Intraductal papillary mucinous neoplasms in high-risk individuals: incidence, growth rate, and malignancy risk

Background and Aims: In high-risk individuals (HRIs), we aimed to assess the cumulative incidence of intraductal papillary mucinous neoplasms (IPMNs) and compare IPMN growth, neoplastic progression rate, and the value of growth as predictor for neoplastic progression to these in sporadic IPMNs. Methods: We performed annual surveillance of Dutch HRIs, involving carriers of germline pathogenic variants (PVs) and PV-negative familial pancreatic cancer kindreds. HRIs with IPMNs were compared with Italian individuals without familial risk under surveillance for sporadic IPMNs. Results: A total of 457 HRIs were followed for 48 (range 2–172) months; the estimated cumulative IPMN incidence was 46% (95% confidence interval, 28%–64%). In comparison with 442 control individuals, IPMNs in HRIs were more likely to grow ≥2.5 mm/y (31% vs 7%; P < .001) and develop worrisome features (32% vs 19%; P = .010). PV carriers with IPMNs more often displayed neoplastic progression (n = 3 [11%] vs n = 6 [1%]; P = .011), while familial pancreatic cancer kindreds did not (n = 0 [0%]; P = 1.000). The malignancy risk in a PV carrier with an IPMN was 23% for growth rates ≥2.5 mm/y (n = 13), 30% for ≥5 mm/y (n = 10), and 60% for ≥10 mm/y (n = 5). Conclusions: The cumulative incidence of IPMNs in HRIs is higher than previously reported in the general population. Compared with sporadic IPMNs, they have an increased growth rate. PV carriers with IPMNs are suggested to be at a higher malignancy risk. Intensive follow-up should be considered for PV carriers with an IPMN growing ≥2.5 mm/y, and surgical resection for those growing ≥5 mm/y.