Cancer data in Australia

Incidence rates of liver cancer among First Nations populations are rising for both males and females.

In 2011, liver cancer incidence for First Nations people was 14 per 100,000 males and 4.9 per 100,000 females. By 2025, estimated rates rise to 20 for males and 9.4 for females per 100,000. The rise in incidence is accompanied by increasing mortality rates (see Figure 8).

Figure 8: First Nations age-standardised liver cancer incidence and mortality rates, by sex, 2011 to 2025

Notes:

1. Data up to 2021 are actuals, exclude South Australia and Tasmania and use imputation to derive Indigenous status where Indigenous status is unknown (for the reporting states and territories).
2. Data for 2022 to 2025 are projections based on the data noted in Note 1.

Source: 2021 Australian Cancer Database

The incidence and mortality rates of liver cancer among First Nations populations are three times higher than the non-Indigenous population.

Similar to lung cancer, liver cancer is characterised by low survival rates and disproportionately affects the First Nations population (Figure 9). In 2025, the projected age-standardised incidence and mortality rates for liver cancer among non-Indigenous individuals are 4.6 cases and 2.8 deaths per 100,000 people, respectively. By contrast, the estimated rates for First Nations individuals in 2025 are much higher, at 14 cases and 9.0 deaths per 100,000 people.

Figure 9: Age-standardised liver cancer incidence and mortality rates, by Indigenous status, persons, 2011 to 2025

Notes:

1. Data up to 2021 are actuals, exclude South Australia and Tasmania and use imputation to derive Indigenous status where Indigenous status is unknown (for the reporting states and territories).
2. Data for 2022 to 2025 are projections based on the data noted in Note 1.

Source: 2021 Australian Cancer Database

The 5-year survival rate for liver cancer among First Nations people is around half that of non-Indigenous individuals.

First Nations 5-year relative survival for liver cancer is 14%, just under half of the non-Indigenous rate at 29%. Lower survival rates occur across all periods, from 1-year (46% vs 57%) to 5-year (Figure 10).

Figure 10: Liver cancer 5-year relative survival, by Indigenous status, persons, 2017–2021 

Note:
 1. Non-Indigenous rates are age-adjusted to the age composition of the First Nations population included within the survival calculations.
 2. Developmental life tables by Indigenous status are used to derive relative survival.

Source: 2021 Australian Cancer Database

First Nations breast cancer incidence rates have decreased over time

Breast cancer incidence rates are lower among First Nations females compared to the non-Indigenous population, mainly due to higher rates of small tumours (≤2cm) in the latter group. Since 2011, First Nations incidence rates have declined from 71 to a projected 59 cases per 100,000 females by 2025 (Figure 11).

Figure 11: Age-standardised breast cancer incidence rates, by Indigenous status, females, 2011 to 2025

Notes:

1. Data up to 2021 are actuals, exclude South Australia and Tasmania and use imputation to derive Indigenous status where Indigenous status is unknown (for the reporting states and territories).
2. Data for 2022 to 2025 are projections based on the data noted in Note 1.
3. Projections are not provided for breast cancer groups where tumour size is stated or unknown

Source: 2021 Australian Cancer Database

The incidence rates of breast cancer with larger tumour sizes among First Nations females are similar to those among non-Indigenous females.

First Nations females have lower breast cancer incidence rates for small tumours, but similar rates for larger tumours. The higher incidence rates from 2012–2016 may be partly due to expanding the National Breast Cancer Screening Program to include ages 70 to 74 (Table 6).

Rising rates of unknown breast tumour sizes have impacted non-Indigenous breast cancer statistics, with this trend not seen in the First Nations population. Between 2012–2016 and 2017–2021, First Nations females showed decreased incidence rates across all tumour sizes (Table 6). Unknown tumour size is linked to lower survival, and larger tumours may be under-reported for both groups. For non-Indigenous females, where the proportion of unknown cases has increased over time.

Table 6: Breast cancer incidence rates by tumour size, cases per 100,000 females, 2012–2016 and 2017–2021

Notes:

1. Data up to 2021 are actuals, exclude South Australia and Tasmania and use imputation to derive Indigenous status where Indigenous status is unknown (for the reporting states and territories).
2. Data for 2022 to 2025 are projections based on the data noted in Note 1.

