Gastrointestinal Stromal Tumor Diagnosis

The esophagus, colon and rectum make up the rest, while a very small number can develop in the abdomen outside of the GI tract.

GIST is not the same as other, more common types of GI tract cancers such as adenocarcinomas and squamous cell carcinomas. Rather than starting in the inner lining of the intestines, GIST forms within the walls of the GI tract, or digestive tract.

GISTs require a different treatment than other GI tract cancers as well. At Winship Cancer Institute of Emory University, Georgia’s only NCI-designated Comprehensive Cancer Center, patients receive the highest quality cancer care from a team of dedicated gastrointestinal cancer physicians and surgeons.

There are several signs and symptoms that can help in confirming a gastrointestinal cancer diagnosis. These include:

• Throwing up blood. This can indicate brisk bleeding from the esophagus or stomach. Because the blood may be partially digested, it could resemble coffee grounds rather than bright red liquid.
• Black and tarry bowel movements, or stools. This can indicate brisk bleeding from the stomach or small intestine.
• Blood in the stool. This can indicate brisk bleeding into the large intestine. When this occurs, the stool could be red with blood.
• Fatigue and weakness. This can indicate a low red blood cell count, due to a slower bleed from the tumor. A person who develops anemia can feel weak and tired.

Other signs and symptoms of GIST may include:

• Stomach pain
• Abdominal swelling
• Nausea and vomiting
• Feeling full after eating only a small amount of food
• Loss of appetite and/or weight loss
• Difficulty swallowing (likely a cause of tumors in the esophagus)

A gastrointestinal cancer diagnosis in its early stage is limited to the organ where GIST first developed. A gastrointestinal cancer diagnosis in its late stage is when the cancer spreads to other organs, such as the liver or the abdominal lining. Staging a gastrointestinal stromal tumor is critical in determining the best treatment plan.

Your Winship care team may use one or more tests and procedures to determine the stage of your cancer:

• Physical exam. Your doctor will discuss your medical history with you, including any risk factors. They will also perform a physical exam, paying close attention to the abdominal area where they will check for any lumps, tenderness or swelling, as these may indicate a GIST.
• Imaging tests. Using advanced imaging techniques, detailed pictures of the inside of the body (i.e., GI tract) can be obtained and can detect any abnormalities or tumors. One or more of the following may be used to diagnosis and assess a GIST:
  • Upper endoscopy — A small, flexible tube with a camera at the end (endoscope) is inserted down the throat and into the esophagus, stomach and part of the small intestine, where it takes a close-up look at the inner lining of the GI tract. If any abnormal growths are present, a biopsy of the tissue may be taken for further analysis. Before the procedure, the patient is given medicine to make them sleepy.
  • Endoscopic ultrasound — A special endoscope with a transducer that uses sound waves to provide a detailed evaluation of the wall of the GI tract. If a tumor is identified, a biopsy under ultrasound guidance can be obtained.
  • Computed tomography (CT) scan — CT scans take cross-sectional images of the inside of your body to detect any unusual growths or tumors. CT scans are useful in staging cancers.
  • Magnetic resonance imaging (MRI) — MRIs show detailed images of the soft tissue of the inside of the body using magnets. MRIs are useful in determining the extent of the GIST and how advanced it is.
  • Positron emission tomography (PET) scan — During a PET scan, a type of radioactive sugar is injected into a patient’s bloodstream, where it is absorbed by cancer cells. A special camera is then used to detect the cancer. PET scans are often combined with CT scans.
  • Colonoscopy (lower endoscopy) — A device called a colonoscope (similar to an endoscope) is passed through the anus and into the colon to check for any abnormal growths. A biopsy may be taken during a colonoscopy if needed. Before the procedure, the patient is given medicine to make them sleepy. Sometimes, general anesthesia is given.
• Biopsy: A small sample of tissue is taken, then analyzed under a microscope to check for cancerous cells. A biopsy can be taken in a number of ways to confirm a gastrointestinal stromal tumor diagnosis: endoscopically, percutaneously or surgically.
• Blood tests. While there is currently no blood test that can confirm a gastrointestinal stromal tumor diagnosis, a complete blood count (CBC) can show whether a person is anemic (low red blood cell count) and a liver function blood test can also be used to see if the cancer has spread to the liver.