Stomach Cancer: Tests After Diagnosis

What tests might I have after being diagnosed?

After a diagnosis of stomach cancer, you will likely have other tests. These tests help your healthcare providers learn more about your cancer. They can help show if the cancer has grown into nearby areas or spread to other parts of the body. The test results help your healthcare providers decide the best ways to treat the cancer. If you have any questions about these or other tests, be sure to talk with your healthcare team.

The tests you may have can include:

  • Computed tomography (CT) scan

  • Endoscopic ultrasound (EUS)

  • Magnetic resonance imaging (MRI)

  • Positron-emission tomography (PET) scan

  • Laparoscopy

Imaging tests

CT scan

A CT scan is a series of X-rays that are put together by a computer. You may have CT scans of your chest, abdomen, and pelvis. These are to check for signs of cancer in other organs like your liver or lungs. The test shows nearby lymph nodes or glands, too. Lymph nodes are common places for stomach and other cancers to spread.

A CT scan is painless. You may be asked to hold your breath 1 or more times during the scan. You may be asked to drink a contrast dye 4 to 6 hours before the scan. Or your healthcare provider may inject the dye into your vein through an intravenous line (IV). The dye helps to show certain tissues and organs better on the images. The dye may cause a warm feeling in your face or chest. Tell your healthcare provider if you’re allergic to or have had a reaction to the dye in the past.

During the test, you’ll lie still on an exam table. The table slides through the center of the ring-shaped CT scanner. The scanner directs a beam of X-rays at a certain part of your body. A computer uses the data from the X-rays to make a series of pictures. The pictures are put together to create a 3-dimensional picture. 


An ultrasound uses sound waves and a computer to make images. An EUS is done from inside your stomach. It uses a tool called an endoscope. An endoscope is a thin, flexible tube with a light and a tiny camera. The scope has a special ultrasound tool at the tip. This test shows how far cancer has spread into the wall of your stomach and nearby tissues and lymph nodes. It gives very specific information about the stage of your stomach cancer. This information helps your healthcare providers plan your treatment.

Before the test, your healthcare provider will spray your throat with anesthetic. This numbs your throat and helps prevent gagging. You may also receive medicine to help you relax. The endoscope is put into your mouth or nose. It’s gently guided down into your throat, your esophagus, and then your stomach. It sends images to a computer.

An EUS can show how far the tumor has grown in or through the walls of your stomach. EUS can also look at lymph nodes around your stomach to see if cancer cells have spread to them. Your healthcare provider may pass a thin needle from the endoscope through your stomach wall and into nearby lymph nodes. Then he or she can take tiny pieces tissue from the lymph nodes. This is called a biopsy. The tiny pieces of tissue are sent it to a pathologist to see if they have cancer cells in them.


An MRI scanner uses large magnets and a computer to make images. This creates very clear images. An MRI is used to see if cancer has spread outside of your stomach. For instance, it can spread to lymph nodes or to your liver or pancreas. An MRI is not used as often as CT scans to look for the spread of stomach cancer. But it can help show if the cancer has spread to your brain and spinal cord.

For this test, you’ll lie still on a table as it slides into a long, narrow, tube-like scanner. The scanner sends a radiofrequency waves at the area of your body to be viewed. A computer puts together the data to create a 3-dimensional image of the inside of your body.

When the scanner is working, it’s very loud. Your healthcare provider may give you earplugs or headphones to wear. The scanner is a small space. If you’re uncomfortable in small spaces, you can ask for a sedative to take before this test. A 2-way intercom will let you talk to technician during the test.

PET scan

This test helps show whether cancer has spread beyond the stomach. During the test, your healthcare provider injects a mildly radioactive sugar (glucose) solution into one of your veins. Cancer cells use the glucose more quickly than normal cells do. A scanner makes images that show where the glucose has collected. This shows areas that may be cancer. 

To do this test, you’ll lie still on a table that’s pushed into the PET scanner. It will rotate around you and take pictures. Other than the injection, a PET scan is painless. Some people are sensitive to the substance. This may cause nausea, a headache, or vomiting. Some newer machines can do PET and CT scans at the same time. This way, areas that show up on the PET scan can be compared with the more detailed image of the CT scan.


This procedure is used to look for cancer that has spread to other organs and tissue, such as the liver and lymph nodes. It can find small growths that are not easily seen on CT scans.

This procedure is done in an operating room. First you’ll receive medicine that puts you into a deep sleep. To do the laparoscopy, your healthcare provider will make a small cut into your abdomen. Then he or she will put a thin flexible tube with a camera on the end into the cut. The camera is moved around your abdomen to get close-up images of the organs and lymph nodes near your stomach.

Working with your healthcare provider

Your healthcare provider will talk with you about which tests you’ll have. Make sure to get ready for the tests as instructed. Ask questions and talk about any concerns you have.