Pasifika women diagnosed with breast cancer are almost twice as likely to die from the disease after five years than Pakeha women, while Māori are 1.76 times more likely, a new study has found.
The three-year study was carried out by researchers at the University of Waikato and the Waikato District Health Board, using data from over 12,000 Auckland and Waikato women that reflected the general population.
It found Pasifika women diagnosed with breast cancer are twice as likely to die from the disease after five years compared with New Zealand European women, while Māori women diagnosed with the disease were 1.76 times more likely to die compared with Pakeha women.
Pasifika women were diagnosed with the disease younger than other groups and the cancer is almost twice as likely to be an aggressive form, the study found.
Māori women were less likely to be diagnosed through mammographic surgery, or receive chemotherapy, Herceptin or surgery.
Older women, particularly those over 70, are also less likely to undergo surgery, or get chemotherapy, radiotherapy, or Herceptin.
The study found those treated with Herceptin were 42 per cent more likely to survive after five years, though Māori and Pacific women were less likely to use the drug than other New Zealanders.
Māori and Pasifika women diagnosed through the screening programme do as well as Pakeha women.
About 62 per cent of women in the study were treated in the public health system and they had a 95 per cent higher average risk of death compared to those in private health care.
Lead investigator Professor Ross Lawrenson said overall outcomes for breast cancer are improving, but the outcomes for Māori and Pasifika women and the treatments for older women needed to improve.
He said the biggest gains for Māori and Pasifika women can be made through earlier diagnosis.
"Firstly, improving access to primary care, and making it easier and cheaper for them to see a GP and get a diagnosis," he said.
"Secondly, improving access to breast screening, focusing on reducing the inequities, rather than only on new drugs and treatments has the potential to significantly improve the situation for the women most at risk, and all women."
Professor Lawrenson also said the gap needed to close in the treatment for those who could afford private healthcare and those who could not.
More than 600 New Zealand women die from breast cancer every year, and thousands more are diagnosed with it.