Stomach cancer is cancer that occurs in the stomach — the muscular sac located in the upper middle of your abdomen, just below your ribs. It occurs due to abnormal and uncontrolled cell growth in the stomach. 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.
Most people with early stomach cancer have no signs or symptoms of the condition. In advanced stages, symptoms may include indigestion; nausea and vomiting; difficulty swallowing; feeling full after eating small amounts of food; loss of appetite; vomiting blood; fatigue; and/or weight loss. Most cases of stomach cancer occur sporadically in people with little to no family history of the condition; however, approximately 10% of stomach cancers are considered “familial.” Although the underlying cause of some familial cases is unknown, genetic changes (mutations) are identified in a subset of people affected by stomach cancer. Hereditary cancer syndromes associated with a predisposition to stomach cancer include hereditary diffuse gastric cancer, Lynch syndrome, Li-Fraumeni syndrome, familial adenomatous polyposis, and Peutz-Jeghers syndrome. In other families, a cluster of stomach cancers may be due to a combination of gene(s) and/or other shared factors such as environment and lifestyle. The best treatment options for stomach cancer depend on many factors including the stage of the condition and may include surgery, chemotherapy, radiation therapy, and/or targeted therapy (such as monoclonal antibody therapy).