Treating Gastrointestinal Tumors: GISTs are different from more common types of GI tumors because of the type of tissue in which they start. GISTs belong to a group of cancers called soft-tissue sarcomas. Soft-tissue sarcomas develop in the tissues that support and connect the body.
How Doctors Treat GIST
Surgery usually comes first. Afterward, you may take drugs that target the proteins that cause GIST. Those proteins are in cells that help move food through the digestive system. You usually don’t need chemotherapy and radiation.
Finding the Tumors
Doctors can use tests like CT and MRI scans to check for suspicious areas. You may drink a barium drink or take a barium enema to enhance X-ray images. Your doctor may insert an endoscope, a tiny flexible tube with a video camera, into the GI tract for a closer look.
Is Tumor Cancer?
When doctors find a tumor, they may remove a few cells from it to test for cancer. It’s hard to do that with GISTs because they grow beneath the lining of the stomach or intestines. Surgeons may try to take a tiny sample with an endoscope. Or they may insert a long needle through the skin to get a sample. Often it’s best to remove the tumor and test it.
Doctors use tests that change color if a tumor has too much of a protein called “cKIT” (tyrosine-protein kinase KIT) or a mutation of the protein called platelet-derived growth factor receptor alpha (PDGFRA). They also look for changes in the genes. And they check how fast cells in the GIST multiply, which helps them know how aggressive it is.
What Stage Is the Cancer?
Doctors assign a stage — ranging from I to IV — to GIST based on:
- Size of the main tumor
- Whether nearby lymph nodes have signs of cancer
- If it spread or metastasized, to other organs
- How fast cells are multiplying
The higher the stage, the more serious the disease. Treatment depends on the stage of cancer.
Will You Need an Operation?
Surgery is the main way to treat GIST. It’s generally the first choice, even if doctors need to remove parts of the surrounding tissue or organs. Some tumors are impossible to cut out because they have spread into vital tissue or into other parts of the body. In those cases, doctors may prescribe medication to shrink tumors so they’re small enough for surgery.
Surgeons can remove small tumors using a laparoscope, a fiber-optic instrument that they insert through a small cut. For larger tumors, they may need to remove parts of affected organs, like the intestine or liver. GIST rarely spreads into nearby lymph nodes, so doctors usually don’t have to remove those.
Problems Before and After Surgery
Before surgery, large tumors may block, tangle, or tear intestines. They may also cause internal bleeding, which can need urgent treatment and blood transfusions. After surgery, there can be infections, bowel obstruction, and heart and lung problems. Keep up with your doctor appointments to make sure you’re OK. If the surgeon removes part of your stomach, you may need to make some diet changes. Ask your doctor about that.
Drugs That Help Treat GIST
The chances of GIST coming back depending on the size of the tumor and how fast it was growing. Medication is important for people at risk for the tumor coming back. A recent study showed that 3 years of medicine improves your chance of living longer. Even when you can’t get surgery, certain drugs may improve your chance or curb problems caused by large tumors.
Medicine for GIST
The first drug that doctors usually prescribe to help treat GIST is imatinib (Gleevec). It blocks the proteins that make the tumors grow. Studies show that imatinib helps control GIST in 9 out of 10 people following surgery and that it can control GIST for at least 3 years. Imatinib can be taken before surgery to shrink tumors, after surgery to make it less likely that cancer will come back, and for tumors that surgeons can’t operate on.
When imatinib doesn’t work, sunitinib (Sutent) It can also slow down the disease and shrink tumors. Sunitinib is also a possibility if you have side effects from imatinib and your doctor wants to try another drug. Regorafenib (Stivarga) is an option if the other two don’t work or you can’t take them. If the tumor has metastasized, your doctor may prescribe the kinase inhibitor avapritinib (Ayvakit).
Experimental Treatments: Researchers are developing new drugs for GIST. Some of them work the same way as imatinib and sunitinib. Others work in different ways. You may want to ask your doctor about clinical trials that you could join, what they involve, and what you can expect if you sign up 🙂 🙂