Value of Positive Lymph Node Ratio for Predicting Postoperative Distant Metastasis and Prognosis in Esophageal Squamous Cell Carcinoma.

BACKGROUND The aim of this study was to investigate the relationship between positive lymph node ratio (PLNR) and postoperative distant metastasis and prognosis in esophageal squamous cell carcinoma (ESCC). PATIENTS AND METHODS 167 ESCC patients with regional lymph node metastasis, who underwent radical esophagectomy and lymphadenectomy at the Ningbo Yinzhou People's Hospital between October 2005 and December 2010, were enrolled in this study. The prognostic value of PLNR was calculated by univariate Kaplan-Meier survival analysis and multivariate Cox proportional hazard model analysis. RESULTS After a median follow-up time of 34 months, 88 (52.7%) of the 167 patients had distant metastasis and 76 (45.5%) had died. Patients with a PLNR of less than 0.15 had a 5-year distant metastasis-free survival (DMFS) rate of 33.3% while those with a PLNR greater than 0.15 had a 5-year DMFS rate of 25.5% (log-rank test, p = 0.002). Multivariate analysis indicated that a PLNR > 0.15 was an independent poor prognostic factor for DMFS (hazard ratio (HR) 1.92, 95% confidence interval (CI) 1.21-3.05) and overall survival (OS) (HR 2.08, 95% CI 1.26-3.43). This analysis was adjusted for patient age, sex, smoking behavior, and pT stage. CONCLUSION The PLNR is an independent prognostic factor for predicting postoperative distant metastasis and prognosis in ESCC, and patients with a PLNR ≤ 0.15 have better OS.