Source: National Cancer Institute Research, www.cancer.gov
The gastrointestinal (GI) tract is part of the body’s digestive system. It helps to digest food and takes nutrients (vitamins, minerals, carbohydrates, fats, proteins, and water) from food so they can be used by the body. The GI tract is made up of the following organs:
Gastrointestinal stromal tumors (GISTs) may be malignant (cancer) or benign (not cancer). They are most common in the stomach and small intestine but may be found 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.
See the PDQ summary about Unusual Cancers of Childhood for information on the treatment of GIST in children.
Anything that increases your risk of getting a disease is called a risk factor. Having a risk factor does not mean that you will get cancer; not having risk factors doesn't mean that you will not get cancer. Talk with your doctor if you think you may be at risk.
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.
GIST may be part of a geneticsyndrome, but this is rare. A genetic syndrome is a set of symptoms or conditions that occur together and is usually caused by abnormal genes. The following genetic syndromes have been linked to GIST:
These and other signs and symptoms may be caused by a GIST or by other conditions. Check with your doctor if you have any of the following:
The following tests and procedures may be used:
If cancer is found, the following tests may be done to study the cancer cells:
Sometimes GISTs are smaller than the eraser on top of a pencil. Tumors may be found during a procedure that is done for another reason, such as an x-ray or surgery. Some of these small tumors will not grow and cause signs or symptoms or spread to the abdomen or other parts of the body. Doctors do not agree on whether these small tumors should be removed or whether they should be watched to see if they begin to grow.
The prognosis (chance of recovery) and treatment options depend on the following:
The process used to find out if cancer has spread within the gastrointestinal (GI) tract or to other parts of the body is called staging. The information gathered from the staging process determines the stage of the disease. The following tests and procedures may be used in the staging process:
Cancer can spread through tissue, the lymph system, and the blood:
When cancer spreads to another part of the body, it is called metastasis. Cancer cells break away from where they began (the primary tumor) and travel through the lymph system or blood.
The metastatic tumor is the same type of tumor as the primary tumor. For example, if a gastrointestinal stromal tumor (GIST) spreads to the liver, the tumor cells in the liver are actually GIST cells. The disease is metastatic GIST, not liver cancer.
For many cancers it is important to know the stage of the cancer in order to plan treatment. However, the treatment of GIST is not based on the stage of the cancer. Treatment is based on whether the tumor can be removed by surgery and if the tumor has spread to other parts of the abdomen or to distant parts of the body.
Treatment is based on whether the tumor is:
Different types of treatments are available for patients with gastrointestinal stromal tumors (GISTs). Some treatments are standard (the currently used treatment), and some are being tested in clinical trials. A treatment clinical trial is a research study meant to help improve current treatments or obtain information on new treatments for patients with cancer. When clinical trials show that a new treatment is better than the standard treatment, the new treatment may become the standard treatment. Patients may want to think about taking part in a clinical trial. Some clinical trials are open only to patients who have not started treatment.
If the GIST has not spread and is in a place where surgery can be safely done, the tumor and some of the tissue around it may be removed. Sometimes surgery is done using a laparoscope (a thin, lighted tube) to see inside the body. Small incisions (cuts) are made in the wall of the abdomen and a laparoscope is inserted into one of the incisions. Instruments may be inserted through the same incision or through other incisions to remove organs or tissues.
Targeted therapy is a type of treatment that uses drugs or other substances to identify and attack specific cancer cells without harming normal cells.
Tyrosine kinase inhibitors (TKIs) are targeted therapy drugs that block signals needed for tumors to grow. TKIs may be used to treat GISTs that cannot be removed by surgery or to shrink GISTs so they become small enough to be removed by surgery. Imatinib mesylate and sunitinib are two TKIs used to treat GISTs. TKIs are sometimes given for as long as the tumor does not grow and serious side effects do not occur.
See Drugs Approved for Gastrointestinal Stromal Tumors for more information.
Watchful waiting is closely monitoring a patient’s condition without giving any treatment until signs or symptoms appear or change.
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. Supportive care helps improve the quality of life of patients who have a serious or life-threatening disease. Radiation therapy is sometimes given as supportive care to relieve pain in patients with large tumors that have spread.
Information about clinical trials is available from the NCI Web site.
For some patients, taking part in a clinical trial may be the best treatment choice. Clinical trials are part of the cancer research process. Clinical trials are done to find out if new cancer treatments are safe and effective or better than the standard treatment.
Many of today's standard treatments for cancer are based on earlier clinical trials. Patients who take part in a clinical trial may receive the standard treatment or be among the first to receive a new treatment.
Patients who take part in clinical trials also help improve the way cancer will be treated in the future. Even when clinical trials do not lead to effective new treatments, they often answer important questions and help move research forward.
Some clinical trials only include patients who have not yet received treatment. Other trials test treatments for patients whose cancer has not gotten better. There are also clinical trials that test new ways to stop cancer from recurring (coming back) or reduce the side effects of cancer treatment.
Clinical trials are taking place in many parts of the country. See the Treatment Options section that follows for links to current treatment clinical trials. These have been retrieved from NCI's listing of clinical trials.
Some of the tests that were done to diagnose the cancer or to find out the stage of the cancer may be repeated. Some tests will be repeated in order to see how well the treatment is working. Decisions about whether to continue, change, or stop treatment may be based on the results of these tests. This is sometimes called re-staging.
Some of the tests will continue to be done from time to time after treatment has ended. The results of these tests can show if your condition has changed or if the cancer has recurred (come back). These tests are sometimes called follow-up tests or check-ups.
Follow-up for GISTs that were removed by surgery may include CT scan of the liver and pelvis or watchful waiting. For GISTs that are treated with tyrosine kinase inhibitors, follow-up tests, such as CT, MRI, or PET scans, may be done to check how well the targeted therapy is working.
Resectablegastrointestinal stromal tumors (GISTs) can be completely or almost completely removed by surgery. Treatment may include the following:
UnresectableGISTs cannot be completely removed by surgery because they are too large or in a place where there would be too much damage to nearby organs if the tumor is removed. Treatment is usually a clinical trial of targeted therapy with imatinib mesylate to shrink the tumor, followed by surgery to remove as much of the tumor as possible.
Treatment of GISTs that are metastatic (spread to other parts of the body) or recurrent (came back after treatment) may include the following:
Many GISTs treated with a tyrosine kinase inhibitor (TKI) become refractory (stop responding) to the drug after a while. Treatment is usually a clinical trial with a different TKI or a clinical trial of a new drug.
Check for U.S. clinical trials from NCI's list of cancer clinical trials that are now accepting patients with gastrointestinal stromal tumor. For more specific results, refine the search by using other search features, such as the location of the trial, the type of treatment, or the name of the drug. Talk with your doctor about clinical trials that may be right for you. General information about clinical trials is available from the NCI Web site.
For more information from the National Cancer Institute about gastrointestinal stromal tumors, see the following:
For general cancer information and other resources from the National Cancer Institute, see the following: