Australia and New Zealand have generally similar health care systems. Both countries have diverse populations in geographical location, ethnicity, and socio-economic factors. Australia has shown good overall cancer survival outcomes in international comparisons. New Zealand has higher mortality as well as mortality to incidence ratio for many cancer sites compared to Australia. Cancer survival in the two countries has not previously been compared systematically.
To explore the differences in cancer survival between two countries and to address the possible reasons for survival discrepancies
We compared cancer survival for patients diagnosed in 2006-10 and in 2000-05, using data from the national cancer registration and mortality systems in each country.
Cancer survival, assessed as relative survival at 1, 5 and 10 years from diagnosis, was significantly higher in Australia than in New Zealand for all cancers combined, in both males and females, and for several major cancer sites, including colorectal, lung, and female breast and ovarian cancer. Other sites showed no differences, including melanoma and laryngeal cancer. These differences were not explained by age differences between the patient populations.
There are substantial differences in cancer survival between New Zealand and Australia, despite generally similar health care systems. These differences are consistent with differences in population-based cancer mortality for major sites, and do not seem explicable by differences in incidence. Possible reasons for these differences will be discussed.