1 Introduction Gastric cancer (GC) is one of the most common tumors in the gastrointestinal (GI) tract in China. It ranks as the fifth most common cancer and the third leading cancer-related cause of death globally in 2018 [1]. The 5-year survival rate of patients with GC has been estimated to be less than 50%; however, that of early gastric cancer (EGC) after resection is > 90% [2]. Therefore, early detection and treatment of GC is vital in clinical practice.