Patterns of Lymph Node Metastases After Multimodality Therapy in Esophageal Carcinoma Treated with Robot-Assisted Minimally Invasive Esophagectomy (RAMIE).

Abstract

Lymph node metastases (LNMs) in esophageal carcinoma demonstrate extensive and variable dissemination. Previous mapping studies are limited to region-based reporting, heterogeneous classification systems, and absence of contemporary multimodality-treated cohorts. This study aimed to characterize the station-level distribution of LNMs after standardized robot-assisted minimally invasive transthoracic esophagectomy (RAMIE) with two-field lymphadenectomy and to evaluate patterns in relation to key preoperative parameters. A prospective, single-center observational cohort of patients undergoing transthoracic RAMIE for adenocarcinoma (AC) or squamous cell carcinoma (SCC) between 2018 and 2024 was analyzed. The primary outcome was station-level distribution of LNMs in relation to histology, tumor location, clinical T stage, clinical N stage, and receipt of neoadjuvant therapy. Analyses were descriptive. Among 210 patients (74% AC, 26% SCC), median lymph node yield was 44 (interquartile range [IQR], 34-52). Lymph node metastases were present in 42% of the patients, with a median of two positive nodes (IQR, 1-4). Although 91% received neoadjuvant therapy (85% CROSS, 7% FLOT), residual nodal disease remained frequent and widely distributed. Metastases occurred most frequently in the paraesophageal (11%) subcarinal (10%) mediastinal stations, and along the left gastric artery (22%) and right paracardial (15%) nodes. Thoracic duct LNM was identified in 9% of the patients. Patterns were similar across preoperative parameters. Occult nodal disease was observed in 32% of cN0 patients. Lymphatic dissemination in esophageal cancer remains extensive and unpredictable, even after multimodality therapy. The persistence of cross-diaphragmatic nodal involvement across subgroups underscores the ongoing necessity of a systematic two-field lymphadenectomy to achieve optimal locoregional control and accurate pathologic staging.