Stomach cancer begins when the cells form in the inner lining of your stomach. These cells can grow into a tumor. Infection with a common bacterium, H pylori can cause ulcers. Inflammation in your gut can cause gastritis. It produces a specific type of long-lasting anemia called pernicious anemia. Growths in your stomach called polyps can increase your risk for cancer.
Other variables that may increase your risk for cancer include smoking, being overweight, Epstein Barr virus infection, specific genes, exposure to asbestos, and having type A blood. Stomach cancer is more common in old age, as usually, those people over the age of sixty are more susceptible.