Screening and Diagnosis

Screening and Diagnosis of Gastric Cancer

Gastric Cancer Risk Factors

The cause of gastric cancer is unknown, but risk factors include:

  • Diet
  • Alcohol and tobacco use
  • Pernicious anemia, or vitamin B deficiency
  • Gastric polyps
  • Ulcers
  • Exposure to certain chemicals

Diagnosing Gastric Cancer

Your care team will use a variety of leading-edge methods to diagnose stomach cancer.

Diagnosing stomach cancer begins with an assessment of your medical history and a physical exam. Your physician may also order diagnostic tests, including:

  • Fecal occult blood test to search for blood in your stool
  • Upper gastrointestinal (GI) series using a barium swallow with X-ray
  • Upper endoscopy (EGD), using a thin, flexible and lighted tube called an endoscope to look at your digestive system
  • Endoscopic ultrasound (EUS) imaging using a thin, flexible tube with an ultrasound probe to examine your digestive system
  • Biopsy via EGD or EUS taking a small sample of tissue from the stomach lining

Looking at the cells from a biopsy under a microscope is the only definitive way to diagnose stomach cancer. Once a cancer is confirmed, specific stains help to identify features of the cancer that may guide the treatment. These special stains will include mismatch repair proteins, HER-2 receptors and programmed cell death receptors.

Gastric Cancer Stages

“Staging” is the term oncologists (physicians specially trained in cancer care) use to define where gastric cancer is located and how much it has spread. After the stage of gastric cancer is determined, your physician can recommend a particular course of treatment.

Most cancer teams use the system developed by the American Joint Committee on Cancer, known as the TNM staging system.

T = Tumor
Where is the primary tumor and how large is it?

N = Nodes
Has the tumor spread to nearby lymph nodes (part of your immune system)?

M = Metastasis
Has cancer spread to other parts of the body?

For each letter, there are five numbered stages, from zero to four, depending on how much the cancer has spread. The lower the number, the more the cancer cells look like normal cells and the easier they are to treat and cure. A higher number means it has spread more.

The place where cancer forms is called the primary site. Cancer can spread from the primary site to other parts of the body. Even if gastric cancer is found in other parts of your body, it’s still considered gastric cancer. For example, if gastric cancer has spread to the liver, it’s called metastatic gastric cancer, not liver cancer.

For treatment, physicians often use a simpler system of categorizing gastric cancer:

  • Resectable cancer: These cancers can be surgically removed (resected).
  • Borderline resectable cancer: These cancers can be surgically removed but are very close to major blood vessels, or other important parts of your body.
  • Locally advanced cancer: These cancers are still only in the area around the gastric, but they cannot be removed completely with surgery, often because they are growing into nearby blood vessels. This category is also called unresectable because the cancer cannot be removed with surgery.
  • Metastatic cancer: These cancers have spread to other parts of the body, so they cannot be removed completely with surgery (meaning they are also unresectable). Surgery may still be done, but it's used to relieve symptoms that the tumors in other areas of your body are causing.

Talk to your physician about your stage of cancer and how that will impact your treatment.

For more information about the stages of gastric cancer, please visit our Health Library.