What is small bowel cancer?

Small bowel cancer (also called small intestine cancer) occurs when cells in the small bowel becomes abnormal and keep growing and form a mass or lump called a tumour. The type is defined by the particular cells that are affected.

Malignant (cancerous) tumours have the potential to spread to other parts of the body through the blood stream or lymph vessels and form  another tumour at a new site. This new tumour is known as secondary cancer or metastasis.

Types of small bowel cancer

The most common types include:

Adenocarcinoma – These start in epithelial cells (which release mucus) that line the inside of the small bowel, often in the duodenum.

Sarcoma – These start in connective tissue (which support and connect all the organs and structures of the body). Gastro-intestinal stromal tumours (GIST) starts in nerve cells anywhere in the small bowel. Leiomyosarcoma starts in muscle tissues in the wall of the small bowel, often in the ileum.

Neuroendocrine (carcinoid) tumours (NETs) – These form in neuroendocrine cells inside the small bowel, often in the ileum. The neuroendocrine system is a network of glands and nerve cells that make hormones and release them into the bloodstream to help control normal body functions.

Lymphoma – These form in lymph tissue (part of the immune system which protects the body) in the small bowel, often in the jejunum. Non-Hodgkin lymphoma starts in lymphocytes, a type of white blood cell.

How common is small bowel cancer?

Small bowel cancer is rare. About 530 Australians are diagnosed each year (this is about 2 cases per 100,000 people). It is more likely to be diagnosed in men than women, and people aged over 60 years.