Signs and Symptoms of GIST: Signs to Be Aware of

Where does GIST occur?

GIST can occur anywhere along the GI tract. Approximately 60% of GISTs are found in the stomach; 25% in the small intestine; 5% in the rectum; 2% in the esophagus; and 5% in other locations including the appendix, gallbladder, and pancreas.

GI Tract Diagram

What are the symptoms of GIST?

The most common symptoms of GIST are abdominal discomfort or pain and bleeding into the intestinal tract. The bleeding may appear as dark or black bowel movements. The bleeding may result in anemia (low blood cell counts), and this in turn may manifest as tiredness or shortness of breath.

Nausea, vomiting, loss of appetite, and weight loss may also be present.

GIST symptoms may not be apparent until the tumors become a certain size or grow in a certain location.

Diagnosing GIST: And Why It's Sometimes Misdiagnosed

How is GIST diagnosed?

A test for GIST, known as KIT staining, is the most reliable way to make an accurate diagnosis and get a patient started on needed treatment.

95% of GISTs stain positive for KIT, making it the most common tumor marker for the illness.

GIST is sometimes misdiagnosed

It is only within the last few decades that scientists have discovered the true nature of GIST. In fact, it was not until 1983 that the phrase stromal tumor was introduced, thus acknowledging its difference from other gastrointestinal tumors.

Most GISTs occur in 2 major patterns. One type, called spindle cell, represents 70% of all GIST cases. A spindle-cell GIST resembles other cancers, which can make it difficult to accurately identify.

Another type of GIST, called epithelioid, accounts for 20% of all cases. The remaining 10% consists of a mixture of spindle cell and epithelioid.

Symptoms of GIST resemble those of more common ailments. Because of this, and since GIST is so rare, most doctors may not immediately identify the condition.

Prognosis for GIST: How Size and Grade Factor in

What is the prognosis after GIST is discovered?

The prognosis for GIST is dependent on a number of factors. These include the size of the tumor, the grade, and whether or not it has spread (metastasized).

How size is a factor

The smaller the tumor, the less likely it is to spread, therefore the better the prognosis. The best outlook is for tumors that are less than an inch.

What is tumor grade?

A tumor's grade is a measure of its tendency to grow and spread. For GIST, the grade is determined by finding out how many dividing cells there are. Using a microscope, a pathologist will count the number of cells undergoing division.

*Eligible patients are those being treated with GLEEVEC for KIT+ GIST and who reside in the U.S. and Puerto Rico. Residents of Massachusetts and patients participating in a federal or state government-related healthcare program that pays in whole or in part for prescription drugs are not eligible.

 

 

Side Effects

Almost all people taking GLEEVEC experience side effects.

Be sure to talk to your doctor and/or healthcare professional about any GLEEVEC side effects you are experiencing.

Serious side effects include:

  • Severe fluid retention, which can cause swelling around the eyes or swelling of the lower legs, lungs, and heart; fatal in rare cases (reported in 9%–13.1% of patients)
  • Increased pressure in the heart or brain; fatal in rare cases
  • Low levels of certain blood cells
  • Heart failure
  • Liver problems
  • Hemorrhage (abnormal bleeding) [reported in 12.9% of patients in Phase 3 studies and 5% of patients in the Phase 2 study]
  • Skin blistering
  • Low levels of thyroid hormone

Some common side effects are:

  • Fluid retention
  • Muscle cramps or pain and bone pain
  • Abdominal pain
  • Vomiting
  • Diarrhea
  • Decreased hemoglobin (an oxygen-carrying protein in red blood cells)
  • Nausea
  • Fatigue
  • Rash
  • Anorexia (loss of appetite)

Supportive care may help reduce the severity of some side effects, whereas others require discontinuation or dosage adjustment. Don't stop taking your medication or change your dose without talking to your doctor.

GLEEVEC can cause fetal harm when administered to a pregnant woman. Women should be aware of the potential harm to the fetus. Be sure to inform your doctor if you are or think you may be pregnant. You should not breast-feed while taking GLEEVEC.

