If your doctor suspects you have stomach cancer, he or she will use a thin, tube-like instrument called an endoscope to examine the inner lining of the stomach wall. The endoscope is inserted through the mouth and guided into the stomach, and the camera at the end of the tube enables the doctor to see inside the stomach. Your doctor may take a small tissue sample (biopsy) of any concerning areas. A diagnosis is made based on how the tissue and its individual cells look under a microscope. If you have had this procedure done before coming to Memorial Sloan Kettering, our pathologists will review the biopsy slides as part of your initial evaluation to confirm the diagnosis. Sometimes a second endoscopy may be necessary if the diagnosis is unclear.
For another diagnostic test, the barium x-ray, the patient drinks a liquid containing barium, a silver-white metal that helps outline the image of the stomach on an x-ray. The test may be performed in a doctor's office or in the radiology department of a hospital.
Staging the Tumor
Once a diagnosis has been made, a number of tests may be performed to determine if and how far the cancer may have spread to the other layers of the stomach, nearby organs, and nearby lymph nodes. This process is called staging, and it is an important factor in deciding which treatment would be most beneficial to the patient.
CT scanning is often used for staging stomach cancer, as is PET scanning. Endoscopic ultrasound is another test that may be used during both diagnosis and staging. Similar to endoscopy, endoscopic ultrasound involves the insertion of a thin tube into the mouth and down into the stomach. At the tip of the tube is a small ultrasound probe that bounces sound waves off the walls of the stomach. Endoscopic ultrasound may also be used to determine whether laparoscopy is necessary.(1)
Laparoscopy is a minimally invasive surgical technique doctors may use to stage stomach cancer. During this procedure, a laparoscope — a thin, lighted tube with a camera on its tip — is inserted into the abdominal area through a small incision and the image is projected onto a large viewing screen. Guided by the laparoscope, the surgeon is able to inspect the inside of the abdomen and remove tissue samples using specially designed surgical instruments. With this procedure the surgeon can inspect the outside wall of the stomach, examine lymph nodes, and evaluate the surfaces of other abdominal organs to determine if the cancer has spread to those areas.
Doctors use the TNM (tumor, node, metastasis) system to describe the stage of a cancer. This abbreviation summarizes the depth of penetration of the tumor into the stomach wall (T), whether it has spread to nearby lymph nodes (N), and whether it has metastasized, or spread, to other parts of the body (M).