Gastrointestinal Stromal Tumors

Gastrointestinal stromal tumors (GIST) begin in the interstitial cells of Cajal (ICCs), which are located in the wall of the gastrointestinal tract. ICCs help with the muscle contraction that moves food and liquid along the digestive tract.

Gastrointestinal Stromal Tumor Causes

As with many types of cancer, what causes gastrointestinal stromal tumors isn’t known. Lifestyle changes and environmental risk factors don’t appear to play a role in the development of GISTs, however, changes in genes (made up of DNA) may cause the condition. Gene mutations related to GISTs can be passed down from a parent to a child, but many gene changes appear to occur for no reason.

In many cases of gastrointestinal stromal tumors, either one of the following gene mutations are present:

  • A mutation in the KIT oncogene – The KIT oncogene produces the CD117 protein which directs cells to grow and divide. In 95% of people with GIST, the KIT gene is mutated and is active in ICCs, resulting in an overproduction of cells.
  • A mutation in the PDGFRA gene – Similar to KIT mutations, changes in the PDGFRA gene in ICCs cause an excess of PDGFRA protein to be made. An overproduction of growing and dividing cells is the result.

Gastrointestinal Stromal Tumor Symptoms

Many patients don’t experience symptoms with gastrointestinal stromal tumors. But others may experience:

  • Bloating or abdominal pain
  • Bleeding from the bowel
  • Tiredness
  • Decreased appetite

Diagnosing Gastrointestinal Stromal Tumors

Diagnosing GISTs typically involves:

  • A physical examination
  • Blood work
  • An upper endoscopy and biopsy
  • Computed tomography (CT) scan
  • Positron emission tomography (PET) scan

Gastrointestinal Stromal Tumor Treatments

Gastrointestinal stromal tumors are typically treated with:

  • Surgery to remove localized, low-risk GISTs
  • A medication called imatinib

At Tampa General Hospital’s Cancer Institute, our expert gastrointestinal oncologists will tailor a treatment plan based on each patient’s needs and the severity of their condition.