Until the late 1930s, stomach cancer was the leading cause of cancer death in the United States. Now, stomach cancer is well down on this list.

Gastric (stomach) cancer is a disease in which malignant (cancer) cells form in the lining of the stomach. The stomach is in the upper abdomen and helps digest food.

Almost all gastric cancers are adenocarcinomas (cancers that begin in cells that make and release mucus and other fluids). Other types of gastric cancer are gastrointestinal carcinoid tumors, gastrointestinal stromal tumors, and lymphomas.