Stomach cancer, also known as gastric cancer, is a cancer that develops from the lining of the stomach. Gastric cancer is the sixth most common cancer and the third most common cause of cancer-related death in the world. Although rates are low in North America and Northern Europe—in the United States, stomach malignancy is currently the 15th most common cancer the disease remains difficult to cure in Western countries, primarily because most patients present with advanced disease. See the image below.