Gastric cancer is a disease in which malignant (cancerous) cells form in the lining of the stomach.
The stomach is J-shaped and located in the upper abdomen. The stomach is part of the digestive system, which is responsible for processing ingested nutrients (vitamins, minerals, carbohydrates, fats, and water) and helping to get waste out of the body. Food moves from the pharynx to the stomach through the esophagus, a hollow, muscular tube. The partially digested food leaves the stomach and enters the small intestine and then the large intestine.
The esophagus and stomach are part of the upper GI (digestive) system.
The stomach wall is composed of three layers of tissue: the mucosal layer (inner layer), the muscular layer (middle layer), and the plasma layer (outer layer). Gastric cancer begins in the mucosal layer along the cells of the wall and spreads to the outer layer with continued growth.
Refer to the following PDQ summaries for more information about gastric cancer:
Gastric cancer is not common in the United States.
Gastric cancer is relatively uncommon in the United States compared to some parts of Asia, Europe, Central America, and South America. Stomach cancer is one of the leading causes of death in these regions.
Since 1930, new cases of gastric cancer have declined dramatically in the United States. The reasons for the decline are not clear, but may be related to improved food storage conditions and dietary changes, such as a reduction in salt intake.
Advanced age and some chronic diseases increase the risk of developing gastric cancer.
Any cause that increases the chance of developing the disease is called a risk factor. Having a risk factor does not mean you will develop cancer; not having a risk factor does not mean you will not get cancer. If you think you may be at risk for developing stomach cancer, talk to your doctor. Risk factors for stomach cancer include the following:
People from countries with a high incidence of stomach cancer are at increased risk of developing stomach cancer.