A term that refers to the staging of a gastric neuroendocrine tumor according to the American Joint Committee on Cancer, 8th edition. This staging system applies to gastric ""carcinoid"" tumors (NET G1 and G2, and rare well-differentiated G3). Gastric high-grade neuroendocrine carcinoma and gastric mixed adenoneuroendocrine carcinoma are not included in this staging system. (from AJCC 8th Ed.) [from NCI]