803. 2-YEAR RESULTS IN ESOPHAGOGASTRIC JUNCTION CANCER TREATMENT

Abstract Background Esophagogastric junction (EGJ), also known as cardia, tumors have unique characteristics with a widespread of lymph node (LN) metastatic patterns influenced by the extent of esophageal involvement. Besides, there is no worldwide consensus about its classification and the optimal lymphadenectomy and surgical resection extend. Recently, mapping the distribution of LN metastasis in these patients could provide some insights about the extent that should be the target. Furthermore, the balance between resection extension and the procedure safety is also difficult to achieve. This work aims to review the last 2 years of EGJ tumor treatment in a single oncological center. Methods We present a retrospective, single center study that included all the patients with EGJ cancer undergone surgical resection between 2022 and 2023. These tumors were classified using our modified Siewert (mSiewert) classification based on mapping endoscopy with measures of the full extension and not only the tumor’s epicenter. Patient demographics, tumor characterization, neoadjuvant treatment, surgical procedure and postoperative results were assessed, alongside with pathological and oncological metrics as recurrence, disease-free survival (DFS) and overall survival (OS). Results We included 64 cardia cancer patients who underwent a curative treatment strategy, with a median age of 68 years, mostly men (87.5%), with a median BMI of 25 kg/m2. 68.2% were classified as ECOG-PS 0 however 62.5% were classified as ASA III-IV. Most tumors were moderately (39.2%) or poorly (31.4%) differentiated adenocarcinomas. Majority were locally advanced (cT3, 78.1%) and in stage III (85.9%). Regarding tumor location, 49.2% were classified as mSiewert I-II (49.2%), followed by I-II-III (18%) and II-III (18%). 36.1% had esophageal involvement ≥4cm, 87.5% received neoadjuvant treatment split between the CROSS and FLOT protocols. Our resection rate was 85.9%. We mostly performed Mckeown esophagectomy (49.1%) and transhiatal esophagectomy (18.2%). We had a 12.7% admission rate to the intensive care unit and a 27.3% major complication rate (Clavien-Dindo ≥ 3b). Anastomotic dehiscence occurred in 16.4% of cases, with hospital mortality rate of 3.6%. The median hospital stay was 6 days, with a 16.4% readmission rate. Pathological staging revealed that 47.3% were stage III, with a median lymph node yield of 28 and a 98.2% R0 resection rate. Most patients received adjuvant treatment, primarily FLOT protocol or Nivolumab, in 38.2% and 29.1%, respectively. The recurrence rate was 28%, with a median time to recurrence of 26 weeks, mainly occurring as distant metastasis pattern (64.3%). One-year overall survival (OS) was 88.7%, and one-year disease-free survival (DFS) was 66.4%, with a median follow-up time of 48 weeks and only a 3.6% loss to follow-up rate. Conclusion This study highlights the unit’s adaptation of EGJ tumor treatment to new insights, emphasizing the importance of comprehensive classification and multimodal and multidisciplinary approach to enhance patient outcomes.