Gastrointestinal stromal tumour (GIST)

A GIST is a rare type of sarcoma found in the wall of the digestive system. It is most often found in the stomach, but it can also grow in other parts. A soft tissue sarcoma is a type of cancer.

What is a GIST?

Gastrointestinal means the sarcoma starts in the digestive system Open a glossary item (the gastrointestinal tract). Stromal means it develops from the interstitial cells of Cajal that play a role in the movement of the digestive system. These cells send signals to the muscles in the wall of the digestive system that help move food and liquid along. A tumour means a lump or growth in the body, which may or may not be cancer.

Most GISTs develop in the digestive system. But some start outside the digestive system in nearby areas such as the:

  • large flat fatty tissue layer that covers the organs in the tummy (abdomen) Open a glossary item, also called the omentum
  • thin lining of tissue that covers the organs and lines the inside of the tummy, also called the peritoneum Open a glossary item 

Some GISTs behave in a non cancerous (benign Open a glossary item) way. Generally, a tumour that behaves in a benign way tends to be relatively slow growing. And is less likely to come back.

A tumour that behaves in a cancerous (malignant Open a glossary item) way is faster growing and is more likely to come back or spread. 

The larger the GIST, the more likely it is to behave like cancer. And if left untreated, a benign behaving tumour can start to act like a cancer.

Who gets GIST?

GISTs are most common in older people aged 60 to 65 and in males.

GISTs are linked with conditions such as:

  • Type 1 neurofibromatosis 
  • Carney triad syndrome
  • Carney-Stratakis syndrome
  • Familial GIST

GISTs in children and adolescents are rare.

Symptoms

People with an early stage GIST often do not have any symptoms Open a glossary item. So an early stage GIST may be found when people are having tests for other medical conditions. Most GISTs are diagnosed in later stages of the disease. The symptoms of an advanced GIST are likely to include:

  • pain or discomfort in the tummy

  • a feeling of fullness

  • being sick

  • blood in your stools or vomit

  • feeling very tired

  • a low red blood cell count (anaemia)

  • a lump in the body you can feel

Other medical conditions apart from cancer can cause these symptoms. If you have these symptoms you should see your doctor. A GIST is rare, so they are more likely to be caused by something less serious, but it is always best to check.

Treatment for GIST

Your treatment usually depends on the level of risk of your cancer, and your general health. Your doctor will look at several factors to decide whether your GIST is:

  • very low risk
  • low risk
  • intermediate risk
  • high risk

Surgery

If your GIST is smaller than 2 cm, you might have an endoscopic ultrasound Open a glossary item, usually with fine needle aspiration Open a glossary item or core needle biopsy Open a glossary item. Your surgeon might delay surgery until it grows bigger or you have symptoms. This is because small tumours are usually lower risk. But you will be followed up yearly. Your doctor might suggest this if it is an option for you.

For a GIST of more than 2 cm, surgery is usually the main treatment. Your surgeon aims to remove as much of the cancer as possible with a border of healthy tissue (clear margin Open a glossary item) around it. Having a border of healthy tissue without any cancer cells is important as it lowers the risk of the cancer coming back.

Surgery might cure a smaller GIST. But it might not be possible for a surgeon to remove a larger GIST completely.

GIST can sometimes spread to other parts of the body. This spread is called a secondary or metastases. In some situations, it might be possible for a surgeon to remove these secondaries.

GIST in the stomach means your surgeon might need to remove all or part of your stomach. They may also need to remove your spleen Open a glossary item. Surgery to the stomach is a big operation and it will take some time to adjust your eating afterwards. You will probably have to eat small, frequent meals (about two hourly) for quite a long time after the operation.

Targeted cancer drugs

Cancer cells have changes in their genes (DNA) that make them different from normal cells. These changes mean that they behave differently. Cancer cells can grow faster than normal cells and sometimes spread. Targeted cancer drugs work by ‘targeting’ those differences that a cancer cell has.

