Advances in the study of the relationship between neurotransmitters and gastric cancer.

Emerging evidence underscores the critical, yet frequently underrecognized, role of the nervous system in the development and progression of gastric cancer (GC), primarily mediated through complex neuro-tumoral interactions and modulation of immune responses. GC cells actively invade neural structures, inducing aberrant nerve growth, while, in parallel, neural components infiltrate the tumor microenvironment, collectively promoting tumor proliferation, dissemination, and resistance to therapy. These bidirectional processes are regulated by diverse neurotransmitter systems-including monoaminergic, cholinergic, amino acid-based, peptidergic, and purinergic pathways-which are aberrantly produced by both neurons and malignant cells. Beyond their canonical function in neural signaling, these neuromediators exert diverse effects on tumor biology, coordinating multiple facets of GC progression, including invasion, metastasis, and cellular expansion. This review synthesizes current advances and outlines future directions in elucidating the mechanistic contributions of neurotransmitters to GC pathophysiology.