Some screening tests are used because they have been shown to be helpful both in finding cancers early and in decreasing the chance of dying from these cancers. Other tests are used because they have been shown to find cancer in some people; however, it has not been proven in clinical trials that use of these tests will decrease the risk of dying from cancer.
Scientists study screening tests to find those with the fewest risks and most benefits. Cancer screening trials also are meant to show whether early detection (finding cancer before it causes symptoms) decreases a person's chance of dying from the disease. For some types of cancer, the chance of recovery is better if the disease is found and treated at an early stage.
Clinical trials that study cancer screening methods are taking place in many parts of the country. Information about ongoing clinical trials is available from the
Upper endoscopy has been studied as a screening test to find stomach cancer at an early stage. Upper endoscopy is a procedure to look inside the esophagus, stomach, and duodenum (first part of the small intestine) to check for abnormal areas. An endoscope, a thin, tube-like instrument with a light and a lens for viewing, is passed through the mouth and down the throat into the esophagus. It may also have a tool to remove tissue to be checked under a microscope for signs of disease.
Some studies show that screening tests for stomach cancer, such as upper endoscopy, would not result in a lower death rate. More research is needed to decide if it would be worthwhile to screen people in the United States who have a high risk for the disease. High risk groups that may benefit from stomach cancer screening include: