Prognostic relevance of morphological types of intraductal papillary mucinous neoplasms of the pancreas

Abstract

Objective: The clinicopathological significance of four morphological types of intraductal papillary mucinous neoplasms of the pancreas (IPMNs; gastric, intestinal, pancreatobiliary and oncocytic) was assessed.

Design: Retrospective multicentre analysis of 283 surgically resected IPMNs.

Results: Of the 283 IPMNs, 139 were of the gastric type, 101 were intestinal, 19 were pancreatobiliary and 24 were oncocytic. These types were significantly associated with clinicopathological factors including sex (p = 0.0032), age (p = 0.00924), ectatic duct size (p = 0.0245), detection of mural nodules (p = 4.09 × 10⁻⁶), histological grade (p < 2.20 × 10⁻¹⁶), macroscopic types with differential involvement of the pancreatic duct system (p = 3.91 × 10⁻⁵), invasive phenotypes (p = 3.34 × 10⁻¹²), stage (p < 2.20 × 10⁻¹⁶) and recurrence (p = 0.00574). Kaplan-Meier analysis showed significant differences in patient survival by morphological type (p = 5.24 × 10⁻⁶). Survival rates at 5 and 10 years, respectively, were 0.937 (95% CI 0.892 to 0.984) for patients with gastric-type IPMNs; 0.886 (95% CI 0.813 to 0.965) and 0.685 (95% CI 0.553 to 0.849) for those with intestinal-type IPMNs; 0.839 (95% CI 0.684 to 1.000) and 0.734 (95% CI 0.526 to 1.000) for those with oncocytic-type IPMNs; and 0.520 (95% CI 0.298 to 0.909) and undetermined for those with pancreatobiliary-type IPMNs. Analysis by the Cox proportional hazards model comparing prognostic risks determined by stage and the morphological and macroscopic types indicated that staging was the most significant predictor of survival (p = 3.68×10⁻⁸) followed by the morphological type (p = 0.0435). Furthermore, the morphological type remained a significant predictor in a subcohort of invasive cases (p = 0.0089).

Conclusion: In this multicentre retrospective analysis, the morphological type of IPMN appears to be an independent predictor of patient prognosis.