A Proposed New Clinical Classification of Metastatic Gastric Cancer: Pyloric and Antral Gastric Cancer

Background We aimed to classify metastatic pyloric/antral gastric cancer in terms of macroscopic morphology and metastatic form. Methods Thirty-eight patients with pyloric/antral gastric cancer were included in the study. Patients were classified according to a combination of Borrmann classification type and metastatic type, and the clinicopathological characteristics of each group were compared. Result Of the 38 patients, 33 (type II: 9 and type III: 24) (87%) had ulcerative gastric cancer. Ulcerative gastric cancer was classified into four groups: lymphatic only group (L+H-P-), lymphatic + hematogenous group (L+H+P-), disseminated ± lymphatic group (L±H-P+), and lymphatic + hematogenous + disseminated group (L+H+P+). In the L+H-P- group, all patients had bulky lymph nodes and serum levels of both carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9) were high; the condition of patients was good, and the therapeutic response was good. In the L+H+P- group, metastases other than liver metastases were rare, and serum CEA levels were high. In the L±H-P+ group, the predominant histological type was signet ring cell carcinoma; both serum CEA and CA19-9 levels were low. Patients in the L+H+P+ group had higher serum CA19-9 levels and were more prone to hematogenous metastasis to various organs; these patients had worse patient status and lower treatment response. Gastric cancer other than ulcerative type was only detected in five patients (type V: 3, type IV: 1, type I: 1). Conclusion Classification by a combination of macroscopic and metastatic form in pyloric/antral metastatic gastric cancer might be useful for diagnosis and treatment.