Invasive intraductal papillary-mucinous neoplasm of the pancreas: comparison with pancreatic ductal adenocarcinoma.

BACKGROUND AND OBJECTIVES: The aim of this study was to clarify the clinicopathological differences between patients with invasive intraductal papillary-mucinous neoplasm (IPMN) of the pancreas and pancreatic ductal adenocarcinoma.

METHODS: The medical records of 16 patients with invasive IPMN and 106 patients with pancreatic ductal adenocarcinoma, who underwent surgical resection, were retrospectively reviewed, and the clinicopathological factors and survival were compared between the two groups.

RESULTS: The presence of retroperitoneal tissue invasion, portal or splenic vein invasion, nodal involvement, and positive surgical margins were significantly lower in patients with invasive IPMN than in those with ductal adenocarcinoma (P < 0.05). The actuarial 5-year overall survival rates in patients with invasive IPMN and ductal carcinoma were 40% and 18%, respectively (P = 0.008). However, the actuarial 5-year survival rate of patients with invasive IPMN was only 27% for UICC stage II disease, although this was significantly higher than that of patients with UICC stage II ductal adenocarcinoma (P = 0.049).

CONCLUSIONS: Invasive IPMN has a favorable prognosis compared with pancreatic ductal adenocarcinoma that is likely due to the less aggressive nature of the disease. However, the prognosis for cases of advanced invasive IPMN is not always favorable despite complete tumor resection.