What Is a Gastrointestinal Stromal Tumor?

A gastrointestinal stromal tumor, or GIST, is a tumor that develops in the gastrointestinal tract (most often in the stomach, small intestine or esophagus). These tumors can be either cancerous or noncancerous, although both forms are relatively uncommon.

How do gastrointestinal stromal tumors develop?

GISTs typically develop in the muscular layer of the bowel. More specifically, these tumors develop in the interstitial cells of Cajal, which are the cells that help stimulate the smooth muscles of the intestines to aid with digestion.

Most GISTs develop with no known cause, although some can develop as a result of a hereditary (inherited) genetic mutation. Specific mutations involving the following genes can cause a gastrointestinal stromal tumor to develop:

  • The KIT gene
  • The PDGFRA gene
  • The BRAF gene 

As abnormal cells accumulate within the bowel, they can form small tumors, which are usually slow-growing. GISTs are also less likely than other tumors to spread to other parts of the body, although they can grow into other layers of the small intestine or invade nearby lymph nodes.

What are the treatment options for GISTs?

Most gastrointestinal stromal tumors can be completely removed through surgery. Targeted therapy, chemotherapy or radiation therapy may be recommended before or after surgery, or potentially even in place of surgery if a gastrointestinal stromal tumor cannot be removed. The options recommended for a patient will depend on the size, stage, location and cellular makeup of his or her GIST.

At Moffitt Cancer Center, we have a team of gastrointestinal oncologists who specialize in treating GISTs and other cancers of the intestines. To request an appointment with one of these oncologists, call 1-888-663-3888 or submit a new patient registration form online. Referrals are welcome, but not required.