Baseline Tumor Biology Predicts Survival After Recurrence in Gastric Cancer: Impact of LVI, PNI, and HER2 Status.

BACKGROUND Lymphovascular invasion (LVI) and perineural invasion (PNI) are established markers of aggressive disease in primary gastric cancer, but their specific prognostic role in patients who develop recurrence after curative surgery is less clear. This study aimed to evaluate clinicopathological and treatment-related factors associated with overall survival (OS) and disease-free survival (DFS) in a cohort of gastric cancer patients who experienced recurrence. MATERIAL AND METHODS This retrospective study included 70 patients who underwent curative gastrectomy and subsequently developed confirmed recurrence. OS (from diagnosis) and DFS (from surgery to recurrence) were analyzed using Kaplan-Meier curves and Cox regression. Multivariate models were constructed with a limited number of variables to avoid overfitting. RESULTS The median OS was 38.9 months, and the median DFS was 22.4 months. In multivariate analysis, LVI positivity (HR=3.39; 95% CI: 1.59-7.19; P=0.001) and advanced clinical stage were independent predictors of worse OS, while adjuvant chemoradiotherapy (HR=0.44; P=0.017) and receiving first-line systemic therapy after recurrence (HR=0.22; P<0.001) were protective. For DFS, PNI positivity predicted shorter DFS (HR=1.91; P=0.033). HER2 positivity was associated with longer DFS (HR=0.78; P=0.015); notably, 42.9% of HER2-positive patients received trastuzumab upon recurrence. CONCLUSIONS In gastric cancer patients who develop recurrence, baseline biological markers (LVI, PNI, HER2) retain significant prognostic value for OS and DFS from the time of diagnosis and surgery, respectively. Integrating these markers with treatment parameters may improve risk stratification. This study did not evaluate pure post-recurrence survival (PRS); OS was calculated from diagnosis and therefore reflects pre- and post-recurrence periods combined.