Australian Indigenous HealthInfoNet
http://www.healthinfonet.ecu.edu.au

 

Cancer

  • Home
    • » Health facts
      • » Overview of Australian Indigenous health status 2013
        • » Selected health conditions
          • » Cancer

Please select category from the dropdown list below.

Cancer

Cancer is the term used for a variety of diseases that cause damage to the genetic blueprint (DNA) of the cells resulting in uncontrolled growth (cells normally grow and multiply in a controlled manner) [1][2]. If these damaged cells ‘spread into surrounding areas, or to different parts of the body [metastasise], they are known as malignant’ [2]. Cancerous cells can arise from almost any cell, so cancer can occur almost anywhere in the body.

Until recently, the impact of cancer on Indigenous people has attracted much less attention than it deserves: there are two main reasons for this. First, the level of identification of Indigenous people in cancer notifications is known to be incomplete [3][4]. Indigenous identification in the cancer registries has been improving [5][6], but, due to incompleteness of Indigenous identification cancer notifications in several jurisdictions, there is currently no national information on cancer incidence among Indigenous people [7]. Provision for the identification of Indigenous people is not yet included on all pathology forms [8], and the extent to which Indigenous cancer patients are identified in hospital inpatient statistics varies across Australia [6]. Second, cancer has often been reported in terms of the proportions of deaths it causes rather than by rates; the comparison of proportions of deaths under-estimates the relative impact of cancer on Indigenous and non-Indigenous people.

Extent of cancer among Indigenous people
Incidence

In the five-year period 2004-2008, an average of 775 Indigenous people living in NSW, Qld, WA and the NT were diagnosed with cancer each year [7][8][7].1 After age-adjustment, the cancer incidence rate was slightly higher for Indigenous people than that for non-Indigenous people (461 and 434 cases per 100,000 people, respectively).

Cancer incidence rates were significantly higher for males than for females for both the Indigenous and non-Indigenous populations [8]. After age-adjustment, the rates for Indigenous people were slightly higher than those for non-Indigenous people for both males (549 and 525 per 100,000, respectively) and females (400 and 361 per 100,000, respectively). These rates were significantly different for females, but not for males.

The most common cancer diagnosed among Indigenous people living in NSW, Qld, WA and the NT in 2004-2008 was lung cancer (average of 121 cases per year), followed by breast cancer (females only) (average of 88 cases per year), bowel cancer (average of 70 cases per year) and prostate cancer (males only) (average of 58 per year) (Table 1) [8]. The highest Indigenous:non-Indigenous rate ratios were for liver cancer (rate ratio 3.0), cancer of the cervix (2.8), lung cancer (1.9) and cancer of unknown site (1.9).

Table 1: Age-standardised incidence rates for selected cancers, by Indigenous status, and Indigenous:non-Indigenous rate ratios, NSW, Qld, WA and the NT, 2004-2008
Site of primary cancerIndigenous peopleNon-Indigenous peopleRate ratio
Source: AIHW and Australasian Association of Cancer Registries, 2013 [8]
Notes:
  1. Cancers are ordered by numbers among Indigenous people (not shown in table)
  2. Rates per 100,000 population, age-standardised to the Australian population at 30 June 2001
  3. Ratio is the Indigenous rate divided by the non-Indigenous rate
  4. Due to the incomplete identification of Indigenous status, these figures probably under-estimate the true difference between Indigenous and non-Indigenous rates
Lung 80 43 1.9
Breast (females) 82 104 0.8
Bowel 48 59 0.8
Prostate (males) 105 148 0.7
Unknown primary site 24 12 1.9
Non-Hodgkin lymphoma 14 16 0.9
Cervix (females) 18 7 2.8
Uterus (females) 24 15 1.6
Liver 15 5 3.0
Pancreas 15 10 1.5
All cancers 461 434 1.1

For all types of cancer combined, incidence rates were higher for Indigenous people living in NSW, Qld, WA and the NT in 2004-2008 than for their non-Indigenous counterparts for all age-groups except for people aged less than 45 years [8].

Hospitalisation

There were 5,240 hospital separations for cancer among Indigenous people in 2011-12, representing 2.6% of separations identified as Indigenous (excluding dialysis) [9]. For the period 2006-07 to 2010-11, the age-standardised hospitalisation rates for cancer for Indigenous people living in NSW, Vic, Qld, WA, SA and NT were lower than for their non-Indigenous counterparts (113 and 170 per 100,000, respectively) [8].

In terms of specific cancers, the age-standardised hospitalisation rate for liver cancer and lung cancer for Indigenous people living in NSW, Vic, Qld, WA, SA and the NT during the period 2006-07 to 2010-11 were respectively 2.0 and 1.6 times higher than those for their non-Indigenous counterparts [8]. The hospitalisation rate for cervical cancer for Indigenous women was three times higher than that for other females.

Mortality

Cancer was responsible for one-in-five deaths (524 deaths) of Indigenous people living in NSW, Qld, SA, WA and the NT in 2012 [10]. After age-adjustment, the death rate for Indigenous people was 1.5 times higher than that for their non-Indigenous counterparts. Cancers of the trachea, bronchus and lung cancers were the third leading cause of death for Indigenous people (138 deaths: 77 males and 61 females), with the overall death rate 2.3 times that for non-Indigenous people.

