What is GIST?
Gastrointestinal stromal tumor, also known as GIST, is a type of cancer that develops within the gastrointestinal (GI) tract. Most GIST cancers start in the stomach wall, but they can also start in the intestines, though this isn’t as common. Exactly why GISTs start to grow is not known, but some tumors have been found to have mutations in particular genes, including KIT and PDGFRA genes. These genetic changes have been found to lead to the development of cancer.
Symptoms of GIST can vary from person to person but can include the following:
- Throwing up blood or substance that looks like coffee grounds
- Blood in the stool
- Stool that looks dark or tarry
- Feeling very tired
- Pain in the abdomen
- Nausea and vomiting
- Decreased appetite
- Weight loss
When GIST is discovered, a tumor biopsy must be obtained to get the specific diagnosis. The stage or extent of cancer needs to be determined as well to help determine the exact treatment that will be best.
Imaging tests used to help determine the extent of cancer can include CT scans, MRIs, and PET scans. Other studies include upper endoscopy and colonoscopy, where a camera is inserted into the stomach and intestines to see if there are any suspicious areas of cancer.
Blood tests to evaluate blood cell counts as well as kidney and liver function.
The oncologist will order the exact treatment for GIST once the diagnosis is made and the cancer stage is known.
Surgery is often recommended for GIST, especially if they are smaller and haven’t spread to other areas. During surgery, the tumor and healthy tissue around the tumor are removed.
A medication called imatinib (Gleevec) might be recommended after surgery if the tumor has high-risk features that may make it more likely to come back. This medication is often taken for a few years after surgery. Sometimes imatinib is given for a period of time before surgery to
help shrink the tumor. It can also be used if cancer is metastatic or has grown in other body areas.
Other medications that can be used to treat metastatic GIST include:
- Sunitinib (Sutent)
- Regorafenib (Stivarga)
- Ripretinib (Qinlock)
- Sorafenib (Nexavar)
- Dasatinib (Sprycel)
- Nilotinib (Tasigna)
If you’ve been diagnosed with GIST, talk to your cancer team about the specifics of your cancer. They can help you understand your diagnosis and how best to treat it.