A type of targeted cancer drug used for GIST is called a tyrosine kinase inhibitor (TKI). Tyrosine kinase inhibitors (TKIs) block chemical messengers (enzymes) called tyrosine kinases. Tyrosine kinases help to send growth signals in cells, so blocking them stops the cell from growing and dividing.

Examples of TKIs used to treat GIST include:

  • imatinib (Glivec)
  • sunitinib (Sutent)
  • regorafenib (Stivarga)

Imatinib (Glivec)

You might have imatinib to treat a GIST that can’t be completely removed with surgery, or which has spread before surgery.

Some people with GIST have a higher risk of their cancer coming back after surgery. This is called a high risk GIST. Imatinib can help to reduce the chances of the GIST coming back. So in this situation, your doctor may recommend you take imatinib for up to 3 years after your operation.

You may also have imatinib to shrink a GIST before surgery, so that your surgeon can remove it more easily. Sometimes a surgeon can completely remove a GIST after treatment with imatinib.

Protein testing for imatinib

Your doctor needs a sample of your GIST to carry our protein testing. This sample might be from when you had a biopsy to diagnose GIST, or an operation to remove the GIST. The cells are tested to see if they have a receptor on their surface called CD117.

This CD117 protein is made by a gene Open a glossary item called c-kit. A fault in this gene causes the c-kit gene to make too much CD117 protein.  Most GISTs have c-kit gene mutations.

If the GIST cells are CD117 positive, imatinib is likely to work very well. But it can work even for GISTs that are CD117 negative.

Sunitinib (Sutent)

Your doctor might recommend that you have sunitinib (Sutent) in one of the following situations:

  • imatinib has stopped working 
  • you have had severe side effects with imatinib treatment

You must have GIST that cannot be completely removed or has spread.

Regorafenib (Stivarga)

Regorafenib (Stivarga) is used to treat advanced GIST. Your doctor might recommend regorafenib if you have had treatment with imatinib and sunitinib and these drugs:

  • have not worked
  • or caused bad side effects

Advanced GIST means you cannot have surgery to remove the GIST, or it has spread. You must be fairly fit and well to have this drug.

Coping

Coping with a diagnosis of a rare cancer can be especially difficult. Knowing more about your sarcoma and its treatment can make it easier. It can help you to make decisions and cope with what happens.

Sarcoma UK has support and information for people affected by soft tissue and bone sarcoma.

The Rare Cancer Alliance offer support and information to people with rare cancers.

Talking to other people who have the same thing can also help.

Our discussion forum Cancer Chat is a place for anyone affected by cancer. You can share experiences, stories and information with other people who know what you are going through.

GIST Support UK is an organisation for people with GIST and their families. It offers support and information. 

  • Gastrointestinal stromal tumour (GIST): British Sarcoma Group clinical practice guidelines
    I Judson and others
    British journal of cancer, June 2024

  • Devita, Hellman and Rosenberg's Cancer: Principles and Practice of Oncology (12th edition)
    VT Devita, TS Lawrence and SA Rosenberg
    Wolters Kluwer Health, 2023

  • Perspectives on the evolving state of the art management of gastrointestinal stromal tumours
    Z Szucs1 and RL Jones
    Translational Gastroenterology and Hepatology, 2018. Volume 3, Issue 21, pages 1 to 11

  • Gastrointestinal stromal tumors: A multidisciplinary challenge
    J M Sanchez-Hidalgo and others
    World Journal of Gastroenterology, 2018, Volume 24, Issue 18, pages 1925 to 1941

  • Identification of preoperative factors associated with outcomes following surgical management of intra-abdominal recurrent or metastatic GIST following neoadjuvant tyrosine kinase inhibitor therapy

    C Rowland and others

    Journal of Surgical Oncology, 2018. February 15 doi: 10.1002/jso.2498

Last reviewed: 
15 Aug 2024
Next review due: 
15 Aug 2027

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