The Prognostic Impact of Lymph Node Involvement in Large Scale Operable Node-Positive Esophageal Squamous Cell Carcinoma Patients: A 10-Year Experience

BACKGROUND: Lymph node (LN)-related factors including the number of LN regions involved, the LN ratio (LNR), and the number of metastatic LNs are strong prognostic indicators for esophageal squamous cell carcinoma (ESCC) patients. Accurately staging LN involvement may improve the stratification of patients and guide the management of patients. METHODS: A total of 688 potentially resectable patients who had regional LN metastases were enrolled in this retrospective study. RESULTS: ESCC involving a single region was associated with better outcomes than that involving multiple regions (P < 0.001 for both PFS and OS). An increased number of metastatic LNs was significantly associated with reduced PFS and OS based on univariate analysis (P < 0.001). PFS and OS were significantly higher in patients with a lower cancer-involved LNR, with 5-year OS rates of 9.7% and 31.4% for patients with a lower and higher cancer-involved LNR, respectively. Based on multivariate analysis, patients with N1 LN involvement experienced longer survival than patients with N2 LN involvement (HR: 1.37; 95% CI: 1.12-1.68) or N3 LN involvement (HR: 1.96; 95% CI: 1.52-2.53). Higher LNR resulted in longer OS than lower LNR based on multivariate analysis (HR: 1.45; 95% CI: 1.15-1.84; P = 0.002). CONCLUSIONS: Our study has shown that not only the number of metastatic LNs but also the number of involved LN regions predicts outcomes after definitive surgery among Chinese patients with N-positive ESCC. LNR might serve as a powerful indicator that should be included in TNM staging for EC patients.