Melanesia, Polynesia and Western Africa.
The lifetime risk of dying from breast cancer was highest in Fiji (1 in 24) and Africa (1 in 47).
“A woman who develops breast cancer in a low-middle income country has a higher likelihood of dying from her cancer than her counterpart in a high-income country,” Houssami says.
“These disparities in breast cancer deaths are not new but have become more evident in the current analysis.”
According to the study, this gap in mortality reflects inequities in early detection, timely diagnosis and access to comprehensive breast cancer management. As a result, advanced stage at diagnosis is common in many low- and middle-income countries, with up to 26% being metastatic.
The research projects that breast cancer cases and deaths will have increased by 38% and 68% by 2050, with 3.2 million new cases and 1.1 million deaths, disproportionately impacting low-HDI countries.
According to Houssami, the results flag “…an urgent need for governments, especially in low-middle income countries, to invest in providing access to breast cancer diagnosis and treatment services.”
