Prognostic impact of lymph node harvest for patients with node-negative esophageal squamous cell carcinoma: a large-scale multicenter study

BACKGROUND: We examined the association between the number of resected lymph nodes and survival to determine the optimal lymphadenectomy for thoracic esophageal squamous cell carcinoma (ESCC) patients with negative lymph node. METHODS: We included 1,836 patients from Chinese three high-volumed hospitals with corresponding clinicopathological characters such as gender, age, tumor location, tumor grade and TNM stage of patients. The median follow-up of included patients was 45.7 months (range, 1.03–117.3 months). X-Tile plot was used to identify the lowest number of lymphadenectomy. The multivariate model’s construction was in use of parameters with clinical significance for survival and a nomogram based on clinical variable with P