Tasamy, thank you for your questions. First, stomach cancer, also called gastric cancer, is generally rare in the United States, but is on the rise among younger people. Second, it's not clear what causes stomach cancer. Experts believe most stomach cancers start when something hurts the inside lining of the stomach such as having an infection in the stomach, long-standing acid reflux, and eating a lot of salty foods. To give you more information, visit this webpage on mayoclinic.org:
https://www.mayoclinic.org/diseases-conditions/stomach-cancer/symptoms-causes/syc-20352438