562. COMPARATIVE ANALYSIS OF THE OUTCOMES OF GASTRECTOMY VS. ENDOSCOPIC SUBMUCOSAL DISSECTION FOR THE TREATMENT OF GASTRIC TUBE CANCER AFTER ESOPHAGECTOMY

Abstract Background Although multimodal treatment and minimally invasive surgery for esophageal cancer have improved therapeutic outcomes for esophagectomy, this improvement has led to many reports of metachronous cancers following esophagectomy. After esophagectomy for esophageal cancer, the locations where metachronous cancers occur most frequently are the oropharynx, hypopharynx, and larynx, followed by the gastric tube. Due to a paucity of reports, much remains unknown about gastric tube cancer, such as the site of common occurrence, pattern of metastasis, treatment method. This study investigated the clinical characteristics of patients with gastric tube cancer and to examine the outcomes of gastrectomy versus endoscopic submucosal dissection. Methods Of 49 patients who underwent treatment for gastric tube cancer that developed 1 year or more after esophagectomy, 30 patients underwent subsequent gastrectomy (Group A), and 19 patients underwent endoscopic mucosal resection (EMR) or endoscopic submucosal dissection (ESD) (Group B). The characteristics and outcomes of these two groups were compared. Results The interval between esophagectomy and diagnosis of gastric tube cancer ranged from 1 to 30 years. The most common location was the lesser curvature of the lower gastric tube. When the cancer was detected early, EMR or ESD was performed, and the cancer did not recur. In advanced tumors, gastrectomy was performed but the gastric tube was difficult to approach and lymph node dissection was difficult; two patients died as a result of the gastrectomy. In Group A, recurrence occurred most often as axillary lymph node, bone, or liver metastases; in Group B, no recurrence or metastases were observed. Conclusion In addition to recurrence and metastasis, gastric tube cancer is often observed after esophagectomy. The present findings highlight the importance of early detection of gastric tube cancer after esophagectomy and that the EMR and ESD procedures are safe and have significantly fewer complications compared with gastrectomy. Follow-up examinations should be scheduled with consideration given to the most frequent sites of gastric tube cancer occurrence and the time elapsed since esophagectomy.