Comparison of the clinicopathological characteristics and results of endoscopic submucosal dissection for esophagogastric junction and non-junctional cancers.

BACKGROUND Esophagogastric junction (EGJ) cancers are not only located in regions anatomically difficult for endoscopic submucosal dissection (ESD), but they also have higher clinicopathological malignant potential than non-junctional gastric cancers (NJC). Despite this, no ESD-based comparative studies of junctional cancer (JC) and NJC have been conducted to date. The aims of this study were to clarify the clinicopathological characteristics of EGJ cancers and the short- and long-term outcomes after ESD. METHODS Between April 2005 and December 2010, ESD was performed on 1,463 lesions that were divided into the following three groups: Barrett's adenocarcinoma (BA; n = 25); JC (n = 103), and NJC (n = 1,335). They were assessed for short-term outcomes, clinicopathological malignancy and long-term outcomes. RESULTS Rates of complete and curative resection were significantly lower for BA than for JC and NJC (64.0 vs. 96.1 and 96.0%; and 48.0 vs. 80.6 and 85.8%, respectively). The perforation rate was significantly higher for BA than for JC and NJC (20.0 vs. 2.9 and 2.7%). Clinicopathologically, submucosal invasion rates were higher in BA and JC than in NJC (32.0 and 30.1 vs. 13.6%), and positive rates of lymphatic and/or vascular invasion were remarkably higher in BA and JC versus NJC (24.0 vs. 9.7 vs. 4.8%, respectively). The 5-year survival rate in all patients with curative resection was 100%. CONCLUSION This study confirmed the technical and theoretical validity of ESD for EGJ as a diagnostic treatment. However, we have to pay attention to the high rates of submucosal and lymphovascular invasive malignant potential of these cancers.