The doctor will ask about your symptoms, and medical and family history. The abdominal area will be carefully examined. Your doctor may look for other possible causes of your symptoms. Your doctor may recommend different tests in order to identify if cancer or other gastrointestinal conditions are suspected.

If you are having gastrointestinal symptoms, your doctor may conduct certain tests to identify abnormalities. These may include:

  • Blood tests:
    • Complete blood count—Low red blood cell counts may be present if there is bleeding in the stomach from cancerous growths.
    • Comprehensive metabolic panel—To assess if other organs are affected.
    • Look for certain proteins in the blood that may indicate the presence of cancer.
  • Fecal occult blood test—A small sample of stool is placed on a special card. It is then tested by a lab for hidden blood. Blood can be present in the stool for many reasons. Stomach cancer will not always cause blood in the stool.
  • Upper GI series—A series of x-rays is taken after drinking contrast material. The contrast material makes it easier to see images of the esophagus, stomach, and first part of the small intestine.
  • Upper GI endoscopy—A tube with a lighted tip and camera is inserted through the mouth and throat. The scope is threaded down the esophagus, and into the stomach and first part of the small intestine to look for any abnormalities. Any abnormal tissue will be removed and examined under a microscope.
  • Endoscopic ultrasound—A small transducer is placed on the tip of an endoscope to view the walls of your digestive tract and other nearby organs.
  • Abdominal CT scan—An imaging test used to view structures in the chest, abdomen, and pelvis. Contrast material may be used to make the structures easier to see.
  • Positron emission tomography scan—A substance that gives off a tiny amount of radiation is put into your body and images are made that show activity in body tissues.
  • Chest x-ray—May be done to look for any cancer spread into the chest.

Diagnosis of stomach cancer is confirmed with a biopsy. A biopsy is a collection of tissue samples that are removed from the stomach lining. Tissue samples can also be taken from the esophagus and first part of the small intestine. After removal, the samples are examined under a microscope. This is the only way to confirm a diagnosis.

If stomach cancer is confirmed, results from completed tests and new tests will help determine the stage of cancer. Staging is used to determine characteristics of the tumor that will help develop the prognosis and treatment plan. Factors that play a role in staging include where the tumor is found, how far the original tumor has spread, whether lymph nodes are involved, if cancer has spread to other tissue, and microscopic cellular details.

Surgical staging is done with an exploratory laparotomy or endoscopy. During exploratory laparotomy, an incision is made in the abdominal wall to gain access to the abdominal and pelvic cavities. The areas can be examined for the presence of tumors. If cancer has not visibly spread, a peritoneal wash may be done. Saline solution is used to wash the abdominal cavity. Samples are taken to look for the presence of cancer cells in the wash. Their presence indicates that cancer has spread beyond the stomach, even if tumors are not visible.

Tests that may help determine stomach cancer stage:

  • Blood tests
  • Imaging tests—To help determine how deep the tumor has moved into the layers of the stomach or nearby structures. They may also help to determine if there are any metastatic growths in other areas of the body. Some tests use contrast material to highlight structures so they are easier to see.
  • Tissue evaluation—Cancer tissue from the biopsy will be closely examined to look for characteristics that can help with prognosis and treatment selection.

The stomach is made of a number of tissue layers.

  • The inner layer is called the mucosa. It has 3 layers, including:
    • Columnar epithelium
    • Lamina propria
    • Muscularis mucosa
  • A submucosa layer is next and helps support the mucosa.
  • The next layer is a muscular tissue called muscularis propria.
  • The subserosa and serosa are the final 2 layers that surrounds the outside of the stomach.

The location and depth of tumor is important in staging. Stomach cancer is staged from 0-IV.

  • Stage 0—Carcinoma in situ—Abnormal cells are found only in the innermost lining of the stomach wall.
  • Stage I—The cancer is found in the mucosa.
    • Stage IA—The cancer is growing into the submucosa.
    • Stage IB—Either of the following:
      • The cancer has grown into the submucosa and has spread to 1 or 2 lymph nodes near the stomach.
      • The cancer has grown into the muscle layer, but has not spread to nearby lymph nodes.
  • Stage IIA—Any of the following:
    • The cancer has grown beneath the lamina propria, muscularis mucosa, or the submucosa. It and has spread to 3 to 6 nearby lymph nodes.
    • The cancer has grown into the muscularis propria and has spread to 1 or 2 nearby lymph nodes.
    • The cancer has grown through the muscularis propria into the subserosa.
  • Stage IIB—Any of the following:
    • The cancer has grown beneath the mucosa into the lamina propria, muscularis mucosa, or the submucosa and has spread to 7 or more nearby lymph nodes.
    • The cancer has grown into the muscularis propria and has spread to 3 to 6 nearby lymph nodes.
    • The cancer has grown into the subserosa layer and has spread to 1 or 2 nearby lymph nodes.
    • The cancer has grown completely through all the layers of stomach wall into the serosa.
  • Stage IIIA—Any of the following:
    • The cancer has grown into the muscularis propria and has spread to 7 or more nearby lymph nodes.
    • The cancer has grown into the subserosa layer and has spread to 3 to 6 nearby lymph nodes
    • The cancer has grown into the serosa and has spread to 1 or 2 nearby lymph nodes
  • Stage IIIB—Any of the following:
    • The cancer has grown into the subserosa layer and has spread to 7 or more nearby lymph nodes.
    • The cancer has grown into the serosa and has spread to 3 to 6 nearby lymph nodes.
    • The cancer has grown through the stomach wall and into nearby organs or structures such as the spleen, intestines, liver, pancreas, or major blood vessels. It may also have spread to up to 2 nearby lymph nodes.
  • Stage IIIC—Either of the following:
    • The cancer has grown completely into the serosa and has spread to 7 or more nearby lymph nodes.
    • The cancer has grown through the stomach wall and into nearby organs or structures such as the spleen, intestines, liver, pancreas, or major blood vessels and has spread to 3 or more nearby lymph nodes.
  • Stage IV—Cancer has spread to other parts of the body. The most common sites for metastatic stomach cancer are lymph nodes in other parts of the body, the liver, lungs, brain, and bones.

For planning treatment, sometimes another staging method is used. In this method, staging is based on whether or not the tumor can be surgically removed. These stages include

  • Resectable—Cancer that can be completely removed during surgery.
  • Unresectable—Cancer cannot be completely removed during surgery because it has spread to nearby structures.

Prognosis is a forecast of the probable course and/or outcome of a disease or condition. Prognosis is most often expressed as the percentage of patients who are expected to survive over 5 or 10 years. Cancer prognosis is an inexact science. This is because the predictions are based on the experience of large groups of patients with cancer in various stages. Using this information to predict the future of an individual patient is always imperfect and often flawed, but it is the only method available.

Stomach cancer is usually found in later stages. As a result, the number of patients who survive for 5 years or more after diagnosis is fairly low, about 29%.

Individual rates depend on the stage of the cancer at the time of diagnosis, survival decreases with higher stage.

  • If it is found early and does not affect nearby lymph nodes (stage I), survival rates can reach 80%.
  • Metastatic stomach cancer (stages IV) usually causes death with in a year of diagnosis.