Incidence of mediastinal lymph node positivity in patients undergoing robotic transthoracic esophagectomy.

379 Background: Esophageal cancer is increasing in incidence worldwide. Robotic approaches have quickly become mainstream due to the improved visualization and possible increase in nodal harvest. There remains significant debate on the utility of mediastinal lymph node dissection in esophageal cancer patients. We sought to analyze the incidence of mediastinal lymph node positivity and to evaluate its impact on survival in patients with esophageal cancer undergoing robotic assisted trans-thoracic esophagectomy (RATE). Methods: Utilizing a prospectively maintained esophageal database, we identified patients who were diagnosed with EC and underwent RATE between 2009-2024. We then identified patients with positive lymph nodes and stratified by location (celiac or mediastinal). Baseline univariate comparisons were made for continuous variables using both the Mann-Whitney U and Kruskal Wallis tests. Pearson’s Chi-square test was used to compare categorical variables. Survival analysis was performed via Kaplain-Meier method. Results: We identified 201 patients who underwent RATE with a median age of 70 (41-91). There were 160 (79.6%) males and 41 (20.4%) females. The mean BMI was 26.5 ± 5.5 and mean ASA score was 3.1 ± 0.6. Adenocarcinoma was the predominate histology at 162(80.6%). Locally advanced T3/T4 tumors were identified in 53 (26.4%) patients and 63(31.3%) had clinical node + disease. Neoadjuvant therapy was utilized in 159(79.1%) patients. The median lymph nodes resected 18 (14 – 22), and length of hospitalization 8 (7 – 11) days. The 30 and 90-day mortality were 2.2% and 2.6% respectively. R0 resections was performed in 200 (99.5%) of patients and the pathologic complete response rates were 42.1%. The incidence of mediastinal lymph node positivewas 6.3% vs 76.3% abdominal. There were 17.6% of patients that had both mediastinal and abdominal lymph nodes positive. The median survival was 23 months for abdominal LN+, 19.5 months for mediastinal LN+ p=0.23. Multivariate analysis revealed that age, neoadjuvant radiation, nodal positivity were predictors of survival. Conclusions: The incidence of mediastinal positive lymph nodes are much higher than previously reported. Perhaps the improved visualization and manipulation of tissue with robotic approaches have enhanced our ability to resect these nodes. Mediastinal lymph node positivity is a poor prognostic factor for survival in patients undergoing robotic esophagectomy. Given these findings, we would continue to support aggressive nodal resection in patients diagnosed with esophageal cancer.