Breast cancer is the most common cancer for Kiwi women and the third most common cancer overall
It affects one in eight New Zealand women over their lifetime.
About 70% of women who are diagnosed with breast cancer and about 80% of women who die from it are aged 50 years or older. Some women are at greater risk of breast cancer because there is a history of close family members having the disease.However, most women who develop breast cancer have no relatives with the disease. Even among women who do have relatives with breast cancer, most will never develop it. (Ministry of Health 2015)
While it is less common, young women can get breast cancer too. 6% of breast cancer in NZ occurs under the age of 30 years. Although it is uncommon, men also get breast cancer. About 25 men are diagnosed in New Zealand each year.
Eight New Zealand women, on average, will hear the news today that they have breast cancer.
80% of people with breast cancer survive 10 years or more (95% if detected early on a screening mammogram) but tragically, more than 600 women die of the disease every year.
As indicated in the following table, a woman’s chance of developing breast cancer increases with age. Approximately 75% of breast cancers are diagnosed in women 50 years and older. While breast cancer is less common in women under the age of 40, women in their 20s and 30s can get it too (approximately 6% of cases are in this age group).
|If a women is now in her:||Risk of breast cancer in the next ten years:|
|20s||1 in 2,118|
|30s||1 in 208|
|40s||1 in 57|
|50s||1 in 40|
|60s||1 in 33|
|70s||1 in 39|
Recent research from Australia and the United Kingdom shows a 1 in 9 lifetime risk of a woman being diagnosed with breast cancer; however, the USA has a higher incidence with a 1 in 8 to 1 in 7 lifetime risk.
The following table shows that while the number of people (female and male) diagnosed with breast cancer in NZ is increasing (18% over the last decade), the death rate from breast cancer in NZ decreased by 24% from 1995 to 2005.
Some possible explanations for the increasing incidence are:
- An increase in the number of women attending breast screening
- An aging population – simply getting older increases the risk for most cancers
- Lifestyle factors, such as increase alcohol consumption and the rise of obesity rates
- Having children at an older age, and having fewer children, along with a reduction in breastfeeding rate
Source: International Agency for Research on Cancer (IARC) and World Health Organization (WHO)