255 OUTCOME OF ADDITIONAL ESOPHAGECTOMY AFTER NON-CURATIVE ENDOSCOPIC SUBMUCOSAL DISSECTION FOR C-MM-SM1ESOPHAGEAL CANCER.

Abstract For patients diagnosed cT1(MM-SM1)N0 esophageal cancer, we perform endoscopic submucosal dissection (ESD) as a primary treatment. Furthermore, additional treatments were performed for the patients diagnosed pT1b(SM) in resected tumor by ESD. Our aim of this study is to investigate whether additional esophagectomy after non-curative ESD can be considered a valid treatment. Methods Forty-four patients who received esophagectomy with lymph node (LN) dissection in neck, mediastinum and upper abdomen as additional surgery after non-curative ESD between 2006 and 2019 were enrolled. Histological examination revealed that squamous cell carcinoma in 41 and adenocarcinoma in 3 patients. We examined the rate of pathological LN metastasis and outcomes of patients received esophagectomy. Results The cT was LPM in 9(20%), MM-SM1 in 35 (80%) patients. However, the pT was MM in 3(7%), SM1 in 14 (32%) and SM2 in 27 (61%) patients. Lymphatic invasion was positive in 32 (73%) and venous invasion was positive in 16(36%) patients. Seven patients had pathological metastatic LN (1–2 LNs/case) (total 10 metastatic LNs). The metastatic LNs existed in neck, mediastinum and upper abdomen. The recurrences were occurred in 2 patients (No.106recL LN and No. 112ao-A LN). One patient died by esophageal cancer (LN recurrence, 38 months alive). One patient died of gastric tube ulcer perforation (16 months). Conclusion We showed that esophagectomy with extended LN dissection is sufficient as additional treatment for the patients treated non-curative ESD. To expand the indications of ESD for pSM esophageal cancer, new methods are needed, such as the risk diagnosis of LN metastasis using genetic analysis.