Small bowel cancer

What is small bowel cancer?

The small bowel is the part of the body connecting the stomach to the large bowel (colon). It’s made up of three main sections:

• The duodenum
• The jejunum
• The ileum

As part of the digestive system, its job is to help you digest food and absorb nutrients. Cancer in the small bowel is very rare.

Small bowel cancer is a type of cancer that develops between the stomach and large bowel. It’s usually found in people aged between 55-75. Small bowel cancers are not usually caused by the spread (metastasis) of disease from another part of the body. There are four main types.

• Adenocarcinoma – this is when a tumour develops in the lining of the small bowel. It is the most common type of small bowel cancer
• Lymphoma – this type of bowel cancer starts in the lymph tissue of the small bowel. The lymph tissue plays a role in the body’s immune system. Usually, lymphomas begin in the jejunum and ileum sections of the small bowel
• Neuroendocrine – this is generally found in the ileum. It can sometimes develop in the appendix too
• Sarcoma – several types of sarcoma develop in the small bowel. Leiomyosarcomas grow in the muscle wall of the small bowel. An even rarer type – gastrointestinal stromal tumours (GISTs) – can develop anywhere in the small bowel

Causes of small bowel cancer

The causes of small bowel cancer are not always clear. However, some conditions may increase your risk of developing it:

• Coeliac disease
• Crohn’s disease
• Familial adenomatous polyposis (FAP)
• Peutz-Jegher’s syndrome
• Previous cancers in the colon or rectum
• Smoking or obesity