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 2024, 234 Victorians were diagnosed with small bowel cancer. Of these, there were 133 males and 101 females, representing 57% and 43% of the total Victorian small bowel cancer diagnoses, respectively. Currently, small bowel cancer is diagnosed at a rate of 3.3 per 100,000 males and 2.3 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 0.58% of all cancers diagnosed and 0.56% of all cancer-related deaths in 2024, small bowel cancer was the 32nd most commonly diagnosed cancer and the 29th most common cause of cancer-related deaths in Victoria.

Trends in small bowel cancer over time

Figure 3a shows for males between 1982 to 2024 the age standardised incidence rate of small bowel cancer increased by an average of 3.3% per year.

For females between 1982 to 2024 the age standardised incidence rate of small bowel cancer increased by an average of 3.3% per year.

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%, present as neuroendocrine tumours.

Small bowel cancer subtypes

Figure 5 provides a breakdown of small bowel cancers by subsite location in 2024. Most (39%) are found in the Duodenum.

Small bowel cancer in people born overseas

Figure 6 shows the standardised incidence ratios (SIRs) of small bowel cancers in Australian-born Victorians compared to other major migrant groups, over the five-year period 2019 to 2023. The highest standardised incidence ratio (SIR) for small bowel cancers was 1.7 for males born in the South and Central America region and the lowest SIR of 0.38 was observed in males born in the North-East Asia region. The highest standardised incidence ratio (SIR) of small bowel cancers was 1.6 for females born in the Africa region and the lowest SIR of 0.27 was observed in females born in the South and Central America region.

Small bowel cancer five-year relative survival

Figure 7 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 1985-1989 and 2020-2024 from 52% to 73%.