Intraductal papillary mucinous neoplasms of the pancreas: Effect of invasion and pancreatic margin status on recurrence and survival

Background: The natural history and prognosis for patients with intraductal papillary mucinous neoplasms (IPMN) with and without invasion remain poorly defined. This study evaluated the outcome after pancreatectomy for IPMN according to the pancreatic transection margin status and the presence or absence of invasive carcinoma. Methods: Data from a prospective pancreatic tumor database and medical records were reviewed for all patients who underwent pancreatic resection for IPMN at our institution between July 1990 and July 2003. Surgical specimens were re-reviewed by a single pathologist. Results: IPMN was diagnosed in 35 (26%) of 137 patients who underwent pancreatic resection for cystic neoplasms. Invasive IPMN was confirmed in 13 (37%) of 35 patients. Noninvasive IPMN was found in 22 (63%) of 35 patients; pathology re-review changed the original diagnosis from invasive to noninvasive IPMN in 6 patients. Noninvasive IPMN was found at the final pancreatic margin in eight patients; none developed recurrent disease at a median follow-up of 34 months. Recurrent disease was identified in 7 (58%) of 13 patients with invasive IPMN and in none with noninvasive IPMN. The median overall survival was 22.9 and 84.9 months in patients with invasive and noninvasive IPMN, respectively (P = .0009). Conclusions: Distinction between invasive and noninvasive IPMN is essential in estimating prognosis and determining the need for adjuvant therapy and the frequency of follow-up surveillance. Noninvasive IPMN, even if present at the pancreatic margin, was not associated with recurrent disease. In contrast, invasive IPMN was associated with early recurrence and short survival.