Background: The objective of this study was to evaluate the prognostic value of Metastatic lymph node ratio (MLNR) after curative gastrectomy in patients with gastric cancer (GC) and the potential for new indicators to strengthen the current guidelines.
Methods: We retrospectively researched 3864 GC patients with curative gastrectomy between February 2011 and February 2016. The following clinical data were collected from the included patients: gender, type of gastrectomy, tumor location, T stage, N stage, ELN, tumor size, age at surgery, perineural invasion, vascular invasion, TNM stage, survival time and survival status. Patients were divided into low-MLNR (L-MLNR), and high-MLNR (H-MLNR) groups based on adjusted the X-tile cutoff-value of 0.25 for MLNR, the survival rates and clinicopathological characteristics of each group were compared. For the assessment of significant associations between clinicopathological characteristics and patients' survival, univariate and multivariate analyses were performed using the Kaplan-Meier method and Cox proportional hazards analysis. The log-rank test was used to examine the statistical significance of differences among different survival curves. Clinicopathological features significantly associated with MLNR were assessed by the Chi-square test and multinomial logistic regression. The discriminative ability was measured by calculating the Bayesian Information Criterion (BIC) values for each category. Assessment of the effect of clinicopathological features on MLNR for predicting prognosis of GC patients used stratum analysis through Kaplan-Meier analysis and Cox proportional risk Analysis.
Results: Survival analysis indicated that MLNR was negatively associated with overall survival (OS) (p < .001) and was an independent prognostic predictor in 3864 GC patients (p < .001). MLNR had significant prognostic significance in various subgroups with clinicopathological characteristics (gender, type of gastrectomy, tumor location, T stage, N stage, ELN, tumor size, age at surgery, perineural invasion, vascular invasion, and TNM stage) (p < .001).
Conclusions: The MLNR may become a new indicator to assess the prognosis of GC patients who underwent curative gastrectomy. The results may have potential clinical implications that should be considered when developing clinical practice guidelines or the design of the future investigation.
Keywords: Metastatic lymph node ratio; abdominal surgery; gastric cancer; lymph node; prognosis; survival analysis.