Key Points for This Section

Gastric cancer is a disease in which malignant (cancer) cells form in the lining of the stomach. Age, diet, and stomach disease can affect the risk of developing gastric cancer. Possible signs of gastric cancer include indigestion and stomach discomfort or pain. Tests that examine the stomach and esophagus are used to detect (find) and diagnose gastric cancer. Certain factors affect prognosis (chance of recovery) and treatment options.

Gastric cancer is a disease in which malignant (cancer) cells form in the lining of the stomach.

The stomach is a J-shaped organ in the upper abdomen. It is part of the digestive system, which processes nutrients (vitamins, minerals, carbohydrates, fats, proteins, and water) in foods that are eaten and helps pass waste material out of the body. Food moves from the throat to the stomach through a hollow, muscular tube called the esophagus. After leaving the stomach, partly-digested food passes into the small intestine and then into the large intestine.

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The stomach and esophagus are part of the upper digestive system.

The wall of the stomach is made up of 3 layers of tissue: the mucosal (innermost) layer, the muscularis (middle) layer, and the serosal (outermost) layer. Gastric cancer begins in the cells lining the mucosal layer and spreads through the outer layers as it grows.

Stromal tumors of the stomach begin in supporting connective tissue and are treated differently from gastric cancer. Refer to the PDQ summary on Adult Soft Tissue Sarcoma Treatment for more information.

Age, diet, and stomach disease can affect the risk of developing gastric cancer.

Risk factors include the following:

• Helicobacter pylori infection of the stomach.
• Chronic gastritis (inflammation of the stomach).
• Older age.
• Being male.
• A diet high in salted, smoked, or poorly preserved foods and low in fruits and vegetables.
• Pernicious anemia.
• Smoking cigarettes.
• Intestinal metaplasia.
• Familial adenomatous polyposis (FAP) or gastric polyps.
• A mother, father, sister, or brother who has had stomach cancer.

Possible signs of gastric cancer include indigestion and stomach discomfort or pain.

These and other symptoms may be caused by gastric cancer. Other conditions may cause the same symptoms.

In the early stages of gastric cancer, the following symptoms may occur:

• Indigestion and stomach discomfort.
• A bloated feeling after eating.
• Mild nausea.
• Loss of appetite.
• Heartburn.

In more advanced stages of gastric cancer, the following symptoms may occur:

• Blood in the stool.
• Vomiting.
• Weight loss for no known reason.
• Stomach pain.
• Jaundice (yellowing of eyes and skin).
• Ascites (build-up of fluid in the abdomen).
• Trouble with swallowing.

A doctor should be consulted if any of these problems occur.

Tests that examine the stomach and esophagus are used to detect (find) and diagnose gastric cancer.

The following tests and procedures may be used:

• Physical exam and history: An exam of the body to check general signs of health, including checking for signs of disease, such as lumps or anything else that seems unusual. A history of the patient¡¯s health habits and past illnesses and treatments will also be taken.
• Blood chemistry studies: A procedure in which a blood sample is checked to measure the amounts of certain substances released into the blood by organs and tissues in the body. An unusual (higher or lower than normal) amount of a substance can be a sign of disease in the organ or tissue that produces it.
• Complete blood count: A procedure in which a sample of blood is drawn and checked for the following:
  • The number of red blood cells, white blood cells, and platelets.
  • The amount of hemoglobin (the protein that carries oxygen) in the red blood cells.
  • The portion of the sample made up of red blood cells.
• Upper endoscopy: A procedure to look inside the esophagus, stomach, and duodenum (first part of the small intestine) to check for abnormal areas. An endoscope (a thin, lighted tube) is passed through the mouth and down the throat into the esophagus.

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  Upper endoscopy. A thin, lighted tube is inserted through the mouth to look for abnormal areas in the esophagus, stomach, and first part of the small intestine.

• Fecal occult blood test: A test to check stool (solid waste) for blood that can only be seen with a microscope. Small samples of stool are placed on special cards and returned to the doctor or laboratory for testing.
• Barium swallow: A series of x-rays of the esophagus and stomach. The patient drinks a liquid that contains barium (a silver-white metallic compound). The liquid coats the esophagus and stomach, and x-rays are taken. This procedure is also called an upper GI series.

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  Barium swallow. The patient swallows barium liquid and it flows through the esophagus and into the stomach. X-rays are taken to look for abnormal areas.

• Biopsy: The removal of cells or tissues so they can be viewed under a microscope to check for signs of cancer. A biopsy of the stomach is usually done during the endoscopy.
• CT scan (CAT scan): A procedure that makes a series of detailed pictures of areas inside the body, taken from different angles. The pictures are made by a computer linked to an x-ray machine. A dye may be injected into a vein or swallowed to help the organs or tissues show up more clearly. This procedure is also called computed tomography, computerized tomography, or computerized axial tomography.

Certain factors affect prognosis (chance of recovery) and treatment options.

The prognosis (chance of recovery) and treatment options depend on the following:

• The stage and extent of the cancer (whether it is in the stomach only or has spread to lymph nodes or other places in the body).
• The patient¡¯s general health.

When gastric cancer is found very early, there is a better chance of recovery. Gastric cancer is often in an advanced stage when it is diagnosed. At later stages, gastric cancer can be treated but rarely can be cured. Taking part in one of the clinical trials being done to improve treatment should be considered. Information about ongoing clinical trials is available from the NCI Web site.