Source: 2021 Australian Cancer Database

First Nations breast cancer mortality rates have reduced over time

First Nations breast cancer mortality rates decreased from 15 deaths per 100,000 females in 2011 to an estimated 11 per 100,000 in 2025. Non-Indigenous rates remain lower but have also declined, with the mortality gap staying about the same. 

Figure 12: Age-standardised breast cancer mortality rates, by Indigenous status, females, 2011 to 2025

Notes:

1. Data up to 2021 are actuals, exclude South Australia and Tasmania and use imputation to derive Indigenous status where Indigenous status is unknown (for the reporting states and territories).
2. Data for 2022 to 2025 are projections based on the data noted in Note 1.

Source: 2021 Australian Cancer Database

As discussed earlier, breast cancer survival rates for First Nations females are quite close to the non-Indigenous population. The greater difference for overall breast cancer survival rates is due to non-Indigenous females greater rates of smaller tumour sizes.

First Nations melanoma of the skin incidence rates remain much lower than the non-Indigenous population

Melanoma of the skin has one of the highest rates of unknown Indigenous status. At over 20% in 2011 and increasing to 30% in 2021, there is greater uncertainty of rates for incidence (for all cancers combined and excluding skin cancers incidence, the rate of unknown for 2011 was 5.4% and in 2021 was 7.1%). The very high rates of unknown First Nations status occur due to melanoma of the skin also being diagnosed in different places, such as skin clinics, dermatologists and General Practitioners of Australia. These services may not collect Indigenous status, or to the same extent as occurs in other services where cancer is more commonly diagnosed. Mortality data has much lower rates of unknown Indigenous status due to Indigenous status being obtained from death certificates.

There is a considerable disparity of rates for this cancer (where records are known) and as one of Australia’s leading cancers, it is reported to provide some indication of the rates. While there are relatively high levels of uncertainty as to precise rates, the data is supportive of the general understanding that First Nations melanoma of the skin rates are much lower than non-Indigenous. 

Melanoma of the skin has 5-year survival rates higher than 90% in Australia. High survival leads to a considerable disparity between the mortality and incidence rates. While the First Nations melanoma of the skin incidence rates are around half of the non-Indigenous population, the mortality rates are closer, with both being relatively low and decreasing between 2012-2016 and 2017-2021.

Notes:

1. Data up to 2021 are actuals, exclude South Australia and Tasmania and use imputation to derive Indigenous status where Indigenous status is unknown (for the reporting states and territories)..

Source: 2021 Australian Cancer Database

First Nations melanoma of the skin 5-year relative survival is over 90%

First Nations and non-Indigenous populations have comparable 5-year relative survival rates for melanoma. Breslow thickness is the measurement, in millimetres, of how deeply a melanoma has grown into the skin from the surface (Figure 13). 

Figure 13: Melanoma of the skin 5-year relative survival, by Indigenous status, persons, 2017–2021

Note:

1.  Non-Indigenous rates are age-adjusted to the age composition of the First Nations population included within the survival calculations. 
2. Developmental life tables by Indigenous status are used to derive relative survival.
3. Relative survival may be above 100%. Relative survival is relative to the general population. A rate of 50% suggests the survival is half that of the general population. A rate of more than 100% suggests the survival is greater than the general population.

Source: 2021 Australian Cancer Database

First Nations pancreatic cancer mortality rates are increasing

Pancreatic cancer is the third leading cause of cancer death in Australia, with increasing incidence and mortality. Among First Nations people, it also ranks third and very close to the second leading cancer causing death (colorectal cancer) (Table 8).

Pancreatic cancer is another low survival cancer where the First Nations population has higher incidence and mortality rates than the non-Indigenous population. First Nations pancreatic cancer incidence rates decreased slightly between 2012–2016 and 2017–2021 while, for the non-Indigenous population, it was the opposite. The First Nations mortality rate increased between 2012-2016 and 2017–2021 while non-Indigenous mortality rates were more stable over this period. 

Table 8: Age-standardised pancreatic cancer incidence (cases per 100,000 persons) and mortality rates (deaths per 100,000 persons), by Indigenous status, 2012–2016 and 2017–2021 

Notes:

1. Data up to 2021 are actuals, exclude South Australia and Tasmania and use imputation to derive Indigenous status where Indigenous status is unknown (for the reporting states and territories)..

Source: 2021 Australian Cancer Database

The five-year relative survival rate for pancreatic cancer among First Nations people is less than half that of the non-Indigenous population.

