Evaluation of three lymph node staging systems for prognostic prediction in gastric cancer: A systematic review and meta-analysis.

Abstract

Background: Lymph node status is a critical prognostic factor in gastric cancer (GC), but stage migration may occur in pathological lymph nodes (pN) staging. To address this, alternative staging systems such as the positive lymph node ratio (LNR) and log odds of positive lymph nodes (LODDS) were introduced.

Aim: To assess the prognostic accuracy and stratification efficacy of three nodal staging systems in GC.

Methods: A systematic review identified 12 studies, from which hazard ratios (HRs) for overall survival (OS) were summarized. Sensitivity analyses, subgroup analyses, publication bias assessments, and quality evaluations were conducted. To enhance comparability, data from studies with identical cutoff values for pN, LNR, and LODDS were pooled. Homogeneous stratification was then applied to generate Kaplan-Meier (KM) survival curves, assessing the stratification efficacy of three staging systems.

Results: The HRs and 95% confidence intervals for pN, LNR, and LODDS were 2.16 (1.72-2.73), 2.05 (1.65-2.55), and 3.15 (2.15-4.37), respectively, confirming all three as independent prognostic risk factors for OS. Comparative analysis of HRs demonstrated that LODDS had superior prognostic predictive power over LNR and pN. KM curves for pN (N0, N1, N2, N3a, N3b), LNR (0.1/0.2/0.5), and LODDS (-1.5/-1.0/-0.5/0) revealed significant differences (P < 0.001) among all prognostic stratifications. Mean differences and standard deviations in 60-month relative survival were 27.93% ± 0.29%, 41.70% ± 0.30%, and 26.60% ± 0.28% for pN, LNR, and LODDS, respectively.

Conclusion: All three staging systems are independent prognostic factors for OS. LODDS demonstrated the highest specificity, making it especially useful for predicting outcomes, while pN was the most effective in homogeneous stratification, offering better patient differentiation. These findings highlight the complementary roles of LODDS and pN in enhancing prognostic accuracy and stratification.