Cancer starts when cells in the body begin to grow out of control. Cells in nearly any part of the body can become cancer, and can spread to other areas of the body. To learn more about how cancers start and spread, see What Is Cancer?

Gastrointestinal stromal tumors (GISTs) start in special cells in the wall of the gastrointestinal (GI) tract, also known as the digestive tract. To understand GISTs, it helps to know something about the structure and function of the GI tract.

How the gastrointestinal tract works

The gastrointestinal (GI) tract processes food for energy and rids the body of solid waste. After food is chewed and swallowed, it enters the esophagus, a tube that carries food through the neck and chest to the stomach. The esophagus joins the stomach just beneath the diaphragm (the thin band of muscle below the lungs).

The stomach is a sac-like organ that helps the digestive process by mixing the food with gastric juices. The food and gastric juices are then emptied into the small intestine. The small intestine, which is about 20 feet long, continues breaking down the food and absorbs most of the nutrients into the bloodstream.

The small intestine joins the large intestine, the first part of which is the colon, a muscular tube about 5 feet long. The colon absorbs water and mineral nutrients from the remaining food matter. The waste left after this process goes into the rectum as stool (feces), where it is stored until it passes out of the body through the anus.

Survival rates tell you what portion of people with the same type and stage of cancer are still alive a certain amount of time (usually 5 years) after they were diagnosed. They can’t tell you how long you will live, but they may help give you a better understanding about how likely it is that your treatment will be successful. Some people will want to know the survival rates for their cancer, and some people won’t. If you don’t want to know, you don’t have to.

What is a 5-year survival rate?

Statistics on the outlook for a certain type and stage of cancer are often given as 5-year survival rates. The 5-year survival rate is the percentage of people who live at least 5 years after being diagnosed with cancer. For example, a 5-year survival rate of 70% means that an estimated 70 out of 100 people who have that cancer are still alive 5 years after being diagnosed. Keep in mind, however, that many of these people live much longer than 5 years after diagnosis. 

Relative survival rates are a more accurate way to estimate the effect of cancer on survival. These rates compare people with cancer to people in the overall population. For example, if the 5-year relative survival rate for a specific stage of gastrointestinal stromal tumor (GIST) is 80%, it would mean that people who have that stage of cancer are, on average, about 80% as likely as people who don’t have that cancer to live for at least 5 years after being diagnosed. 

But remember, the 5-year relative survival rates are estimates – your outlook can vary based on a number of factors specific to you.

Cancer survival rates don’t tell the whole story

Survival rates are often based on previous outcomes of large numbers of people who had the disease, but they can’t predict what will happen in any particular person’s case. There are a number of limitations to remember:

• The numbers below are among the most current available. But to get 5-year survival rates, doctors have to look at people who were treated at least 5 years ago. As treatments are improving over time, people who are now being diagnosed with GISTs may have a better outlook than these statistics show.
• These statistics are based on the stage of the cancer when it was first diagnosed. They do not apply to cancers that later come back or spread, for example.
• The outlook for people with GISTs varies by the stage (extent) of the cancer – in general, the survival rates are higher for people with earlier stage cancers. But many other factors can affect a person’s outlook, such as age and overall health, where the cancer is in the body, and how well the cancer responds to treatment. The outlook for each person is specific to their circumstances.

Your doctor can tell you how these numbers may apply to you, as he or she is familiar with your particular situation.

Survival rates for GISTs

It is very hard to get accurate numbers on survival rates for GISTs. Part of this is because these tumors are not common. In the past, they were often classified as other types of cancers, which made the numbers available for study even smaller. Treatment has also changed dramatically in recent years now that newer, targeted therapy drugs are being used. The survival rates below are based on people treated many years ago, largely before these newer treatments were used, so people being treated for GISTs today are likely to have a better outlook.

Based on people diagnosed between 2003 and 2009 the overall relative 5-year survival rate of people diagnosed with a malignant GIST was estimated to be about 76%.

• If the tumor was still just in the organ where it started, the 5-year relative survival was 91%.
• If it had grown into nearby structures (or spread to nearby lymph nodes) when it was first diagnosed, the 5-year relative survival was around 74%.
• If it had spread to distant parts of the body when it was first diagnosed, the 5-year relative survival was 48%.

Remember, these survival rates are only estimates – they can’t predict what will happen to any individual person. We understand that these statistics can be confusing and may lead you to have more questions. Talk to your doctor to better understand your specific situation.

Important research on gastrointestinal stromal tumors (GISTs) is going on in many university hospitals, medical centers, and other institutions around the world. Scientists are learning more about what causes the disease and how best to treat it. There has been a great deal of progress in recent years, especially in treating GISTs. 

Targeted therapy drugs

As researchers have come to understand the genetic changes that cause these tumors, they’ve been able to use newer treatments to target these changes.

Doctors know targeted treatments like imatinib (Gleevec), sunitinib (Sutent), and regorafenib (Stivarga) often work, but they still aren’t sure exactly how and when to give them to make them most effective. For example, should these types of drugs be given after surgery to all patients, even those with very small tumors? How long should drug treatment be continued? These and other questions are now being studied in clinical trials.

Other drugs that target the KIT or PDGFRA proteins are also being studied for use against GISTs. Some of these, such as sorafenib (Nexavar), nilotinib (Tasigna), dasatinib (Sprycel), pazopanib (Votrient), and ponatinib (Iclusig), have helped some patients in early studies. Other, newer drugs that target these proteins, such as crenolanib and BLU-285, are also being studied.

Many other drugs that target different proteins involved in tumor cell growth are now being tested as well.

Immunotherapy

Immunotherapy is the use of medicines to boost the body’s own immune response to help fight the cancer.

For example, immune system cells normally have proteins that act as checkpoints to keep them from attacking other healthy cells in the body. Cancer cells sometimes take advantage of these checkpoints to avoid being attacked by the immune system.