Pancreatic cancer 5-year relative survival rates are amongst the lowest of all cancer types. In 2017–2021, First Nations pancreatic cancer 5-year relative survival was 8.8%. The non-Indigenous equivalent rate was more than double this at 19%. The difference in survival rates is apparent from 1-year relative survival where First Nations survival was 31% while the non-Indigenous survival was 47% (Figure 14). 

Figure 14: Pancreatic cancer relative survival, by years after diagnosis, Indigenous status, persons, 2017–2021

Note:
 1. Non-Indigenous rates are age-adjusted to the age composition of the First Nations population included within the survival calculations.
 2. Developmental life tables by Indigenous status are used to derive relative survival.

Source: 2021 Australian Cancer Database

First Nations cervical cancer incidence rates for younger populations move closer to the non-Indigenous rates

From 2012–2016 to 2017–2021, First Nations cervical cancer age-standardised incidence rates fell from 10.9 to 10.3 cases per 100,000 females; non-Indigenous rates were 5.1 and 5.0, respectively.

While First Nations age-standardised incidence rates are around double that of the non-Indigenous population, there are signs that the rates are likely to continue to decrease for both populations. A risk factor for cervical cancer is human papillomavirus. In 2007, a national HPV vaccination program commenced for school age children around the ages of 12 to 13 as well as a catch up program. As the HPV vaccinated population ages and enters age groups where cervical cancer becomes more likely to be diagnosed, there have been decreasing incidence rates in Australia. One such age group is the 25 to 29 year-old age group in which the cervical cancer incidence rates have decreased for both populations and are now much closer (Table 9). More information about cervical cancer and the program is available in Cancer data commentary number 15.

Table 9: Age-specific cervical cancer incidence rates, 25 to 29 years of age (cases per 100,000 females), by Indigenous status, 2012–2016 and 2017–2021 

Note:
 1. Non-Indigenous rates are age-adjusted to the age composition of the First Nations population included within the survival calculations.
 Source: 2021 Australian Cancer Database

The cervical cancer incidence reductions that may be due to the HPV vaccination program are only more recently becoming apparent in younger age groups. Where reductions in incidence occur and assuming similar survival rates, reductions in mortality should become apparent over time.

From 2012–2016 to 2017–2021, First Nations cervical cancer mortality fell from 4.4 to 3.7 deaths per 100,000 females; non-Indigenous rates declined from 1.1 to 0.9.

The First Nations 5-year relative survival rates for First Nations females were 67% and the non-Indigenous rates were 80%. As with other cancers where there is a considerable disparity in 5-year relative survival, the difference is also apparent in 1-year relative survival (81% compared to 93%). While cervical cancer incidence rates for First Nations females were around double those for non-Indigenous, the lower survival contributes to First Nations cervical cancer mortality rates being over 4 times those of the non-Indigenous population (an estimated 3.8 deaths per 100,000 females in 2025 compared to 0.8 deaths per 100,000).

First Nations oesophageal cancer incidence and mortality rates have decreased over time

In 2011, the First Nations age-standardised incidence rate was 7.5 cases per 100,000 people and in 2025 it was estimated to have reduced to 5 cases per 100,000 people. The much lower non-Indigenous rate of 2.7 cases per 100,000 in 2011 decreased to an estimated 2.4 cases per 100,000 people in 2025. With oesophageal cancer relative survival rates being low, the changes in incidence rate trends are also apparent in mortality rates (Figure 15).

The First Nations 5-year relative survival for 2017–2021 was 19% and for non-Indigenous people it was 29%. Like many other cancers, the difference in survival commences from the first year (1-year relative survival (42% and 58% respectively).

Figure 15: Age-standardised oesophageal cancer incidence and mortality rates, by Indigenous status, persons, 2011 to 2025

Notes:

1. Data up to 2021 are actuals, exclude South Australia and Tasmania and use imputation to derive Indigenous status where Indigenous status is unknown (for the reporting states and territories).
2. Data for 2022 to 2025 are projections based on the data noted in Note 1.

Source: 2021 Australian Cancer Database

First Nations uterine cancer incidence rates have been relatively stable over time but mortality rates have increased

Within Australia, uterine cancer age-standardised incidence and mortality rates have increased over time. The increasing uterine cancer incidence rates are not apparent for the First Nations population while mortality has been increasing. The non-Indigenous mortality and incidence trends are reflective of the Australian trends with both increasing (Figure 16)

First Nations uterine cancer 5-year relative survival in 2017–2021 was 76%; it was 86% for the non-Indigenous population. The 1-year respective survival rates were 90% and 95%. 

