Surgery for EG Junction Cancer

Abstract

Should esophagogastric junction (EGJ) cancer be classified or managed as gastric cancer or esophageal cancer or else? The debate focused on the issue has still remained [1], though EGJ cancer is increasing worldwide, in Asia [2–5] as well as western countries [6–8]. Squamous cell carcinoma developed in EGJ region is unanimously treated as esophageal cancer. For EGJ adenocarcinoma, Siewert classification has been widely applied: type I (adenocarcinoma of the distal esophagus), tumors with an epicenter located more than 1 cm above the EGJ; type II (true cardia cancer), tumors with an epicenter located within 1 cm oral and 2 cm aboral from the EGJ; and type III (subcardial cancer), tumors with an epicenter located below 2 cm from the EGJ [9, 10]. Among Siewert classifications, Siewert type I and III tumors are usually managed like esophageal and gastric cancers, respectively. However, in 7th AJCC TNM classification, both Siewert type II and III tumors had been classified as esophageal cancer. After some discussions [11–13], in 8th version, type III was changed to gastric cancer classification, while type II still stays in esophageal classification [14–15]. There have been many papers regarding the clinicopathologic features of Siewert type II tumors to identify the pathogenesis and appropriate treatment strategy. Some papers showed that the characteristics of Siewert type II were quite similar with gastric cancers [11, 12]. However, some papers reported that there were two distinct pathways of tumorigenesis of EGJ adenocarcinoma, related or unrelated to intestinal metaplasia, gastric atrophy, and gastric acid secretion [16–17]. The etiology as well as the treatment strategy has still remained controversy, especially for Siewert type II tumors.