A tumor in the stomach, also called gastric cancer, starts when cells that normally make mucus in the stomach lining grow out of control. They form a mass (tumor) that can spread to other parts of the body and interfere with digestion. This can lead to pain, bloating, vomiting and nausea.
The disease typically grows slowly over years, and people with it don’t usually have any symptoms in the early stages. So it can be hard to diagnose and treat.
Your doctor might check your stomach for a lump or mass by doing an endoscopy, which uses a long, flexible tube passed down the throat and into the stomach to examine the lining. This can help diagnose cancer and find out whether it has spread to other parts of your body.
If the cancer is small, your doctor might remove it by cutting it away from the inside lining with special scissors or cutters. This type of surgery is called endoscopic mucosal resection. It might be an option for people who have stage 1 cancer that is growing on the inside lining of their stomachs.
It might also be used to remove cancers that have grown into the muscle layer of the stomach wall. It can relieve some stomach symptoms and may reduce the risk of developing an infection in your stomach that might be life-threatening (septic peritonitis).
There are several types of tumors that can occur in the stomach. The most common is adenocarcinoma, which occurs in about 90 percent of all stomach cancers. It occurs most often in men and older adults. Other types are gastrointestinal stromal tumors (GIST) and lymphomas, which occur in the immune system.
These types of tumors are slow-growing and less aggressive than adenocarcinoma. They can be treated with drugs that target specific mutations in cancer cells.
Some people with stomach cancers have a genetic change in their DNA that makes them more likely to develop the cancer. This can be caused by a condition such as diabetes or exposure to certain chemicals and foods.
Your health care team will test your stomach for cancer with a CT scan, MRI or X-ray. The tests will show where the cancer is in your stomach and how large it is. They also can help identify any problems with the esophagus or other nearby organs.
A needle biopsy is another method of identifying cancer in your stomach or other parts of the digestive tract. This is a procedure in which a sample of the suspicious tissue is taken by a doctor and examined under a microscope. It can help your doctor diagnose the type of cancer and decide what treatment is best for you.
The most common stomach cancers are adenocarcinomas, which begin in cells that produce mucus. They are the most common form of stomach cancer and account for about 90 percent to 95 percent of all cases.
Other types of stomach cancers include carcinoid tumors, which start in neuroendocrine cells. These are cells that do some nerve cell functions and some of the work of cells that make hormones.
