Inclusion Of Perineural Invasion With AJCC-TNM Staging: Outcomes From A South East Asian Cohort Of Curatively Treated Gastric Cancer Patients

Abstract Background: The incidence of perineural invasion (PNI) in patients with gastric cancer (GC) is high, and patients with PNI positive disease have a poor prognosis compared to PNI negative disease. The present study aims to study the incidence and evaluate the impact of PNI on the survival outcome of a cohort of Eastern Asian GC patients. Material and Methods: All consecutive patients undergoing curative gastrectomy were included in the study. The incidence of PNI and correlation with different clinicopathological features and overall survival was performed.Results: 59.54% had PNI positive disease and the median OS of PNI+ve patients was 29.3 months, while it was not reached in PNI-ve patients. The PNI positivity was a significant prognostic factor for overall survival both on univariate and multivariate analysis. On TNM-PNI staging, those with TNM stage I / II patients with PNI+ve disease had similar OS to all stage III patients (p=0.835) and was worse than that of PNI-ve patients (p<0.05). Conclusion: The incidence of PNI in gastric cancer is high. The inclusion of PNI with AJCC-TNM staging may better stratify prognostic staging in curatively treated gastric cancer patients.