Newer drugs called immune checkpoint inhibitors work by blocking these checkpoint proteins, which can boost the immune response against cancer cells in the body. These drugs have been shown to be helpful against many types of cancer in recent years. Some of these drugs, such as such as nivolumab (Opdivo) and ipilimumab (Yervoy), are now being studied for use against GISTs.

Other types of immunotherapy are now being explored as well.

People with GISTs who are no longer responding to standard treatments may want to ask their doctor about clinical trials of these newer types of treatments.

Gastrointestinal stromal tumors (GISTs) are often found because a person is having signs or symptoms. Others are found during exams or tests for other problems. But these symptoms or initial tests aren’t usually enough to know for sure if a person has a GIST or another type of gastrointestinal (GI) tumor. If a GI tumor is suspected, you will need further tests to confirm the diagnosis.

Medical history and physical exam

The doctor will ask you questions about your medical history, including your symptoms, possible risk factors, family history, and other medical conditions.

Your doctor will give you a thorough physical exam to get more information about the possible signs of a GI tumor, like a mass in the abdomen, or other health problems.

If there is a reason to suspect that you may have a GIST (or other type of GI tumor), the doctor will use imaging tests or endoscopy exams to help find out if it is cancer or something else. If it is a GIST, further tests will be done to help determine the stage (extent) of the cancer.

Imaging tests

Imaging tests use x-rays, magnetic fields, or radioactive substances to create pictures of the inside of the body. Imaging tests may be done for a number of reasons, including:

• To help find out if a suspicious area might be cancer
• To learn how far cancer has spread
• To help determine if treatment has been effective
• To look for signs that the cancer has come back

Most people who have or might have a GI tumor will have one or more of these tests.

Barium x-rays

Barium x-rays are not used as much today as in the past. In many cases they are being replaced by endoscopy – where the doctor actually looks into your colon or stomach with a narrow fiber-optic scope (see below).

For these types of x-rays, a chalky liquid containing barium is used to coat the inner lining of the esophagus, stomach, and intestines. This makes abnormal areas of the lining easier to see on x-ray. These tests are sometimes used to diagnose GI tumors, but they can miss some small intestine tumors.

You will probably have to fast starting the night before the test. If the colon is being examined, you might need to take laxatives and/or enemas to clean out the bowel the night before or the morning of the exam.

Barium swallow: This is often the first test done if someone is having a problem swallowing. For this test, you drink a liquid containing barium to coat the inner lining of the esophagus. A series of x-rays is then taken over the next few minutes.

Upper GI series: This test is similar to the barium swallow, except that x-rays are taken after the barium has time to coat the stomach and the first part of the small intestine. To look for problems in the rest of the small intestine, more x-rays can be taken over the next few hours as the barium passes through. This is called a small bowel follow through.

Enteroclysis: This test is another way to look at the small intestine. A thin tube is passed through your mouth or nose, down your esophagus, and through your stomach into the start of the small intestine. Barium is sent through the tube, along with a substance that creates more air in the intestines, causing them to expand. Then x-rays are taken of the intestines. This test can give better images of the small intestine than a small bowel follow through, but it is also more uncomfortable.

Barium enema: This test (also known as a lower GI series) is used to look at the inner surface of the large intestine. For this test, the barium solution is given through a small, flexible tube inserted in the anus while you are lying on the x-ray table. When the colon is about half full of barium, you roll over so the barium spreads throughout the colon. For a regular barium enema, x-rays are then taken. After the barium is put in the colon, air may be blown in to help push the barium toward the wall of the colon and better coat the inner surface. Then x-rays are taken. This is called an air-contrast barium enema or double-contrast barium enema.

Computed tomography (CT) scan

A CT scan uses x-rays to make detailed, cross-sectional images of your body. Unlike a regular x-ray, a CT scan creates detailed images of the soft tissues in the body.

CT scans can be useful in patients who have (or might have) GISTs to find the location and size of a tumor, as well as to see if it has spread into the abdomen or the liver.

In some cases, CT scans can also be used to guide a biopsy needle precisely into a suspected cancer. However, this can be risky if the tumor might be a GIST (because of the risk of bleeding and a possible increased risk of tumor spread), so these types of biopsies are usually done only if the result might affect the decision on treatment. (See the biopsy information below.)

Magnetic resonance imaging (MRI) scan

Like CT scans, MRI scans show detailed images of soft tissues in the body. But MRI scans use radio waves and strong magnets instead of x-rays. 

MRI scans can sometimes be useful in people with GISTs to help find the extent of the cancer in the abdomen, but usually CT scans are enough. MRIs can also be used to look for cancer that might havecome back (recurred) or spread (metastasized) to distant organs, particularly in the brain or spine.

Positron emission tomography (PET) scan

For a PET scan, you are injected with a slightly radioactive form of sugar, which collects mainly in cancer cells. A special camera is then used to create a picture of areas of radioactivity in the body. The picture is not detailed like a CT or MRI scan, but a PET scan can look for possible areas of cancer spread in all areas of the body at once.

Some newer machines can do both a PET and CT scan at the same time (PET/CT scan). This lets the doctor see areas that “light up” on the PET scan in more detail.

PET scans can be useful for looking at GISTs, especially if the results of CT or MRI scans aren’t clear. This test can also be used to look for possible areas of cancer spread to help determine if surgery is an option.

PET scans can also be helpful in finding out if a drug treatment is working, as they can often give an answer quicker than CT or MRI scans. The scan is usually obtained about 4 weeks after starting the medicine. If the drug is working, the tumor will stop taking up the radioactive sugar. If the tumor still takes up the sugar, your doctor may decide to change your drug treatment.

