GIST

What Are Gastrointestinal Stromal Tumors (GISTs)?

A gastrointestinal stromal tumor (GIST) is a disease in which abnormal cells form in the tissues of the gastrointestinal tract. Some GISTs grow slowly over time and may never cause a problem for a patient, while others can grow and spread very quickly. They are most common in the stomach and small intestine but can occur anywhere in or near the GI tract. Some scientists believe that GISTs begin in cells called Interstitial Cells of Cajal (ICC) in the wall of the GI tract.

Genetic Factors

The genes in cells carry the hereditary information received from a person's parents. The risk of GIST is increased in people who have inherited a mutation (change) in a certain gene. In rare cases, GISTs can be found in several members of the same family.

Signs and Symptoms

• Blood (either bright red or very dark) in the stool or vomit
• Pain in the abdomen which may be severe
• Feeling very tired
• Trouble or pain when swallowing
• Feeling full after only a little food is eaten

Testing

• Physical exam and health history: An exam of the body to check general signs of health, including checking for signs of disease, such as lumps or anything else that seems unusual.
• CT scan (CAT scan): A procedure that makes a series of detailed pictures of areas inside the body taken from different angles.
• MRI (magnetic resonance imaging): A procedure that uses a magnet, radio waves, and a computer to make a series of detailed pictures of areas inside the body.
• Endoscopic ultrasound and biopsy: Endoscopy and ultrasound are used to make an image of the upper GI tract, and a biopsy (removal of tissue) is done.

If your provider finds cancer, they may conduct the following tests to study the cancer cells

• lmmunohistochemistry: A laboratory test that uses antibodies to check for certain antigens (markers) in a sample of a patient's tissue
• Mitotic rate: A measure of how fast the cancer cells are dividing and growing. Our specialists determine the mitotic rate by counting the number of cells dividing in a certain amount of cancer tissue

Prognosis Factors

The prognosis and treatment options depend on the following:

• How quickly the cancer cells are growing and dividing
• The size of the tumor
• Where the tumor is in the body
• Whether surgery can completely remove the tumor
• Whether the tumor has spread to other parts of the body

Treatment Options

Four types of standard treatments are used:

• Surgery - If the GIST has not spread and is in a place where surgery is a safe option, the tumor and some of the tissue around it may be removed.
• Targeted therapy - A type of treatment that uses drugs or other substances to identify and attack specific cancer cells.
• Watchful waiting - Closely monitoring a patient's condition without giving any treatment until signs or symptoms appear or change.
• Supportive care - If a GIST gets worse during treatment or there are side effects, supportive care is usually given. The goal of supportive care is to prevent or treat the symptoms of a disease, side effects caused by treatment, and psychological, social, and spiritual problems related to a disease or its treatment.

Clinical Trials

In addition to offering standard approaches, our providers are continuously testing new treatments in clinical trials. Patients may want to consider taking part in a trial, and can enter before, during, or after starting their cancer treatment.

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This content was last medically reviewed in May 2022 by Sharlotte Manley, MSN, FNP, Erlanger Gastroenterology.