What is bowel cancer?

Bowel cancer is cancer in any part of the large bowel, including the colon, rectum and rectosigmoid. It is sometimes known as colorectal cancer and might also be called colon or rectal cancer, depending on where it starts in the bowel.

You can access further information about bowel cancer, including risk factors, symptoms, diagnosis and treatment from Cancer Council Victoria. You can also call our trusted cancer nurses on 13 11 20 for support and to learn about our range of services for people affected by cancer.

The Victorian Cancer Registry also operates an interactive web portal, Data Explorer, which provides more trends and statistics than published here.

How common is bowel cancer?

In 2022, 3504 Victorians were diagnosed with bowel cancer. Of these, there were 1814 males and 1690 females, representing 51.8% and 48.2% of the total Victorian bowel cancer diagnoses, respectively. Currently, bowel cancer is diagnosed at a rate of 31 per 100,000 males and 24.9 per 100,000 females. The median age at diagnosis of bowel cancer is 69 years in males and 72 in females (Figure 1 & 2). Accounting for 9.7% of all cancers diagnosed and 11% of all cancer-related deaths in 2022, bowel cancer was the 3rd most commonly diagnosed cancer and the 2nd most common cause of cancer-related deaths in Victoria in 2022.

Trends in bowel cancer over time

Figure 3 shows that for males between 1982 to 2001 the incidence of bowel cancer increased by an average of 0.6% per year, between 2001 to 2019 incidence declined by an average of 1.6% per year, and between 2019 to 2022 incidence declined by an average of 5.8% per year.

For females between 1982 to 1992 the incidence of bowel cancer was stable, between 1992 to 2017 incidence declined by an average of 0.7% per year, and between 2017 to 2022 incidence declined by an average of 3.6% per year.

For males between 1982 to 1996 the mortality of bowel cancer declined by an average of 0.9% per year, between 1996 to 2006 mortality declined by an average of 3.7% per year, between 2006 to 2009 mortality stabilised, and between 2009 to 2022 mortality declined by an average of 3.9% per year.

For females between 1982 to 2022 the incidence of bowel cancer declined by an average of 2.3% per year.

Bowel cancer morphology

Figure 4 provides a summary of the different types of cells (morphology) which have caused bowel cancer among all cases. Most bowel cancer tumours, 81%, present as Adenocarcinoma tumours.

Geographical variance in bowel cancer by local government area

Figure 5 demonstrates variation in age-standardised incidence rates of bowel cancer, by local government areas. Darker shading indicates areas with higher rates of bowel cancer.

Bowel cancer in people born overseas

Figure 6 shows the age standardised incidence rates of bowel cancer in Australian-born Victorians compared to other major migrant groups, over the five-year period 2017 to 2021. The highest age standardised incidence rate for bowel cancer was 40.2 for males born in the Southern Europe region and the lowest rate of 20.1 was observed in males born in the Southern and Central Asia region. The highest age standardised incidence rate for bowel cancer was 30.1 for females born in the Australia and New Zealand region and lowest rate of 15.3 was observed in females born in the Southern and Central Asia region.

Bowel cancer distribution by stage at diagnosis

Figure 7 shows distribution of bowel cancer by stage of disease at diagnosis in 2022. In males, Stage unknown accounted for the largest proportion (25.2%) of new diagnoses and Stage 3 for the lowest proportion (17.2%) of new bowel cancer diagnoses. In females, Stage unknown accounted for the largest proportion (23.4%) of new diagnoses and Stage 4 accounted for the lowest proportion (17.4%) of new bowel cancer diagnoses.

Bowel cancer five-year relative survival

Figure 8 shows the change in 5-year survival for bowel cancer, and the 5-year survival trend for all cancers over the same time period. It demonstrates that five-year relative survival has increased for bowel cancer between 1982-1986 and 2017-2021 from 46% to 72%.