Endoscopy

For these tests, the doctor puts a flexible lighted tube (endoscope) with a tiny video camera on the end into the body to see the inner lining of the gastrointestinal (GI) tract. If abnormal areas are found, small pieces can be biopsied (removed) through the endoscope. The biopsy samples can be looked at under the microscope to find out if they contain cancer and if so, what kind of cancer it is.

GISTs are often below the surface (mucosa) of the inner lining of the GI tract. This can make them harder to see with endoscopy than more common GI tract tumors, which typically start in the mucosa. The doctor may see only a bulge under the normally smooth surface if a GIST is present. GISTs that are below the mucosa are also harder to biopsy through the endoscope. This is one reason that many GISTs are not diagnosed before surgery.

If the tumor breaks through the inner lining of the GI tract and is easy to see on endoscopy, there is a greater chance that the GIST is cancerous (malignant).

Upper endoscopy

For this procedure, an endoscope is passed through the mouth and down the throat to look at the inner lining of the esophagus, stomach, and first part of the small intestine. Biopsy samples may be taken from any abnormal areas.

Upper endoscopy can be done in a hospital, in an outpatient surgery center, or in a doctor’s office. You are typically given medicine through an intravenous (IV) line to make you sleepy before the exam. The exam itself usually takes 10 to 20 minutes, but it might take longer if a tumor is seen or if biopsy samples are taken. If medicine is given to make you sleepy, you will need someone you know to drive you home (not just a cab or rideshare service).

This test is also known as an EGD (short for esophagogastroduodenoscopy).

Colonoscopy (lower endoscopy)

For this test, a type of endoscope known as a colonoscope is inserted through the anus and up into the colon. This lets the doctor look at the inner lining of the rectum and colon and to take biopsy samples from any abnormal areas.

To get a good look at the inside of the colon, it must be cleaned out before the test. Your doctor will give you specific instructions. You might need to follow a special diet for a day or more before the test. You will also likely have to drink a large amount of a liquid laxative the evening before, which means you will spend a lot of time in the bathroom.

A colonoscopy can be done in a hospital, in an outpatient surgery center, or in a doctor’s office. You will be given intravenous (IV) medicine to make you feel relaxed and sleepy during the procedure. The exam typically takes 15 to 30 minutes, but it can take longer if a tumor is seen and/or a biopsy taken. Because medicine is given to make you sleepy, you will need someone you know to drive you home (not just a cab or rideshare service).

Capsule endoscopy

Unfortunately, neither upper endoscopy nor colonoscopy can reach all areas of the small intestine. Capsule endoscopy is one way to look at the small intestine.

This procedure does not actually use an endoscope. Instead, you swallow a capsule (about the size of a large vitamin pill) that contains a light source and a very small camera. Like any other pill, the capsule goes through the stomach and into the small intestine. As it travels through the intestine (usually over about 8 hours), it takes thousands of pictures. These images are transmitted electronically to a device worn around your waist. The pictures can then be downloaded onto a computer, where the doctor can view them as a video. The capsule passes out of the body during a normal bowel movement and is discarded.

This test requires no sedation – you can just continue normal daily activities as the capsule travels through the GI tract. This technique is fairly new, and the best ways to use it are still being studied. One disadvantage is that any abnormal areas seen can’t be biopsied during the test.

Double balloon enteroscopy (endoscopy)

This is another way to look at the small intestine. The small intestine is too long and has too many curves to be examined well with regular endoscopy. But this method gets around these problems by using a special endoscope that is made of 2 tubes, one inside the other.

You are given intravenous (IV) medicine to help you relax, or even general anesthesia (so that you are asleep). The endoscope is then inserted either through the mouth or the anus, depending on if there is a specific part of the small intestine to be examined.

Once inside the small intestine, the inner tube, which has the camera on the end, is advanced forward about a foot as the doctor looks at the lining of the intestine. Then a balloon on the end of the endoscope is inflated to anchor it. The outer tube is then pushed forward to near the end of the inner tube and is anchored in place with a second balloon. The first balloon is deflated and the endoscope is advanced again. This process is repeated over and over, letting the doctor see the intestine a foot at a time. The test can take hours to complete.

This test may be done along with capsule endoscopy. The main advantage of this test over capsule endoscopy is that the doctor can take a biopsy if something abnormal is seen. Like other forms of endoscopy, because you are given medicine to make you sleepy for the procedure, someone you know will need to drive you home (not just a cab or rideshare service).

Endoscopic ultrasound (EUS)

This is a type of imaging test that uses an endoscope. Ultrasound uses sound waves to take pictures of parts of the body. For most ultrasound exams, a wand-like probe (called a transducer) is placed on the skin. The probe gives off sound waves and detects the pattern of echoes that come back.

For an EUS, the ultrasound probe is on the tip of an endoscope. This allows the probe to be placed very close to (or on top of) a tumor in the wall of the GI tract. Like a regular ultrasound, the probe gives off sound waves and then detects the echoes that bounce back. A computer then translates the echoes into an image of the area being looked at.

EUS can be used to find the precise location of the GIST and to determine its size. It is useful in finding out how deeply a tumor has grown into the wall of the GI tract. The test can also help show if the tumor has spread to nearby lymph nodes or has started growing into other tissues nearby. In some cases it may be used to help guide a biopsy (see below).

You are typically given medicine before this procedure to make you sleepy. Because of this, you need to have someone you know drive you home (not just a cab or rideshare service).

Biopsy

Even if something abnormal is seen on an imaging test such as a barium x-ray or CT scan, these tests often cannot tell if the abnormal area is a GIST, some other type of tumor (benign or cancerous), or some other condition (like an infection). The only way to know what it is for sure is to remove cells from the area. This procedure is called a biopsy. The cells are then sent to a lab, where a doctor called a pathologist looks at them under a microscope and might do other tests on them.

