Intrapancreatic Nerve Invasion as a Predictor for Recurrence After Pancreaticoduodenectomy in Patients With Invasive Ductal Carcinoma of the Pancreas

Background: Neural invasion is a distinct route for the spread of pancreatic carcinoma. However, the clinicopathologic significance of neural invasion, with particular reference to intrapancreatic nerve invasion, remains to be elucidated. Methods: One hundred fifty-three patients who underwent pancreaticoduodenectomy for invasive ductal carcinoma of the pancreas between 2004 and 2008 were retrospectively examined. The clinical and histopathologic factors, including intrapancreatic nerve invasion, were analyzed in these patients. The relationships between the degree of intrapancreatic nerve invasion and disease-free survival, as well as various histopathologic factors, were investigated. Results: There were significant differences in the degree of intrapancreatic nerve invasion with regard to disease-free survival (P < 0.001). A lack of lymph node metastases (P = 0.001), lower incidence of intrapancreatic nerve invasion (P = 0.001), and negative surgical margin (P = 0.011) significantly increased the disease-free survival. The tumor stage was not associated with intrapancreatic nerve invasion (P = 0.255). However, a larger tumor size (P = 0.024), a higher incidence of lymphatic invasion (P = 0.036), and the presence of extrapancreatic nerve plexus invasion (P < 0.001) were identified as independent factors associated with a higher incidence of intrapancreatic nerve invasion. Conclusions: Intrapancreatic nerve invasion may be useful as a predictor for recurrence after pancreaticoduodenectomy in patients with invasive ductal carcinoma of the pancreas.