309. COMPARATIVE OUTCOMES OF OPEN VS. MINIMALLY INVASIVE ESOPHAGECTOMY FOR ESOPHAGEAL AND GASTRO-ESOPHAGEAL JUNCTION TUMORS: INSIGHTS FROM A THORACO-ABDOMINAL STRATIFICATION MODEL

Abstract Background Minimally invasive esophagectomy (MIE) has demonstrated improved outcomes for fit patients with esophageal/gastro-esophageal junction tumors. However, challenges arise in patients less tolerant of prolonged anesthesia or harboring extensive advanced-stage tumors, which limit the utilization of MIE, increasing the risk of referral to nonsurgical strategies. To date, the criteria for considering left thoraco-abdominal esophagectomy (TAE) and the corresponding outcomes in this specific patient population remain unclear. Therefore, our institutional study aimed to identify clinical characteristics for the consideration of TAE, offering insights into treatment selection strategies for esophageal cancer patients. Additionally, we compared the short-term outcomes between TAE and MIE. Methods We included all consecutive patients who underwent esophagectomy with gastric conduit reconstruction for stage I-IVa esophageal and gastro-esophageal junction tumors at a tertiary referral center from 2015 to 2023. Predictors for considering TAE were identified through a multivariable regression model utilizing multivariate imputation by chain equation for missing data of pulmonary and cardiac function, using the predicted mean matching method. Significant variables were used to develop a stratification model, evaluated through the receiver-operating curve. Differences in outcome were assessed using the Kruskal-Wallis rank sum for continuous and Pearson’s chi-squared or Fischer’s exact test for categorical variables. Results This study included 744 patients; 317 (43%) underwent TAE and 427 (57%) had MIE. Patient characteristics were significantly different. Following multivariable analysis, age (1.04 [1.02-1.06]; p<0.001), ECOG-status (1.43 [1.09-1.87]; p=0.009), comorbidity index (1.26 [1.10-1.46]; p<0.001), DLCO (0.98 [0.97-0.99]; p<0.001), ejection fraction (0.97 [0.94-1.00]; p=0.021), tumor location (GEJ: 1.58 [1.10-2.27], Middle: 0.38 [0.18-0.79]; p<0.001), cStage (II: 2.03 [1.02-4.19], III: 3.29 [1.78-6.33], IVa: 3.42 [1.74-6.97]; p<0.001) and adenocarcinoma (2.44 [1.39-4.55]; p=0.002) were identified as predictors for TAE. The stratification model demonstrated an area-under-the-curve of 0.76 [0.73-0.80]. Leave-one-out-cross-validation demonstrated a 70% accuracy. The short-term outcomes were comparable between TAE and MIE (Table 1). Conclusion Our study demonstrated that age, ECOG status, comorbidity index, diffusion capacity, ejection fraction, tumor location, stage and histology were independent predictors for the consideration of thoraco-abdominal esophagectomy. In this context, our stratification model demonstrated a robust predictive value. Moreover, our model suggests considering MIE below a probability threshold of 30% and TAE above 60%, demonstrating an 85% sensitivity and 90% specificity at these thresholds, respectively. Decisions within the 30% to 60% range should be individualized and based on specific patient and tumor characteristics. Short-term outcomes were comparable between TAE and MIE, emphasizing the significance of adequate stratification before surgery.