The Log Odds of Positive Lymph Nodes Predict Survival of Advanced-Stage Endometrial Cancer: A Retrospective Analysis of 3230 Patients in the Surveillance, Epidemiology, and End Results Database

Objective: The aim of this study was to establish the effective and prognostic value of the log of odds (LODDS) of positive lymph nodes for predicting the survival of patients undergoing surgical staging for endometrial cancer (EC). Materials and Methods: This retrospective cohort study used the Surveillance, Epidemiology, and End Results (SEER) database of EC cases diagnosed from 2010 to 2015. The LODDS was calculated using the equation: logpLN+0.5/nLN+0.5, when pLN = number of positive lymph nodes and nLN = number of negative lymph nodes. LODDS and FIGO staging were compared, using a Kaplan-Meier (K-M) analysis and univariate Cox regression modeling to analyze the risk factors for survival. The independent prognostic effect of univariate Cox model variables was evaluated with a multivariate Cox regression model. Results: The analyses included 3230 EC cases from the SEER database (International Federation of Gynecology and Obstetrics [FIGO] stage IIIC1 = 1546, FIGO stage IIIC2 = 958, and FIGO stage IV = 726). Among these cases, 58.0% had high-grade histology (FIGO grade 3-4) and 59.0% were classified as type II EC. There were 925 EC-specific deaths. Cases were categorized into 2 groups: (1) LODDS < -0.12707 and (2) LODDS ≥ -0.12707. K-M curve analyses showed 1-, 3-, and 5-year disease-specific survival (DSS) rates of 93.9, 75.9, and 67.5% for LODDS < -0.12707; and 78.6, 49.6, and 38.1% for LODDS ≥ -0.12707, respectively. Cumulative 1-, 3-, and 5-year DSS were 91.0, 71.1, and 62.2%, respectively. In multivariate analysis, LODDS is an independent prognostic factor for EC mortality (hazard ratio = 2.14; 95% confidence interval: 1.85-2.47; p < 0.0001). Conclusions: LODDS classification has significant prognostic value for survival among patients with EC. (J GYNECOL SURG 38:278).