Endoscopic Treatment Of Early Adenocarcinoma Of The Esophagogastric Junction

Background Esophagogastric junction adenocarcinoma and distal gastric cancer are different in etiology,biological behavior and clinicopathological characteristics.AEGJ has high lymph node metastasis rate and poor prognosis.However,ESD for AEGJ still follows the guidelines for indications of ESD for early gastric cancer(EGC)and lacks its own guidelines.Recently,curative criteria after ESD for EGC were updated by the Japanese Gastric Cancer Association.According to the long-term follow-up of JCOG 0607 clinical trials,the prognosis of patients with differentiated EGC who met the expanded indications of ESD,was no statistical difference form those with absolute indications.So the expanded indications of ESD for EGC were incorporated into the absolute indications group.The purpose of this study was to validate the clinical efficacy of the application of the curative criteria of the 5th edition of the Japanese gastric cancer treatment guidelines for early AEGJ after ESD.Methods Patients who underwent ESD for Siewert type Ⅱ adenocarcinoma between January 2013 and June 2018 were eligible for this study.Clinical and pathological features and treatment outcomes were retrospectively reviewed using medical records.The study reclassified the pathologic findings into 3 groups as follows:the absolute-indication group(group 1,G1),the expanded-indication group(group 2,G2),and the relative-indication group(group 3,G3).The en-bloc resection rate,complete resection rate,curative resection rate,eCura system and complication rate were analyzed and compared by SPSS software.Results A total of 177 cases of AEGJ treated with ESD were included in this study.There was no significant difference between G1 group and G2 group in ER and ER of these three groups were 98.8%,98.6%and 88.0%respectively.The CR rates among three groups were 89.2%,84.1%and 76.0%respectively and there was no significant difference.The CuR rates were 84.3%,69.6%and 32.0%,but there was no significant difference between G1 and G2.According to the eCura scoring system,89 patients(50.3%)were categorized as eCura A,36(20.3%)as eCura B,17(9.6%)as eCura C-1,and 35(19.8%)as eCura C-2.Five of the patients categorized as eCura C-2 underwent radical surgery,and two of which was confirmed to lymph node metastasis according to pathological outcomes.There was no statistical difference in the incidence of complications among the three groups.Conclusions This is the first study to evaluate the efficacy of ESD for AEGJ according to the curative criteria of the 5th edition of the Japanese gastric cancer treatment guidelines.There are no significant differences in the ER,CR,CuR and complication rate between the absolute indication group and the expanded indication group,but there are still statistical differences in eCura system.Since this study was a single-center retrospective study with relatively short follow-up time,additional large-scale,multi-center and long-term follow-up prospective clinical trials are needed to verify the best indications criteria for ESD in AEGJ.