The Prognostic Value of Log Odds of Positive Lymph Nodes in Early-Stage Esophageal Cancer Patients: A Study Based on the SEER Database and a Chinese Cohort

OBJECTIVE: Early detection and timely treatment are important for improving the prognosis of esophageal cancer (EC). Identification of the prognostic risk factors could help us to discern the high-risk population. This study was aimed at exploring the prognostic significance of log odds of positive lymph nodes (LODDS) in early-stage EC patients. METHODS: Patients who underwent esophagectomy and diagnosed as pathologic T1-2 N0 EC were reviewed between January 2005 and December 2015 from the Surveillance, Epidemiology, and End Results (SEER) database (the development cohort, n = 1004). The X-tile software was used to determine the optimal cutoff values of LODDS. A separate Chinese cohort including 245 patients (the validation cohort) was used to externally validate the results of the SEER database. RESULT: Patients were divided into two groups based on the cutoff points of LODDS: <−1.40 (LODDS1) and ≥−1.40 (LODDS2). In the development cohort, the 5-year overall survival (OS) rate was 75.3% for patients in the LODDS1 group, compared with 67.5% for those in the LODDS2 group (P=0.002). In multivariate Cox analysis, LODDS was associated with OS significantly (hazard ratio (HR), 1.48; 95% confidence intervals (CI), 1.19–1.85). In the validation cohort, the 5-year OS rate was 76.6% for patients in the LODDS1 group, compared with 64.4% for those in the LODDS2 group (P=0.006). The HR value in multivariate Cox analysis for OS was 2.00 (95% CI, 1.26–3.18). CONCLUSION: LODDS was an important independent factor for survival in early-stage EC patients.