Not everyone who has a tumor that might be a GIST needs a biopsy before treatment. If the doctor suspects a tumor may be a GIST, biopsies are usually done only if they will help determine treatment options. GISTs are often fragile tumors that tend to break apart and bleed easily. Any biopsy must be done very carefully, because of the risk that the biopsy might cause bleeding or possibly increase the risk of cancer spreading.

There are several ways to biopsy a GI tract tumor.

Endoscopic biopsy

Biopsy samples can be obtained through an endoscope. When a tumor is found, the doctor can insert biopsy forceps (pincers or tongs) through the tube to take a small sample of the tumor.

Even though the sample will be very small, doctors can often make an accurate diagnosis. However, with GISTs, sometimes the biopsy forceps can’t go deep enough to reach the tumor because it's underneath the inner lining of the stomach or intestine.

Bleeding from a GIST after a biopsy is rare, but it can be a serious problem. If this occurs, doctors can sometimes inject drugs into the tumor through an endoscope to constrict blood vessels and stop the bleeding.

Needle biopsy

Sometimes, a biopsy is done using a thin, hollow needle to remove pieces of the area. The most common way to do this is during an endoscopic ultrasound (described above). The doctor uses the ultrasound image to guide a needle on the tip of the endoscope into the tumor.

Less often, the doctor may place a needle through the skin and into the tumor while guided by an imaging test such as a CT scan.

Surgical biopsy

If a sample can’t be obtained from an endoscopic or needle biopsy, or if the result of a biopsy wouldn’t affect treatment options, your doctor might recommend waiting until surgery to remove the tumor to get a sample of it.

If the surgery is done through a large cut (incision) in the abdomen, it is called a laparotomy. Sometimes the tumor can be sampled (or small tumors can be removed) using a thin, lighted tube called a laparoscope, which lets the surgeon see inside the belly through a small incision. The surgeon can then sample (or remove) the tumor using long, thin surgical tools that are passed through other small incisions in the abdomen. This is known as laparoscopic or keyhole surgery.

Lab tests of biopsy samples

Once tumor samples are obtained, a pathologist looks at them under a microscope. The pathologist might be able to tell that a tumor is most likely a GIST just by looking at the cells. But sometimes further lab tests might be needed to be sure.

Immunohistochemistry: For this lab test, a part of the sample is treated with man-made antibodies that will attach only to a certain protein. The antibodies cause color changes if the protein is present, which can be seen under a microscope.

Some of the proteins most often tested for if GIST is suspected are KIT (also known as CD117) and DOG1.  Most GIST cells have these proteins, but cells of most other types of cancer do not, so tests for these proteins can help tell whether a GI tumor is a GIST or not. Other proteins, such as PDGFRA, might be tested for as well.

Molecular genetic testing: If the doctor is still unsure if the tumor is a GIST, testing might be done to look for mutations in the KIT or PDGFRA genes themselves, as most GIST cells have mutations in one or the other. Less often, tests might be done to look for changes in other genes, such as SDH.

Mitotic rate: If a GIST is diagnosed, the doctor will also look at the cancer cells in the sample to see how many of them are actively dividing into new cells. This is known as the mitotic rate. A low mitotic rate means the cancer cells are growing and dividing slowly, while a high rate means they are growing quickly. The mitotic rate is an important part of the stage of the cancer. (See Gastrointestinal Stromal Tumor Stages.)

Blood tests

Your doctor may order some blood tests if he or she thinks you may have a GIST.

There are no blood tests that can tell for sure if a person has a GIST. But blood tests can sometimes point to a possible tumor (or to its spread). For example, a complete blood count (CBC) can tell if you have a low red blood cell count (that is, if you are anemic). Some people with GIST may become anemic because of bleeding from the tumor. Abnormal liver function tests may mean that the GIST has spread to your liver.

Blood tests are also done to check your overall health before you have surgery or while you get other treatments such as targeted therapy.

After someone is diagnosed with cancer, doctors will try to figure out if it has spread, and if so, how far. This process is called staging. The stage of a cancer describes how much cancer is in the body. It helps determine how serious the cancer is and how best to treat it. Doctors also use a cancer's stage when talking about survival statistics.

The stages for gastrointestinal stromal tumors (GIST) range from stages I (1) through IV (4). As a rule, the lower the number, the less the cancer has spread. A higher number, such as stage IV, means cancer has spread more. And within a stage, an earlier letter means a lower stage. Although each person’s cancer experience is unique, cancers with similar stages tend to have a similar outlook and are often treated in much the same way.

How is the stage determined?

The staging system most often used for GIST tumors is the American Joint Committee on Cancer (AJCC) TNM system, which is based on 4 key pieces of information:

• The extent of the tumor (T): How large is the cancer?
• The spread to nearby lymph nodes (N): Has the cancer spread to nearby lymph nodes?
• The spread (metastasis) to distant sites (M): Has the cancer spread to distant organs such as the liver?
• The mitotic rate is a lab test measurement of how fast the cancer cells are growing and dividing. It is described as either low or high. A low mitotic rate predicts a better outcome.

Numbers or letters after T, N, and M provide more details about each of these factors. Higher numbers mean the cancer is more advanced. Once a person’s T, N, and M categories have been determined, this information is combined in a process called stage grouping to assign an overall stage. The stage grouping for GIST tumors depends on where the tumor starts:

• The stomach or the omentum (The omentum is an apron-like layer of fatty tissue that hangs over the organs in the abdomen.) OR
• The small intestine, esophagus, colon, rectum, or peritoneum. (The peritoneum is a layer of tissue that lines the organs and walls of the abdomen. Tumors in these locations are more likely to grow quickly compared to GISTs that start in the stomach or omentum.)

For more information see Cancer Staging.

The staging system in the table below uses the pathologic stage (also called the surgical stage). It is determined by examining tissue removed during an operation. Sometimes, if surgery is not possible right away or at all, the cancer will be given a clinical stage instead. This is based on the results of a physical exam, biopsy, and imaging tests. The clinical stage will be used to help plan treatment. Sometimes, though, the cancer has spread further than the clinical stage estimates, and might not predict the patient’s outlook as accurately as a pathologic stage.

