The Significance of Negative Lymph Nodes in Esophageal Cancer After Curative Resection: A Retrospective Cohort Study.

OBJECTIVE: The impact of negative lymph nodes (NLNs) count on prognosis in esophageal cancer (EC) was analyzed using two institutions surgical database. METHODS: We conducted a retrospective study of 768 EC patients treated by surgical resection between January 2010 and December 2012. The effects of the NLNs count on prognosis was analyzed. Cox regression model was conducted to determine the significant prognostic elements. RESULTS: The number of NLNs was studied as a categorical variable based on the quartiles (Q1: ≤15, Q2: 16-21, Q3: 22-30, Q4: ≥31). And a better overall survival (OS) was observed with increasing number of NLNs (HR= 0.762; 95% CI, 0.596-0.974 for Q2, HR= 0.666; 95% CI, 0.516-0.860 for Q3 and HR= 0.588; 95% CI, 0.450-0.768 for Q4) (all P<0.05). Multivariate regression analysis revealed that the NLNs count was an independent prognostic factor. Besides, for patients in T2 or T3 stage, a high number of NLNs was found to be significantly associated with a favorable OS (log rank P<0.001). CONCLUSION: A higher number of NLNs is independently related to the better OS in EC patients after surgical resection.