Stomach cancer - How stomach cancer is diagnosed

If you have symptoms that could be a sign of stomach cancer, see your GP as soon as possible.

Your GP will ask about your symptoms and examine your stomach for any lumpiness or tenderness.

Tests at hospital

If your GP thinks you may have stomach cancer, they will refer you to a specialist for tests.

These may include a blood test and chest X-ray, which will assess your overall health. A sample of your stools may also be tested for blood.

Due to the potentially serious nature of stomach cancer you should be referred to the specialist within two weeks. Read more about waiting times.

The main tests used to diagnose stomach cancer are outlined below.

Endoscopy and endoscopic ultrasound

An endoscopy is a procedure where a healthcare professional examines the inside of your stomach using a device known as an endoscope, which is a long, thin flexible tube with a light and a video camera at the end.

If you need to have an endoscopy, you will not be able to eat or drink for between four to eight hours before the procedure. This is to ensure your stomach and duodenum (top of the small intestine) are empty.

You will be awake for the endoscopy, but may be given a sedative by injection to make you feel drowsy and relaxed. You may also have a local anaesthetic sprayed onto the back of your throat, so the area is numbed.

The endoscope will then be passed down your throat and into your stomach so the specialist can look for any stomach ulcers or signs of cancer. If tissue is found that may be cancerous, your specialist will take a sample of it for testing. This procedure is known as a biopsy. The sample will be examined beneath a microscope in a laboratory. The results will show whether the cells are cancerous (malignant) or non-cancerous (benign) and normally take seven to 10 days to come back.

The endoscopy itself usually takes about 15 minutes, although you should allow about two hours for your visit.

If your specialist thinks you may have cancer in the top part of your stomach, you may have an ultrasound scan at the same time as an endoscopy, known as an endoscopic ultrasound. This uses high frequency sound waves to produce an image of your stomach (this method is commonly used to view an unborn baby in the womb).

If you have an endoscopic ultrasound, an ultrasound probe will be attached to the end of the endoscope before it is passed down your throat. The scan will help to show the stage of any cancer in the top part of your stomach.

After an endoscopy, or an endoscopic ultrasound, you will not be able to drive for several hours, due to the sedative. You may also have a sore throat, although this should pass within a few days.

Barium meal X-ray

A barium meal X-ray or barium swallow uses a liquid containing a substance called barium, which makes your stomach show up on an X-ray. Nowadays, however, it's less commonly used to diagnose stomach cancers.

Normally, organs such as your stomach do not show up on an X-ray because they are made of soft tissue that is not dense enough to stop the X-rays passing through. However, when these organs are filled with barium, it blocks the X-rays and shows up white on an X-ray screen.

If you need to have a barium meal X-ray, you will not be able to eat or drink for at least six hours before the procedure, as your stomach and duodenum need to be empty. You may be given an injection to relax the muscles in your digestive system.

You will then lie down on a couch, and your specialist will give you a white, chalky liquid to drink that contains barium. As the barium fills your stomach, your specialist will be able to see your stomach on an X-ray monitor, as well as any ulcers, or abnormal growths. Your couch may be tipped slightly during the test so the barium fills all the areas of your stomach.

A barium swallow usually takes about 15 minutes to perform. Afterwards, you will be able to eat and drink as normal, although you may need to drink more water to help flush the barium out of your system. You may feel slightly sick after a barium meal X-ray, and the barium may cause constipation. Your stools may also be white for a few days afterwards as the barium passes through your system.

Further testing

If you are diagnosed with stomach cancer, further tests may be needed to help determine how far it has spread and how quickly it is likely to spread (known as the stage and grade). Your cancer specialist (oncologist) will discuss this with you.

However, it may not always be possible to identify the exact stage of your condition until your treatment starts.

Laparoscopy

Your specialist may need to examine your stomach in more detail to see if the cancer has spread, especially to the lining of the abdominal cavity (peritoneum). If it has, you may need to have a small operation called a laparoscopy.

This procedure is carried out under a general anaesthetic, so you will be asleep.

Your specialist will insert a thin viewing tube with a camera on the end (a laparoscope) into your stomach through a small cut (incision) in the lower part of your tummy. In some cases, your specialist may need to examine more than one area of your stomach and may need to make more than one incision.

Computerised tomography (CT) or positron emission tomography (PET) scan

CT scans or PET scans take a series of X-ray images of your body. A computer then puts them together, creating a detailed picture of the inside of your body.

These scans will help your doctor assess how advanced your cancer is. It allows them to see whether the cancerous cells have formed tumours anywhere else in the body. The scan helps your doctors work out which type of treatment will be most effective and appropriate for you.

Liver ultrasound scan

If your specialist thinks your stomach cancer may have spread to your liver, you may need to have a liver ultrasound. This type of scan uses high frequency sound waves to produce an image of your liver.

Staging and grading

One method of assessing stomach cancer uses a number system to measure the spread of the cancer:

Stage 1A:

• the cancer is contained within the inner lining of the stomach, and no lymph nodes are affected

Stage 1B:

• the cancer is still contained within the stomach lining, but has spread to one or two lymph nodes, or
• the lymph nodes are unaffected, but the cancer has spread into muscles that surround the inner lining

Stage 2A:

• the cancer is still contained within the stomach lining but has now spread to between three and six lymph nodes, or
• it has spread into the surrounding muscles and to one or two lymph nodes, or
• the lymph nodes are unaffected, but the cancer has now spread into the outer layer of the stomach

Stage 2B:

• the cancer is still contained inside the lining, but has now spread into seven or more lymph nodes, or
• it has spread into the muscles and also to between three and six lymph nodes, or
• it has spread into the outer layer of the stomach and also into one or two lymph nodes, or
• the lymph nodes are still unaffected, but the cancer has spread outside the stomach

Stage 3A:

• the cancer has spread into surrounding muscles and into seven or more lymph nodes, or
• the cancer has spread into the outer layer of the stomach and also to between three and six lymph nodes, or
• the cancer has spread outside of the stomach and also into one or two lymph nodes

Stage 3B:

• the cancer has spread into the outer layer of the stomach and also into seven or more lymph nodes, or
• the cancer has spread outside of the stomach and also to between three and six lymph nodes, or
• the cancer has spread further outside of the stomach into surrounding tissue and may also affect up to two lymph nodes

Stage 3C:

• the cancer has spread beyond the stomach into nearby tissues, organs and also into three or more lymph nodes

Stage 4:

• the cancer has spread to another part of the body such as the liver or lungs

The majority of stomach cancers are at stage three or four when diagnosed, meaning a cure is not usually possible.

There are three grades of stomach cancer:

• low-grade – the cancer may grow slowly
• medium-grade – the cancer may grow faster
• high-grade – the cancer is more aggressive and likely to grow more quickly