Gastric polyps of three centimeters are cancerous, so you should go to the hospital in time for treatment. Gastric polyp is a limited, elevated lesion formed by the gastric mucosa protruding from the gastric cavity. The occurrence of gastric polyps is related to many factors, including long-term chronic inflammatory stimulation of the gastric mucosa (e.g. Helicobacter pylori infection, bile reflux), long-term use of proton pump inhibitors, genetic factors, and bad habits (e.g., smoking, alcohol consumption, high-fat diet, low-fiber diet, etc.). The risk of cancer may be increased in gastric polyps ≥1 cm in diameter, and endoscopic resection is usually recommended. In order to identify whether a gastric polyp has developed into a malignant polyp, the diagnosis can be confirmed by pathologic biopsy, which is usually sent to the pathology department for biopsy after endoscopic resection. If the polyp is diagnosed as a benign lesion, surgical removal is sufficient, and annual review in the hospital is sufficient. If the polyp is malignant, surgical treatment is required, and timely consultation is recommended.