Influence of Perineural Invasion on Survival and Recurrence in Patients with Resected Pancreatic Cancer

Background: Perineural invasion (PNI) has been reported as one of the sources of locoregional recurrence inresected pancreatic cancer (PC). However the impact of PNI in resected pancreatic cancer remains controversial.The purpose of this study was to determine the association between PNI status and clinical outcomes.
Methods:Publications were identified which assessed prognostic significance of PNI status in resected pancreatic cancerup to February 2013. A meta-analysis was performed to clarify the association between PNI status and clinicaloutcomes.
Results: A total of 21 studies met the inclusion criteria, covering 4,459 cases. Analysis of these datashowed that intrapancreatic PNI was correlated with reduced overall survival only in resected pancreaticductal adenocarcinoma (PDAC) patients (HR=1.982, 95%CI: 1.526-2.574, p=0.000). Extrapancreatic PNI wascorrelated with reduced overall survival in all resected pancreatic cancer patients (HR=1.748, 95%CI: 1.372-2.228, p=0.000). Moreover, intrapancreatic PNI status may be associated with tumor recurrence in all resectedpancreatic cancer patients (HR=2.714, 95%CI: 1.885-3.906, p=0.000).
Conclusion: PNI was an independent andpoor prognostic factor in resected PDAC patients. Moreover, intrapancreatic PNI status may be associated withtumor recurrence.