Preventive tests for gastric cancer include many items that can help to screen for gastric cancer at an early stage. Commonly used preventive tests for gastric cancer include: 1. blood tests, including blood tumor markers, such as carcinoembryonic antigen (CEA), glycoantigen 72-4 (CA72-4), glycoantigen 19-9 (CA19-9) and CA50, which may be able to get some early signals of gastric cancer through blood tests; and routine blood tests. This is also a preventive test for gastric cancer; 2. There is also fecal occult blood, which is a stool test. If there is occult blood in the stool, which cannot be seen by the naked eye, but the occult blood is positive, it may be an early sign of gastric cancer; 3, other tests include gastrointestinal imaging, and dual gas-barium imaging is very common, which is very helpful to see some gastric ulcers and precancerous lesions of the stomach; 4, another test for gastric cancer is upper abdominal ultrasound, which is not advantageous for early gastric cancer. Because there are some gases in the stomach and intestines, ultrasound still does not look particularly accurate, but when the size of gastric cancer is relatively large and obvious, or even when there is a mass formed outside the stomach, ultrasound is also a common way to screen for gastric cancer. If you have chronic gastric diseases, especially chronic atrophic gastritis, atypical hyperplasia of mucosal epithelium of stomach, especially moderate to severe atypical hyperplasia, you should undergo gastroscopy regularly.