Cancer in Indigenous people in New South Wales, 1994-2002 : a growing problem

Background: Indigenous Australians have significantly lower life expectancies than the peoples of developing nations including India, Thailand and Bangladesh. Indigenous peoples of Australia also have a much lower life expectancy than the Indigenous peoples of Canada, New Zealand and the United States of America. Cancer is the second highest killer of Indigenous Australians. The most common cancer causes of death in Indigenous people perhaps reflect lifestyle factors such as tobacco use,alcohol use and poor diet. However, until now, very little was known about cancer incidence in Indigenous Australians due to previous low rates of Indigenous identification on hospital and disease registers. Methods: We vastly improved the rate of Indigenous identification on the New South Wales Central Cancer Registry using information from death certificates. Using indirect standardisation we then compared the Indigenous people’s cancer incidence and mortality to that of the non-Indigenous New South Wales population. Results: Both Indigenous males and females had a 20% lower incidence of all cancers combined, although rates for lung cancer were significantly higher in both sexes. However, standardised mortality ratios for all cancers combined were 66% and 59% higher for males and females respectively. Both incidence and mortality from lung cancer for both sexes was more than 50% higher than the NSW population .The incidence of other tobacco related cancers such as tongue was more than twice (the Standardised Incidence Ratio was 2.5, 95% Confidence Interval 1.1-4.4) that of the non-Indigenous male population. Indigenous males also had a 96% (1.1-3.1) higher incidence rate of oesophageal cancer. Cervical cancer incidence in Indigenous women was 59% (1.1-2.2) higher than in non-Indigenous and mortality was more than three-times (Standardised Mortality Ratio 3.7,95% CI 1.9-6.2) the rate of non-Indigenous women. Conclusions: Cancer is an important, but often overlooked, disease and cause of death in Indigenous peoples in New South Wales and Australia. Lung cancer in particular is a lifestyle disease where Indigenous Australians are over-represented in its incidence and mortality. Issues such as improving the access to, and the suitability of Pap-test screening has been identified by others as a way to reduce the incidence and mortality of cervical cancer in Indigenous women.