Figure 16: Age-standardised uterine cancer incidence and mortality rates, by Indigenous status, females, 2011 to 2025

Notes:

1. Data up to 2021 are actuals, exclude South Australia and Tasmania and use imputation to derive Indigenous status where Indigenous status is unknown (for the reporting states and territories).
2. Data for 2022 to 2025 are projections based on the data noted in Note 1.

Source: 2021 Australian Cancer Database

First Nations blood cancer incidence rates and trends are similar to non-Indigenous rates

First Nations cancer incidence rates and trends for all blood cancers combined are very similar to the non-Indigenous rates and trends. Both are generally within the low 30 cases per 100,000 people range and have been relatively stable over time. First Nations mortality rates are higher than non-Indigenous rates and, similar to non-Indigenous rates, may be decreasing to some extent. First Nations cancer incidence and mortality rates are generally more volatile due to their smaller populations, and it is not yet apparent if the 2021 higher mortality is an outlier or the rate reductions of the previous several years are likely to continue (Figure 17).

Figure 17: Age-standardised all blood cancers combined incidence and mortality rates, by Indigenous status, persons, 2011 to 2025

Notes:

1. Data up to 2021 are actuals, exclude South Australia and Tasmania and use imputation to derive Indigenous status where Indigenous status is unknown (for the reporting states and territories).
2. Data for 2022 to 2025 are projections based on the data noted in Note 1.

Source: 2021 Australian Cancer Database

Between 2017 and 2021, the 5-year relative survival rate for blood cancers was 66% among First Nations people, compared to 77% for non-Indigenous individuals. The gap is most pronounced in certain types, especially non-Hodgkin lymphoma. Although First Nations survival rates are typically lower overall, the difference is less marked in other blood cancer types than it is for myelodysplastic syndromes, non-Hodgkin lymphoma and acute myeloid leukaemia. For non-Hodgkin lymphoma, the 1-year survival rates were 82% for First Nations and 91% for non-Indigenous people; for acute myeloid leukaemia, these rates were 48% and 67%, respectively. Similarly, the 1-year survival difference is apparent for myelodysplastic syndromes 65% and 78%.

Table 10: Incidence rates and 5-year relative survival for selected blood cancer types, by Indigenous status, persons, 2017–2021 

Notes:

1. Data up to 2021 are actuals, exclude South Australia and Tasmania and use imputation to derive Indigenous status where Indigenous status is unknown (for the reporting states and territories).
2. Non-Indigenous survival rates are age-adjusted to the age composition of the First Nations population included within the survival calculations.
3. Developmental life tables by Indigenous status are used to derive relative survival.
4. Incidence rates are expressed as cases per 100,00 people

Source: 2021 Australian Cancer Database

First Nations prostate cancer mortality rates are lower than non-Indigenous and have decreased over time

First Nations prostate cancer incidence rates were lower than non-Indigenous for the entire period between 2011 and 2025 and broadly follow the national trends. Prostate cancer 5-year relative survival for First Nations people is 93.1% and for non-Indigenous people it is 97.1%. While both survival rates are high, the disparity between them brings First Nations age-standardised mortality rates to be higher than non-Indigenous males. For both populations, age-standardised prostate cancer mortality rates have decreased.

Figure 18: Age-standardised prostate cancer incidence and mortality rates, by Indigenous status, males, 2011 to 2025

Notes:

1. Data up to 2021 are actuals, exclude South Australia and Tasmania and use imputation to derive Indigenous status where Indigenous status is unknown (for the reporting states and territories).
2. Data for 2022 to 2025 are projections based on the data noted in Note 1.

Source: 2021 Australian Cancer Database

First Nations people are more likely to be diagnosed with rare and less common cancers

Rare Cancers Australia and RARECARENet defines a cancer to be ‘rare’ if it has an incidence rate of less than 6 cases per 100,000 people per year. If the incidence rate is greater than or equal to 6 cases per 100,000 people per year but less than 12 cases per 100,000 people per year, the cancer is ‘less common’. ‘Common’ cancers are defined as those with an incidence rate of 12 or more cases per 100,000 people per year. Crude Australian incidence rates have been used to define cancer rarity. 

