After food is chewed and swallowed, it goes into the esophagus, a tube that brings food through the throat and chest to the stomach. The esophagus joins the stomach at the gastroesophageal (GE) junction, which is simply underneath the diaphragm (the thin sheet of breathing muscle under the lungs). The stomach is a sac-like organ that holds food and begins to absorb it by producing stomach juice. The food and gastric juice are combined and then emptied into the first part of the little intestine called the duodenum.
Some people use the word stomach to refer to the area of the body between the chest and the pelvic area. The medical term for this area is the abdominal area. For example, some people with pain in this area would say they have a “stomachache”, when in reality the pain could be coming from the appendix, small intestinal tract, colon (large intestinal tract), or other organs in the area. Medical professionals would call this symptom abdominal pain, since the stomach is just one of many organs in the abdomen.
Stomach cancers tend to establish gradually over several years. Before a true cancer develops, pre-cancerous modifications often happen in the inner lining (mucosa) of the stomach. These early changes rarely cause symptoms and therefore typically go undiscovered.
Cancers starting in different sections of the stomach may cause various symptoms and have the tendency to have different results. The cancer’s location can also affect the treatment alternatives. For example, cancers that begin at the GE junction are staged and treated the same as cancers of the esophagus. A cancer that starts in the cardia of the stomach however then becomes the GE junction is likewise staged and dealt with like a cancer of the esophagus.
The majority of (about 90% to 95%) cancers of the stomach are adenocarcinomas. A stomach cancer or gastric cancer almost always is an adenocarcinoma. These cancers establish from the cells that form the inner lining of the stomach (the mucosa).
These are cancers of the immune system tissue that are often discovered in the wall of the stomach. The treatment and outlook depend on the type of lymphoma.
Gastrointestinal stromal tumor (GIST)
These unusual tumors start in extremely early kinds of cells in the wall of the stomach called interstitial cells of Cajal. Some of these tumors are non-cancerous (benign); others are cancerous. Although GISTs can be found anywhere in the digestive tract, many are found in the stomach.
These tumors begin in hormone-making cells of the stomach. Most of these tumors do not spread to other organs. These tumors are discussed in more information in Gastrointestinal Carcinoid Tumors.
Other types of cancer, such as squamous cell cancer, small cell carcinoma, and leiomyosarcoma, can also begin in the stomach, however these cancers are really rare.