About GISTs

Find out about GIST ~ how rare it is, it's possible symptoms, and diagnosis...

Gastro Intestinal Stromal Tumour, or GIST for short, is a very rare cancer, a kind of sarcoma (cancer of the soft/connective tissues, rather than a carcinoma). About 0.2% of tumours in the gastrointestinal area are GISTs.

GISTs are malignant tumours of soft tissues in the gastro-intestinal tract (the stomach and intestines).

  • Gastro-Intestinal means that it occurs in the digestive tract, anywhere from the oesophagus to the rectum i.e. the gullet, stomach, intestines.
  • Stromal indicates that the tumours occur, not in the "functioning" part of the organ but in the tissues (the stromal cells) that hold the organ in place in the body. So, for example, a GIST in or near the colon is not "cancer of the colon" because it does not occur in the functioning part of the colon but in the tissues which support the colon.
  • Tumour simply means that the GIST condition is producing a solid(ish) lump unlike, e.g. leukaemia.
Digestive Tract

Digestive Tract

How common is GIST?

  • There are around 900 new cases each year in the UK.
  • GISTs mostly affect people between 55 and 65, but there are GIST patients both younger and older.
  • GIST in children and young adults is very rare.
  • Most GISTs are treatable through surgery and/or drugs.  Some very rare GISTs don't respond to standard treatements (see PAWS GIST  for more details of treatment for these).
  • It has only been possible to diagnose GISTs unambiguously since 2000, and because of their rarity many GPs will never see a case in the whole of their career.

You can find more about the general occurrence of GISTs in the UK on the 'National Picture' section of this website.

 

Possible Symptoms

  • Discomfort or pain in the stomach or intestines
  • Indigestion
  • Nausea
  • Swelling
  • Bleeding from the stomach or intestines
  • Weight gain
  • Weight loss
  • Fever
  • Night sweats

Because GISTs do not interfere directly with the workings of an organ, they often grow for some time without producing any symptoms. Even when they do produce symptoms, these are very varied, and all of them can be caused by other things. It is the presence of one or more of these symptoms, which cannot be explained in any other way, which should lead to a possible diagnosis of GIST.

Diagnosis

A firm diagnosis of GIST can only be made by a pathologist looking at the tumour tissue with a microscope.  Hence, there needs to be a tissue sample.  A biopsy may be done endoscopically using an instrument passed into the stomach or intestines through the mouth, or anus.  Many GISTs are only firmly diagnosed after surgery and they are sometimes found when the patient is being operated on for something else.

There are two main definitive criteria for diagnosis:

  1. Finding the location of the tumour
  2. Finding a positive c-KIT (CD 117) or PDGFRA enzyme receptor abnormality

GIST can now be diagnosed unambiguously and there are effective drug treatments for most types.  See the page on Treatments for the common approaches and that on current Clinical Trials for possible treatments for those that don't respond to the standard drugs.

 

Things to Read

Visit our Publications page for a list of literature which will help you understand GIST and its treatment.

We would recommend that you start with GIST for Beginners. This is published by GCUK and gives a good explanation of GIST and the methods of treatment currently available under the NHS.