The system described below is the most recent AJCC system, effective January 2018. Cancer staging can be complex, so ask your doctor to explain it to you in a way you understand.

GIST that starts in the stomach or the omentum

 

AJCC stage	Stage grouping	Mitotic rate	Stage description*
IA	T1 or T2 N0 M0	Low	The cancer is: 2 cm (4/5 of an inch) or less (T1) OR Larger than 2 cm but not more than 5 cm (2 inches) (T2). It has not spread to nearby lymph nodes (N0) or to distant sites (M0). The mitotic rate is low.
IB	T3 N0 M0	Low	The cancer is larger than 5 cm (2 inches) but not more than 10 cm (T3). It has not spread to nearby lymph nodes (N0) or to distant sites (M0). The mitotic rate is low.
II	T1 N0 M0	High	The cancer is 2 cm or smaller (T1). It has not spread to nearby lymph nodes (N0) or to distant sites (M0). The mitotic rate is high.
	OR
	T2 N0 M0	High	The cancer is larger than 2 cm but not more than 5 cm (T2). It has not spread to nearby lymph nodes (N0) or to distant sites (M0). The mitotic rate is high.
	OR
	T4 N0 M0	Low	The cancer is larger than 10 cm (T4). It has not spread to nearby lymph nodes (N0) or to distant sites (M0). The mitotic rate is low.
IIIA	T3 N0 M0	High	The cancer is larger than 5 cm (2 inches) but not more than 10 cm(T3). It has not spread to nearby lymph nodes (N0) or to distant sites (M0). The mitotic rate is high.
IIIB	T4 N0 M0	High	The cancer is larger than 10 cm (T4). It has not spread to nearby lymph nodes (N0) or to distant sites (M0). The mitotic rate is high.
IV	Any T N1 M0	Any rate	The cancer is any size (Any T) AND it has spread to nearby lymph nodes (N1). It has not spread to distant sites (M0). The cancer can have any mitotic rate.
	OR
	Any T Any N M1	Any rate	The cancer is any size (Any T) AND it might or might not have spread to nearby lymph nodes (Any N). It has spread to distant sites such as the liver(M1). The cancer can have any mitotic rate.

*The following additional categories are not listed in the table above:

• TX: Main tumor cannot be assessed due to lack of information.
• T0: No evidence of a primary tumor.
• NX: Regional lymph nodes cannot be assessed due to lack of information.

GIST of the small intestine, esophagus, colon, rectum, or peritoneum

 

AJCC stage	Stage grouping	Mitotic rate	Stage description*
I	T1 or T2 N0 M0	Low	The cancer is: 2 cm (4/5 of an inch) or less (T1) OR Larger than 2 cm but not more than 5 cm (2 inches) (T2). It has not spread to nearby lymph nodes (N0) or to distant sites (M0). The mitotic rate is low.
II	T3 N0 M0	Low	The cancer is larger than 5 cm (2 inches) but not more than 10 cm(T3). It has not spread to nearby lymph nodes (N0) or to distant sites (M0). The mitotic rate is low.
IIIA	T1 N0 M0	High	The cancer is 2 cm or smaller (T1). It has not spread to nearby lymph nodes (N0) or to distant sites (M0). The mitotic rate is high.
	OR
	T4 N0 M0	Low	The cancer is larger than 10 cm (T4). It has not spread to nearby lymph nodes (N0) or to distant sites (M0). The mitotic rate is low.
IIIB	T2 N0 M0	High	The cancer is larger than 2 cm but not more than 5 cm (T2). It has not spread to nearby lymph nodes (N0) or to distant sites (M0). The mitotic rate is high.
	OR
	T3 N0 M0	High	The cancer is larger than 5 cm (2 inches) but not more than 10cm (T3). It has not spread to nearby lymph nodes (N0) or to distant sites (M0). The mitotic rate is high.
	OR
	T4 N0 M0	High	The cancer is larger than 10 cm (T4). It has not spread to nearby lymph nodes (N0) or to distant sites (M0). The mitotic rate is high.
IV	Any T N1 M0	Any rate	The cancer is any size (Any T) AND it has spread to nearby lymph nodes (N1). It has not spread to distant sites (M0). The cancer can have any mitotic rate.
	OR
	Any T Any N M1	Any rate	The cancer is any size (Any T) AND it might or might not have spread to nearby lymph nodes (Any N). It has spread to distant sites such as the liver(M1). The cancer can have any mitotic rate.

*The following additional categories are not listed in the table above:

• TX: Main tumor cannot be assessed due to lack of information.
• T0: No evidence of a primary tumor.
• NX: Regional lymph nodes cannot be assessed due to lack of information.

Resectable versus unresectable tumors

The AJCC staging system gives a detailed summary of how far a GIST has spread. But for treatment purposes, doctors are often more concerned about whether the tumor can be removed (resected) completely with surgery.

Whether or not a tumor is resectable depends on its size and location, if it has spread to other parts of the body, and if a person is healthy enough for surgery:

• Tumors that can clearly be removed without causing major health problems are defined as resectable.
• Tumors that can’t be removed completely (because they have spread or for other reasons) are described as unresectable.
• In some cases, doctors may describe a tumor as marginally resectable or borderline resectable if it’s not clear if it can be removed completely.

If a tumor is considered unresectable or marginally resectable when it is first found, treatments such as targeted therapy may be used first to try to shrink the tumor enough to make it resectable.

Most gastrointestinal stromal tumors (GISTs) occur in the stomach or small intestine. These tumors often grow into the empty space inside the gastrointestinal (GI) tract, so they might not cause symptoms right away unless they are in a certain location or reach a certain size.

