Biopsy
A biopsy is the removal of a small amount of tissue for examination under a microscope. Other tests can suggest that cancer is present, but only a biopsy can make a definite diagnosis. The sample removed during the biopsy is analyzed by a pathologist. A pathologist is a doctor who specializes in interpreting laboratory tests and evaluating cells, tissues, and organs to diagnose disease. Diagnosing Stomach Cancer.
Imaging Tests
Imaging tests use x-rays, magnetic fields, sound waves, or radioactive substances to create pictures of the inside of your body. Imaging tests may be done for a number of reasons, including:
- To help find out whether a suspicious area might be cancerous
- To learn how far cancer may have spread
- To help determine if treatment has been effective
This test can help find out if the cancer has spread to the lungs. It might also determine if there are any serious lung or heart diseases present. This test is not needed if a CT scan of the chest has been done.
• Barium Meal
A barium meal is a type of X-ray investigation. This test is not commonly used now for stomach cancer. You can have it as an outpatient. You won't be able to eat or drink anything for 6 hours before you have your test. When you get to the X-ray department, the nurse will ask you to change into a hospital gown. When the test is about to begin, you will have:
- An injection to relax the muscles of your digestive system
- A white liquid to drink
The whole test takes about an hour. You should be able to go home straight after the test. You can eat and drink normally as soon as the test is over. But some people feel sick for a while afterwards. You may find the barium makes you constipated. Your bowel motions will be white for a day or so as your body gets rid of the barium.
• Computed Tomography (CT or CAT) Scan
A CT scan creates a three-dimensional picture of the inside of the body with an x-ray machine. A computer then combines these images into a detailed, cross-sectional view that shows any abnormalities or tumors. A CT scan can also be used to measure the tumor’s size. Sometimes, a special dye called a contrast medium is given before the scan to provide better detail on the image. This dye is usually given as a solution to swallow.
CT-guided needle biopsy: CT scans can also be used to guide a biopsy needle into a suspected area of cancer spread. The patient remains on the CT scanning table while a doctor moves a biopsy needle through the skin toward the mass. CT scans are repeated until the needle is within the mass. A fine-needle biopsy sample (tiny fragment of tissue) or a core-needle biopsy sample (a thin cylinder of tissue) is then removed and looked at under a microscope.
• Magnetic Resonance Imaging (MRI) Scan
An MRI uses magnetic fields, not x-rays, to produce detailed images of the body. MRI can also be used to measure the tumor’s size. A special dye called a contrast medium is given before the scan to create a clearer picture. This dye is usually injected into a patient’s vein.
• Positron Emission Tomography (PET) Scan
In this test, radioactive substance (usually a type of sugar related to glucose, known as FDG) is injected into a vein. (The amount of radioactivity used is very low and will pass out of the body over the next day or so.) Because cancer cells are growing faster than normal cells, they use sugar much faster, so they take up the radioactive material. After about an hour, you are moved onto a table in the PET scanner. You lie on the table for about 30 minutes while a special camera creates a picture of areas of radioactivity in the body.
PET is sometimes useful if your doctor thinks the cancer might have spread but doesn’t know where. The picture is not finely detailed like a CT or MRI scan, but it provides helpful information about the whole body. Although PET scans can be useful for finding areas of cancer spread, they aren’t always helpful in certain kinds of stomach cancer because these types don’t take up glucose very much.
Some machines can do both a PET and CT scan at the same time (PET/CT scan). This lets the doctor compare areas of higher radioactivity on the PET with the more detailed appearance of that area on the CT. PET/CT may be more helpful than PET alone for stomach cancer. This can help show if the cancer has spread beyond the stomach to other parts of the body, in which case surgery might not be a good treatment.
• Upper Gastrointestinal (GI) Series
This is an x-ray test to look at the inner lining of the esophagus, stomach, and first part of the small intestine. This test is used less often than endoscopy to look for stomach cancer or other stomach problems, as it may miss some abnormal areas and does not allow the doctor to take biopsy samples. But it is less invasive than endoscopy, and it might be useful in some situations. Diagnosing Stomach Cancer
For this test, the patient drinks a white chalky solution containing a substance called barium. The barium coats the lining of the esophagus, stomach, and small intestine. Several x-ray pictures are then taken. Because x-rays can’t pass through the coating of barium, this will outline any abnormalities of the lining of these organs. A double-contrast technique may be used to look for early stomach cancer. With this technique, after the barium solution is swallowed, a thin tube is passed into the stomach and air is pumped in. This makes the barium coating very thin, so even small abnormalities will show up.
