Comparison of survival between three-field and two-field lymph node dissections for thoracic esophageal squamous cell carcinoma

Abstract

Objective To compare survival according to the extent of lymph node dissection in patients with thoracic esophageal squamous cell carcinoma.To identify the subgroups of patients that could get survival benefit from three-field lymph node dissection.Methods Between January 1999 and December 2007,1551 patients with thoracic esophageal squamous cell carcinoma received esophagectomy plus three-field lymph node dissection (3 FL) (n =1131) or two-field lymph node dissection (2FL) (n =420).We retrospectively analyzed the clinical characteristics and patterns of lymphatic spread of thoracic esophageal squamous cell carcinoma.Survival rates between 3FL and 2FL were compared using the Kaplan-Meier method and Log-Rank test.Multivariate analysis were also performed to assess the element which affect the survival in 3FL and 2FL group by Cox regression.Results No significant differences in age,gender and depth of tumor invasion were found between 3 FL group and 2FL group.The 3FL group included more patients with upper thoracic esophageal tumors(17.6％ vs.9.8％) and patients with lymph node metastasis(LNM) (62.7％ vs.52.9％).Cox-proportional multivariate analysis showed that extent of lymph node dissection(3FL vs 2FL) was a significant prognostic factor in overall survival; 3 FL was beneficial for patients with upper thoracic esophageal tumors(P =0.002,5-year survival rate 53.2％ vs.34.1％).The 3FL group in patients with middle/lower thoracic esophageal tumors who had no LNMs(N0) had better 5-year survival than the 2FL group(5-year survival rate 77.5％ vs.70.7％),but no significant differences were found (P =0.235).or; Among patients with middle/lower thoracic esophageal tumors who had 1-6 LNMs (N1-N2),3 FL was beneficial for patients with mediastinum LNMs (P =0.006,5-year survival rate 41.1％ vs.32.8％) For patients with ≥7 LNMs(N3),cervical lymphadenectomy did not show additional survival benefits.Conclusion Our findings suggest that extent of lymph node dissection(3FL vs 2FL) is a significant prognostic factor for thoracic esophageal squamous cell carcinoma.3FL offers survival benefit over 2FL in patients with upper thoracic esophageal tumors or patients with middle/lower thoracic esophageal tumors who have 1-6 LNMs with mediastinum lymph node metastasis. Key words: Esophageal neoplasms; Lymph node dissection ; Survival