245. ESOPHAGECTOMY AFTER NEOADJUVANT CHEMOTHERAPY WITH AN INDICATION FOR CONVERSION SURGERY FOR HIGHLY ADVANCED ESOPHAGOGASTRIC JUNCTION ADENOCARCINOMA

Abstract Background There is currently no strong evidence for preoperative chemotherapy for advanced esophagogastric junction adenocarcinoma. Furthermore, no curative treatment strategy has been established for advanced junction adenocarcinoma, including Stage IV disease, with no indication for conversion surgery. Subjects and Methods In this study, we retrospectively reviewed nine patients with highly advanced esophagogastric junctional adenocarcinoma, including Stage IV adenocarcinoma, who underwent systemic chemotherapy followed by planned resection at our hospital. Results The participants included 6 males and 3 females, with median age of 64 (range: 45–72) years. Pretreatment stages III, IVA, and IVB, categorized based on UICC TNM classification (esophageal adenocarcinoma), were observed in 1, 4, and 4 cases, respectively, with 1 case of (#104) subclavian lymph node metastases, 1 case of (#16) abdominal para-aortic lymph node metastases, and 2 cases of liver metastases, including multiple lesions. All patients received S-1 plus oxaliplatin (SOX) therapy as preoperative chemotherapy (2–40 courses). Although we observed one patient with unresectable abdomen malingnancies, the others underwent R0 resection, six underwent esophagectomy (with three total gastrectomy and one liver resection), and two open (+ continuous right thoracotomy) lower esophagectomy + total gastrectomy. Pathological stages I, II, III, and IV were observed in two, one, four, and one patients, respectively. Postoperatively, stereotactic irradiation, chemotherapy, and immune checkpoint inhibitors were administered to the patients to treat recurrent brain and liver metastases, and the 1-year survival rate was found to be 71.4% with a median observation period of 17 (range: 0–61) months. Among them, downstage and pN0 cases were relatively promising. Conclusion Even in highly advanced cases, cases with promising prognoses with multidisciplinary treatment, including surgery, were observed. We hope that large-scale clinical trials, such as JCOG2203, will help clarifying the significance of this approach, and advancements in chemotherapy regimens are expected.