Diagnosing GIST: Key Challenges and Treatment Insights

Dr. Breelyn Wilky, an associate professor of medicine in the Department of Medical Oncology at the University of Colorado, Anschutz Medical Campus, explains the challenges patients with rare cancers like gastrointestinal stromal tumors (GIST) often face.

One of the biggest hurdles is simply getting the right diagnosis. Symptoms like belly pain, heartburn, or feeling tired are very common and usually caused by something else. Because of that, doctors and patients don’t always think about rare cancers like GIST right away. That’s why awareness is so important, according to Wilky.

A biopsy is crucial to confirm the diagnosis, but sometimes, the tissue sample isn’t clear-cut, and doctors may need to get a second opinion to be sure.

Molecular testing to identify the specific mutation driving the tumor is also key to choosing the right treatment. If the first biopsy doesn’t provide enough material, patients might need another one.

Dr. Wilky, who also serves as the director of Sarcoma Medical Oncology, deputy associate director for Clinical Research, and the Cheryl Bennett and McNeilly Family Endowed Chair in Sarcoma Research at the University of Colorado Cancer Center, UCHealth, stresses that a more streamlined process is vital for patients.

Transcript

What unique challenges do patients face with rare cancers, like GIST, and what are researchers working to overcome?

There are many challenges when you're diagnosed with a rare cancer. First of all is the awareness piece, like making sure you actually get diagnosed with the right rare cancer is super, super important. When you're first presenting with symptoms, they can be very vague, like abdominal pain, heartburn, or feeling more tired than usual. These are very common symptoms, and in about 99.9% of cases, they’re caused by something other than a rare cancer. Even getting to the point of thinking this patient might have cancer based on symptoms, if they have any symptoms at all, is a big leap.

Then, to go from concerns about more common cancers, like pancreas, stomach, or colon cancer, to considering a GIST tumor growing from the small bowel and causing a weird bloating sensation, that’s even less likely. Part of the challenge is simply knowing that GIST exists, that it’s a real, rare entity with recognizable patterns and that it can be diagnosed.

Sometimes things get confusing. We say, “Tissue is always the issue,” meaning that if you have a scan or symptoms concerning for GIST, doctors will usually do a scope to get tissue and a biopsy. It’s crucial to have that biopsy reviewed to confirm whether there’s a GIST. In some cases, it’s very difficult to tell, and the sample needs to be sent out for a second pathology opinion.

Getting molecular testing and knowing the mutation that’s driving your GIST is extremely important for treatment. If you’re going to start therapy, we recommend testing the tumor, if at all possible. Sometimes the initial biopsy is very small and may not provide enough material. That’s when you should talk with your doctor about whether a second biopsy is needed.

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