Prognostic value of lymph node staging systems in gastric cancer patients undergoing laparoscopic surgery: A case-series in Vietnam

Introduction

Lymph node metastasis is the most important prognostic factor for gastric cancer (GC). While the pN staging system is widely used, it does not account for the total number of dissected lymph nodes, potentially leading to stage migration in patients with suboptimal lymphadenectomy. Alternative systems such as the lymph node ratio (LNR) and log odds of positive nodes (LODDS) may provide superior prognostic accuracy. Our aim is to compare the prognostic significance of the lymph node ratio (LNR), log odds of positive nodes (LODDS), and number of positive lymph nodes (pN).

Methods

Eighty-six GC patients treated with curative laparoscopic surgery were retrospectively analyzed. Survival outcomes were assessed using Kaplan-Meier analysis and the log-rank test. Prognostic accuracy was evaluated using receiver operating characteristic (ROC) curves and the area under the curve (AUC) values.

Results

All three lymph node classification systems, pN, LNR, and LODDS, were significant prognostic factors for survival in gastric cancer, (p = 0.007, 0.002, and 0.036, respectively) based on the log-rank test. Notably, in cases with fewer than 15 lymph nodes dissected, only the LNR system retained prognostic significance (p = 0.037), whereas both LNR and LODDS were effective in the ≥15 lymph node subgroup.

Conclusions

LNR and LODDS can be recommended for evaluating lymph node metastasis in gastric cancer, particularly in patients with inadequate lymph node dissection. This is the first study in Vietnam to evaluate and support the integration of LNR and LODDS as complementary prognostic tools in gastric cancer staging.