Epidemiology of cancer in Indigenous Australians: Implications for service delivery

Registry data indicates that although Indigenous Australians have an age-standardised incidence of cancer for all cancer types combined that is no higher than the incidence for the non-Indigenous population, their age-standardised cancer death rates are about 45% higher. This higher mortality is partly due to an elevated incidence in many Indigenous populations of cancer types with a high case fatality. Examples include cancers of the lung, oesophagus/pharynx/mouth (intra-oral), pancreas, stomach, liver and gallbladder, and cancers of unknown organ origin. By comparison, a lower incidence is often observed in Indigenous than non-Indigenous Australians, of cancer types with a low case fatality. Examples include cancers of the female breast, bowel, prostate, skin (melanoma) and lip. The elevation in cancer mortality in Indigenous populations is not entirely explained by differences in cancer type, in that Indigenous populations generally have more advanced cancers at diagnosis. Moreover, even after adjusting for cancer type and stage of progression of cancer at diagnosis, higher case fatalities still present in Indigenous than non-Indigenous populations, suggesting poorer outcomes of treatment. In particular, poorer outcomes are generally seen in Indigenous populations living in remote and rural settings. In this report, cancer data is presented for Indigenous and non-Indigenous Australians, to provide an overview of differences in incidence and outcomes. Although there is an emphasis on South Australian data, to which there was more ready access, reference is also made to data from other states and territories. Possible reasons for differences between Indigenous and non-Indigenous cancer statistics are suggested, along with implications for the provision of preventive services, screening and other early detection services and of treatment and support services for Indigenous people affected by cancer.