Gastrointestinal Stromal Tumor (GIST)

GISTs are rare cancerous tumors. They’re a type of soft tissue sarcoma. The tumors develop in certain cells known as the interstitial cells of Cajal, which are in the wall of organs in your gastrointestinal tract. The tumors typically form in your stomach or small intestine in your gastrointestinal tract.

Some gastrointestinal stromal tumors are small, about the size of a pencil eraser. Smaller tumors may not cause symptoms. Some GISTs can grow large enough to cause symptoms like abdominal pain, fatigue and nausea. Healthcare providers treat GISTs with surgery to remove the tumors.

Symptoms of gastrointestinal stromal tumors

This condition may not cause symptoms. Often, people learn they have a GIST when they have a test or surgery for another reason. When symptoms develop, they may include:

• Abdominal (belly) pain
• Blood in your poop
• Constipation
• Fatigue
• Losing weight without trying
• Loss of appetite
• Vomiting blood

GIST causes

This condition usually happens when the KIT gene changes. The change causes cells to produce a protein (KIT CD117). This protein causes cells in your gastrointestinal tract to multiply and form tumors. The genetic change may happen during your lifetime. But you may develop GIST if you inherit a tumor disorder that increases your risk, including:

• Carney-Stratakis syndrome: This rare condition may increase your risk of developing a GIST.
• Familial GIST syndrome: Rarely, abnormal KIT genes may be passed on from parent to child. This can increase your chances of developing GISTs. If you have familial GIST syndrome, you may develop GIST at a young age. And you may have more than one tumor.
• Neurofibromatosis type 1: This disorder causes certain cells to multiply and form tumors. You may have tumors all over your body.

How doctors diagnose this condition

A healthcare provider will ask you about your symptoms and how long you’ve had them. They’ll do a physical exam. They may also do tests, including:

• Upper endoscopy
• CT scan
• PET scan
• Biopsy, to get tissue samples that a pathologist will examine under a microscope

How are gastrointestinal stromal tumors treated?

Treatment may be a combination of surgery and targeted therapy. Surgery may be the only treatment you need if you have small tumors. But you may have targeted therapy before surgery to shrink a large tumor.

What can I expect if I have a GIST?

Treatment can ease your symptoms and sometimes cure a gastrointestinal stromal tumor. But a GIST may come back. You may have follow-up appointments every three to six months so your oncologist can look for signs of a new GIST. They may do tests, including:

• CT scans of your liver and pelvis
• MRI scans
• PET scans

What’s the survival rate for someone with GIST?

Overall, 85% of people with GIST are alive five years after diagnosis. Other survival rates are:

Cancer survival rate data can be confusing. You may feel anxious about your situation. It’s important to remember that a survival rate is an estimate, not a prediction. Ask your oncologist to explain what you can expect.