Small bowel cancer | Cancer Research UK
Cancer Research UK on Google+ Cancer Research UK on Facebook Cancer Research UK on Twitter

Small bowel cancer

This page tells you about small bowel cancer. There is information about


The small bowel

The small bowel makes up most of the digestive tract. It is actually about 6 metres long, but it is folded up so that it fits inside the abdomen. It has 3 sections, which are the

  • Duodenum (dew-oh-dean-um) – the top part of the small bowel, which connects to the stomach
  • Jejunum (jej-you-num) – the middle part
  • Ileum (ill-ee-um) – the lower part, which connects to the large bowel (colon)

Right at the end of the ileum, just before it joins to the colon, is a small pouch called the appendix.

Diagram showing the position of the small bowel in the digestive system

Diagram showing the parts of the small bowel

Tumours of the small bowel may be either non cancerous (benign) or cancerous (malignant). Benign tumours include polyps and lipomas. Cancers of the small bowel are rare, with just under 1,300 people diagnosed in the UK each year. If you compare this to around 41,600 large bowel (colon) and rectal cancers diagnosed each year, you can see how rare it is. Most cases of small bowel cancer are found in the duodenum.


Types of small bowel cancer

There are several different types of malignant small bowel tumour

  • Adenocarcinoma – around 4 out of 10 small bowel cancers (40%) are adenocarcinomas, making it the most common type. It starts in cells that line the bowel (epithelial cells) and develops most often in the duodenum
  • Neuroendocrine tumours – around 4 out of 10 small bowel tumours (40%) are neuroendocrine which includes carcinoid tumours. These develop from cells that produce hormones, most commonly in the appendix or the ileum
  • Lymphoma – 1 out of 10 small bowel cancers (10%) are lymphomas, usually found in the jejunum
  • Sarcomas – can develop in the soft tissues anywhere in the small bowel, but most often grow in the ileum. There are different types and the most common is a cancer of smooth muscle (leiomyosarcoma)
  • Secondary cancers – these are tumours that have started somewhere else in the body and have spread to the small bowel

We have separate sections about carcinoid tumours, lymphomas and sarcomas. And a page explaining what a neuroendocrine tumour (NET) is. If you have any of these types of small bowel tumour, it may be helpful to look at the section about that cancer type.

If you have a secondary cancer in your small bowel, it may help to look at the section about your type of primary cancer. Cancer cells from your primary tumour have broken away and spread to your small bowel. So these cancer cells have to be treated in the same way as your primary cancer type.


Risks and causes of small bowel cancer

We don’t know what causes most small bowel cancers. But there are a number of factors that may increase your risk. These include having

  • Age - Small bowel cancer is generally diagnosed in older people. The average age of diagnosis is 66 years
  • Familial adenomatous polyposis – a rare condition where an inherited faulty gene makes many polyps develop on the bowel lining
  • Lynch syndrome (Hereditary non polyposis colorectal cancer or HNPCC) - a rare gene fault that increases the risk of several different types of cancer
  • Peutz Jeghers syndrome – an inherited condition where benign (non cancerous) polyps form in the bowel.
  • Crohn’s disease – cancers related to Crohn’s disease are usually adenocarcinomas of the ileum. Only 2 out of 100 people with Crohn's disease (2%) will develop cancer in the small bowel
  • Coeliac disease – may slightly increase your risk of developing lymphoma or adenocarcinoma of the small bowel. Sticking to a gluten free diet reduces the risk
  • A diet rich in red meat or smoked foods, or a high fat diet

Smoking and drinking alcohol has also been linked to the risk of small bowel cancer, but we need further research to confirm this.


Symptoms of small bowel cancer

Small bowel cancer symptoms include

  • Pain in your abdomen
  • Weight loss
  • Feeling and being sick
  • Diarrhoea
  • Tiredness

Other possible symptoms may include bleeding and a blockage in the bowel but these are rare.

Other conditions that affect the bowel can cause all these symptoms too. Many of these are less serious than cancer, such as irritable bowel disease or inflammatory bowel disease. It is also possible to have cancer of the small bowel and not have these symptoms. If you are worried about any symptoms you have you should see your doctor.


