Comparison of cancer mortality and incidence in New Zealand and Australia

Abstract

Aims: To compare cancer mortality and incidence data from New Zealand and Australia, in order to gauge the potential for reducing deaths from cancer in New Zealand.

Methods: For 1996 and 1997, numbers of deaths from cancer, numbers of new cases, and population data were stratified in 5-year age-groups. Numbers observed in New Zealand were compared with numbers expected from Australian rates. Age-standardized mortality and incidence rates for each sex were analysed.

Results: New Zealanders of both sexes experienced more deaths from cancer than expected in every age group. If Australian rates had applied, there would have been 215 fewer cancer deaths per year in New Zealand males, and 616 fewer in females. The largest differences related to breast cancer and lung cancer in women, and colorectal cancer in both sexes. The overall incidence of cancer was higher in New Zealand, but mortality/incidence ratios were also higher for many sites--suggesting that survival after treatment has been poorer in New Zealand than in Australia.

Conclusions: Considerable scope exists for reducing cancer mortality in New Zealand. For a national cancer control strategy, it will be essential to clarify reasons for the high incidence of cancer and to study survival following treatment.