Cancer is probably the one word no one wants to hear. If you’ve recently been diagnosed with a gastrointestinal stromal tumor (GIST), a relatively rare cancer found in the digestive tract, you might be frightened, overwhelmed, and concerned about what happens next.
WebMD talked to experts who shared some facts you should know if you’ve been diagnosed with GIST. “It's important for people diagnosed with GIST to understand that this is a different type of cancer that can range from very slow-growing -- in the vast majority of cases -- to aggressive in a minority of cases,” says Nikhila Khushalani, MD, Section Chief for Soft Tissue and Melanoma at the Roswell Park Cancer Institute in Buffalo, N.Y.
The age-adjusted incidence of carcinoid tumors worldwide is approximately 2 per 100,000 persons.[1,2] The average age at diagnosis is 61.4 years. Carcinoid tumors represent about 0.5% of all newly diagnosed malignancies.[2,3]
Carcinoid tumors are rare, slow-growing tumors that originate in cells of the diffuse neuroendocrine system. They occur most frequently in tissues derived from the embryonic gut. Foregut tumors, which account for up to 25% of cases, arise...
Most cancers are called “carcinomas,” and they develop in the skin or in the lining of internal body structures like the stomach. But GIST is a bit different: it is one of a group of cancers that are called sarcomas. These cancers develop in the connective or supportive tissues of the body like fat, muscle, or bone.
More than half of all GIST tumors are found in the stomach. Other places where GISTs may develop include the duodenum and small intestine, the esophagus, the rectum, and the colon.
Until the late 1990s, doctors didn’t really understand that GIST was different from other kinds of cancers found in the stomach and digestive system. That’s when they learned that the cells of tumors make a specific protein called KIT, and that 95% of GIST tumors have mutations or changes in the gene that makes the KIT protein.
How is GIST Diagnosed?
GIST is a more difficult kind of cancer to diagnose than more common cancers like breast and prostate cancer. While a doctor may suspect that a particular cancer is GIST based on how it looks on a CT scan, the only way to be sure is through pathology -- studying the tumor cells in a laboratory.
Because it is a complex diagnosis, it’s very important that GIST be diagnosed and treated by a multidisciplinary team that has experience with this type of tumor.