Prognostic significance of extranodal extension for early postoperative recurrence following curative surgery in advanced gastric cancer.

[BACKGROUND] More than half of recurrences in advanced gastric cancer (AGC) occur within 2 years of curative surgery. Identifying predictive factors for early recurrence is crucial for improving patient survival. We aimed to evaluate the impact of extranodal extension (ENE) and the largest metastatic lymph-node (LLN) size on early recurrence in patients with AGC.

[METHODS] Data of patients who underwent adjuvant chemotherapy after radical gastrectomy were extracted from the registry. Clinicopathological characteristics were compared according to ENE status and LLN size. Cox proportional hazard models were used to assess associations between ENE, LLN size, and oncologic outcomes.

[RESULTS] This study included 244 patients (mean age, 61.4 ± 10.7 years; male, 75.0%). ENE positivity was significantly associated with higher T and N stages, and larger LLN size. In the univariable analysis, ENE (hazard ratio [HR]: 5.43, p < 0.001) and LLN size ≥ 5 mm (HR: 3.52, p = 0.001) were significant predictors of early recurrence. However, in the multivariable analysis, only ENE was an independent risk factor (HR: 3.34, p = 0.007). For 5-year RFS, ENE positivity (HR: 2.15, p = 0.003), higher T stage (HR: 1.93, p = 0.044), and advanced N stage (HR: 2.59, p = 0.007) were independent prognostic factors, whereas LLN size lost statistical significance. Similarly, ENE positivity remained an independent prognostic factor for OS (HR: 2.04, p = 0.015).

[CONCLUSION] ENE is a strong independent prognostic factor for early recurrence and long-term survival in AGC, whereas LLN size, despite its association with tumour aggressiveness, loses prognostic significance after multivariable adjustment, highlighting ENE's clinical relevance in risk stratification and postoperative management strategies.