Stomach cancer is cancer that occurs in the stomach — the muscular sac located in the upper middle of your abdomen, just below your ribs. Your stomach receives and holds the food you eat and then helps to break down and digest it.
Another term for stomach cancer is gastric cancer. These two terms most often refer to stomach cancer that begins in the mucus-producing cells on the inside lining of the stomach (adenocarcinoma). Adenocarcinoma is the most common type of stomach cancer.
Stomach cancer is uncommon in the United States, and the number of people diagnosed with the disease each year is declining. Stomach cancer is much more common in other areas of the world, particularly China and Japan.