What do we know about cancer among Indigenous people?

What is cancer?

Cancer is a disease of the body's cells (the basic building blocks of the body) [1]. Normally cells multiply and grow in an ordered way, but sometimes the genetic blueprint (DNA) of cells is damaged and uncontrolled growth can occur; this is cancer. Cancer can occur almost anywhere in the body. Cancer cells are ‘benign' if they do not spread into surrounding areas or to different parts of the body, and are not generally dangerous. If cancer cells spread into surrounding areas, or to different parts of the body (metastasise), they are known as ‘malignant'. Malignant cancers can cause illness and death.

What is known about cancer in the Indigenous population?

In 2004-2008, that the overall rate of new cases (incidence rate) of cancer was slightly higher for Indigenous people than for non-Indigenous people [2]. Incidence rates vary depending on the type of cancer. Indigenous people had higher incidence rates than did non-Indigenous people in 2004-2008 for:

• lung and other smoking-related cancers
• cervical cancer (for women)
• cancer of the pancreas
• cancers of 'unknown primary site' (the part of the body where the cancer started) [3].

Indigenous people had lower incidence rates than did non-Indigenous people in 2004-2008 for:

• breast cancer (for women)
• prostate cancer (for men)
• bowel cancer
• non-Hodgkin lymphoma (the lymphoid system is part of the body's immune system, the system that helps the body ward off diseases)
• melanoma (skin cancer that occurs in the pigment cells) [3].

In 2006-2010, cancer was the second most common cause of death for Indigenous people [2]. The types of cancer that caused the most deaths among Indigenous people were lung cancer, cancer of 'unknown primary site', breast cancer (for women), and bowel cancer [3]. The likelihood of getting lung cancer increases when people smoke tobacco.
The fact that Indigenous people are more likely than non-Indigenous people to die from cancer could be because:

• the types of cancers they develop (such as cancers of the lung and liver) are more likely to result in death
  
• their cancer may be more advanced by the time it is found (which is partly because Indigenous people may visit their doctor later and/or may not participate in screening programs)
• they are less likely to receive adequate treatment [4].

References

1. Australian Institute of Health and Welfare (2010) Cancer in Australia 2010: an overview. Canberra: Australian Institute of Health and Welfare
2. 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
3. Australian Institute of Health and Welfare, Australasian Association of Cancer Registries (2012) Cancer in Australia: an overview 2012: supplementary tables. Canberra: Australian Institute of Health and Welfare
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