Development of Pancreatic Cancer, Disease-specific Mortality, and All-Cause Mortality in Patients with Nonresected IPMNs: A Long-term Cohort Study

Purpose: To determine the cumulative incidence, disease-specific mortality, and all-cause mortality of pancreatic cancer (PC) in patients with intraductal papillary mucinous neoplasms (IPMNs) and to identify imaging findings that are associated with these outcomes. Materials and Methods: This retrospective study had institutional review board approval, and the need to obtain patient consent was waived. Data from an electronic database were analyzed and supplemented by chart reviews for 285 patients with nonresected IPMNs who were periodically followed up with imaging (1273 multidetector computed tomography and 750 magnetic resonance cholangiopancreatography examinations). The Kaplan-Meier method was used to estimate the cumulative development of PC, PC mortality, and all-cause mortality (factors were compared by using the log-rank test). Results: Over a median imaging follow-up period of 39 months, 12 (4.2%) of 285 patients developed PC; the cumulative 5-year PC incidence was 3.9% for branch duct (BD)-IPMNs, 45.5% for main duct (MD)-IPMNs (P < .01), 7.7% for cysts 30 mm or larger, and 5.3% for cysts smaller than 30 mm (P = .82). Over a median survival follow-up period of 47.5 months, seven (2.5%) of 285 patients died of PC and 14 (4.9%) patients died of other causes. Cumulative 5-year PC mortality was 2.1% for BD-IPMNs, 18.5% for MD-IPMNs (P < .01), 2.6% for cysts 30 mm or larger, and 2.8% for cysts smaller than 30 mm (P = .90). Cumulative 5-year all-cause mortality was 5.5% for BD-IPMNs, 18.5% for MD-IPMNs (P < .01), 12.5% for cysts 30 mm or larger, and 5.9% for cysts smaller than 30 mm (P = .89). Conclusion: Five-year PC development, disease-specific mortality, and all-cause mortality were approximately 4%, 2%, and 6% for BD-IPMNs and 46%, 19%, and 19% for MD-IPMNs, respectively. The presence of an MD-IPMN, but not cyst size, was significantly associated with PC development and subsequent mortality. (C) RSNA, 2015