Diagnosis

Tests and procedures used to diagnose stomach cancer include:

• A tiny camera to see inside your stomach (upper endoscopy). A thin tube containing a tiny camera is passed down your throat and into your stomach. Your doctor can use it to look for signs of cancer.
• Removing a sample of tissue for testing (biopsy). If any suspicious areas are found during the upper endoscopy, special tools can be used to remove a sample of tissue for testing. The sample is sent to a lab for analysis.
• Imaging tests. Imaging tests used to look for stomach cancer include CT scans and a special type of X-ray exam called a barium swallow.

Determining the extent (stage) of stomach cancer

The stage of your stomach cancer helps your doctor decide which treatments may be best for you. Tests and procedures used to determine the stage of cancer include:

• Blood tests. Blood tests to measure organ function may indicate whether other organs in your body, such as your liver, may be affected by cancer.
• Endoscopic ultrasound. During an endoscopic ultrasound, a thin tube with a camera on the tip is passed down your throat and into your stomach. A special ultrasound tool is used to create pictures of your stomach. Endoscopic ultrasound helps doctors determine how deeply a cancer penetrates the stomach wall.
• Imaging tests. Tests may include CT and positron emission tomography (PET).
• Exploratory surgery. Your doctor may recommend surgery to look for signs that your cancer has spread beyond your stomach, within your chest or abdomen. Exploratory surgery is usually done laparoscopically. This means the surgeon makes several small incisions in your abdomen and inserts a special camera that transmits images to a monitor in the operating room.

Other staging tests may be used, depending on your situation.

Your doctor uses the information from these procedures to assign a stage to your cancer. The stages of stomach cancer are indicated by Roman numerals that range from 0 to IV, with the lowest stages indicating that the cancer is small and affects only the inner layers of your stomach. By stage IV, the cancer is considered advanced and may have spread to other areas of the body.