Diagnostic tests for stomach cancer

Checking for stomach cancer usually involves a number of tests. The diagnostic tests you have for stomach cancer will depend on your specific situation and may include:

  • an endoscopy and biopsy to find stomach cancer
  • further tests to see if the cancer has spread (metastasised).

Waiting for the test results can be a stressful time. It may help to talk to a friend or family member, or a health professional. You can also call Cancer Council 13 11 20

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Endoscopy and biopsy

An endoscopy (also called a gastroscopy, oesophagoscopy or upper endoscopy) allows your doctor to see inside your digestive tract to examine the lining. This test is usually performed as day surgery.

You will be asked not to eat or drink (fast) for about 4–6 hours before an endoscopy. Before the procedure, your throat will be sprayed with a local anaesthetic and you will probably be given a sedative to help you relax. A flexible tube with a light and small camera on the end (endoscope) will then be passed into your mouth, down your throat and oesophagus, and into your stomach.

If the doctor sees any suspicious-looking areas, they may remove a small amount of tissue from the stomach or oesophageal lining. This is known as a biopsy. A pathologist will examine the tissue under a microscope to check for signs of disease. Biopsy results are usually available within a few days. This waiting period can be an anxious time and it may help to talk to a supportive friend, relative or health professional about how you are feeling.

An endoscopy takes about 15 minutes. You may have a sore throat afterwards and feel a little bloated. Endoscopies have some risks, such as bleeding or getting a small tear or hole in the stomach or oesophagus (perforation). Your doctor should explain all the risks before asking you to consent to the procedure.

Endoscopic ultrasound (EUS)

You may have this test at the same time as a standard endoscopy. The doctor will insert an endoscope with an ultrasound probe on the end. The probe releases soundwaves, which echo when they bounce off anything solid, such as an organ or tumour.

This procedure helps determine whether the cancer has spread into the oesophageal wall, nearby tissues or lymph nodes, and whether you are a suitable candidate for surgery. During the scan, your doctor may take further tissue samples from the oesophagus, lymph nodes and nearby organs.

Further tests

If the biopsy shows you have stomach cancer, you will have a number of other tests to find out whether the cancer has spread to other areas of your body. This is called staging. Here we describe tests that are commonly used to help stage stomach cancer. Some tests may be repeated during or after treatment to check your health and how well the treatment is working.

Blood tests

You might have blood tests to assess your general health, and to see how well your liver and kidneys are working. The test results can help you and your doctor to make treatment decisions.

CT scan

A computerised tomography (CT) scan uses x-rays and a computer to create a detailed picture of an area inside the body. It helps determine how far the cancer has spread from the primary tumour site.

For stomach cancer, you may have a CT scan of your chest, abdomen and pelvis. Before the scan, you may have an injection or be asked to drink a liquid dye. This helps ensure that anything unusual can be seen more clearly. The dye might make you feel hot all over and leave a strange taste in your mouth for a few minutes. Rarely, more serious reactions can occur.

The CT scan machine is large and round like a doughnut. You will need to lie still on a table while the scanner moves around you. The scan itself is painless and takes only a few minutes, but the preparation can take 10–30 minutes.

The dye used in a CT scan can cause an allergic reaction in some people. If you have had an allergic reaction to iodine or dyes during a previous scan, let the medical team know in advance.

PET-CT scan

A positron emission tomography (PET) scan combined with a CT scan is a specialised imaging test. The two scans provide more detailed and accurate information about the cancer. A PET-CT scan is most commonly used to help determine whether stomach cancer has spread to other parts of the body.

A PET scan is able to detect cancer cells that may not have been detected with just a CT scan. Before the scan, you will be injected with a glucose solution containing a small amount of radioactive material. Cancer cells show up brighter on the scan because they take up more glucose solution than the normal cells do.

You will be asked to sit quietly for 30–90 minutes as the glucose spreads through your body, then you will be scanned. The scan itself will take around 30 minutes. Let your doctor know if you are claustrophobic as the scanner is a confined space.


This procedure allows your doctor to look inside your abdomen and examine the outer layer of the stomach to see if the cancer has spread. A laparoscopy is used to stage the stomach cancer to see whether it involves the lining of the abdomen (peritoneum) or other organs

A laparoscopy is usually done as day surgery. You will be admitted to hospital and given a general anaesthetic. The doctor will inflate your abdomen with gas and make small cuts in your abdomen. A tube with a light and camera attached (a laparoscope) will be inserted into your body. Through this tube, the doctor can see cancer cells that are too small to be seen on CT or PET scans. The doctor may take further tissue samples for biopsy. Your doctor will explain the risks before asking you to agree to the procedure.

Gene mutation testing

Some cancers in the stomach and gastro-oesophageal junction are linked with genetic abnormalities. These abnormalities can contribute to the growth of tumours. If other tests show that the stomach cancer is advanced, your doctor might test a tissue sample to see if it contains a particular genetic mutation that may respond to some medicines. See Targeted therapy for stomach cancer for more on this.

This information was last reviewed in September 2017
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