ABSTRACT Gastric cancer is a heterogeneous type of cancer that shows histopathological and epidemiological differences in various countries and is common throughout the world. Gastric cancer may be caused by microbial factors such as Helicobacter pylori and Epstein-Barr virus (EBV) infections, genetic factors including family history, A blood group, E-cadherin gene mutation, and environmental factors such as smoking, alcohol, consumption of foods high in fat, carbohydrate, nitrate, and salt.