Diagnosing small bowel cancer

It can be difficult to diagnose small bowel cancer because the bowel is folded up so much inside the body. And because it is the middle part of the digestive tract, it can be hard for the doctor to examine and take a biopsy. But if you have symptoms that suggest small bowel cancer, your doctor will probably arrange for you to have a number of tests. The tests will help the doctor see any lump or growth in the bowel. Often doctors won’t be able to make a firm diagnosis until you have surgery to remove a lump. 

Tests you might have include

  • Barium X-ray – you drink a white liquid called barium (that shows up on X-rays) and then have X-rays to see how it moves through your bowel
  • Blood tests to check for a low red cell count (anaemia) and see how well your liver is working
  • Endoscopy or colonoscopy – the doctor looks inside your bowel through a flexible tube and can take a biopsy of abnormal areas
  • CT scan – this can show where the tumour is and whether there are signs that the cancer has spread to anywhere else in the body
  • Capsule endoscopy – you swallow a small capsule, which contains a camera and light source and takes pictures of the bowel as it travels through

Treating small bowel cancer

Treatment for small bowel cancer depends on the type of cancer, and where in the small bowel it is. Treatment can include


Surgery is the main treatment for cancer of the small bowel. During surgery, the doctor will remove the tumour, as well as a border of healthy tissue surrounding it. The amount of bowel you need to have removed will depend on the size and the position of your cancer.

Sometimes the surgeon may have to remove other organs as well. If the cancer is at the top end of your small bowel, the surgeon may remove your pancreas. If the cancer is at the lower end of your small bowel, your surgeon may remove part of your large bowel. Your surgeon will remove any lymph nodes nearby in case any cancer cells have spread there.

After removing the bit of bowel with the tumour, your surgeon will join the two ends of the remaining bowel together. If this is not possible, you may need an ileostomy. This is when part of the small bowel is brought up onto the surface of the abdomen to form a stoma. You will need to wear a special bag over the stoma to collect your bowel movements (faeces). We have information about coping with a stoma in the bowel cancer section.

If your cancer is advanced, surgery to remove the cancer is not always possible. Any surgery you have will be to help relieve symptoms. You might be able to have an operation to free a blockage in your bowel.


Radiotherapy is mainly used to treat more advanced small bowel cancers. Advanced cancer means that the cancer has spread to another part of the body. Small bowel cancer may be advanced when it is diagnosed. Or it may be advanced if it comes back after treatment. Radiotherapy can help to control symptoms you have because of advanced cancer, such as pain. 


You might have chemotherapy to treat lymphomas of the small bowel. The drugs you have depends on which type of non Hodgkin lymphoma it is.

For other small bowel cancers, such as adenocarcinoma, you may have chemotherapy after surgery for cancer that has spread to the lymph nodes. Doctors are more likely to use chemotherapy for small bowel cancer that has spread to other areas of the body (metastatic disease). You usually have a combination of chemotherapy drugs, including oxaliplatin or irinotecan, such as FOLFOX or FOLFIRI. These combinations of drugs are commonly used to treat cancer of the large bowel.

Doctors sometimes use the chemotherapy drug fluorouracil with radiotherapy, to help it work better. This is called radiosensitising. You might have this treatment after surgery if your cancer comes back.

Doctors are still trying to find out the value of chemotherapy for small bowel cancer and which drugs will work best. Finding out how well treatments work when a cancer is rare is difficult. It is harder to organise trials because there are fewer people who can take part. This means it takes longer to get meaningful results.

The BALLAD trial is comparing different types of chemotherapy with no chemotherapy after surgery for small bowel cancer. The researchers want to find out if having chemotherapy reduces the risk of the cancer coming back, if adding oxaliplatin to fluorouracil or capecitabine is useful, and to learn more about the side effects.

Biological therapy

Biological therapy uses proteins produced in the body or proteins that change how cells signal to each other to grow. If your cancer of the small bowel is a type of sarcoma called a GIST (gastro intestinal stromal tumour), you may have imatinib (Glivec). Imatinib works by blocking chemicals that the cancer needs to grow. Sunitinib is another type of biological therapy that is sometimes used for GIST when imatinib is no longer working or causes bad side effects.

We have more information about GIST.

Rate this page:
Submit rating


Rated 3 out of 5 based on 32 votes
Rate this page
Rate this page for no comments box
Please enter feedback to continue submitting
Send feedback
Question about cancer? Contact our information nurse team

No Error

Updated: 10 October 2015