Stomach cancer is a disease in which cancerous cells first develop in the stomach. The most common type of this cancer is gastric adenocarcinoma, or cancer of the glandular tissue in the stomach. Symptoms may include indigestion, heartburn, bloody stools, vomiting, unexplained weight loss, and jaundice. Typically, treatment options for the disease usually include surgery, chemotherapy, and radiation therapy.
Stomach cancer, also known as gastric cancer, is a disease in which cancer cells first form in the stomach. In the United States, stomach cancer is the seventh leading cause of cancer deaths. Although the incidence of stomach cancer in the United States has decreased since the 1930s, this type of cancer is a major cause of death worldwide, especially in developing countries.
The stomach is a J-shaped hollow organ that is located in the upper abdomen. The stomach is the part of the digestive system that processes nutrients from food and helps pass waste material out of the body. After the partly digested food leaves the stomach, it will pass into the small intestine and then into the large intestine.
The wall of the stomach is made up of three layers of tissue:
- The mucosal (innermost) layer
- The muscularis (middle) layer
- The serosal (outermost) layer.
The most common type of stomach cancer is gastric adenocarcinoma, or cancer of the glandular tissue in the stomach. Rare forms of stomach cancer include:
- Lymphomas -- cancers involving the lymphatic system (see Lymphoma)
- Sarcomas -- cancers of the connective tissue, such as muscle, fat, or blood vessels.
Stomach cancer can also affect nearby organs and lymph nodes. For example:
- A stomach tumor can grow through the stomach's outer layer into nearby organs, such as the pancreas, esophagus, or intestine
- Stomach cancer cells can spread through the blood to the liver, lungs, and other organs
- Stomach cancer cells also can spread through the lymphatic system to lymph nodes all over the body.
When stomach cancer spreads from its site of origin to another part of the body, the new tumor will have the same kind of abnormal cells and the same name as the original tumor. For example, if stomach cancer spreads to the liver, the cancer cells in the liver are actually stomach cancer cells -- not liver cancer cells. Therefore, it will be treated as stomach cancer. Doctors may call the new tumor "distant" or metastatic disease.
(Click Stomach Cancer Types for more information.)
For the remainder of this article, the term "stomach cancer" will be used to refer to gastric adenocarcinoma.