Gastric cancer is one of the most common human malignant
tumors. Epidemiological investigations have provided
evidence that gastric carcinogenesis is a complex, multistep
and multifactorial event (15). Considering that reactive oxygen
species (ROS) are capable of changing a number of cellular
events involved in the cancer process by which cancer cells
escape the immune system, the status of oxidative stress and
immunity response may be a crucial factor in the development
of gastric cancer.