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Testing for GIST: Tools for Diagnosis

What tests are done for KIT+ GIST?

The following tests may be used to determine the cause of symptoms: computed tomography (CT) scan; positron emission tomography (PET) scan; magnetic resonance imaging (MRI); and endoscopy. Have a question about testing? Look to Testing FAQs.

Why CT scans

CT scans are the most valuable imaging tool for GISTs. They are used for both diagnosis and to assess the efficacy of treatment. Read more.

Why PET scans

PET scans are used to assess the chemical and physical changes occurring within tumors. They are not a substitute for CT scans, but may be performed in conjunction with them after diagnosis. Read more.

Why MRIs

MRIs are used to find the extent of cancer in the abdomen, although usually CT scans are adequate. MRIs are also helpful in assessing recurrence (or metastases) to other organs, particularly the brain or spine. Read more.

Why endoscopy

Endoscopy is occasionally used but because KIT+ GIST tumors often lie below the lining of the GI tract, it is much harder to recognize a GIST compared with other cancers. Read more.

Why endoscopic ultrasound (EUS)

Endoscopic ultrasound (EUS) is used to find the exact location of the tumor and determine its size. Read more.

Scanxiety

 

What is scanxiety?

Scanxiety is the stress that cancer patients experience before, during, and while waiting for the results of periodic tests that their healthcare provider may order to see whether their cancer has grown or not.

What can I do to overcome scanxiety?

Talk to your doctor about any emotional stress. Don't let fear prevent you from seeking necessary tests or treatment. Your doctor may prescribe an anti-anxiety or sleeping medication for you.

Your doctor may recommend psychotherapy to help you with your concerns.

*Eligible patients are those being treated with GLEEVEC for KIT+ GIST and who reside in the United States 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.

Click here for full Prescribing Information, which includes a more complete discussion of the risks associated with GLEEVEC.

 

 

Side effects

Almost all people taking GLEEVEC experience side effects. Be sure to talk to your oncologist and/or healthcare professional about any GLEEVEC side effects you are experiencing.

Some serious side effects include:

  • Severe fluid retention (holding water) and swelling
  • Cytopenias (reduction of certain elements in blood circulation)
  • Severe congestive heart failure (impaired ability of the heart to pump blood) and left ventricular dysfunction (impaired functioning of the left side of the heart)
  • Severe liver problems (hepatotoxicity)
  • Hemorrhage (abnormal bleeding)
  • GI perforation (holes in the stomach or intestine)
  • Hypereosinophilic heart disease (a condition with increased eosinophils, which are a type of white blood cell)
  • Skin reactions (such as fluid-filled blisters)
  • Hypothyroidism (reduction in thyroid hormones)
  • Potential toxicities from long-term use, specifically liver, kidney, and/or heart toxicities
  • Potential harm to an unborn child
  • Growth retardation (slowing of growth)
  • Tumor lysis syndrome (electrolyte disturbance)
  • Dizziness, blurred vision, and somnolence

Some common side effects are:

  • Fluid retention (holding water)
  • Muscle cramps or pain and bone pain
  • Abdominal pain
  • Vomiting
  • Diarrhea
  • Decreased hemoglobin (decrease in blood cells which carry oxygen)
  • Nausea
  • Fatigue
  • Skin reactions, some severe
  • 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 oncologist.

GLEEVEC can cause harm to the unborn child 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 breastfeed while taking GLEEVEC.

Side effects*

Description

How your doctor may manage it

Severe fluid retention (holding water) and swelling

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 checkups 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)
  • Decrease dose of GLEEVEC

Severe congestive heart failure (impaired ability of the heart to pump blood) and left ventricular dysfunction (impaired functioning of the left side of the heart)

Shortness of breath; inability to get a deep breath, especially when lying down; inability to exercise or even walk without fatigue and shortness of breath; fluid backup in the lungs, fluid retention, and swelling
  • Monitor you carefully and treat symptoms

Hepatotoxicity (severe liver problems)

Skin and eyes that appear yellowish (jaundice), abdominal pain and swelling; itchy skin; dark urine; pale stool; bloody or tar-colored stool; extreme tiredness; nausea
  • Test your liver function before starting GLEEVEC and monitor monthly as needed
  • May interrupt therapy and resume at a lower dose
  • For severe cases, a 25% decrease in the recommended dose of GLEEVEC

Hemorrhage (abnormal bleeding)

Bleeding may come from any site along the gastrointestinal (GI) tract, including the esophagus, stomach, small intestine, large intestine, bowels, rectum, and anus. Signs of GI bleeding include: dark, tarry stools; large amounts of blood passed from the rectum; small amounts of blood in the toilet bowl, on toilet paper, or in stool; vomiting blood
  • Monitor GI symptoms when starting GLEEVEC