Medical History and Physical Exam
When taking your medical history, the doctor will ask you questions about your symptoms (eating problems, pain, bloating, etc.) and possible risk factors to see if they might suggest stomach cancer or another cause. The physical exam gives your doctor information about your general health, possible signs of stomach cancer, and other health problems. In particular, the doctor will feel your abdomen for any abnormal changes.
If your doctor thinks you might have stomach cancer or another type of stomach problem, he or she will refer you to a gastroenterologist, a doctor who specializes in diseases of the digestive tract, who will examine you and do further testing.
Upper Endoscopy
Upper endoscopy (also called esophagogastroduodenoscopy or EGD) is the main test used to find stomach cancer. It may be used when someone has certain risk factors or when signs and symptoms suggest this disease may be present. During this test, the doctor passes an endoscope, which is a thin, flexible, lighted tube with a small video camera on the end, down your throat. This lets the doctor see the lining of your esophagus, stomach, and first part of the small intestine. If abnormal areas are seen, biopsies (tissue samples) can be taken using instruments passed through the endoscope. The tissue samples are sent to a lab, where they are looked at under a microscope to see if cancer is present.
When seen through an endoscope, stomach cancer can look like an ulcer, a mushroom-shaped or protruding mass, or diffuse, flat, thickened areas of mucosa known as linitis plastica. Unfortunately, the stomach cancers in hereditary diffuse gastric cancer syndrome often cannot be seen during endoscopy.
Endoscopy can also be used as part of a special imaging test known as endoscopic ultrasound, which is described below. This test is usually done after you are given medication to make you sleepy (sedation). If sedation is used, you will need someone to take you home (not just a cab).
• Endoscopic Ultrasound
This test is similar to an endoscopy, but the gastroscope has a small ultrasound probe on the end that produces a detailed image of the stomach wall. An ultrasound uses sound waves to create a picture of the internal organs. The ultrasound image helps doctors determine how far the cancer has spread into the stomach and nearby lymph nodes, tissue, and organs, such as the liver.
Other Tests
• Lab Tests
When looking for signs of stomach cancer, a doctor may order a blood test called a complete blood count (CBC) to look for anemia (which could be caused by the cancer bleeding into the stomach). A fecal occult blood test may be done to look for blood in stool (feces) that isn’t visible to the naked eye.
The doctor might recommend other tests if cancer is found, especially if you are going to have surgery. For instance, blood tests will be done to make sure your liver and kidney functions are normal and that your blood clots normally. If surgery is planned or you are going to get medicines that can affect the heart, you may also have an electrocardiogram (EKG) and echocardiogram (an ultrasound of the heart) to make sure your heart is functioning well.
• Laparoscopy
If this procedure is done, it is usually only after stomach cancer has already been found. Although CT or MRI scans can create detailed pictures of the inside of the body, they can miss some tumors, especially if they are very small. Doctors might do a laparoscopy before any other surgery to help confirm a stomach cancer is still only in the stomach and can be removed completely with surgery. It may also be done before chemotherapy and/or radiation if these are planned before surgery.
This procedure is done in an operating room with the patient under general anesthesia (in a deep sleep). A laparoscope (a thin, flexible tube) is inserted through a small surgical opening in the patient’s side. The laparoscope has a small video camera on its end, which sends pictures of the inside of the abdomen to a TV screen. Doctors can look closely at the surfaces of the organs and nearby lymph nodes, or even take small samples of tissue. If it doesn’t look like the cancer has spread, sometimes the doctor will “wash” the abdomen with saline (salt water). The fluid (called peritoneal washings) is then removed and checked to see if it contains cancer cells. If it does, the cancer has spread, even if the spread couldn’t be seen.
After The Tests
Your specialist will give you an appointment to come back to the hospital when your test results have come through. The results may take a little time and you are bound to feel anxious. It may help if you ask your specialist how long the results are likely to take so that you have some idea of how long you will have to wait.
While you are waiting for results it may help to talk to a close friend or relative about how you are feeling. Or you may want to contact a cancer support group to talk to someone who has been through a similar experience. Diagnosing Stomach Cancer