Why Is Specialized Care Important For GIST Treatment?

It is vital to pay attention to your body and not ignore vague or early symptoms, according to Dr. Weijing Sun, an associate director at the University of Kansas Cancer Center. He went on to add that it is important to see a specialist to make sure you get the right tests for diagnosis, as well as seek an expert’s opinion when it comes to choosing the best treatment options.

In an interview with CURE, he delved into the topic of GIST treatment, as well as what patients with the disease should know.

Sun also serves as the Sprint Professor of Medical Oncology, a professor of Medical Oncology and Cancer Biology, and the director of Medical Oncology Division, all at the University of Kansas School of Medicine.

CURE: What are the main treatment options for patients with GIST, and how do factors like tumor size, location, and genetic mutations affect the approach?

Sun: With tiny, small, low-risk tumors, you don't always have to have surgery immediately; sometimes, you can just observe them. For other tumors, if the size is relatively bigger, like between two and five centimeters, or if the molecular markers tell us there is a risk of quicker growth, then you need surgery to remove them.

The location of the tumor matters, too. Tiny, small tumors can sometimes be removed endoscopically. Some bigger lesions may require a bigger surgery. The ease of surgery also depends on the location: stomach, esophagus, small intestine, or colon/rectum. Some locations are relatively easy to operate on, and you can surgically remove the tumor quickly, especially if the person is bleeding. On the other hand, some tumor locations are not easy to operate on. For example, if a tumor is wrapped around blood vessels, that area is considered high-risk, which means surgery could cause more trauma or is simply not easy.

Depending on the risk factors, we may give some upfront treatment, which means we give a drug called a targeted therapy or a tyrosine kinase inhibitor, based on the specific mutation you have.

There are basically three approaches: observation, if the tumor is tiny and small, you just need surveillance with periodic imaging because they are so slow-growing; surgery, if the tumor starts to grow, and you need a curative situation, which means you can remove the tumor with surgery; and a third approach, where you might start with treatment before surgery to shrink the tumor, so you can then proceed to surgery.

There are a very few unfortunate situations where patients start with metastatic disease, which is Stage IV and has spread to other places. In these cases, the treatment options are medical treatments with those tyrosine kinase inhibitors.

It sounds complicated, but it all depends on the individual. Many times, when these diseases are diagnosed, we recommend that you consult an expert or take the case to a multidisciplinary conference because an expert opinion is very important, including that of a medical oncologist and a surgeon. This is because the disease is not very common, so expertise and the hospital's location are important.

What should patients know or do after first receiving a rare cancer diagnosis, such as GIST?

Whenever you tell a patient they have a cancer, sarcoma or a special kind of unusual disease, especially when you're talking to a primary care physician who may not be familiar with the disease; it is, of course, a source of tremendous psychological stress for anyone. This includes those patients who are first diagnosed. That's why the first thing to do is to get a specialized, expert opinion [from someone who is familiar with] world-class guidelines. [It is also important to] know where [the tumor is located].

If [you have] a tiny, small tumor, then observation may be enough, and you need to talk to an expert about [your options]. To do this, you need to understand what low risk, intermediate risk, and high risk are, as well as what that means to you [individually], so you can understand at your level in your own language. You also need to have a specific physician or oncologist who is familiar with the disease follow your [case]. When you understand [what your options are], the stress [may] then improve...

So, firstly, you have to look for an expert opinion. You then need to know what kind of disease you're dealing with. Then, you can understand what treatment options you have and what the rationale is. Finally, [you will learn about] the treatment itself. When you get an expert opinion, you get a full diagnostic workup, and then you know what's going on. If you listen to your friends or Google it yourself, this could be much less clear and increase your stress, because every single patient is different.

The most important thing is to not compare yourself to people with a similar diagnosis, [as they may have] a completely different situation.

How important is follow-up care and ongoing monitoring for patients with GIST after successful treatment, and what should they expect long term?

So it's important. That's a very important situation, even for those patients who have curative-intent surgery. You need to know the pathology of the tumor, which means when the tumor is removed, the pathology report will detail the size, mitosis, and mutation.

Of course, regardless of the situation, everybody needs surveillance, which means following up closely. A second group of patients needs what's called adjuvant treatment. Even if their tumors were removed by surgery, those in the intermediate- or high-risk group, meaning the tumor size was bigger than expected, like five to ten centimeters, with more than five mitoses, or with a certain mutation, are candidates for adjuvant treatment. This means you give some treatment afterward to decrease the chance of the cancer coming back, which is called recurrence.

Typically, surveillance means that for the first five years, you need to see a doctor every three to six months for an evaluation with either an endoscopy or a CT scan to ensure there is no evidence of the disease. After five years, most people are followed up with periodically, and they can also have an endoscopy.

There is one small group of people who have a risk of inherited, or genetically related, high-risk conditions, especially something called SDH deficiency. While it sounds complicated, you always need a biological or genetic assessment. If you have a family risk (for example, more than one family member has the same disease or the disease developed at a younger age), I always ask a patient to get a genetic consultation. This is especially so that a genetic expert can help you understand if you do or do not have some risk of a family-inherited situation, which can also help you with long-term follow-up.

These are factors that, even if you had a curative surgery, you still need to consider. Number one, for yourself, you need surveillance. Some people need treatment to decrease the risk of recurrence, and the best thing is to also have a genetic follow-up to ensure there is no other genetic risk for the rest of your family members as well, including yourself.

Transcript has been edited for clarity and conciseness.

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