Abstract
Chronic inflammation is a well-established risk factor for several diseases, including cancer. It influences tumor cell biology and the type and density of immune cells in the tumor microenvironment (TME), promoting cancer development. While proinflammatory cytokines and chemokines modulate cancer development, emerging evidence has shown that prostaglandin E2 (PGE2) is a known mediator connecting chronic inflammation to cancerization. This review highlights recent advances in our understanding of how the elevation of PGE2 production promotes gastrointestinal cancer initiation, progression, invasion, metastasis, and recurrence, including modulation of immune checkpoint signaling and the type and density of immune cells in the tumor/tissue microenvironment.