Every GIST patient (and person in general) is unique, however, there are some common issues that patients may face during their GIST journey. The LRG GIST Patient Registry has collected data on patients’ diagnoses, treatments, evaluations, and other factors for close to 20 years. Some treatment records go back even further and from them we have been able to note some common patterns that make up what we call a “patient journey.”

Again, while no journey is identical, we can learn from commonalities and use that knowledge to help patients thrive with GIST. Leveraging this registry knowledge, we recently began collecting more systematic and detailed information about patient side effects in an attempt to not only better understand what these side effects are, but also how to help patients cope. We also started collecting “interventions”, or the methods which patients use to treat their side effects. In addition to the interventions, we also asked patients to rate the success of these approaches, so as to build up a library of possible strategies we can share with patients to help them treat their side effects just as successfully.

Treatment of side effects is important for a number of reasons. One perhaps obvious reason is the impact on quality of life. This is true even for patients who aren’t on any medication, as it is possible that some side effects may come from the disease itself (or other conditions besides GIST the patient may be going through). Another important reason, that may not seem as obvious at first, is unique to patients who are on medication as their side effects may impact their ability to actually take their medication as prescribed. This is referred to in the scientific literature as compliance or adherence. As you might imagine, if a side effect affects your ability to take your medication, this may mean the medication won’t work as effectively, and that can lead to negative outcomes like medication resistance or tumor progression. Thus, for those who do experience side effects, especially ones that have a major impact on quality of life and/or adherence, management of side effects is an important part of any patient’s treatment journey.

This article will focus on a number of side effects reported by GIST patients. They have been included for two main reasons; some simply because they are reported with higher frequency, and others, because they are interesting from a data perspective, since their frequency seems to vary based on a number of factors, such as the patient’s age or gender.

One other issue that has been observed is that many of the side effects common to GIST are also common to a number of cancers (and other diseases as well), which means that there is a large amount of content already published for patients. One excellent source is our own website where the side effect management page (https://liferaftgroup.org/managing-side-effects/) lists a number of the side effects detailed in this article, and also lists specific side effects for both Gleevec and Sutent.

Fatigue

Fatigue is by far the most commonly reported side effect by LRG Patient Registry members. It is also one of those side effects that is commonly reported by patients facing other cancers or chronic diseases. While everyone, including people not dealing with cancer or another chronic disease diagnosis, may face fatigue from time to time, what we are most concerned with here is fatigue that occurs more consistently and has a demonstrated effect on quality of life. This latter supposition (that most people experience fatigue) is what, from a research perspective, makes it so hard to find causative factors. How do we know if the fatigue is caused by the disease, the medication, increasing age, lifestyle factors, or a combination of all of these? In any case, what we can conclude is that treating the side effect is of the utmost importance.

One possible complication of GIST medications, like Gleevec, is that they can lead to anemia, which is the lowering of a patient’s red blood cell count. As red blood cells carry oxygen, a reduction can contribute to fatigue. If anemia is suspected, you can talk to your doctor about possible medications like Procrit that can increase your red blood cell count, which may help reduce your fatigue. Even for those patients not taking medication, fatigue may still occur due to the nature of the disease itself. This can be due to bleeding tumors or low iron count.

In the latter case, iron supplementation might be helpful. In addition to these methods to treat fatigue, strategies used by patients with other diseases (or no disease at all) might be helpful. Many of these are fairly common-sense recommendations – pacing yourself so as not to get too tired, taking naps when possible, and even joining a support group to learn about (and share) strategies with others. Some may find that light exercise actually helps reduce fatigue as well.

Diarrhea

Diarrhea, much like fatigue, is a very common side effect. In addition to the quality-of-life impact it may cause, including limiting ability to work or travel, a compounded issue involves nutrition. Patients may have difficulty absorbing enough nutrients if the diarrhea goes on for long periods. Coping with this may require a bit of an individualized strategy, as the foods one patient may be able to tolerate may be profoundly different than those of another. Experimenting with what works for you and adjusting accordingly gives you the greatest chance of success.

In general, however, there are a few overarching strategies that may help to start: try to eat smaller meals more frequently rather than large ones; drink plenty of water and/or clear liquids, broths, etc.; avoid higher fiber foods at least at first as they may help with bulking of the stool; and try to concentrate on higher nutrient foods (i.e., protein, minerals, and calories) whenever possible. Spicy foods may irritate the digestive tract, but again that can vary by the individual. In general, stick to a small number of foods that you can tolerate, and then add new foods in individually over time to see if they work for you. There are also of course medications (often over-the-counter) you can use – just remember to discuss these with your physician and/or pharmacist first.

Nausea

Another very common side effect for patients across many diseases, nausea can best be characterized as “feeling as if you are going to vomit” (as opposed to actual vomiting). Sometimes these issues go together, and sometimes a patient experiences nausea but not vomiting. Vomiting is a more severe issue as it directly affects nutrition, and may also affect whether or not you are absorbing the medication you are taking. Nausea can still have quite an impact if it causes the patient to eat less, or stop taking their medication. In addition, nausea may sometimes be accompanied by lightheadedness or dizziness, which may increase the risk of falls. Perhaps the best way to treat nausea is to try to prevent it in the first place if possible. This can be done with medications, often referred to as antiemetics; some are available over the counter and there are also stronger ones available by prescription. If you do take an over-the-counter version it is extremely important to consult your doctor as the drug may have side effects of its own.  