In the five-year period 2007-2011, there was an average of 439 deaths from cancer per year among Indigenous people living in NSW, Qld, WA, SA and the NT [8]. After age-adjustment, the death rate for cancer was 1.5 times higher for Indigenous people than that for their non-Indigenous counterparts (Table 2).

In terms of specific cancers, the annual average numbers of cancer-related deaths among Indigenous people living in NSW, Qld, WA, SA and the NT in 2007-2011 were 110 from lung cancer, 29 from liver cancer, 28 from breast cancer (among women), 26 from cancer of unknown site, and 24 from bowel cancer [8]. The highest Indigenous:non-Indigenous death rate ratios were for cancer of the cervix (rate ratio 3.9), liver cancer (3.3), cancer of the oesophagus (2.3), lung cancer (1.9), and cancer of unknown site (1.9) (Table 2).

Table 2: Age-standardised death rates for selected cancers, by Indigenous status, and Indigenous:non-Indigenous rate ratios, NSW, Qld, WA, SA and the NT, 2007-2011
Site of primary cancerIndigenous peopleNon-Indigenous peopleRate ratio
Source: AIHW and National Mortality Database, 2013 [8]
Notes:
  1. Cancers are ordered by numbers among Indigenous people (not shown in table)
  2. Rates per 100,000 population, age-standardised to the Australian population at 30 June 2001
  3. Ratio is the Indigenous rate divided by the non-Indigenous rate
  4. Due to the incomplete identification of Indigenous status, these figures probably under-estimate the true difference between Indigenous and non-Indigenous rates
  5. Rates for 2007-2009 are final, 2010 are revised and 2011 are preliminary
Lung 64 33 1.9
Liver 17 5 3.3
Breast (female) 28 21 1.3
Unknown primary site 16 10 1.6
Bowel 13 16 0.8
Pancreas 13 9 1.4
Oesophagus 11 5 2.3
Prostate (males) 31 30 1.0
Stomach 7 4 1.7
Cervix (females) 7 2 3.9
All cancers 252 172 1.5

The patterns of Indigenous cancer incidence and mortality are largely explained by the higher level of risk factors, most notably tobacco use [11][12][13]. For example, high rates of smoking are the likely cause of a high incidence of cancers of the lung, mouth and throat [14].

The higher Indigenous:non-Indigenous ratio for deaths from cancer (1.5) than for cancer incidence (1.1) could be due to a number of factors:

References

  1. Australian Cancer Research Foundation (2014) What is cancer?. Retrieved 1 December 2014 from http://www.acrf.com.au/on-cancer/
  2. Cancer Council Australia (2014) What is cancer?. Retrieved 1 December 2014 from http://www.cancer.org.au/about-cancer/what-is-cancer/
  3. Roder D (2007) Epidemiology of cancer in Indigenous Australians: implications for service delivery. Cancer Forum; 31(2): 85-90
  4. Cunningham J, Rumbold AR, Zhang X, Condon JR (2008) Incidence, aetiology, and outcomes of cancer in Indigenous peoples in Australia. Lancet Oncology; 9(6): 585-595
  5. Zhang X, Condon JR, Rumbold AR, Cunningham J, Roder DM (2011) Estimating cancer incidence in Indigenous Australians. Australian and New Zealand Journal of Public Health; 35(5): 477-485
  6. Australian Institute of Health and Welfare (2010) Australia's health 2010: the twelfth biennial report of the Australian Institute of Health and Welfare. Canberra: Australian Institute of Health and Welfare
  7. Australian Institute of Health and Welfare, Australasian Association of Cancer Registries (2012) Cancer in Australia: an overview 2012. Canberra: Australian Institute of Health and Welfare
  8. Australian Institute of Health and Welfare, Cancer Australia (2013) Cancer in Aboriginal and Torres Strait Islander peoples of Australia: an overview. Canberra: Australian Institute of Health and Welfare
  9. Australian Institute of Health and Welfare (2013) Australian hospital statistics 2011–12. Canberra: Australian Institute of Health and Welfare
  10. Australian Bureau of Statistics (2014) Causes of death, Australia, 2012. Canberra: Australian Bureau of Statistics
  11. Threlfall TJ, Thompson JR (2009) Cancer incidence and mortality in Western Australia, 2007. Perth: Department of Health, Western Australia
  12. Condon JR, Barnes T, Cunningham J, Armstrong BK (2004) Long-term trends in cancer mortality for Indigenous Australians in the Northern Territory. Medical Journal of Australia; 180(10): 504-511
  13. Condon J (2004) Cancer, health services and Indigenous Australians. Canberra: Office for Aboriginal and Torres Strait Islander Health, Cooperative Research Centre for Aboriginal and Tropical Health
  14. Australian Bureau of Statistics, Australian Institute of Health and Welfare (2008) The health and welfare of Australia's Aboriginal and Torres Strait Islander Peoples 2008. Canberra: Australian Bureau of Statistics and Australian Institute of Health and Welfare

Endnotes

  1. The overall level of missing data on Indigenous status for cancers diagnosed between 2004 and 2008 in NSW, Qld, WA and the NT was 12%.
 
© 2001-2014 Australian Indigenous HealthInfoNet