Inclusion of Perineural Invasion with AJCC-TNM Staging: Outcomes from a South Asian Cohort of Curatively Treated Gastric Cancer Patients.

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 South 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 clinico-pathological features and overall survival was performed. RESULTS: A total of 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 were 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.