About Gastrointestinal Stromal Tumor (GIST)
A gastrointestinal stromal tumor (GIST) is a rare type of tumor that forms in the digestive tract, usually in the stomach or small intestine. It develops from special cells called interstitial cells of Cajal (ICCs), which help control the movement of food through the digestive system. GISTs mostly affect adults aged 40 to 70, though they can also appear in children and younger adults.
Some GISTs don’t cause noticeable symptoms, but others can lead to issues like belly pain, swelling, nausea, vomiting, loss of appetite, weight loss, anemia (a low count of red blood cells), and bleeding in the digestive system. Often, GISTs are found accidentally during imaging tests or endoscopy.
Treatment usually involves surgery to remove the tumor, and in higher-risk cases, additional therapy may be recommended to help prevent the cancer from returning.
The exact causes of gastrointestinal stromal tumors (GISTs) aren’t fully known. However, some families seem to have a higher risk of getting these tumors due to inherited changes, or mutations, in certain genes, called oncogenes. These gene mutations are the most common known cause of GISTs.
The non-modifiable risk factors for GISTs are factors that cannot be changed. These include:
- Family history: Some people are born with gene mutations that increase the risk of GISTs.
- Genetic factors: Specific genetic traits can make GISTs more likely.
Modifiable risk factors are ones you can change to lower your risk, but for GISTs, none are known at this time. So far, there’s no clear link to lifestyle or environmental factors that could reduce the risk.
Since GISTs are rare, their causes and risks are still being studied. If you’re worried about GISTs or any health issue, it’s best to talk with a healthcare provider who can give you tailored advice and guidance.
The most common early symptoms of GISTs include:
- Acute tumor rupture: When the tumor suddenly breaks open, which can be serious.
- Gastrointestinal obstruction: A blockage in the digestive system that can stop food or liquids from passing through.
- Pain: General discomfort or pain, often in the abdomen.
- Difficulty swallowing (dysphagia): Trouble swallowing food or liquids.
- Early satiety: Feeling full quickly after beginning to eat.
- Sometimes, smaller GISTs are found accidentally during surgery, imaging tests, or endoscopy when looking for something else.
As GISTs progresses or reaches higher severity, the following symptoms may occur:
- Metastasis: GISTs can spread to the liver or within the abdominal cavity (peritoneal dissemination).
- Lymph node and lung involvement: In adults, it’s uncommon for GISTs to spread to lymph nodes, lungs, or areas outside the abdomen.
- Paraneoplastic consumptive hypothyroidism: Rarely, GISTs can cause low thyroid hormone levels due to the tumor’s effects.
It's important to note that these symptoms can vary depending on the individual. If you experience any concerning symptoms or suspect you may have GIST, it is best to consult with your healthcare professional for an accurate diagnosis and appropriate management.
To diagnose GIST, the following examinations, tests, and procedures are commonly performed:
- Physical exam: The healthcare provider will conduct a physical exam to check for signs of a medical problem, such as pain, swelling, or the presence of masses in the body.
- Lab tests: These may include blood tests, urine tests, or tissue samples to help diagnose the disease. The specific lab tests ordered will depend on your symptoms and the diseases being considered.
- Genetic testing: Genetic tests may be recommended to identify changes in genes, chromosomes, or proteins that can confirm or rule out a suspected genetic disease.
- Imaging studies: These allow doctors to look inside the body for clues to help diagnose or manage the disease. The type of imaging study depends on your symptoms and the part of the body being examined. Examples include X-rays, MRI scans, or CT scans.
To determine the stage or severity of GIST, additional examinations, tests, and procedures may be performed:
- Endoscopy: This procedure uses a flexible tube with a camera to examine the inside of the gastrointestinal tract and obtain biopsies if necessary.
- Endoscopic ultrasound (EUS): This test combines endoscopy with ultrasound imaging to assess the depth of tumor invasion and nearby lymph nodes.
- Computed tomography (CT) scan: This imaging technique provides detailed pictures of areas inside the body from different angles and can help determine tumor size and spread.
- Positron emission tomography (PET) scan: A PET scan uses a radioactive tracer to detect cancer cells throughout the body and assess whether the tumor has spread.
Remember that these are general descriptions of common examinations, tests, and procedures for diagnosing and staging GIST. Consult with your healthcare provider for personalized advice based on your specific situation.
The goals of treatment for GISTs include:
- Maintaining tumor capsule integrity: The primary goal in surgery is to remove the tumor without breaking its capsule. This helps prevent cancer cells from spreading during the procedure.
- Achieving negative margins: Surgeons aim to remove the tumor along with a small amount of surrounding healthy tissue to lower the risk of the cancer returning.
The recommended treatments and therapies for GISTs depend on the stage and characteristics of the tumor. Here are some options:
- Surgery: For GISTs that can be removed, surgery is the main treatment. Tumors that are 2 centimeters or larger are removed, and smaller tumors (5 cm or less) may be removed with laparoscopic (minimally invasive) surgery.
- Targeted therapy: Drugs like imatinib mesylate and sunitinib are used to target specific proteins that help the tumor grow. These drugs help to shrink or control the tumor.
- Palliative therapy: Radiation therapy may be used to relieve pain or control bleeding in advanced cases as a comfort measure.
It is important to note that specific treatment recommendations should be made by a healthcare professional based on individual circumstances. Health behavior changes and other treatments may also be recommended on a case-by-case basis.
Medication dosing may be affected by many factors. Check with your health care professional about dosing for your individual situation. Other side effects can occur. Check with your health care professional or read the information provided with your medication for additional side effect information.