GI perforation (tears in the stomach or intestinal lining)

Severe abdominal pain, chills, fever, nausea, or vomiting
  • Recommend GLEEVEC be taken with food and a large glass of water to minimize possible GI irritation

Skin reactions, some severe (including erythema multiforme and Stevens-Johnson syndrome)

Scaly skin; red itchy bumps on skin. Flu-like symptoms followed by painful red or purplish rash
  • Recommend an over-the-counter (OTC) antihistamine
  • Prescribe a corticosteroid or stronger antihistamine
  • Painkillers, sedatives, antibiotics for secondary infections
  • May interrupt therapy and resume at a lower dose

Hypothyroidism (reduction in thyroid hormones)

Sensitivity to cold; constipation; fatigue; heavier menstrual periods; joint or muscle pain; paleness or dry skin; brittle hair or fingernails; weakness; unintentional weight gain
  • Closely monitor thyroid stimulating hormone (TSH) levels

Tumor lysis syndrome (electrolyte disturbance)

High levels of uric acid; dehydration; nausea; diarrhea; anorexia; muscle weakness and cramps; paresthesia (tingling of skin); seizures; irregular heartbeat

Prior to beginning GLEEVEC treatment:

  • Closely monitor tumor growth rate
  • Recommend correction of significant dehydration
  • Treat for high uric acid levels

Dizziness, blurred vision, and somnolence

Motor vehicle accidents involving patients receiving GLEEVEC have been reported. You may experience undesirable effects such as dizziness, blurred vision, or drowsiness (somnolence) during treatment with GLEEVEC
  • Recommend you use caution when driving a car or operating machinery

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

*For a complete description of safety information, please see accompanying full Prescribing Information.

Important information about GLEEVEC® (imatinib mesylate)

GLEEVEC® (imatinib mesylate) 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

SAFETY: Important product information (Please see accompanying full Prescribing Information)

Who should NOT take GLEEVEC
  • Women who are or could be pregnant. Harm to the unborn child can occur when administered to pregnant women. Therefore, women should not become pregnant and should be advised of the potential risk to the unborn child if GLEEVEC is used during pregnancy
  • Women who are breastfeeding because of the potential for serious adverse reactions in nursing infants

Sexually active females should use highly effective 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 (holding water). 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 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. Treatment can be resumed as appropriate depending on the initial severity of the event
  • Cytopenias (reduction or lack of certain cell elements in blood circulation) have occurred. Your doctor will test your blood 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, if the cytopenia is severe, your doctor may discontinue treatment
  • Severe congestive heart failure (impaired ability of the heart to pump blood) and left ventricular dysfunction (impaired functioning of the left side of the heart) have been reported, particularly in patients with other health issues and risk factors. Patients with heart disease or risk factors for heart disease or history of renal failure 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; therefore, GI symptoms should be monitored at the start of treatment
  • GLEEVEC is sometimes associated with GI irritation. GI perforation (small holes or tears in the wall of the stomach or intestine), in some cases fatal, has been reported
  • 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 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 harm to the unborn child 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 breastfeed while taking GLEEVEC
  • Growth retardation (slowing of growth) 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 an 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 who have a higher number of tumor cells and whose tumors are fast growing before beginning therapy. Your doctor should monitor you closely and take appropriate precautions. Correction of clinically significant dehydration and treatment of high uric acid levels are recommended prior to initiation of GLEEVEC
  • Motor vehicle accidents involving patients receiving GLEEVEC have been reported. Patients should be advised that they may experience undesirable effects such as dizziness, blurred vision, or drowsiness during treatment with GLEEVEC. Caution should be recommended when driving a car or operating machinery
Additional important safety information

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

  • Severe fluid retention (holding water), 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 that you may experience include:

  • Fluid retention (holding water)
  • Muscle cramps or pain or bone pain
  • Abdominal pain
  • Vomiting
  • Diarrhea
  • Decreased hemoglobin (decrease in blood cells which carry oxygen)
  • 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 have a history of heart disease or risk factors for heart disease or if you experience side effects, including fever, shortness of breath, blood in your stools, jaundice (yellowing of the skin and/or eyes), sudden weight gain, or symptoms of heart failure during therapy with GLEEVEC. 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); or prescription medications including 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.

Please see accompanying full Prescribing Information, which includes a more complete discussion of the risks associated with
GLEEVEC.

You are encouraged to report negative side effects of prescription drugs to the FDA.

Visit www.fda.gov/medwatch, or call 1-800-FDA-1088.