Side effects

What it feels like

How your doctor may manage it

Swelling and fluid retention

Swollen legs or feet and swelling around the eyes. Fluid retention can appear as quick weight gain or swelling in your lower legs or other parts of your body. Fluid retention can be serious or even life-threatening

  • Regular check-ups to monitor your weight
  • Prescribe a topical steroid cream to reduce the swelling around your eyes
  • Tell you to limit your salt intake
  • Prescribe a diuretic (a medicine to help your body get rid of extra fluids)

Rash

Scaly skin; red itchy bumps on skin

  • Recommend an over-the-counter (OTC) antihistamine
  • Prescribe a corticosteroid or stronger antihistamine

Nausea and vomiting

Feeling queasy or like you have to throw up

You may also feel like you have indigestion

  • Recommend taking GLEEVEC with a meal and a large glass of water (If you have been instructed not to take GLEEVEC with meals, contact your doctor before changing your dose to mealtimes)
  • Recommend OTC medications
  • If you are taking your GLEEVEC once a day, talk to your doctor about possibly dividing the dose in half and taking it twice a day

Muscle cramps

Pain or spasms in the legs, feet, or calves

  • Recommend an OTC pain reliever, like ibuprofen
  • Recommend a prescription pain reliever
  • Recommend calcium and magnesium supplements

Muscle and bone pain

Whole-body ache; twitching or burning muscles

  • Recommend an OTC pain reliever, like ibuprofen
  • Recommend a prescription pain reliever

Diarrhea

More bowel movements; loose stools

  • Recommend an OTC medication
Important information

GLEEVEC® is available only by prescription.

GLEEVEC® Indications
  • GLEEVEC® (imatinib mesylate) tablets are indicated for the treatment of patients with Kit (CD117)–positive gastrointestinal stromal tumors (GIST) that are cancerous, cannot be surgically removed, and/or have spread to other parts of the body
  • GLEEVEC is also approved for use after surgery in patients that have had their Kit (CD117)–positive GISTs completely removed. Approval is based on survival without a return of cancer (recurrence-free survival) with a median follow-up of 14 months. Clinical benefit has not been demonstrated by a long-term effect on recurrence-free survival or survival

SAFETY: Important product information (Click here for full Prescribing Information)

Who should NOT take GLEEVEC
  • Women who are or could be pregnant. Fetal harm can occur when administered to pregnant women; therefore, women should not become pregnant, as well as be advised of the potential risk to the unborn child if GLEEVEC is used during pregnancy
  • Women who are breast-feeding because of the potential for serious adverse reactions in nursing infants
  • Sexually active females should use adequate birth control while taking GLEEVEC

Be sure to talk to your doctor and/or healthcare professional about these issues before taking GLEEVEC.

Warnings and precautions
  • GLEEVEC is often associated with edema (swelling) and serious fluid retention. It is important that patients be weighed and monitored regularly for signs and symptoms of serious fluid retention, or unexpected weight gain. Patients experiencing unexpected rapid weight gain should speak to their doctor about appropriate supportive care treatment. Studies have shown that edema (swelling) tended to occur more often among patients who are 65 and older or those taking higher doses of GLEEVEC. If you experience severe fluid retention, your doctor may treat you with diuretics and may stop your GLEEVEC treatment until the fluid retention has been managed
  • Cytopenias (reduction or lack of certain cell elements in blood circulation), such as anemia, have occurred. Your doctor will perform complete blood counts weekly for the first month, biweekly for the second month, and periodically thereafter. In most cases, your doctor will reduce or interrupt your GLEEVEC therapy; in rare cases, your doctor may discontinue treatment. If the cytopenia is severe, your doctor may reduce your dose or temporarily stop your treatment with GLEEVEC
  • Severe congestive heart failure and left ventricle dysfunction have been reported, particularly in patients with other health issues and risk factors. Patients with heart disease or risk factors will be monitored and treated for the condition
  • Severe liver problems (hepatotoxicity) may occur. Cases of fatal liver failure and severe liver injury requiring liver transplants have been reported with both short-term and long-term use of GLEEVEC. Your doctor will check your liver function before beginning treatment and continue to monitor liver function as needed. If you experience severe liver problems, your doctor may stop your treatment with GLEEVEC until the liver problem has been managed
  • Bleeding may occur. Severe gastrointestinal (GI) bleeding has been reported in patients with KIT+ GIST. GI tumor sites may be the cause of this bleeding
  • In patients with hypereosinophilic syndrome (a condition with increased eosinophils, which are a type of white blood cell) and heart involvement, cases of heart disease (cardiogenic shock/left ventricular dysfunction) have been associated with the initiation of GLEEVEC therapy. Speak to your doctor regarding appropriate supportive care or discontinuing GLEEVEC
  • Skin reactions, such as fluid-filled blisters, have been reported with the use of GLEEVEC
  • Clinical cases of hypothyroidism (reduction in thyroid hormones) have been reported in patients taking levothyroxine replacement during treatment with GLEEVEC. Your doctor should closely monitor your thyroid hormone levels
  • Long-term use may result in potential liver, kidney, and/or heart toxicities; immune system suppression may also result from long-term use
  • GLEEVEC can cause fetal harm when administered to a pregnant woman. Women should be aware of the potential harm to the fetus. Be sure to inform your doctor if you are or think you may be pregnant. You should not breast-feed while taking GLEEVEC
  • GI perforation (small holes or tears in the walls of the stomach or intestine), in some cases fatal, has been reported
  • Growth retardation has been reported in children taking GLEEVEC. The long-term effects of extended treatment with GLEEVEC on growth in children are unknown. Growth retardation may be monitored in children receiving treatment
  • Cases of tumor lysis syndrome (TLS), which refers to a metabolic and electrolyte disturbance caused by the breakdown of tumor cells, have been reported and can be life-threatening in some cases. The patients at risk of TLS are those that have a higher amount of tumor cells and whose tumors are fast-growing before beginning therapy. Your doctor should monitor you closely and take appropriate precautions
Important safety information