Rare Cancers Australia notes several of the specific challenges presented by rare and less common cancers. These include: 

• late diagnosis 
• unclear prognosis 
• limited research or clinical expertise
• barriers to treatment including high out-of-pocket costs, fewer treatment options, and a lack of rural and remote services
• poorer survival outcomes compared to common cancers (RCA, 2025).

The difficulties experienced by First Nations individuals are also apparent when considering cancer incidence by rarity. Notably, there are elevated rates of  less common and rare cancers, which can present the previously described challenges.

While the incidence rates for First Nations people are very similar to non-Indigenous for common cancers, the higher mortality rates will be partly due to generally lower cancer survival outcomes for First Nations people but much is due to higher proportion of lower survival cancers such as lung and pancreatic cancer and lower proportions of high survival cancers, in particular melanoma of the skin. 

Table 11: Age-standardised incidence and mortality rates and 5-year relative survival for cancers by rarity, by Indigenous status, persons, 2017–2021

Notes:

1. Data up to 2021 are actuals, exclude South Australia and Tasmania and use imputation to derive Indigenous status where Indigenous status is unknown (for the reporting states and territories).
2. Non-Indigenous survival rates are age-adjusted to the age composition of the First Nations population included within the survival calculations.
3. Developmental life tables by Indigenous status are used to derive relative survival.
4. Incidence rates are expressed as cases per 100,00 people

Source: 2021 Australian Cancer Database

First Nations colorectal cancer incidence and mortality rates remained relatively stable, while non-Indigenous rates decreased, over time

First Nations colorectal (bowel) cancer incidence rate trends were overall relatively stable around 30 cases per 100,000 people from 2012 to 2025, while non-Indigenous rates have consistently decreased gradually over the same period. For mortality rates, both populations have decreasing mortality  (Figure 19).

Figure 19: Age-standardised colorectal cancer incidence and mortality rates, by Indigenous status, males, 2011 to 2025

Notes:

1. Data up to 2021 are actuals, exclude South Australia and Tasmania and use imputation to derive Indigenous status where Indigenous status is unknown (for the reporting states and territories).
2. Data for 2022 to 2025 are projections based on the data noted in Note 1.

Source: 2021 Australian Cancer Database

Colorectal cancer rates among First Nations individuals in their 30s and 40s have risen over time.

Colorectal cancer rates have risen among Australians in their 30s and 40s, while rates for older groups have declined. A similar pattern exists among the First Nations population; however, reductions in older age groups—those in their 60s and 70s—are less pronounced than among non-Indigenous people. Additionally, incidence rate increases for individuals in their 50s are higher in the First Nations population compared to the steady rates seen in non-Indigenous Australians (see Table 12).

Table 12: Age-specific colorectal cancer incidence rates (cases per 100,000), by Indigenous status, persons, 2012–2016 and 2017–2021 

Notes:

1. Data up to 2021 are actuals, exclude South Australia and Tasmania and use imputation to derive Indigenous status where Indigenous status is unknown (for the reporting states and territories).

Source: 2021 Australian Cancer Database

First Nations 1-year relative survival for colorectal cancer for 2017–2021 was 85% and for non-Indigenous it was 90%. For 5-year survival, the difference in survival rates is greater (66% and 74%).

Appendix

About the First Nations population estimates used for rates

Calculating cancer rates for First Nations requires both their cancer case count and population size. This section discusses uncertainty around the First Nations population.

First Nations cancer reporting within the Cancer data in Australia report includes incidence and mortality rates using the First Nations population as derived from the 2021 Census as well as rates derived from the Census adjusted for changing identification (Census ACI).

The 2021 Census First Nations population estimates are sourced from the Australian Bureau of Statistics (ABS) ‘Estimates and projections, Australian Aboriginal and Torres Strait Islander population, 2021 Census-based estimates and projections of the Aboriginal and Torres Strait Islander population for 2011 to 2031’.

The Census ACI is a constructed First Nations population which uses the above 2021 Census First Nations population for the 2021 First Nations population estimates, the equivalent 2016 ABS report for the 2016 First Nations population and the 2011 equivalent report for the 2011 First Nations population. The years in-between Censuses are interpolated.

Cancer rates using these two First Nations populations can vary significantly. This section clarifies the reasons behind presenting data for both groups and providing separate sets of rates.

Understanding the First Nations population estimates from the 2011, 2016 and 2021 Censuses provides important background. The First Nations population estimates from the Census increased significantly in the 2016 Census and then again in 2021 Census. Much of the change was due to the increase in the propensity to identify as a person of Aboriginal and Torres Strait origin. More information about the changes in population estimates is available in the Understanding change in counts of Aboriginal and Torres Strait Islander Australians: Census report by the Australian Bureau of Statistics.

