Biologic and clinical variations of adenocarcinoma at the esophago-gastric junction: relevance of a topographic-anatomic subclassification.

A topographic-anatomic subclassification of adenocarcinomas of the esophago-gastric junction (AEG) in distal esophageal adenocarcinoma (AEG Type I), true carcinoma of the cardia (AEG Type II), and subcardial gastric cancer (AEG Type III) was introduced in 1987 and is now increasingly accepted and used worldwide. Our experience with now more than 1,300 resected AEG tumors indicates that the subtypes differ markedly in terms of surgical epidemiology, histogenesis and histomorphologic tumor characteristics. While underlying specialized intestinal metaplasia can be found in basically all patients with AEG Type I tumors, this is uncommon in Type II tumors and virtually absent in Type III tumors. Stage distribution and overall long-term survival after surgical resection also shows marked differences between the AEG subtypes. Surgical treatment strategies based on tumor type allow a differentiated approach and result in survival rates superior to those reported with other approaches. The subclassification of AEG tumors thus provides a useful tool for the selection of the surgical procedure and allows a better comparison of treatment results.