Usually, the first thing you do it see your GP, who will examine you. You may have to have blood tests done to check the overall state of your health. If your GP is unsure of what the problem is or if they believe it may be cancer, they will send you to a hospital for specialist treatment and advice.

Your first appointment in the hospital may be for an endoscopy. If the endoscopy suggests you may have cancer, you will see a specialist next. They will ask you about your overall health and prior medical problems and will examine you. You may have to have blood work and x-rays to check on your overall health.

Endoscopy

Endoscopy, also called gastroscopy, is the most commonly used test for diagnosis of stomach cancer.

You will have a thin, flexible tube (endoscope) inserted. This tube will have a small light and camera on the end, making it possible to examine the esophagus, the inside of the stomach, and the beginning of the small intestine. This helps your doctor see any area of abnormality. If necessary, they may take a small sample of cells (biopsy) and examine it under a microscope. This can confirm the presence of cancer, and the procedure isn't painful.

Endoscopies are usually done in the hospital on an outpatient basis, though occasionally it is necessary to stay in the hospital overnight. You will be asked to refrain from eating and drinking for at least four hours before the procedure, and you will be given instructions about the medication you may be taking.

A local anesthetic administered as an aerosol spray may be used on the back part of the throat, or you may be given a sedative to limit your discomfort; sedatives are normally injected into a vein in the arm. In some cases, both methods are used.

An endoscopy can be uncomfortable, though it shouldn't be painful. Tell your doctor if you have chest pain during or after the procedure.

If you have been given a local anesthetic, you will have to stay in the hospital until the effect has worn off; this normally takes about an hour. You will not be able to swallow anything during this time.

Some people have a sore throat afterwards. This is normal and gets better in a couple of days. Tell your doctor if this isn't the case.

Biopsy

During the endoscopy, you may have small samples of tissue removed from areas that are seen to be abnormal (biopsy). This tissue will be examined under a microscope to determine whether there are cancer cells present.

Endoscopic ultrasound

This is like an endoscopy, but it has an ultrasound probe on the end. Ultrasound uses sound waves to create an image of the area. It allows doctors to obtain a deeper image of the wall of the stomach and surrounding area, which may give them a better idea of the depth of the tumor.

They may take a sample of tissue (biopsy) and examine it under a microscope.

You may be given a slightly stronger sedative than when having GI endoscopy, as you must remain still during the procedure.

CT (computed tomography)

A CT takes a series of x-rays, creating a 3-D image of the lower part of the body.

It can be used to identify the exact location of the tumor or to check whether the cancer has spread. These studies take from 10 to 30 minutes and are painless.

A small amount of radiation is used, though it is very unlikely to cause you any harm. You will be asked to refrain from eating and drinking for at least four hours before the test.

You may be given a drink or an injection with a dye, which makes it possible to see certain areas more clearly. This may make you feel hot for a few minutes. It is important that you inform your health professionals if you are allergic to iodine or have asthma, as you may have a reaction to the injection.
CT scans can also be used as a guide during biopsies.

PET / CT

This is a combination of computed tomography and positron emission tomography (PET). PET uses low doses of radiation to measure cell activity in different parts of the body. This test offers more detailed information on the part of the body being scanned.

You will not be able to eat for six hours before the test. A slightly radioactive substance is injected into a vein (normally the arm). This is followed by a wait of at least an hour before the examination, which takes between 30 and 90 minutes.

Laparoscopy

This test entails a small operation carried out under general anesthesia. It is not always necessary, as the necessary information can be obtained using the other tests.

The surgeon will make a small incision of about 2 cm in length in the skin and muscle near your belly button, and will carefully insert a fine tube with a small video camera on its end (laparoscope) into your abdomen. The surgeon will use the laparoscope to observe your organs. They may take a biopsy by making a small cut through which they can insert an instrument that will obtain the sample.

During the procedure, the surgeon may send air into your abdomen to help them see your organs better. This may be uncomfortable and cause pain, though it goes away within one or two days.

You should be able to get up as soon as the effects of the anesthesia wear off. You will have one or two stitches where the incisions were made. You may have to remain in the hospital overnight.

Ultrasound

This test is sometimes used to examine different parts of the stomach. It only takes a few minutes, and during the procedure a gel will be spread across your abdomen and then a small device will be passed over the area where the gel has been applied. This device emits ultrasound waves used to form an image of the organs that can be seen using a computer.