Long-term Prospective Cohort Study of Patients Undergoing Pancreatectomy for Intraductal Papillary Mucinous Neoplasm of the Pancreas Implications for Postoperative Surveillance

Objective: To evaluate long-term follow-up results after surgical treatment of intraductal papillary mucinous neoplasm (IPMN) to optimize postoperative surveillance strategies. Background: Little is known about the postoperative natural history of IPMN, especially about long-term follow-up results in patients with benign or noninvasive IPMN. Methods: Long-term follow-up was undertaken in a prospective cohort of 403 consecutive patients who underwent surgical treatment of IPMN at Seoul National University Hospital. Of these, 37 patients with ductal adenocarcinoma arising in IPMN were excluded from the analysis. Results: Of the 366 patients, 82 had low-grade dysplasia, 171 had intermediate-grade dysplasia, 45 had high-grade dysplasia, and 68 had IPMN with associated invasive carcinoma. During a median follow-up of 44.4 months, the overall recurrence rate was 10.7%. Pathologic grade of dysplasia was associated with recurrence rate (P < 0.001). IPMNs involving main duct had higher rate of recurrence (P = 0.021). Of the 298 patients with benign or noninvasive IPMN, 16 (5.4%) had recurrences including distant metastasis. Multivariate analysis revealed that the degree of dysplasia was the most important predictor of recurrence (P < 0.001). The overall 5-year disease-free survival rate was 78.9% and was significantly lower in patients with high-grade dysplasia than in those with low-or intermediate-grade dysplasia (P = 0.045). Conclusions: Pancreatic IPMNs recur in 10.7% of patients. Recurrence is correlated with the degree of dysplasia, and 5.4% of patients with benign or noninvasive IPMN have recurrences including distant metastasis. Thorough postoperative surveillance is needed not only for patients with invasive IPMN but also for those with benign or noninvasive IPMN, especially for patients with high-grade dysplasia.