The report, Breast cancer survival by size and nodal status in Australia, examined survival rates for over 10,000 women diagnosed with breast cancer in 1997 and found that the five-year survival rate for women whose cancers were 10 mm or less in diameter was almost as high as for women without breast cancer (98% relative survival rate).
'This declined to 73% for women with cancers 30 mm or more in diameter, and to 49% for women with advanced cancer where size had not been measured,' said Christine Sturrock of the AIHW's Health Registers and Cancer Monitoring Unit.
In 1997, 20% of breast cancers diagnosed were 10 mm or less, 17% were 30 mm or more, and 11% did not have a measured size.
'Five-year relative survival was 97% when the cancer had not spread to the lymph nodes, compared with 80% relative survival when the nodes were positive for cancer spread, and 71% when nodal status of the cancer was unknown,' Ms Sturrock said.
'Women with smaller tumours and whose cancer hadn't spread to the lymph nodes had significantly better survival than those whose cancer had spread,' Dr Helen Zorbas, Director of the National Breast Cancer Centre said.
A significant finding of the report is that survival was lower for women younger than 40 years for all tumour sizes (95% relative survival rate for women with cancers 10 mm or less in diameter and 67% for cancers of 30 mm or more). Although the incidence of cancer in this age group is low, the outcome is often not as good.
'This is because younger women's breast cancers tend to be larger and more aggressive tumours. As there is no routine screening program for this age group, breast awareness and early and effective investigation of breast symptoms is vital,' Dr Zorbas said.
'Also of concern was the finding that survival was significantly lower for women in the least socio-economically advantaged areas compared with women in the most advantaged areas. We need to better understand and address the factors that affect survival outcomes for women in this demographic,' said Dr Zorbas.