Description

What Is Stomach Cancer?

Cancer starts when cells in the body begin to grow out of control. Cells in nearly any part of the body can become cancer, and can then spread to other areas of the body. To learn more about cancer and how it starts and spreads, see What Is Cancer?

Stomach cancer, also called gastric cancer, begins when cells in the stomach start to grow out of control.

The stomach

To understand stomach cancer, it helps to know about the normal structure and function of the stomach.

The stomach is a sac-like organ that’s an important part of the digestive system.

After food is chewed and swallowed, it enters the esophagus, a tube that carries food through the throat and chest to the stomach. The esophagus joins the stomach at the gastroesophageal (GE) junction, which is just beneath the diaphragm (the thin sheet of breathing muscle under the lungs). The stomach then starts to digest the food by secreting gastric juice. The food and gastric juice are mixed and then emptied into the first part of the small intestine called the duodenum.

Some people use the word 'stomach' to refer to the belly area. The medical term for this area is the abdomen. For instance, some people with pain in this area would say they have a 'stomach ache', when in fact the pain could be coming from some other organ in the area. Doctors would call this symptom 'abdominal pain,' because the stomach is only one of many organs in the abdomen.

Stomach cancer is different from other cancers that can occur in the abdomen, like cancer of the colon or rectum (large intestine), liver, pancreas, or small intestine. These cancers can have different symptoms, different outlooks, and different treatments.