Clinicopathological features of Siewert type II adenocarcinoma: comparison of gastric cardia adenocarcinoma and Barrett's esophageal adenocarcinoma following endoscopic submucosal dissection.

Siewert type II esophagogastric junction adenocarcinoma encompasses both gastric cardia adenocarcinoma (GCA) and Barrett's esophageal adenocarcinoma (BEA) due to short-segment Barrett's esophagus. We compared these two types of Siewert type II esophagogastric junction adenocarcinoma in terms of background factors and clinical outcomes of endoscopic submucosal dissection (ESD).,We enrolled 139 patients (142 lesions) who underwent ESD from 2006 to 2014 at our institution. Background factors evaluated were age, sex, body mass index, hypertension, hyperlipidemia, hyperuricemia, diabetes mellitus, smoking, drinking, double cancer, and endoscopic findings. Clinical outcomes evaluated were procedure time, en bloc resection rate, curative resection rate, and adverse events.,There were 87 GCA lesions (61.2%) and 55 BEA lesions. Features of BEA [55 lesions (38.8%)] included a younger age, small diameter, and a protruding type, along with a high frequency of esophageal hiatal hernia and less mucosal atrophy. There were no significant differences in lifestyle-related background factors between the GCA and BEA groups. Curative resection rate was greater for GCA (81%) than for BEA (66%) (P = 0.01). There were no serious adverse events in either group. Among the factors for noncurative resection, lymphovascular invasion and depth of invasion were greater for BEA (33.3 vs. 7 and 20.7 vs. 8.2%, respectively (P < 0.01). Of the noncured patients, 70% underwent additional surgery and none had postoperative lymph node metastasis.,Siewert type II adenocarcinoma encompasses two types of cancers with different etiologies: GCA and BEA. Although there are no significant differences in lifestyle-related background factors between GCA and BEA, BEA is a risk factor for noncurative resection via ESD.