Small tumors might not cause any symptoms and may be found accidentally when the doctor is looking for some other problem. These small tumors often grow slowly.

Symptoms related to blood loss

GISTs tend to be fragile tumors that can bleed easily. In fact, they are often found because they cause bleeding into the GI tract. Signs and symptoms of this bleeding depend on how fast it occurs and where the tumor is located.

• Brisk bleeding into the esophagus or stomach can cause the person to throw up blood. When the blood is thrown up it may be partially digested, so it might look like coffee grounds. 
• Brisk bleeding into the stomach or small intestine can make bowel movements (stools) black and tarry.
• Brisk bleeding into the large intestine is likely to turn the stool red with visible blood.
• If the bleeding is slow, it often doesn’t cause the person to throw up blood or have a change in their stool. Over time, though, slow bleeding can lead to a low red blood cell count (anemia), and make a person feel tired and weak.

Bleeding from the GI tract can be very serious. If you have any of these signs or symptoms, see a doctor right away.

Other possible symptoms of GISTs

Other symptoms of GISTs can include:

• Abdominal (belly) pain
• A mass or swelling in the abdomen
• Nausea, vomiting
• Feeling full after eating only a small amount of food
• Loss of appetite
• Weight loss
• Problems swallowing (for tumors in the esophagus)

Sometimes the tumor grows large enough to block the passage of food through the stomach or intestine. This is called an obstruction, and it can cause severe abdominal pain and vomiting. Because GISTs are often fragile, they can sometimes rupture, which can lead to a hole (perforation) in the wall of the GI tract. This can also result in severe abdominal pain. Emergency surgery might be needed in these situations.

Although many of the possible symptoms of GISTs (like belly pain and nausea) can be caused by things other than cancer, if you have these symptoms, especially if they last for more than a few days, it's important to see a doctor.

Surgery is usually main treatment for gastrointestinal stromal tumors (GISTs) that haven’t spread. The goal of the surgery is to remove all of the cancer.

The type of surgery needed depends on the location and size of the tumor.

Surgery for small GISTs

If the tumor is small, it often can be removed along with a small area of normal tissue around it. This is done through a cut (incision) in the skin. Unlike many other cancers, GISTs almost never spread to the lymph nodes, so removing nearby lymph nodes is usually not needed.

For some small cancers, “keyhole” (laparoscopic) surgery is an option. Instead of making a large incision in the skin to remove the tumor, several small ones are used. The surgeon inserts a thin lighted tube with a tiny video camera on the end (a laparoscope) through one of them. This lets him or her see inside the belly. Long, thin surgical tools are then used through the other incisions to remove the tumor. Because the incisions are small, patients usually recover more quickly from this type of surgery than from traditional surgery that requires a longer incision.

Surgery for larger GISTs

If the tumor is large or growing into other organs, the surgeon might still be able to remove it entirely. To do this, parts of organs (such as a section of the intestines) might need to be removed. The surgeon might also remove tumors that have spread elsewhere in the abdomen, such as the liver.

Another option for tumors that are large or have grown into nearby areas might be to have the patient take the targeted drug imatinib (Gleevec) first. This can often shrink the tumor, which can make it easier to remove with surgery.

Choosing your surgeon

No matter what type of surgery is done, it's very important that it is done by a surgeon experienced in treating GISTs. GISTs are often delicate tumors, and surgeons must be careful not to open the outer lining that surrounds them (known as the capsule), because it might increase the risk of spreading the cancer. GISTs also tend to have a lot of blood vessels, so your surgeon has to be careful to control any bleeding from the tumor.

For more information about surgery, see Cancer Surgery.

Chemotherapy (chemo) is the use of drugs to treat cancer. Often, these drugs are injected into a vein (IV) or given by mouth. They enter the bloodstream and reach throughout the body, making this treatment potentially useful for cancers that have spread beyond the organ they started in.

Any drug used to treat cancer can be considered chemo – even the targeted therapy drugs like imatinib (Gleevec) that are now commonly used to treat gastrointestinal stromal tumors (GISTs). But the term chemo is usually used to describe certain drugs that work by attacking quickly growing cells anywhere in the body, which includes cancer cells.

Before targeted therapy drugs were found to be helpful in treating GISTs, traditional chemo drugs were often tried. But GISTs rarely shrank in response to these drugs, so traditional chemo is rarely used today. Patients considering chemo may want to consider taking part in a clinical trial.

Possible side effects

Chemo drugs can cause side effects. These depend on the specific drugs used, their doses, and how long treatment lasts. Common side effects of chemo include:

• Nausea and vomiting
• Loss of appetite
• Mouth sores
• Diarrhea
• Hair loss
• An increased chance of infection (from a shortage of white blood cells)
• Problems with bleeding or bruising (from a shortage of blood platelets)
• Fatigue or shortness of breath (from low red blood cell counts)

Along with the risks above, some chemo drugs can cause other side effects.

Ask your health care team about what side effects you can expect based on the specific drugs you will get. Be sure to tell your doctor or nurse if you do have side effects, as there are often ways to help with them. For example, drugs can be given to help prevent or reduce nausea and vomiting.

To learn more, see Chemotherapy.

Gastrointestinal stromal tumors (GISTs) are not common, and the exact number of people diagnosed with these tumors each year is not known. Until the late 1990s, not much was known about these tumors (and doctors didn’t have good ways of identifying them with lab tests), so many of them ended up being classified as other kinds of GI cancers.

Current estimates for the total number of GIST cases each year in the United States range from about 4,000 to about 6,000.

These tumors can start anywhere in the GI tract, but they occur most often in the stomach (about 60%) or the small intestine (about 35%). Most of the rest are found in the esophagus, colon, and rectum. A small number develop in the abdomen outside the GI tract.

GISTs are most commonly found in people in their 60s. These tumors are rare in people younger than 40, but they can occur in people at any age.

