Is adenocarcinoma of the gastric cardia a distinct entity independent of subcardial carcinoma?

Cardia carcinoma has been defined diversely. The purpose of this study was to determine whether cardia carcinoma should be categorized as a distinct entity independent of subcardial carcinoma. We retrospectively analyzed 65 patients undergoing resection for adenocarcinoma involving the esophagogastric junction (EGJ) with the tumor center within 5 cm of the EGJ. Adenocarcinomas of the EGJ were classified into Type I, Type II, and Type III according to Siewert's criteria. There was only one Type I adenocarcinoma, and it was associated with Barrett's esophagus. No tumors had their center between 1 cm and 2 cm proximal to the EGJ. Clinicopathologic features and prognosis were compared among patients with Type II adenocarcinomas (n = 31), patients with Type III adenocarcinomas (n = 33), and patients with adenocarcinomas in the upper third of the stomach not invading the EGJ (n = 153). Siewert's Type II adenocarcinoma was associated with a higher male/female ratio and with higher incidences of well-demarcated appearance and differentiated histology than carcinoma of the upper third of the stomach without esophageal invasion. Lymph nodes along the greater curvature and parapyloric nodes were rarely involved in Type II tumors. Within the pT2 category, patients with Siewert's Type II tumors showed a higher incidence of lymph node metastasis and a significantly lower survival rate than did patients with tumors of the upper third of the stomach without esophageal invasion. In conclusion, cardia carcinoma, appropriately defined as adenocarcinoma with its epicenter between I cm proximal and 2 cm distal to the EGJ, should be categorized as a distinct entity.