What is a gastrointestinal stromal tumor?
Gastrointestinal stromal tumor (abbreviated and often referred to as GIST) is a rare cancer of the gastrointestinal (GI) tract. Most GISTs develop in the stomach or in the small intestine, and a small percentage develops elsewhere in the GI tract. GIST is difficult to diagnose and to treat because it “hides” in the abdomen and often does not cause any symptoms. When GIST first develops, the tumor stays in one area, such as the stomach. This is referred to as the primary or original tumor site. GISTs that stay in their original location are called localized tumors. However, when GISTs advance, they can spread to other parts of the body. When a GIST spreads, it becomes a metastatic tumor, or a tumor that has metastasized. GISTs often grow quite large before they are discovered, and they often spread to other organs, such as the liver. Scientists have discovered the defect, or mutations, that cause GISTs to grow. Now there are treatments that can block tumor growth signals.
