Gastrointestinal Stromal Tumor



Cancer is when cells grow out of control. The cells form a clump of tissue called a growth or tumor. Cancer cells can invade nearby tissues. It can then spread to other parts of the body. Why a person has a GIST is not known. Many people with a GIST have a problem with a certain gene. The gene is active when it should not be and it lets cells grow and divide without order. This may explain why a GIST forms.

Risk Factors

This problem is more common in people who are more than 50 years of age. Other things that may raise the risk are:

  • Inherited conditions such as neurofibromatosis type 1
  • A family history of GIST (rare)



A person with a GIST may have:

  • Tiredness and weakness
  • Nausea or vomiting
  • Problems swallowing
  • A feeling of being full after eating a small amount of food
  • Weight loss
  • Swelling or a lump in the belly
  • Belly pain
  • Blood in stool or vomit


The doctor will ask about symptoms and health history.

Images may be taken of the belly with:

  • Abdominal CT scan
  • MRI scan
  • PET scan

A sample of the tumor will be taken to confirm the diagnosis. This can be done with a fine-needle biopsy.

Genetic tests may also be done. This can be done with blood tests.

Cancer is staged from 1 to 4. A stage 1 GIST is a small tumor that has stayed in one area. Stage 4 GIST is a larger tumor or it has spread to other parts of the body.



The goal of treatment is to get rid of the tumor. Treatment will depend on the tumor's size and if it has spread to other parts of the body. Options are:

  • Checking very small tumors for any changes
  • Medicines to shrink the tumor or stop it from growing
  • Surgery to remove some or all of a tumor that has not spread


A GIST cannot be prevented.

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.

Edits to original content made by Denver Health.