Adenocarcinomas of the distal esophagus and "gastric cardia" are predominantly esophageal carcinomas

Background: Adenocarcinoma of the distal esophagus and gastric cardia are defined by the relationship of its epicenter to the gastro-esophageal junction, which is presently defined as the end of the tubular esophagus. We have recently suggested that the true gastro-esophageal junction is best defined by the proximal limit of gastric oxyntic mucosa. Aim: To reclassify adenocarcinomas of this region by the relationship of the tumor to the proximal limit of gastric oxyntic mucosa. Methods: Seventy-four patients who had esophago-gastrectomy for adenocarcinomas in this region were classified as adenocarcinoma of distal esophagus (38 patients) and gastric cardia (36 patients) by present criteria. The epithelial type at the epicenter and distal edge of these tumors was assessed. Results: The epicenter of the tumor in 64 patients with noncircumferential tumors had squamous (5 cases), cardiac (21 cases), oxymo-cardiac (4 cases), and intestinal (Barrett-type) (34 cases) epithelia. None had gastric oxyntic mucosa. Of the 10 patients with circumferential tumors, 7 had cardiac or oxyntocardiac epithelium at the distal tumor edge. Conclusions: If the gastro-esophageal junction is defined histologically as the proximal limit of oxyntic mucosa, 71/74 patients would be classified as adenocarcinoma of the distal esophagus. The other 3 patients were questionable as to gastric or esophageal origin. We suggest that this reclassification based on the proposed new definition of the gastro-esophageal junction provides an explanation for the epiderniologic relationship that exists between adenocarcinorna of the "gastric cardia" and gastro-esophageal reflux disease.