Colorectal cancer (C18–C20)

In 2009–2013, 612 new cases of colorectal cancer were diagnosed in Indigenous Australians—an average of 122 cases per year. In 2011–2015, 153 Indigenous Australians died from colorectal cancer—an average of 31 deaths per year.

In 2007–2014, Indigenous Australians diagnosed with colorectal cancer had a 58% chance, on average, of surviving for five years compared with their counterparts in the Indigenous population. Non-Indigenous Australians diagnosed with colorectal cancer had a 67% chance, on average, of surviving for five years compared with their counterparts in the non-Indigenous population.

Disparities in participation in bowel screening are likely to have effects on cancer incidence and mortality in Indigenous Australians. This is because the NBCSP is able to detect precancerous abnormalities, thereby preventing cancers from developing and reducing the incidence of malignant disease. Cancers that are detected through screening are also more likely to be at an earlier stage (the extent of cancer in the body), which tends to be associated with better survival if treated.

Sex

More Indigenous males than females were diagnosed with and died from colorectal cancer. Five-year relative survival was lower in Indigenous males than females.

Explore the data below for information on incidence (2009–2013), mortality (2011–2015) and relative survival (2007–2014) by sex and Indigenous status.

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Life stage

For both Indigenous and non-Indigenous Australians, the age-specific incidence and mortality rates for colorectal cancer increased with each life stage.

For Indigenous Australians, five-year relative survival was lowest for life stage 25–44 and then increased for life stage 45–64, before decreasing for life stage 65 or older. Five-year relative survival for non-Indigenous Australians decreased with each life stage.

Explore the data below for information on incidence (2009–2013), mortality (2011–2015) and relative survival (2007–2014) by sex, Indigenous status and life stage.

Trend

For Indigenous Australians, the age-standardised incidence and mortality rates for colorectal cancer have varied over time. Estimated trend lines indicate a significant increase in the colorectal cancer incidence rate for Indigenous Australians. No statistically significant increasing or decreasing trend was observed in the colorectal cancer mortality rate for Indigenous Australians from 1998 to 2015.

For non-Indigenous Australians, the age-standardised incidence rate for colorectal cancer varied over time, while the mortality rate has fallen. Estimated trend lines indicate a significant decrease in the colorectal cancer mortality rate for non-Indigenous Australians. No statistically significant increasing or decreasing trend was observed in the colorectal cancer incidence rate for non-Indigenous Australians from 1998 to 2013.

Data for individual years have been presented for trend figures to demonstrate the variation in rates from year to year. Estimated trend lines have been applied to figures based on a least-squares regression equation where trends were found to be statistically significant. Differences between the rates for Indigenous and non-Indigenous Australians may be related to a range of factors including differences between the two populations in the prevalence of risk and/or protective factors such as smoking, alcohol consumption, access to health-care services and uptake of screening and diagnostics testing.

Explore the data below for information on incidence and mortality by sex, Indigenous status and year.

State and territory

For the jurisdictions for which data were available (see Summary or Notes section for details), the age-standardised incidence rate for colorectal cancer ranged from 22 per 100,000 to 73 per 100,000 for Indigenous Australians. For non-Indigenous Australians, the incidence rate ranged from 54 per 100,000 to 59 per 100,000.

For the jurisdictions for which data were available (see Summary or Notes section for details), the age-standardised mortality rate for colorectal cancer ranged from 11 deaths per 100,000 to 16 per 100,000 for Indigenous Australians. For non-Indigenous Australians, the mortality rate ranged from 13 per 100,000 to 19 per 100,000.

Observed differences may be due to differences in population characteristics, for example, Indigenous Australians are more likely to live in remote areas of Australia than non-Indigenous people.

Explore the data below for information on incidence (2009–2013) and mortality (2011–2015) by sex, Indigenous status and state and territory.

Remoteness area

For Indigenous Australians, the age-standardised incidence rate for colorectal cancer ranged from 21 per 100,000 to 51 per 100,000 across remoteness areas. The age-standardised mortality rate for colorectal cancer ranged from 7.6 per 100,000 to 13 per 100,000 across remoteness areas.

For non-Indigenous Australians, the age-standardised incidence rate for colorectal cancer ranged from 43 per 100,000 to 50 per 100,000 across remoteness areas. The age-standardised mortality rate for colorectal cancer ranged from 8.6 per 100,000 to 12 per 100,000 across remoteness areas.

Explore the data below for information on incidence (2009–2013) and mortality (2011–2015) by sex, Indigenous status and remoteness area.

National Bowel Cancer Screening Program (NBCSP

Between 2014–2015, Indigenous Australians participated in the National Bowel Cancer Screening Program at a lower rate than non-Indigenous Australians. Indigenous Australians had a higher screening positivity rate than non-Indigenous Australians, however they also had a lower follow-up diagnostic assessment rate than non-Indigenous Australians.

There are limitations in the data available to estimate Indigenous Australians’ participation in the NBCSP due to the relatively high proportion of Indigenous status that is ‘not stated’ in the data sets used. An overall rate has been estimated, but these limitations should be considered when interpreting these data. Opportunities to improve the accuracy of calculating Indigenous participation rates will continue to be explored.

Explore the data below for information on NBCSP indicators.