What is small bowel cancer?
Small bowel cancer (also known as small intestine cancer) occurs when cells in the tissue of the small intestine grow and divide in an abnormal way. When cancer starts in another area of the body and spreads to the small bowel (intestine), it is referred to as secondary or metastatic cancer.
You can access further information about small 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 small bowel cancer?
In 2021, 217 Victorians were diagnosed with small bowel cancer. Of these, there were 116 males and 101 females, representing 53.5% and 46.5% of the total Victorian small bowel cancer diagnoses, respectively. Currently, small bowel cancer is diagnosed at a rate of 2 per 100,000 males and 1.6 per 100,000 females. The median age at diagnosis of small bowel cancer is 67 years in males and 68 in females (Figure 1 & 2). Accounting for 0.6% of all cancers diagnosed and 0.6% of all cancer-related deaths in 2021, small bowel cancer was the 27th most commonly diagnosed cancer and the 27th most common cause of cancer-related deaths in Victoria.
Trends in small bowel cancer over time
Figure 3 shows that since 1982 incidence of small bowel cancer has increased by an average of 3.7% per year in males and increased by an average of 4% per year in females. Over the past 39 years, mortality from small bowel cancer has increased by 1.6% per year in males and increased by 3% per year in females.
Small bowel cancer morphology
Figure 4 provides a summary of the different types of cells (morphology) which have caused small bowel cancers among all cases. Most small bowel cancer tumours, 55.4%, present as Neuroendocrine tumours.
Small bowel cancer subtypes
Figure 5 provides a breakdown of small bowel cancers by subsite location in 2021. Most (33.6%) are found in the Duodenum.
Geographical variance in small bowel cancer by local government area
Figure 6 demonstrates variation in age-standardised incidence rates of small bowel cancer, by local government areas. Darker shading indicates areas with higher rates of small bowel cancer.
Small bowel cancer in people born overseas
Figure 7 shows the age standardised incidence rates of small bowel cancers 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 small bowel cancers was 4 for males born in the South and Central America region and the lowest rate of 0.3 was observed in males born in the North-East Asia region. The highest age standardised incidence rate of small bowel cancers was 2.6 for females born in the North America region and the lowest rate of 0.1 was observed in females born in the North-East Asia region.
Small bowel cancer five-year relative survival
Figure 8 shows the change in 5-year survival for small 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 small bowel cancer between 1986-1990 and 2016-2020 from 46% to 68%.