Log odds of positive lymph nodes is a novel prognostic indicator for advanced ESCC after surgical resection.

Background: To investigate the prognostic value of the log odds of positive lymph nodes (LODDS) in patients with advanced esophageal squamous cell carcinoma (ESCC) after surgical resection.

Methods: Clinical data of 260 patients with advanced ESCC undergoing surgical resection were retrospectively reviewed. Univariate and multivariate analysis were done using the chi-square test and Cox regression model. Receiver-operating-characteristic (ROC) curve was used to compare the association of pathologic nodal (pN) and LODDS with 3- or 5-year overall survival (OS). The cut-point analyses were performed to determine whether there was a cutoff LODDS related to the greatest OS difference.

Results: The mean follow-up duration was 30 months (range, 3 to 106 months). The 1-, 3-, 5-year OS rates were 70.0%, 41.9% and 30.3%, respectively. Univariate analyses indicated that the 5-year OS rates were 51.2%, 30.5%, 24.6%, and 14.2% in LODDS1, LODDS2, LODDS3, and LODDS4, respectively, and the median survival times were 68.7, 34.6, 24.0, and 14.6 months, respectively (P=0.000) for all patients, and subgroup analysis showed the effect did not change in 155 patients without lymph node (LN) metastasis (P=0.024). Multivariate analysis showed that LODDS [hazard ratio (HR) =1.309, P=0.003] to be independent and significant prognostic factors for all patients, so as in node-negative patients LODDS (HR =1.610, P=0.038). The AUC of LODDS stage (AUC =0.630) was larger than that of pN stage (AUC =0.621) in prediction of 3-year OS, however LODDS were smaller in prediction of 5-year OS (AUC =0.620, 0.631, respectively), and the differences were not statistically significant (P>0.05 all). Lastly, the step analysis identified the best cut-off point for LODDS as -1.2 that is significantly associated with the prognosis of the node-negative patients (P=0.024), and the ROC analysis also indicated that a cut-off value of -1.2 for LODDS provided the highest sensitivity and specificity interestingly.

Conclusions: LODDS may be suitable for evaluation of OS in advanced ESCC patients without LN metastasis.