346. ESOPHAGOGASTRIC JUNCTION SIEWERT II TUMORS, A CHALLENGE FOR THE SURGEON: RESULTS OF TRANSHIATAL EXTENDED GASTRECTOMY VS. IVOR LEWIS ESOPHAGECTOMY

Abstract Background Esophagogastric junction (EGJ) Siewert type II tumors pose unique challenges in terms of adequate surgical treatment due to their anatomical location and potential for abdominal and mediastinal lymph node metastasis. The optimal surgical approach for these tumors remains a topic of debate, with options including transhiatal extended gastrectomy or transthoracic esophagectomy. Understanding the different outcomes associated with these surgical interventions is crucial for informed decision-making and patient-tailored management. The aim of this study was to compare the perioperative and oncological outcomes of these two surgical technique to access which could be the treatment of choice for Siewert II type tumours. Methods This study is a retrospective non-randomized cohort study from a single center. We reviewed the data of all the patients who underwent surgery for EGJ Siewert type II tumors between December 2014 and February 2023. The patients were divided into two groups: those who underwent transthoracic esophagectomy were assigned to “TE group” (72 patients) and those who underwent transhiatal extended gastrectomy were assigned to “TEG group” (21 patients). Results Patients in the TEG group were older (p=0.011) and in worst clinical condition (Charlson Comorbidity Index 4.15±1.78 vs. 4.95±1.46, p=0.064). The tumour stage at the diagnosis was more advanced in the TE group (p=0.004), and upfront surgery was infrequent in this group (p<0.001). The average duration of surgery was higher in the TE group (p<0.001). No difference was seen in the tumour length (p=0.924), implying a statistically significant difference in the proximal margin length (p<0.001), and distal margin length (p<0.001), with a R0 resection rate higher in the TE group (93.1% vs. 66.7%, p=0.002). The higher rate of R1 resection in the TEG group was mainly due to proximal margin infiltration. No difference was seen in the number of harvested lymph nodes (p=0.339). Overall postoperative complications rates were similar (p=0.144). No differences were found in the length of ICU stay (p=0.676) and in hospital stay (p=0.075). At a median follow up of 20 months, there were no statistical differences in Overall Survival and Disease-Free Survival at 5 years. Conclusion Our data suggests that transthoracic esophagectomy for EGJ Siewert type II tumors should be the treatment of choice for patients in good clinical condition, but transhiatal extended gastrectomy could be a good choice for patients presenting in worse clinical condition. A multidisciplinary approach is essential for optimal patient care, and the selection of the surgical technique should be based on a thorough evaluation of the patient's condition and tumor characteristics