The 2021 Census is used to revise First Nations population estimates over time. According, to the 2021 Census, there were 825,000 First Nations people living in Australia in 2011. This is the revised figure whereas the 2011 Census noted there were 670,000 First Nations people. Much of the difference is due to more First Nations people identifying in the respective Census over time. The 2011 First Nations population estimate from the 2021 Census would therefore effectively be ‘based on 2021 population counts, back cast for births and deaths, and had the First Nations population propensity to identify in 2011 be the same as in 2021, there would be 825,000 First Nations people in Australia in 2011’.

Figure A1 shows the cancer incidence rates by Indigenous status when using the 2021 Census. It suggests that First Nations and non-Indigenous cancer incidence rates used to be quite similar in 2011 but since then, First Nations cancer incidence rates have been increasing quite strongly while non-Indigenous rates have been gradually decreasing.

That First Nations and non-Indigenous cancer rates were similar in 2011 is unlikely. If we consider that the changing propensity to identify was not restricted to the Census, then the number of First Nations cancer cases would also be understated due to fewer First Nations people identifying.

If we work on an assumption that the propensity to identify in the cancer data is broadly equivalent to the Census, then the First Nations population estimates from the 2011 Census should provide more meaningful rates for 2011 cancer data (as the 2011 cancer data and 2011 Census had similar propensity for First Nations people to identify). Similarly, the 2016 Census and 2016 cancer data may have had similar propensity to identify and so too for 2021 Census and 2021 cancer data.

Figure A1 also provides age-standardised cancer incidence trends using the Census ACI. It provides a fundamentally different picture of First Nations cancer trends. It suggests that First Nations cancer incidence rates have been consistently higher than non-Indigenous but both populations have decreasing incidence overall.

Figure A1: Estimated age-standardised cancer incidence trend comparisons using different Census populations, by Indigenous status, 2011 to 2021, persons

Notes:

1. Data up to 2021 are actuals, exclude South Australia and Tasmania and use imputation to derive Indigenous status where Indigenous status is unknown (for the reporting states and territories).

Source: 2021 Australian Cancer Database

In developing the Census ACI, its times series were contrasted with the Census 2021 results. In general, the Census ACI offered more plausible trends and rates. Using the Figure A1 comparison, it is more likely that First Nations cancer incidence rates have consistently been higher over time (Census ACI) than were similar to non-Indigenous but have since moved in different directions (Census 2021). It is more likely that, like the Census, the 2011 cancer data had a lower propensity for First Nations people to identify and so it would be more appropriate to use Census estimates with a similar propensity to identify, rather than the revised estimates for 2021.

Why provide both the Census 2021 and Census ACI?

Given the uncertainty in rates, First Nations incidence and mortality rates cannot be considered with certainty. Outside of the CdiA, most published First Nations rates will use the Census 2021 time series. Census 2021 rates are provided within the First Nations cancer reporting to adhere to the standard reporting. If Census 2021 rates were reported alone, it would need to be noted that increasing First Nations cancer counts and rates may be due to the increasing propensity for First Nations people to identify. The Census ACI provides an estimate of the propensity to identify over time and is our recommended option when discussing cancer incidence and mortality trends.

How different are the Census 2021 and Census ACI populations?

Table A1 outlines the difference in First Nations population when using the Census of the time with the Census 2021 population estimates.

 Table A1: Census First Nations populations, persons

Referring to Table A1, the Census 2021 estimate for 2011 First Nations population is essentially, ‘based on 2021 identification, there were 806,000 First Nations people in 2011’. The Census ACI instead uses the 2011 First Nations population estimate which is essentially ‘based on 2011 identification, there were 670,000 First Nations people in 2011’. The cancer data for 2011 likely has identification more similar to 2011 Census identification levels. The lower First Nations cancer incidence rates when using the Census 2021 are more likely due to fewer people identifying as such in the cancer data. We use the Census ACI as it more likely better aligns the likelihood of First Nations people to identify in the cancer data (the numerator for rates) and the Census of the time (the denominator for rates).

Finally, we cannot know the reliability of trends with certainty. However, the overview is based on rates and trends that appear more plausible.

