Gastrointestinal Stromal Tumor: Causes, Symptoms, and Treatment
Medically reviewed by Achuta Uppu, MD, Internal Medicine. Last reviewed: October 23, 2026.
What kind of doctor treats Gastrointestinal Stromal Tumor?
An oncologist, a doctor who treats cancer, usually leads care for a gastrointestinal stromal tumor. A surgeon, often a surgical oncologist, may remove the tumor. A gastroenterologist, a doctor who treats digestive problems, may help find it with an endoscopy. A direct primary care or concierge doctor can be a first stop for an evaluation and can refer you to a specialist when needed.
What is a gastrointestinal stromal tumor?
A gastrointestinal stromal tumor, or GIST, is a type of tumor in the digestive tract. It most often occurs in the stomach or small intestine. It is thought to grow from special cells in the digestive tract wall called interstitial cells of Cajal.
Some GISTs grow slowly over time and may never cause a problem. Others can grow and spread very quickly. Very small GISTs are common. Doctors do not agree on whether to remove these small tumors or watch them for growth.
GISTs are usually found in adults between ages 40 and 70.
Symptoms
Small tumors may cause no symptoms. When symptoms do occur, they can include:
- Pain or swelling in the belly.
- Nausea, vomiting, or loss of appetite.
- Weight loss.
- Feeling full after only a little food.
- Trouble or pain when swallowing.
- Feeling very tired.
A GIST can also bleed into the digestive tract. This may lead to anemia, which means a low red blood cell count, with weakness and tiredness. Bleeding into the intestines may cause black, tarry stools. Bleeding into the throat or stomach may cause vomiting of blood, which is an emergency.
Causes and who gets it
Changes in certain genes are involved in the formation of GISTs. About 80 percent of cases are linked to a change in the KIT gene. About 10 percent are linked to a change in the PDGFRA gene.
Most cases are not inherited. The gene change happens only in the tumor cells during a person's lifetime. In rare cases, GISTs are found in several members of the same family.
A GIST may be part of a genetic syndrome, a set of conditions that occur together because of abnormal genes. This is rare. Neurofibromatosis type 1 and Carney triad have been linked to GIST.
How doctors diagnose it
Doctors start with a physical exam and a health history. Tests that examine the digestive tract are then used. These can include a CT scan or an MRI, which make detailed pictures of the inside of the body.
Another test is an endoscopic ultrasound with a biopsy. A thin tube is passed through the mouth. Sound waves make a picture, and a thin needle removes a small sample. A pathologist, a doctor who studies tissue, looks at the sample under a microscope for cancer cells.
If cancer is found, more tests study the cancer cells. One checks how fast the cells are dividing.
Treatment
Four kinds of standard treatment are used: surgery, targeted therapy, watchful waiting, and supportive care. Treatment is not based on the stage of the cancer. It is based on whether surgery can remove the tumor and whether the tumor has spread.
If the GIST has not spread and surgery can be done safely, the tumor and some tissue around it may be removed.
Targeted therapy uses drugs that attack specific cancer cells. Tyrosine kinase inhibitors, or TKIs, block signals that tumors need to grow. Imatinib and sunitinib are two examples of TKIs used to treat GISTs. They may be used for GISTs that cannot be removed by surgery, or to shrink a GIST so it can be removed. Treatment for a GIST may cause side effects.
After surgery, the need for more treatment depends on how likely the GIST is to come back. If that risk is medium or high, imatinib is often recommended after surgery. For a GIST that has spread or has come back, imatinib is usually the first treatment. Sunitinib may be used if the tumor grows during imatinib. Your doctor decides how long you take these medicines. Watchful waiting means closely monitoring your condition without treatment until symptoms appear or change. Supportive care aims to prevent or treat symptoms and treatment side effects.
When to see a doctor
Call 911 or go to the emergency room if you vomit blood, faint, or have severe belly pain or pressure.
See a doctor if you have blood in your stool, whether bright red or very dark, or any of the symptoms listed above. These symptoms can come from a GIST or from other conditions.
How a direct primary care or concierge doctor fits in
A direct primary care doctor charges a flat monthly fee instead of billing insurance, while a concierge doctor usually charges more and often works alongside insurance. This doctor can review symptoms such as belly pain, tiredness, or black stools and order first tests. They can also help you reach the right specialists and keep track of follow-up scans and visits during and after cancer care.
Common questions
Do all GISTs cause symptoms?
No. Small tumors may cause no signs or symptoms. Some GISTs grow slowly and may never cause a problem, while others can grow and spread very quickly. Very small GISTs are common.
Is a GIST inherited?
Usually not. Most cases are not inherited. The gene change happens only in the tumor cells during a person's lifetime. In rare cases, GISTs are found in several members of the same family.
Do all GISTs need surgery?
No. Surgery is one of four standard treatments. Treatment depends on whether the tumor can be removed and whether it has spread.
Sources
- MedlinePlus Genetics - Gastrointestinal stromal tumor
- National Cancer Institute - Gastrointestinal Stromal Tumors Treatment (PDQ) - Patient Version
- American Cancer Society - Treating Gastrointestinal Stromal Tumors
Medical Disclaimer
This content is for general educational and informational purposes only and is not medical advice. It is not a substitute for professional medical advice, diagnosis, or treatment, and reading it does not create a doctor-patient relationship. Always seek the advice of your physician or another qualified health provider with any questions about a medical condition, and never disregard or delay seeking professional advice because of something you read here. If you think you may have a medical emergency, call 911 (or your local emergency number) immediately.