The following serious side effects have been reported in patients taking GLEEVEC:

  • Severe fluid retention, which can cause swelling around the eyes or swelling of the lower legs, lungs, and heart; fatal in rare cases
  • Increased pressure in the heart or brain; fatal in rare cases
  • Low levels of certain blood cells
  • Heart failure
  • Liver problems
  • Hemorrhage (abnormal bleeding)
  • Skin blistering
  • Low levels of thyroid hormone

Your doctor will check you closely for any side effects to stop more serious complications from occurring. Patients with heart disease or risk factors for heart failure should also be monitored carefully.

GLEEVEC is sometimes associated with stomach or intestinal irritation. GLEEVEC should be taken with food and a large glass of water to minimize this problem. There have been rare reports, including deaths, of stomach or intestinal perforation (a small hole or tear).

If you are experiencing any of the above-mentioned side effects, please be sure to speak with your doctor immediately.

Common side effects of GLEEVEC

Almost all patients with KIT+ GIST treated with GLEEVEC experience side effects at some time. In various studies, a range of 5%-17% of patients stopped taking GLEEVEC due to side effects. Some common side effects you may experience include:

  • Fluid retention
  • Muscle cramps or pain and bone pain
  • Abdominal pain
  • Vomiting
  • Diarrhea
  • Decreased hemoglobin
  • Nausea
  • Fatigue
  • Rash
  • Anorexia (loss of appetite)

If you are experiencing any of the above-mentioned side effects, please be sure to speak with your doctor immediately.

The severity of some side effects may be reduced with the help of other medicines and advice from your doctor, while others may require stopping GLEEVEC therapy or changing the dose. However, in some cases, GLEEVEC therapy may need to be discontinued.

Tell your doctor if you experience side effects during therapy with GLEEVEC, including fever, shortness of breath, blood in your stools, jaundice (yellowing of the skin and/or eyes), sudden weight gain, symptoms of heart failure, or if you have a history of heart disease or risk factors for heart disease.

After the approval of GLEEVEC, the following adverse events have been reported in patients treated with GLEEVEC: compression of the heart due to increased fluid, swelling of the brain, GI perforation (holes in the stomach or intestine), and sudden lung failure. These events, including some fatalities, may or may not have been drug related.

Take GLEEVEC exactly as prescribed. Do not change your dose or stop taking GLEEVEC unless you are told to do so by your doctor. If you miss a dose, take your dose as soon as possible, unless it is almost time for your next dose. In this case, your missed dose should not be taken. A double dose should not be taken to make up for any missed dose. You should take GLEEVEC with a meal and a large glass of water.

Do not take any other medications without talking to your doctor or pharmacist first, including over-the-counter medications such as Tylenol® (acetaminophen); herbal products (St. John's wort, Hypericum perforatum); Coumadin® (warfarin sodium); rifampin; erythromycin; metoprolol; ketoconazole; and Dilantin® (phenytoin). Taking these with GLEEVEC may affect how they work, or affect how GLEEVEC works.

You should also tell your doctor if you are taking or plan to take iron supplements. Patients should also avoid grapefruit juice and other foods that may affect how GLEEVEC works.

Tylenol (acetaminophen) is a registered trademark of McNeil Consumer & Specialty Pharmaceuticals, a division of McNeil PPC, Inc. Coumadin (warfarin sodium) is a registered trademark of Bristol Myers Squibb Company. Dilantin (phenytoin) is a registered trademark of Parke-Davis, a division of Pfizer Inc.

Click here for full Prescribing Information