Tests for stomach cancer

You usually have a number of tests to check for stomach cancer. Stomach cancer is also called gastric cancer.

The tests you might have include:

  • blood tests
  • a test to look inside your stomach. This is a gastroscopy

Tests your GP might do

Most people start by seeing their GP if they have symptoms that could be due to cancer. Some people are also diagnosed with stomach cancer after they become unwell and go to A&E.

Your GP asks about your symptoms including when they started and how often you have them. If you have had a telephone appointment, your GP might arrange for you to come in and see them.

The tests your GP might do include:

  • a physical examination
  • blood tests

After the examination, your GP may ask you to have a gastroscopy. You usually have this test at your local hospital. Or your GP may refer you straight to see a specialist. 

Physical examination

This examination involves your doctor feeling your tummy (abdomen). They feel for any areas that are swollen or might not feel normal. And if you have any pain, they will feel those areas.

They also listen to your chest and abdomen to find out if it sounds normal. For example, they can listen for signs of fluid collecting, or your digestive system Open a glossary item working.

Blood tests

Blood tests can check your general health including:

  • how well your liver and kidneys are working
  • check the number of blood cells such as red blood cells


A gastroscopy is a test that looks at the inside of your:

  • food pipe (oesophagus)
  • stomach
  • the first part of the small bowel (intestine)

It is also called endoscopy or oesophago gastric duodenoscopy (OGD).

Your doctor uses a long flexible tube with a small camera and light at the end. They can check the stomach for growths or abnormal looking areas. Doctors can also take samples of tissue (biopsies) of any abnormal looking areas. They send the samples to the laboratory to be checked for cancer cells.

Usually you're awake when you have this test, but you can choose to have a medicine to help you relax. This makes you drowsy (sedation).

Tests your specialist might do

Depending on your symptoms and the results of your tests, your GP might refer you to a specialist. You are usually referred to an upper gastrointestinal (GI) clinic where you see a GI specialist doctor.

Your specialist usually does more tests. These include:

  • CT scan
  • endoscopic ultrasound (EUS)
  • laparoscopy
  • PET-CT scan

CT scan

CT (or CAT) stands for computed (axial) tomography. It is a test that uses x-rays and a computer to create detailed pictures of the inside of your body.

You may have a CT scan of your chest, tummy and pelvis. This is to find out where the cancer is and whether it has spread to other parts of the body.

Endoscopic ultrasound (EUS)

This test combines an ultrasound and endoscopy to look at your food pipe and stomach.

Your doctor uses a long flexible tube called an endoscope with a tiny camera and light. The endoscope also has an ultrasound probe. The probe uses high frequency sound waves to create a picture of the inside of your body.

This test can help find out the size of the cancer and whether it has spread.

PET-CT scan

A PET-CT scan combines a CT scan and a PET scan. This type of scan can give detailed information about your cancer. You might have a PET-CT scan to find out exactly where the cancer is and whether it has spread.


Laparoscopy is a small operation to look inside your tummy. It is also called keyhole surgery. Your surgeon can look for any signs of cancer and whether it has spread. You might have it to find out if stomach cancer has spread and help plan your treatment.

You have this operation under general anaesthetic Open a glossary item.

Tests on your stomach cancer cells

After a biopsy or surgery, your doctor sends samples of cancer cells to the laboratory. A doctor called a pathologist does various tests on the cells. The tests help to diagnose stomach cancer.

Tests on the cancer cells can also help doctors decide on the best treatment for you. For example, you may be able to have treatment with a drug called trastuzumab if you have large amounts of HER2 proteins on the surface of cancer cells. These are called HER2 positive stomach cancers.

Other drugs only work for people who have:

  • large amounts of a protein called PD-L1
  • genes changes called high microsatellite instability (MSI) and mismatch repair deficiency (MMRd)

Some of these tests are only for people who have stomach cancer that has spread to other parts of the body. This is advanced stomach cancer. Your doctor can tell you more about these tests.


The tests you have help your doctor find out if you have stomach cancer and how far it has grown. This is the stage of the cancer.

This is important because doctors recommend your treatment according to the stage of the cancer.

Coping with stomach cancer

Coping with a diagnosis of stomach cancer can be difficult. There is help and support available to you and your family.

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