Stomach Cancer: Diagnosis

This section has been reviewed and approved by the Cancer.Net Editorial Board, 05/2014

ON THIS PAGE: You will find a list of the common tests, procedures, and scans that doctors can use to find out what’s wrong and identify the cause of the problem. To see other pages, use the menu on the side of your screen.

Doctors use many tests to diagnose cancer and find out if it has spread to other parts of the body, called metastasis. Some tests may also determine which treatments may be the most effective. For most types of cancer, a biopsy is the only way to make a definitive diagnosis of cancer. If a biopsy is not possible, the doctor may suggest other tests that will help make a diagnosis. Imaging tests may be used to find out whether the cancer has spread. This list describes options for diagnosing this type of cancer, and not all tests listed will be used for every person. Your doctor may consider these factors when choosing a diagnostic test:

  • Age and medical condition
  • Type of cancer suspected
  • Signs and symptoms
  • Previous test results

In addition to a physical examination, the following tests may be used to diagnose stomach cancer:

Biopsy. A biopsy is the removal of a small amount of tissue for examination under a microscope. Other tests can suggest that cancer is present, but only a biopsy can make a definite diagnosis. The sample removed during the biopsy is analyzed by a pathologist. A pathologist is a doctor who specializes in interpreting laboratory tests and evaluating cells, tissues, and organs to diagnose disease.

Endoscopy. This test allows the doctor to see the inside of the body. The person may be sedated, and the doctor inserts a thin, lighted, flexible tube called a gastroscope or endoscope through the mouth, down the esophagus, and into the stomach and small bowel. Sedation is giving medication to become more relaxed, calm, or sleepy. The doctor can remove a sample of tissue during an endoscopy and check it for signs of cancer.

Endoscopic ultrasound. This test is similar to an endoscopy, but the gastroscope has a small ultrasound probe on the end that produces a detailed image of the stomach wall. An ultrasound uses sound waves to create a picture of the internal organs. The ultrasound image helps doctors determine how far the cancer has spread into the stomach and nearby lymph nodes, tissue, and organs, such as the liver.

X-ray. An x-ray is a way to create a picture of the structures inside of the body using a small amount of radiation.

Barium swallow. In a barium swallow, a person swallows a liquid containing barium, and a series of x-rays are taken. Barium coats the lining of the esophagus, stomach, and intestines, so tumors or other abnormalities are easier to see on the x-ray.

Computed tomography (CT or CAT) scan. A CT scan creates a three-dimensional picture of the inside of the body with an x-ray machine. A computer then combines these images into a detailed, cross-sectional view that shows any abnormalities or tumors. A CT scan can also be used to measure the tumor’s size. Sometimes, a special dye called a contrast medium is given before the scan to provide better detail on the image. This dye is usually given as a solution to swallow.

Magnetic resonance imaging (MRI). An MRI uses magnetic fields, not x-rays, to produce detailed images of the body. MRI can also be used to measure the tumor’s size. A special dye called a contrast medium is given before the scan to create a clearer picture. This dye is usually injected into a patient’s vein.

Positron emission tomography (PET) scan. A PET scan is a way to create pictures of organs and tissues inside the body. A small amount of a radioactive sugar substance is injected into the patient’s body. This sugar substance is taken up by cells that use the most energy. Because cancer tends to use energy actively, it absorbs more of the radioactive substance. A scanner then detects this substance to produce images of the inside of the body.

LaparoscopyA laparoscopy is a minor surgery in which the surgeon inserts a scope into the abdominal cavity to evaluate spread of the stomach cancer to the lining of the abdominal cavity or liver. This pattern of cancer spread often cannot be seen on a CT or PET scan.

After diagnostic tests are done, your doctor will review all of the results with you. If the diagnosis is cancer, these results also help the doctor describe the cancer; this is called staging. 

The next section helps explain the different stages for this type of cancer. Use the menu on the side of your screen to select Stages, or you can select another section, to continue reading this guide.