Regional Gastrointestinal Consultants

Gastrointestinal Stromal Tumors

Gastrointestinal Stromal Tumors

Gastrointestinal Stromal Tumors

Overview

Gastrointestinal stromal tumors (GISTs) are uncommon tumors of the GI tract. These tumors start in very early forms of special cells found in the wall of the GI tract, called the interstitial cells of Cajal (ICCs). ICCs are cells of the autonomic nervous system, the part of the nervous system that regulates body processes such as digesting food. ICCs are sometimes called the “pacemakers” of the GI tract because they signal the muscles in the digestive system to contract to move food and liquid through the GI tract.

More than half of GISTs start in the stomach. Most of the others start in the small intestine, but GISTs can start anywhere along the GI tract. A small number of GISTs start outside the GI tract in nearby areas such as the omentum (an apron-like layer of fatty tissue that hangs over the organs in the abdomen) or the peritoneum (the layer of tissue that lines the organs and walls of the abdomen).

Not all GISTs are cancerous. Some are benign (not cancerous) and don’t grow into other areas or spread to other parts of the body. Doctors have ways to find out whether a GIST is benign or cancerous.

It is important to understand that GISTs are not the same as other, more common types of GI tract cancers. Cancers can occur anywhere in the GI tract from the esophagus to the anus. Usually, these cancers start in glandular cells that line most of the GI tract. The cancers that develop in these cells are called adenocarcinomas. Most cancers of the GI tract, including those of the esophagus, stomach, colon, and rectum, are adenocarcinomas.

Some parts of the GI tract, like the upper part of the esophagus and the end of the anus, are lined with flat cells called squamous cells. These are the same type of cells found on the surface of the skin. Cancers starting in these cells are called squamous cell carcinomas.

Symptoms

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:

  • 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.

The following tests and procedures may be used to detect and diagnose gastrointestinal stromal tumors.:

  • Physical exam and 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. A history of the patient’s health habits and past illnesses and treatments will also be taken.
  • CT scan (CAT scan): A procedure that makes a series of detailed pictures of areas inside the body, taken from different angles. The pictures are made by a computer linked to an x-ray machine. A dye may be injected into a vein or swallowed to help the organs or tissues show up more clearly. This procedure is also called computed tomography, computerized tomography, or computerized axial tomography.
  • 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. This procedure is also called nuclear magnetic resonance imaging (NMRI).
  • Endoscopic ultrasound and biopsy: Endoscopy and ultrasound are used to make an image of the upper GI tract and a biopsy is done. An endoscope (a thin, tube-like instrument with a light and a lens for viewing) is inserted through the mouth and into the esophagus, stomach, and first part of the small intestine. A probe at the end of the endoscope is used to bounce high-energy sound waves (ultrasound) off internal tissues or organs and make echoes. The echoes form a picture of body tissues called a sonogram. This procedure is also called endosonography. Guided by the sonogram, the doctor removes tissue using a thin, hollow needle. A pathologist views the tissue under a microscope to look for cancer cells. If cancer is found, the following tests may be done to study the cancer cells:
  • Immunohistochemistry: A test that uses antibodies to check for certain antigens in a sample of tissue. The antibody is usually linked to a radioactive substance or a dye that causes the tissue to light up under a microscope. This type of test may be used to tell the difference between different types of cancer.

  • Mitotic rate: A measure of how fast the cancer cells are dividing and growing. The mitotic rate is found by counting the number of cells dividing in a certain amount of cancer tissue.

Treatment

There are different types of treatment for patients with gastrointestinal stromal tumors. 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.

Four types of standard treatment are used:

Surgery

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

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

Watchful waiting is 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. 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.

New types of treatment are being tested in clinical trials as well.

IMPORTANT HEALTH NOTE

We recommend that people experiencing gastrointestinal symptoms do not attempt self-treatment. With many medications being available over the counter, and numerous do-it-yourself online unqualified remedy recommendation, it is natural to consider treating yourself but we highly recommend against this.

If you are experiencing gastrointestinal symptoms you may have a more significant issue than you would expect from the sometimes muted or infrequent symptom you may be experiencing. It is important to keep in mind that is you are having gastrointestinal symptoms or concerns it is best see a doctor to have those symptoms diagnosed and any conditions treated. Also, it is worth noting, that if health conditions do exist, the earlier they are diagnosed and treated, the greater the probability will be to successfully eliminate or manage a present condition, in fact successful outcomes will increase significantly with early detection.

If you have gastrointestinal concerns or are experiencing any gastrointestinal symptoms, please contact us promptly to schedule a consultation with a physician.


DISCLAIMER: PLEASE READ CAREFULLY

The information on this website is to provide general information. In no way, does any of the information provided reflect definitive medical advice and self-diagnoses should not be made based on information obtained online. It is important to consult a best in class physician regarding ANY and ALL symptoms or signs as it may a sign of a serious illness or condition. A thorough consultation and examination should ALWAYS be performed for an accurate diagnosis and treatment plan. Be sure to call a physician or call our office today at (215) 321-4700 to schedule a consultation.