Definition of Gastric cancer:

Gastric cancer is cancer that starts in the stomach.

Causes, incidence, and risk factors:

Several different types of cancer can occur in the stomach. The most common type is called adenocarcinoma, which starts from one of the common cell types found in the lining of the stomach.

There are several types of adenocarcinoma. Because other types of gastric cancer are more rare, this article focuses on adenocarcinoma of the stomach.

Adenocarcinoma of the stomach is a common cancer of the digestive tract worldwide, although it is uncommon in the United States. It occurs most often in men over age 40. This form of gastric cancer is very common in Japan, Chile, and Iceland.

The rate of most types of gastric adenocarcinoma in the United States has gone down over the years. Experts think the decrease may be because people are eating less salted, cured, and smoked foods.

Risk factors for gastric cancer are:

• Family history of gastric cancer
• Helicobacter pylori infection (a common bacteria that can also cause stomach ulcers)
• History of an adenomatous gastric polyp larger than 2 centimeters
• History of chronic atrophic gastritis
• History of pernicious anemia
• Smoking