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.