Stomach cancer is characterized by a growth of cancerous cells within the lining of the stomach. Also called gastric cancer, this type of cancer is difficult to diagnose because most people typically don’t show symptoms in the earlier stages.
It's not clear what causes stomach cancer, though research has identified many factors that can increase the risk.
Stomach cancer begins when a cell in the stomach develops changes in its DNA. A cell's DNA contains the instructions that tell the cell what to do. The changes tell the cell to grow quickly and to continue living when healthy cells would die. The accumulating cells form a tumor that can invade and destroy healthy tissue. With time, cells can break off and spread (metastasize) to other areas of the body.
Factors that increase the risk of stomach cancer include:
Some of the most common symptoms of advanced stomach cancer are:
In the early stages when the cancer is limited to the superficial (uppermost) layers of the stomach, the cancer can be removed through an upper endoscopy performed by a gastroenterologist. In this procedure (endoscopic submucosal dissection, or ESD), the tumor is dissected from the rest of the gastric wall and removed through the mouth.
Once the tumor invades beyond the superficial layers of the stomach, surgery will be required to remove the stomach and connect the esophagus (the tube through which food passes) to the small intestines to allow for digestion.
Radiation therapy uses high-powered beams of energy to kill cancer cells. Chemotherapy uses chemicals to kill the cancer cells. These treatments are generally combined.
There are also several drugs to treat stomach cancer. Treatment depends on how severe the cancer is and is decided upon by a doctor after diagnosis.