Extra-tumor perineural invasion predicts postoperative development of peritoneal dissemination in pancreatic ductal adenocarcinoma

Peritoneal dissemination is one of the major patterns of postoperative recu rrence and a major cause of death in pancreatic ductal adenocarcinoma. To p redict the development of postoperative peritoneal dissemination (PPD), cor relations between the occurrence of PPD and clinicopathological factors wer e analyzed in 23 patients with pancreatic ductal carcinoma who underwent tu mor resection and were carefully monitored after the operation. Fifteen cas es (65.2%) developed PPD, but the other 8 cases (34.8%) did not meet the cr iteria for a diagnosis of PPD. Location of the tumor in the pancreatic tail or body (p=0.0041, HR=10.827, 95% CI=2.126-55.127) and the presence of ext ra tumoral perineural invasion (ETNI) (p=0.0490, HR=0.114, 95% CI=0.013-0.9 90) were found to have predictive value for the development of PPD. These r esults suggested that intensive therapy selectively focused on the peritone um in cases with ETNI, might prevent the development of PPD and reduce the side effects of treatment in cases without ETNI.