Imputation is used for Indigenous status unknown

Rates and counts are based on imputed data and when age-standardised incidence and mortality rates are adjusted to the Census 2021 First Nations population. Cancer data commentary 13 discusses imputation.

We encourage people using First Nations cancer data to read the commentary because of the challenges associated with First Nations reporting and that it can be prone to subjectivities not typical to most statistics.

About the choice to age-standardise to the 2021 First Nations population

In this summary, we use the 2021 First Nations population as the reference point to standardise cancer incidence and mortality rates. Figure 1b shows crude cancer incidence rates for First Nations people, as well as rates standardized to the 2001 Australian Standard Population (2001 ASP), the 2025 Australian Population (2025 AP), and the 2021 First Nations Population (2021 FNP).

The crude rate of cancer for First Nations people in 2011 was around 259 cases per 100,000 people and in 2021 it was around 314 cases per 100,000 people. When age-standardised to the 2021 FNP, the rates move from 342 to 315 cases per 100,000 people. The crude rate increase of 55 cases per 100,000 people is attributable to the First Nations population ageing as age-standardised rates decrease by around 27 cases per 100,000 people. Rates age-standardised to the 2021 FNP are cohesive with the crude rates.

When age-standardised to the 2001 ASP, the rate changes from 605 to 561 cases per 100,000. The rates are considerably higher because the First Nations population is much younger than the age-structure of the 2001 ASP. When age-standardising to this population the First Nations population is effectively made older and consequently rates increase considerably (because cancer rates are higher in older populations). 

When a rate is age-standardised to a population and the rate changes considerably, the rate is of little relevance to the population that changes. For cancers such as colorectal cancer where incidence rates are increasing in the young, but not the older populations, the choice of population can have a greater impact. Here is 2001 ASP 2012-2016 rate was 56.5 cases per 100,000 people and reduced slightly to 55.8 cases per 100,000 people. For the same data, the 2021 FNP change was 29.9 to 30.2. The 2021 FNP does not give additional weight to the older population (where rates are decreasing) and so provides a more reliable indication of change as it relates to the First Nations population. 

As this paper discusses and focusses on First Nations people, we use the 2021 ASP to provide more relevant rates and rate change descriptions. The 2001 ASP is commonly used and as the standard for Australia, is well suited to age-standardised rates to be compared across data sources. For those who wish to use rates age-standardised to the 2001 Australian population, these rates are available within the First Nations data. 

Figure A2: Age-standardised all cancers combined and crude incidence trend comparisons using different Census populations, by Indigenous status, 2011 to 2025, persons

A note about survival rates

Developmental life tables by Indigenous status were used to calculate relative survival. The survival rates within this paper will often be a little different to elsewhere in the Cancer data in Australia report. While some of the difference may be attributable to the First Nations reporting excluding South Australia and Tasmania, much will be because non-Indigenous rates are also age-standardised to the First Nations population and survival rates are higher for younger populations. 

Brain cancer provides a useful example, for this cancer in 2017–2021:

• the Australian 5-year relative survival for brain cancer was 23.8%. 
• For the First Nations population, it was 46.8%
• The non-Indigenous was 23.1% before age-standardisation

The comparison suggest First Nations brain cancer survival is much higher than non-Indigenous. However, this is before age-standardisation. When the non-Indigenous is age-adjusted it moves to 45.4% - around the same as First Nations population. The non-Indigenous population has its rate age adjusted within this report so the First Nations survival reflects that which occurred and the First Nations population is the focal point of this report.

It should be noted that the brain cancer age-adjustment is much greater than commonly occurs. In standardising to the younger population, the brain cancer survival has a greater weight on younger brain cancer rates where survival is higher than the older populations where the 5-year survival is very low (for example, in 2017–2021 the survival for people aged 15 to 19 was 78%, 45 to 49 was 34% and for 80 to 84 it was 1.9%). 

Cunningham J, Rumbold AR, Zhang X & Condon J 2008. Incidence, aetiology, and outcomes of cancer in Indigenous peoples in Australia. Lancet Oncology 9:585-95.

Hall SE, Bulsara CE, Bulsara MK, Leahy TG, Culbong MR, Hendrie D et al. 2004. Treatment patterns for cancer in Western Australia: does being Indigenous make a difference? The Medical Journal of Australia 181:191-4.

Valery P, Youlden D, Baade P, Ward L, Green A & Aitken J 2013. Cancer survival in Indigenous and non-Indigenous Australian children: what is the difference? Cancer Causes & Control 24:2099-106.