GIST
Meaning of GIST: GIST is a tumor arising from the gastrointestinal tract's specialized pacemaker cells, most often driven by a specific gene mutation and treated with targeted drugs.
Definition of GIST
GIST, or gastrointestinal stromal tumor, is a type of tumor that develops from specialized cells within the wall of the gastrointestinal tract called interstitial cells of Cajal, which normally help control the rhythmic muscular contractions that move food through the digestive system. GIST can occur anywhere along the gastrointestinal tract but arises most often in the stomach or small intestine.
Most cases of GIST are driven by a mutation in one of two genes, KIT or PDGFRA, that causes the affected cells to grow and divide uncontrollably. A GIST can be benign or malignant, and its behavior is assessed based on features such as tumor size and how rapidly its cells are dividing.
Because GIST is defined by its specific cell of origin and genetic driver rather than by resembling other gastrointestinal cancers, it is treated differently, often with a targeted medication such as imatinib that blocks the abnormal signaling caused by the KIT or PDGFRA mutation, in addition to surgery when the tumor can be removed.
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Used in a sentence
Genetic testing of the tumor confirmed a KIT mutation consistent with GIST.
Good to know
GIST is defined by its origin from the gastrointestinal tract's specialized pacemaker cells and a specific gene mutation, which is why it is managed differently from the more common gastrointestinal cancers that arise from the lining of the digestive tract.