Advanced gastrointestinal stromal tumor (GIST) is a rare disease of the digestive tract. Also known as GISTs for short, many of these tumors grow slowly and don’t cause problems. But if you have advanced GISTs, tumors may spread fast and can be life-threatening.
Around 10% to 20% of people with GISTs are diagnosed when they already have metastatic disease. That’s when the original cancer cells spread to other parts of the body.But some people with advanced GISTs have multiple primary tumors in different places.
There’s no cure for advanced GISTs, but your doctor can help you find treatment to feel better and live as long as possible.
Where in the Body Can GISTs Spread?
More than half of these tumors start out in the stomach. Another one-third of GISTs begin in the small intestine. The rest usually form somewhere along the soft tissue of your digestive tract, including the rectum, colon, or esophagus.
If you have advanced GISTs, cancer may affect your:
Liver. Blood from your stomach and intestines goes through your liver. And this organ is one of the most common sites for advanced GISTs.
Peritoneum. The peritoneum is a layer of smooth tissue that lines your belly and pelvis. It surrounds organs like your stomach, liver, and small or large intestines. It’s another top spot for advanced GISTs.
Nearby belly tissue. Less commonly, GIST cells may spread to areas outside of the GI tract. That might include the layer of fat that surrounds your stomach and intestines (omentum) or the tissue that holds your intestines in place (mesentery).
Non-belly organs. It’s uncommon for advanced GISTs to affect areas outside of the liver or abdomen. But these tumors have been found in distant places like lymph nodes, lungs, bones, and ovaries. Very rarely, doctors have found these tumors in breast or muscle tissue.
What Are the Odds GISTs Will Come Back After Treatment?
GISTs tend to recur or spread in about 40% to 50% of people who have surgery on a primary tumor. But if you have advanced GISTs, your cancer may be too big to take out completely. Your doctor may give you medication to shrink your tumor, even though it’s not a cure.
There are certain things that make GIST cancer cells more aggressive. You may hear your doctor call this malignant potential. The main ones are:
- Tumor size. Your cancer can come back no matter how big or small your tumors are, but the chances are higher for larger GISTs.
- Original tumor site. GISTs that start in the stomach are generally less likely to come back, compared to tumors found in other areas of the body.
- Mitotic rate or index. This refers to how fast cancer cells grow and make copies of themselves. The higher the “mitotic index,” the more aggressive the tumor tends to be.
Other risk factors for advanced GIST recurrence include:
- If your tumor ruptures by itself or during surgery
- How the tumor looks in CT scans or ultrasound
- If your lymph nodes are involved
- Certain genetic changes in the tumor
Your doctor will keep an eye on your tumors throughout your cancer journey. They usually do this by using the same tests used to diagnose advanced GISTs in the first place. For example, you might need repeat CT, MRI, or PET scans to see how well your treatment is working.
Managing Advanced GIST and Daily Life
There are several ways this cancer and its treatment can affect your daily life. Things that you might need to plan for include:
Follow-up care. Advanced GIST is considered a chronic (long-term) cancer. That usually means you’ll need medical care for the rest of your life. You might get targeted drugs or other therapies to slow your cancer or ease symptoms caused by the tumors.
You may need to check in with your doctor every 3 to 6 months. During these visits, they may go over how you’re feeling or run tests to look at your cancer. They may also go over a long-term strategy for how to handle life with cancer. You may hear this called a survivorship care plan.
Here are some questions to get you started:
- Can I get a schedule for when I’ll need follow-up exams or other tests?
- Which tests will I need to check for long-term health problems from cancer or treatment?
- Will I need tests for other kinds of cancer?
- What late or lasting side effects may come from my treatment?
- Who can I talk to for diet and exercise tips?
Physical effects. These tumors may not cause big problems for you. But advanced GISTs and their treatment can make you feel different or uncomfortable.
The tumors may cause:
- Less feelings of hunger
- Stomach pain
- Weight loss
- Tiredness
- Trouble with bowel movements
Some advanced GIST treatment side effects to watch for might include: :
- Sick feeling in your stomach
- Diarrhea or constipation
- Muscle cramps
- Tiredness
- Changes to your hair or skin
Talk to your doctor about supportive care before, during, or after treatment. You may also hear this called palliative care. You’ll work with health professionals to prevent or ease symptoms and side effects that come from the disease or cancer treatment.
Emotional challenges. It’s normal for anyone with a serious illness to have feelings of depression, anxiety, or fear. Lean on your loved ones or spiritual community for support. If you need extra help, ask your doctor to help you find a psychiatrist, psychologist, or cancer counselor.
Members of the cancer community may offer a special kind of support. While this is an uncommon kind of cancer, you can find people who know what you’re going through. You may find in-person or virtual meetups through groups like GIST Support International.
You’ll find general cancer support through the websites of the American Cancer Society or Cancer Support Community. And make sure to ask your doctor for more resources in your area.
