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.
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. See the PDQ summary on for more information. For more information about cancers of the stomach, see the following PDQ summaries:
- Unusual Cancers of Childhood
- Stomach (Gastric) Cancer Prevention
- Stomach (Gastric) Cancer Screening
Age, diet, and stomach disease can affect the risk of developing gastric cancer.Anything that increases your risk of getting a disease is called a risk factor. Having a risk factor does not mean that you will get cancer; not having risk factors doesn't mean that you will not get cancer. Talk with your doctor if you think you may be at risk. Risk factors for gastric cancer include the following:
Having any of the following medical conditions:
- Helicobacter pylori (H. pylori) infection of the stomach.
- Chronic gastritis (inflammation of the stomach).
- Pernicious anemia.
- Intestinal metaplasia (a condition in which the normal stomach lining is replaced with the cells that line the intestines).
- Familial adenomatous polyposis (FAP) or gastric polyps.
- Eating a diet high in salted, smoked foods and low in fruits and vegetables.
- Eating foods that have not been prepared or stored properly.
- Being older or male.
- Smoking cigarettes.
- Having a mother, father, sister, or brother who has had stomach cancer.
Symptoms of gastric cancer include indigestion and stomach discomfort or pain.These and other signs and symptoms may be caused by gastric cancer or by other conditions. 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.
- Blood in the stool.
- Weight loss for no known reason.
- Stomach pain.
- Jaundice (yellowing of eyes and skin).
- Ascites (build-up of fluid in the abdomen).
- Trouble swallowing.
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 (CBC): A procedure in which a sample of blood is drawn and checked for the following:
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.
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.
- 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.
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.One or more of the following tests may be done on the samples of tissue that are removed:
- Immunohistochemistry study: A laboratory test in which a substance such as an antibody, dye, or radioisotope is added to a sample of cancer tissue to test for certain antigens. This type of study is used to tell the difference between different types of cancer.
- FISH (fluorescence in situ hybridization): A laboratory technique used to look at genes or chromosomes in cells and tissues. Pieces of DNA that contain a fluorescent dye are made in the laboratory and added to cells or tissues on a glass slide. When these pieces of DNA bind to specific genes or areas of chromosomes on the slide, they light up when viewed under a microscope with a special light. The sample of blood or bone marrow is checked for HER2/neu to help decide the best treatment.
Certain factors affect prognosis (chance of recovery) and treatment options.The prognosis (chance of recovery) and treatment options depend on the following:
- The stage 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.