Objectives Neuropilin 1 (NRP-1) appears to promote angiogenesis by acting as a coreceptor with vascular endothelial growth factor receptor. We correlated NRP-1 expression with microvessel density (MVD) and overall survival (OS) in human pancreatic ductal adenocarcinomas (PDACs). Methods Neuropilin 1 expression was graded semiquantitatively using immunohistochemistry in patients with resected PDAC. Moreover, MVD was determined with an anti-CD31 antibody staining. Expression of NRP-1 was correlated with MVD and clinicopathologic features in patients with PDAC. Overall survival effects of NRP-1 expression were evaluated by multivariate Cox regression and Kaplan-Meier analyses. Results High NRP-1 expression was associated with advanced Union for International Cancer Control stage (P = 0.046), T stage (P = 0.031), and lymph node invasion (P = 0.045). Microvessel density was significantly higher in the tumors with high NRP-1 expression than that in the tumors with low NRP-1 expression (mean, 13.9 [SD, 9.1] vs 10.2 [SD, 7.2] per high-power field; P = 0.001). The multivariate Cox regression analysis demonstrated that high NRP-1 expression was independently associated with reduced OS (hazard ratio, 2.10; 95% confidence interval, 1.19-3.70). Conclusions Neuropilin 1 is highly expressed in PDACs, and high expression of NRP-1 is significantly correlated with angiogenesis, advanced tumor-node-metastasis stage, p T stage, node invasion, and poor postoperative OS.
