Implication of perineural invasion in patients with stage II gastric cancer

Background Perineural invasion (PNI) is regarded as a prognostic factor for patients with GC. However, the significance of PNI in patients with stage II GC remains unclear. This study aimed to investigate the clinical implication of PNI in patients with stage II GC undergoing curative resection. Methods Patients with stage II GC who underwent curative resection were retrospectively evaluated from January 2010 to July 2019. According to PNI status, all patients were divided into two groups: with or without PNI. The prognostic value of PNI was analyzed by univariate and multivariate Cox proportional hazards regression models. Results A total of 233 patients were included in this study. There were 100 patients with PNI (42.92%) and 133 patients without PNI (57.08%). The overall survival (OS) and disease-free survival (DFS) rates for patients with PNI were significantly lower than that for patients without PNI ( p = 0.019 and p = 0.032, respectively). Multivariate analysis indicated that the presence of PNI was an independent risk factor for OS (hazard ratio (HR): 1.76, 95% confidence interval (CI) 1.02–3.06, p = 0.044) and DFS (HR: 1.70, 95% CI 1.04–2.80, p = 0.035), while adjuvant chemotherapy (AC) was an independent protective factor for OS (HR: 0.51, 95% CI 0.30–0.88, p = 0.016) and DFS (HR: 0.52, 95% CI 0.31–0.86, p = 0.011). Furthermore, among patients with PNI, those who received AC had better OS ( p = 0.022) and DFS ( p = 0.027) than their counterparts. When patients with PNI received AC, the OS ( p = 0.603) and DFS ( p = 0.745) appeared to be similar to those without PNI and no AC. Conclusion In patients with stage II GC undergoing curative resection, the presence of PNI was associated with worse survival, which appeared to improve with the treatment of AC, indicating a potential need for more intensive AC.