Cancer Types – Gastrointestinal Stromal Tumor – GIST

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Gastrointestinal Stromal Tumor – GIST: Overview

Approved by the Cancer.Net Editorial Board, 12/2014

About gastrointestinal stromal tumors (GISTs)

A tumor begins when normal cells change and grow uncontrollably. A tumor can be cancerous or benign. A cancerous tumor is malignant, meaning it can invade other tissues and spread to other parts of the body. A benign tumor means the tumor will not spread. A tumor can start in any part of the GI tract, and there are several different types of GI tumors, including gastrointestinal stromal tumors (GISTs).

GISTs are different from other more common types of GI tumors because of the type of tissue in which they start. GISTs belong to a group of cancers called soft tissue sarcoma. Soft tissue sarcomas develop in the tissues that support and connect the body, and the sarcoma cells resemble the cells that hold the body together, including fat cells, muscles, nerves, tendons, joints, blood vessels, or lymph vessels.

Originally, GISTs were thought to be either muscle or nerve tumors, but modern research has shown that GISTs begin in “pacemaker” cells found in the walls of the GI tract, called interstitial cells of Cajal (ICC). These cells send signals to the GI tract to help move food and liquid through the digestive system.

It is important to note that all GISTs can be cancerous. Sometimes it may be difficult for the doctor to tell immediately whether a GIST is likely to come back after being surgically removed. As a result, the doctor will look at many factors to determine the best treatment, including the size of the tumor, whether it has already spread, how many dividing cells there are, its genetic makeup, and the tumor’s location. More information about these factors and GIST treatment options are outlined in other sections of this guide.

Read more about gastrointestinal stromal tumors (GISTs) here.

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