Mapping of Lymph Node Metastasis and Efficacy Index in Thoracic Esophageal Squamous Cell Carcinoma: A Large-Scale Retrospective Analysis

BackgroundEsophageal squamous cell carcinoma has a high mortality rate in China. The metastatic pattern in the lymph nodes and the value of their dissection on the overall survival of these patients remain controversial. The primary aim of this study was to provide a basis for accurate staging of esophageal cancer and to identify the relationship between esophageal cancer surgery, lymph node dissection, and overall survival rates.MethodsWe utilized our hospital database to retrospectively review the data of 1727 patients with esophageal cancer who underwent R0 esophagectomy from January 2010 to December 2017. The lymph nodes were defined according to Japanese Classification of Esophageal Cancer, 11th Edition. The Efficacy Index (EI) was calculated by multiplying the frequency (%) of metastases to a zone and the 5-year survival rate (%) of patients with metastases to that zone, and then dividing by 100.ResultsThe EI was high in the supraclavicular and mediastinal zones in patients with upper esophageal tumors, and the EI of 101R was 17.39, which was the highest among the lymph node stations. In patients with middle esophageal tumors, the EI was highest in the mediastinal zone, followed by the celiac and supraclavicular zones. Furthermore, the EI was highest in the celiac zone, followed by the mediastinal zones in patients with lower esophageal tumors.ConclusionsThe EI of resected lymph nodes was found to vary between stations and was related to the primary location of the tumor.