Treatment

The treatment of GIST depends on the size and location of the tumor, if it is cancerous, whether the cancer has spread, and the person’s overall health. In many cases, a team of doctors will work with the patient to determine the best treatment plan.

This section outlines treatments that are the standard of care (the best treatments available) for this specific type of cancer. Patients are also encouraged to consider clinical trials as a treatment option when making treatment plan decisions. A clinical trial is a research study to test a new treatment to prove it is safe, effective, and possibly better than standard treatment. Your doctor can help you review all treatment options. For more information, visit the Clinical trials section.

Surgery

For patients with GIST, surgery is the standard of care and should be performed whenever possible. The goal of surgery is to completely remove the tumor. Sometimes the tumor may be large or spread into nearby organs. In many of these cases, a drug called imatinib (see below) will be given before surgery. The surgeon will most likely still try to remove the entire tumor in an effort to reduce the risk that the tumor will recur (come back after treatment) or block the GI tract. In order to remove the entire tumor, it is possible that the surgeon may have to remove parts of nearby organs, depending on the location of the tumor. The removal of lymph nodes is not generally needed in the treatment of a GIST because it does not often spread to the lymph nodes.

Targeted therapy

Targeted therapy is a treatment that targets faulty genes or proteins that contribute to cancer growth and development. The U.S. Food and Drug Administration (FDA) has approved imatinib (Gleevec) for the treatment of GIST. Imatinib is a tyrosine kinase inhibitor, and is the drug of choice in treating GIST. It is usually given as either the only treatment or in combination with surgery (before or after surgery). It is a cytostatic agent, which stops tumor growth, rather than cytotoxic, such as conventional chemotherapy, which kills fast-growing cells. Therefore, the medication will be taken by patients for a prolonged period of time. Since this drug has become available, the prognosis for patients with GIST has improved considerably. The usual dose of imatinib is 400 milligrams (mg) daily. In some patients the dose can be raised to 800 mg daily. Sunitinib (Sutent), like imatinib, is a tyrosine kinase inhibitor with anti-angiogenic (a form of targeted therapy that stops tumors from creating new blood vessels) properties, and it was approved in 2006 by the FDA for treating GIST when the tumor continues to grow even after treatment with imatinib, or in cases where imatinib cannot be given.

For more information, read Cancer.Net Feature: Understanding Targeted Treatments.

The medications used to treat cancer are continually being evaluated. Talking with your doctor is often the best way to learn about the medications you’ve been prescribed, their purpose, and their potential side effects or interaction with other medications. Learn more about your prescriptions through Drug Information Resources, which provides links to searchable drug databases.

Radiation therapy

Radiation therapy is the use of high-energy x-rays or other particles to kill cancer cells. The most common type of radiation treatment is called external-beam radiation therapy, which is radiation given from a machine outside the body.

In GIST, radiation therapy is not effective for treating the tumor itself, but may be used as a palliative treatment (treatment used to reduce pain, control symptoms, or make a patient more comfortable) to relieve pain. Radiation therapy, like chemotherapy, may damage healthy cells as well as cancerous cells. Side effects from radiation therapy include tiredness, mild skin reactions, upset stomach, and loose bowel movements. Most side effects go away soon after treatment is finished.

Chemotherapy

Chemotherapy is the use of drugs to kill cancer cells. Chemotherapy is not effective in treating GIST; therefore, it is not used.

To learn about the terms used in this section, read the Cancer.Net Feature: Cancer Terms to Know: During Treatment.