This article describes the molecular mechanisms and key markers of tumor autophagy, the signaling pathways involved in GC-associated autophagy (PI3K/AKT/mTOR, AMPK, MAPK, p53), and summarizes the mechanism of autophagy and Helicobacter pylori infection in GC, how autophagy interacts with apoptotic and iron-death processes and the wide-ranging influences that these factors play in the process. This evidence concerns the gene PIK3CA and gastric cancer.