In the Western world, adenocarcinoma of the proximal stomach and esophagogastric junction (AEG) continues to rise in incidence and prevalence.1 The literature regarding the optimal surgical approach to these tumors has been a source of considerable controversy. Much of this debate stems from the fact that many surgeons still practice a rather indiscriminate approach to adenocarcinomas that arise at or close to the AEG.2 As a consequence of the worldwide acceptance of the AEG classification system and use of this system in several prospective trials, clearer guidelines on how to treat the various types of AEG adenocarcinomas are now being published.
In 1998 we defined adenocarcinomas of the AEG as tumors that have their center within 5-cm proximal and distal of the anatomic cardia and comprise one of three distinct tumor entities within this area.3 These entities are (1) adenocarcinoma of the distal esophagus (AEG type I tumors), which usually arises from an area with specialized intestinal metaplasia of the esophagus, that is, Barrett's esophagus, and may infiltrate the AEG from above; (2) true carcinoma of the cardia (AEG type II tumors), which arises from the cardiac epithelium or very short segments with intestinal metaplasia at the AEG; and (3) subcardial gastric carcinoma (AEG type III tumors), which infiltrates the AEG and distal esophagus from below (Fig. 11-1).
This system of classification is purely morphologic and based on the anatomic topographic location of the tumor center or, in patients with an advanced tumor, the dominant location of the tumor mass. Although all three of these tumor types share a number of common features, there are marked discrepancies in epidemiology, etiology, tumor biology, and pattern of lymphatic spread, particularly between type I and III tumors.4 Type II tumors include those type I tumors that arise from short Barrett's mucosa segments as well as typical cardia gastric cancers. Accordingly, in approximately 25% of the specimens of resected AEG type II tumors, it is possible to demonstrate goblet cells (i.e., tumors that arise from short Barrett mucosa segments), whereas 75% are typical cardia gastric cancers. As a consequence, one can combine the AEG type II and type III tumors at least with respect to the surgical consequences.5–7
Only has the most recent version of the unified International Union Against Cancer (UICC) and the American Joint Committee on Cancer (AJCC) TNM classification system taken AEG into account.8 The gastric cardia is now clearly considered to be part of the stomach. Consequently, tumors that arise in this location should be staged according to gastric cancer guidelines. When assigning a T category, it must be considered that the gastroesophageal junction, the posterior wall of the proximal fundus, and large portions of the lesser and greater curvature of the proximal stomach are not covered by the visceral peritoneum, ...