WHAT IS GIST?

GIST is an abbreviation for GastroIntestinal Stromal Tumour.

  • Gastrointestinal 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. (For reference, the functioning parts of any organ are made up of so-called parenchyal cells).

  • Tumour simply means that the GIST condition is producing a solid(ish) lump unlike, e.g. leukaemia.

GISTs are malignant tumours of soft tissues in the gastro-intestinal tract (the stomach and intestines). They are a very rare kind of sarcoma. Around about 2% of tumours in the gastrointestinal area are GISTs.

How common is GIST?

There are probably between 200-900 new cases each year in the UK. GISTs mostly affect people between 55 and 65, but there are GIST patients both younger and older. 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.

GIST in children is even rarer, maybe 50 cases worldwide. There is a group in America gathering data on this super-rare paediatric GIST, which does behave differently in some ways from GIST in adults.

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.

If a tumour is found which could be a GIST, current opinion is that it is probably best to remove the tumour, if possible, without doing a biopsy. Many GISTs are only firmly diagnosed after surgery. They are sometimes found when the patient is being operated on for something else. If it is not possible to remove the tumour, then a biopsy may be done endoscopically. (Using an instrument passed into the stomach or intestines through the mouth, or anus.)

Diagnosis

A firm diagnosis of GIST can only be made by a pathologist looking at the tumour tissue with a microscope. There are two main definitive criteria for diagnosis: finding the location of the tumour, and finding a positive c-KIT (CD 117) or PDGFRA enzyme receptor abnormality.

Today the diagnosis of GIST has different implications from those it had even a few years ago.

  • GIST can now be diagnosed unambiguously
  • Scientists’ understanding of GIST is increasing daily
  • An operation and/or Glivec® offer genuine treatment options

New drugs are being developed. One of them, Sutent, completed clinical trials and was launched by Pfizer in 2006. Other drugs are still in the trial stage.

(See the pages on Treatments and Clinical Trials.)

Things to Read

There is an excellent illustrated book produced by Das Lebenshaus, which is the support organisation for German-speaking people who have been affected by GIST. This book gives a very good explanation of GIST and currently available methods of treatment. A first edition of the book was published in 2006 and a revised edition has just been published in 2008. Both editions have been translated into English. Click here to download the 2008 (English) edition as a PDF file. Note that the file is quite large and will take several seconds to download even with a broadband connection. This 2008 edition has now (August 2009) been printed in Germany and we have copies available. A donation to cover the cost of postage would be welcome

Another very helpful book is "100 Questions & Answers about Gastrointestinal Stromal Tumor (GIST)" by DeMatteo, Symcox and Demetri (ISBN-13:978-0-7637-3838-9/ISBN-10:0-7637-3838-7). Although this book has been written very much with an American readership in mind, it nevertheless carries a lot of very helpful information about GIST and its treatment. You can order the book through any good bookseller and it costs about £10.

GIST Patient Booklet

We are grateful to our member Peter Greenwood for producing this convenient pocket-sized booklet in which you can note details about your GIST and any medication you are on. It is intended for use in the event of a medical emergency. It has spaces for your the name of your oncologist, the drugs you are on, etc, and lists the drugs to be avoided if you are on Glivec or Sutent. The booklet is a translation from the German of an equivalent booklet produced by Das Lebenshaus. For your own copy of the booklet please contact (A donation of £1 would be welcome to cover costs and postage!)

(Page last updated January 2009)

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