Skins Issues – Rashes, etc.

Skin issues are a common side effect of many medications, and they often can be placed on a scale of mild to severe, with minor skin eruptions and rashes on one end, and more pronounced issues like hand and foot syndrome on the other. In all of these cases, we are referring to irritations of the skin that can, if not treated, lead to blistering, and possible infection. This can lead to a number of quality-of-life implications, up to and including decreased mobility if the irritation is on the feet as is often the case with hand and foot syndrome, or even difficulty taking medication if it is on the palms. If a patient has a condition such as diabetes, or another that affects wound healing and increased susceptibility to infection, these issues become even more of a concern and should be dealt with as soon as possible and brought to the attention of your doctor. 

If it appears as if the skin issue has been brought about by medication (such as when first starting a medication, or increasing dosage), it is important to let your doctor know as they may be able to adjust your dose or suggest an alternative medication. Should that not be possible, treating the issue can often be accomplished by using creams and or ointments. Some of these may contain steroids, urea, or other compounds that help heal the skin. It is also important to minimize sun exposure as this may exacerbate some of these conditions. When outside, be sure to use sunscreen with adequate protection, and also if possible, cover your skin with clothing so as to further reduce exposure. In colder climates (such as winter) realize that in addition to the sun, wind may also become an issue. Protect yourself from the wind and also wear moisturizer if you can, to reduce your skin drying out.    

Cramping/Muscle Cramps

Cramping and muscle cramps are similar sensations but occur in different locations of the body. Cramping can occur anywhere, including internally, such as in the stomach or intestines (and may lead to diarrhea). Muscle cramps occur in the muscles themselves, often in the extremities. Both types of cramping could be a result of dehydration, and might benefit from increased intake of fluids, including electrolyte replacement beverages like Gatorade. 

Muscle cramps are due to a mineral imbalance. Often calcium or magnesium are the culprit, and sometimes vitamin D. In the case of Gleevec patients, both overly high and low levels of phosphorous have been noted. Having these levels checked by a doctor might be a good idea if that is suspected. It is also important to observe whether your activity levels have changed to see if that is the more likely cause (such as recently starting an exercise program or engaging in a physical activity new to you). 

One interesting trend that has been observed in the LRG Patient Registry is that muscle cramping is a side effect more frequently reported by males than females. This occurs independent of age. While we are not sure of the exact reason for this at this time, it suggests some interesting concepts from a research perspective. How do side effects vary across different factors such as gender or age? Perhaps side effects treatment programs should take that into consideration.   

Edema

Edema, or swelling, is brought about by fluid retention. Edema can occur throughout the body. For GIST patients this often occurs around the eyes (known as periorbital edema) so we will address that in the next section under eye issues. Edema can lead to further complications, such as shortness of breath, and in rare cases can travel to the lungs which is more severe. Many patients experience edema temporarily, and often that can be treated by dietary changes (ie., reducing your salt intake and caffeine, and eating more fiber and potassium). In cases where it lasts for longer periods of time, medications like diuretics may be needed, and you may also be advised to limit standing for long periods of time, and elevating your feet (in the case of edema in the feet or legs). 

What’s most important is being aware of any changes. If you see that you are gaining weight (especially if it looks like it’s “puffy” water weight) and you haven’t increased your food intake and/or decreased your activity levels, it is best to play it safe and notify your doctor. This will help your doctors get ahead of any issues that may arise if you wait too long to deal with the edema. Interestingly, while muscle cramping is predominately reported by males, edema is predominately reported by females, particularly those over the age of 50. Again, this suggests ramifications for side effect management, and in this case those ramifications extend beyond gender but to age as well. 

Eye Issues

If GIST patients were to pick one side effect that is most associated with their disease, and particularly those taking Gleevec, high on the list would be eye issues. Patients often even refer to this as “Gleevec eyes”, which shows just how prevalent it is. It’s characterized by puffiness or swelling around the eyes, and occasionally eye bleeds. For many but not all patients, it tends to be worse in the morning. 

While many patients simply “deal with it” and don’t treat this side effect, topical solutions and antihistamines have been used by some and have provided various degrees of relief.One thing to note about our observations in general is that patients often report that their side effects reduce in severity over time. Whether this is due to an actual reduction or just the patient learning to cope with it better and then perceiving it as more tolerable is still an open question. 

In any case, managing side effects is a better strategy than simply ignoring them, or taking medication irregularly. Beyond what we’ve offered here, there are a number of resources you can use including the LRG Patient Registry itself. If you are currently a member and are dealing with a side effect and would like some guidance, please reach out to the LRG Registry Staff. They have a great deal of experience dealing with side effects. If you are not currently a member, please consider joining. In addition to having access to the aforementioned help, the data you provide about your side effects helps us learn more not only about what side effects patients are experiencing, but also the interventions they are using to treat them. This helps your fellow GIST patients as we are able to share what we learn in articles such as this one and on our website. 

Another resource worth exploring is GIST Chat, which is a chat system limited to LRG patients and caregivers that can be used to discuss a number of topics, of which side effects is one of the most frequent

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