Theoretical therapeutic impact of lymph node dissection on adenocarcinoma and squamous cell carcinoma of the esophagogastric junction

The aim of this study was to evaluate the theoretical therapeutic impact of dissecting each lymph node station for adenocarcinoma and squamous cell carcinoma of the esophagogastric junction. This multicenter study included 431 junctional cancer patients (381 adenocarcinomas and 50 squamous cell carcinomas) who fulfilled the following criteria: (1) the center of the tumor was located between 1 cm above and 2 cm below the esophagogastric junction, and (2) the tumor invaded the junction. The theoretical therapeutic impact of dissecting each lymph node station was evaluated based on the therapeutic value index calculated by multiplying the frequency of metastasis to each station and the 5-year survival rate of patients with metastasis to that station. The 5-year overall survival rates (95 % confidence interval) were 60.4 % (55.1-65.7) in the adenocarcinoma cases and 52.3 % (35.6-69.0) in the squamous cell carcinoma cases. The nodal stations showing the first to fifth highest index were the paracardial and lesser curvature nodes (nos. 1, 2 and 3), nodes at the root of the left gastric artery (no. 7) and lower mediastinal lymph nodes, regardless of the histology. Nodal dissection achieved by proximal gastrectomy and lower esophagectomy should be the minimal requirement for junctional cancer regardless of the histology, considering the therapeutic value indices for the relevant lymph node stations.