Survival statistics for GIST are discussed in Survival Rates for Gastrointestinal Stromal Tumors.

A risk factor is anything that affects a person’s chance of getting a disease like cancer. Different cancers have different risk factors. Some risk factors, like smoking, can be changed. Others, like a person’s age or family history, can’t be changed.

But having a risk factor, or even several, does not mean that a person will get the disease. And many people who get the disease may have few or no known risk factors.

Currently, there are very few known risk factors for gastrointestinal stromal tumors (GISTs).

Being older

These tumors can occur in people of any age, but they are rare in people younger than 40 and are most common in people aged 50 to 80.

Genetic syndromes

Most GISTs are sporadic (not inherited) and have no clear cause. In rare cases, though, GISTs have been found in several members of the same family. These family members have inherited a gene mutation (change) that can lead to GISTs.

Primary familial GIST syndrome: This is a rare, inherited condition that leads to an increased risk of developing GISTs. People with this condition tend to develop GISTs at a younger age than when they usually occur. They are also more likely to have more than one GIST.

Most often, this syndrome is caused by an abnormal KIT gene passed from parent to child. This is the same gene that is mutated (changed) in most sporadic GISTs. (See What Causes Gastrointestinal Stromal Tumors?) People who inherited this abnormal gene from a parent have it in all their cells, while people with sporadic GISTs only have it in the cancer cells.

Less often, a change in the PDGFRA gene causes this genetic syndrome. Defects in the PDGFRA gene are found in about 5% to 10% of sporadic GISTs.

Sometimes people with familial GIST syndrome also have skin spots like those seen in patients with neurofibromatosis (discussed below). Before tests for the KIT and PDGFRA genes became available, some of these people were mistakenly thought to have neurofibromatosis.

Neurofibromatosis type 1 (von Recklinghausen disease): This disease is caused by a defect in the NF1 gene. This gene change may be inherited from a parent, but in some cases it occurs before birth, without being inherited.

People affected by this syndrome often have many benign (non-cancerous) tumors that form in nerves, called neurofibromas, starting at an early age. These tumors form under the skin and in other parts of the body. These people also typically have tan or brown spots on the skin (called café au lait spots).

People with this condition have a higher risk of GISTs, as well as some other types of cancer.

Carney-Stratakis syndrome: People with this rare inherited condition have an increased risk of GISTs (most often in the stomach), as well as nerve tumors called paragangliomas. GISTs often develop when these people are in their teens or 20s. They are also more likely to have more than one GIST.

This syndrome is caused by a change in one of the succinate dehydrogenase (SDH) genes, which is passed from parent to child.

We do not know exactly what causes most gastrointestinal stromal tumors (GISTs). But in recent years, scientists have made great progress in learning how certain changes in DNA can cause normal cells to become cancerous. DNA is the chemical in each of our cells that makes up our genes, which control how our cells function. We usually look like our parents because they are the source of our DNA. But DNA affects more than just how we look.

Some genes control when cells grow and divide into new cells:

• Certain genes that help cells grow and divide are called oncogenes. 
• Genes that help slow down cell division or cause cells to die at the right time are called tumor suppressor genes.

Cancers can be caused by DNA changes that turn on oncogenes or turn off tumor suppressor genes.

Gene changes that can lead to GISTs

The gene changes that lead to most GISTs are now understood, but it’s still not clear why these changes occur. There are no known lifestyle-related or environmental causes of GIST. Some might have causes that haven’t been found yet, but many of these changes may just be random events that sometimes happen inside cells that unfortunately lead to cancer.

A few families have gastrointestinal stromal tumors (GISTs) caused by a gene mutation passed down from parent to child. (See Gastrointestinal Stromal Tumor Risk Factors.) But most gene mutations related to GISTs are not inherited. These changes occur for no apparent reason, and are called acquired or sporadic.

Changes in KIT or PDGFRA genes

The cancer cells of most patients with GISTs have a change in an oncogene called KIT. This gene directs cells to make a protein called KIT, which causes the cells to grow and divide. Usually the KIT gene is inactive in interstitial cells of Cajal (ICCs), which are the cells from which GISTs develop. The KIT gene is only active if there is a need for more ICCs. But in most GISTs the KIT gene is mutated and is always active, so the cells are always growing and dividing.

In about 5% to 10% of GISTs, the cancer cells have mutation in a different gene called PDGFRA, which causes the cells to make too much of a different protein (also called PDGFRA). This has the same effect on the cells as does KIT.

Most GISTs have changes in either the KIT or the PDGFRA gene, but not both.

Other gene changes

A small number of GISTs, especially those in children, do not have changes in either of these genes. Many of these tumors have changes in one of the SDH genes. Researchers are still trying to determine what other gene changes can lead to these cancers.

As doctors have learned more about the gene and protein changes in GIST cells, they have been able to use this information to help diagnose and treat these cancers. (See Targeted Therapy for Gastrointestinal Stromal Tumors.)

Screening is testing for diseases like cancer in people who do not have any symptoms. Screening tests can find some types of cancer early, when treatment is most likely to be effective. But at this time, no effective screening tests have been found for gastrointestinal stromal tumors (GISTs), so routine testing of people without any symptoms is not recommended.

Many GISTs are found because of symptoms a person is having, but some GISTs may be found early by chance. Sometimes they are seen on an exam for another problem, like during colonoscopy to look for colon cancer. Rarely, a GIST may be seen when an imaging test, like a computed tomography (CT) scan or barium study, is done for another reason. Some GISTs may also be found incidentally (unexpectedly) during abdominal surgery for another problem.

