This measure provides data on cancer incidence for Aboriginal and Torres Strait Islander peoples sourced from New South Wales, Queensland, Western Australia and the Northern Territory. The data account for about 82.9%4 of all Aboriginal and Torres Strait Islander people in Australia.
Data source
When a new case of cancer in Australia is diagnosed, it is reported to the cancer registry in the state or territory where the person lives. Notification of new cancer diagnoses to the cancer registry is required by law. National data, using data from each state and territory cancer registry, is collated in the Australian Cancer Database, which is maintained by the Australian Institute of Health and Welfare (AIHW).5
Data about cancer among Aboriginal and Torres Strait Islander peoples in Australia rely on information being collected in cancer registries about whether a person diagnosed with cancer identifies as Aboriginal or Torres Strait Islander. While every registry collects information about Aboriginal and Torres Strait Islander status, the consistency of this information varies. For more information see ‘Aboriginal and Torres Strait Islander identification in national cancer data’. Currently, information about Aboriginal and Torres Strait Islander status from cancer registries in four states and territories is considered to have sufficient consistency for inclusion in national reports and analyses of cancer incidence: i.e., New South Wales, Queensland, Western Australia, and the Northern Territory.
Cases vs rates
Cancer incidence data are presented as absolute numbers of cases or as incidence rates. Absolute numbers indicate the total number of cases of cancer diagnosed in a specified time period. Cancer incidence rates are reported as the number of cases of cancer diagnosed per 100,000 people in the population of interest. Incidence rates are often age-standardised to remove the influence of age when comparing cancer data among different populations. This is because the likelihood of being diagnosed with most types of cancer increases with age.1,3 Cancer incidence rates in Australia are standardised to the Australian population as at 30 June 2001.
For example:5
• number of cases: in 2011–2015, 1,040 Aboriginal and Torres Strait Islander people were diagnosed with lung cancer
• age-standardised incidence: in 2011–2015, the age-standardised incidence rate of lung cancer among Aboriginal and Torres Strait Islander people was 82.8 cases per 100,000 people.
Age-specific cancer incidence rates are used to compare cancer incidence across specific age groups.1,3
For example:5
• during the period 2011–2015, the incidence of lung cancer among Aboriginal and Torres Strait Islander people aged 55–64 years was 195.1 cases per 100,000 people compared with 341.2 cases per 100,000 people for those aged 85+ years.
Cancer types
Data about cancer incidence (including age-standardised and age-specific incidence data) are published by the AIHW for individual cancer types and cancer groupings.3 Tumour types and groupings are classified by ICD-10 code.6 Cancer incidence data exclude basal and squamous cell carcinomas of the skin.5