It’s important to have honest, open discussions with your cancer care team. Ask any question, no matter how small it might seem. Some questions to consider:

When you’re told you have a gastrointestinal stromal tumor (GIST)

• How sure are you that my tumor is a GIST?
• Where is my tumor located? How big is it?
• How likely is this tumor to grow or spread quickly?
• Has my tumor spread beyond where it started?
• What is the stage of my cancer, and what does that mean?
• Will I need any other tests before we can decide on treatment?
• Will I need to see any other doctors?
• If I'm concerned about costs and insurance coverage for my diagnosis and treatment, who can help me?

When deciding on a treatment plan

• How much experience do you have treating these tumors?
• What are my treatment options?
• What do you recommend? Why?
• What’s the goal of the treatment?
• Should I get a second opinion? How do I do that? Can you recommend someone?
• What are the chances my cancer can be cured?
• How quickly do we need to decide on treatment?
• What should I do to be ready for treatment?
• How long will treatment last? What will it be like? Where will it be done?
• What risks or side effects I should expect? How long are they likely to last?
• Will treatment affect my daily activities?
• How likely is it that the cancer will come back after treatment? Is there anything I can do to lower this risk?

During treatment

• How will we know if the treatment is working?
• Is there anything I can do to help manage side effects?
• What symptoms or side effects should I tell you about right away?
• How can I reach you on nights, holidays, or weekends?
• Do I need to change what I eat during treatment?
• Are there any limits on what I can do? 
• Should I exercise? What should I do, and how often?
• Can you suggest a mental health professional I can see if I start to feel overwhelmed, depressed, or distressed?

After treatment

• Are there any limits on what I can do?
• What symptoms should I watch for?
• What kind of exercise should I do now?
• What type of follow-up will I need after treatment?
• How often will I need to have follow-up exams and tests?
• How will we know if the cancer has come back? What should I watch for?
• What will my options be if the cancer comes back?

Along with these sample questions, be sure to write down some of your own. For instance, you might want more information about second opinions or about clinical trials for which you may qualify.

Keep in mind that doctors aren’t the only ones who can give you information. Other health care professionals, such as nurses and social workers, can answer some of your questions. To find more about speaking with your health care team, see The Doctor-Patient Relationship.

For some people with a gastrointestinal stromal tumor (GIST), treatment can remove or destroy the cancer. Completing treatment can be both stressful and exciting. You may be relieved to finish treatment, but find it hard not to worry about cancer coming back. (When cancer comes back after treatment, it’s called a recurrence.) This is a very common concern if you've had cancer.

For some people, the GIST may never go away completely. These people may get regular treatments with targeted therapy drugs or other therapies to help keep the cancer in check and to help releive symptoms. Learning to live with cancer that doesn't go away can be difficult and very stressful.

Follow-up care

Whether you have completed treatment or are still being treated, your doctors will still want to watch you closely. It's very important to go to all follow-up appointments, as GISTs can sometimes come back after treatment.

Some treatment side effects might last a long time or might not even show up until years after you have finished treatment. Your doctor visits are a good time to ask questions and talk about any changes or problems you notice or concerns you have.

Exams and tests

During your follow-up visits, your doctors will ask about symptoms, examine you, and may order imaging tests like CT scans. Because of the risk that a GIST may come back after treatment, most doctors recommend follow-up visits and imaging tests every 3 to 6 months for at least several years after treatment. If you're still being treated with imatinib (or any other targeted drug), you will also need to have CT scans to make sure that the drug is still working.

Ask your doctor for a survivorship care plan

Talk with your doctor about developing a survivorship care plan for you. This plan might include: 

• A suggested schedule for follow-up exams and tests
• A schedule for other tests you might need in the future, such as early detection (screening) tests for other types of cancer, or tests to look for long-term health effects from your cancer or its treatment
• A list of possible late- or long-term side effects from your treatment, including what to watch for and when you should contact your doctor
• Diet and physical activity suggestions

Keeping health insurance and copies of your medical records

Even after treatment, it’s very important to keep health insurance. Tests and doctor visits cost a lot, and even though no one wants to think of their cancer coming back, this could happen.

At some point after your treatment, you might find yourself seeing a new doctor who doesn’t know about your medical history. It’s important to keep copies of your medical records to give your new doctor the details of your diagnosis and treatment. Learn more in Keeping Copies of Important Medical Records.

Can I lower my risk of the tumor progressing or coming back?

If you have (or have had) a GIST, you probably want to know if there are things you can do that might lower your risk of the tumor growing or coming back, such as exercising, eating a certain type of diet, or taking nutritional supplements. Unfortunately, it’s not yet clear if there are things you can do that will help.

Adopting healthy behaviors such as not smoking, eating well, getting regular physical activity, and staying at a healthy weight might help, but no one knows for sure. However, we do know that these types of changes can have positive effects on your health that can extend beyond your risk of GIST or other cancers.

About dietary supplements

So far, no dietary supplements (including vitamins, minerals, and herbal products) have been shown to clearly help lower the risk of cancers such as GIST progressing or coming back. This doesn’t mean that no supplements will help, but it’s important to know that none have been proven to do so.

Dietary supplements are not regulated like medicines in the United States – they do not have to be proven effective (or even safe) before being sold, although there are limits on what they’re allowed to claim they can do. If you’re thinking about taking any type of nutritional supplement, talk to your health care team. They can help you decide which ones you can use safely while avoiding those that might be harmful.

If the GIST comes back

If cancer does recur, your treatment options will depend on the location of the cancer, and what treatments you’ve had before, and your current health and preferences. For more information on how recurrent cancer is treated, see Treatment Choices for Gastrointestinal Stromal Tumor Based on Tumor Spread. For more general information on dealing with a recurrence, see Coping With Cancer Recurrence.

Getting emotional support

Some amount of feeling depressed, anxious, or worried is normal when cancer is a part of your life. Some people are affected more than others. But everyone can benefit from help and support from other people, whether friends and family, religious groups, support groups, professional counselors, or others. Learn more in Coping With Cancer.