Real life management of intraductal papillary mucinous neoplasms of the pancreas: Final data from the prospective Italian pancreatic cysts (PANCY) registry

Background: Studies on surveillance of Intraductal Papillary Mucinous Neoplasms (IPMNs) are mainly retrospective with inherited bias. Aim: To identify factors associated with the development of relevant changes in low risk IPMN under surveillance. Methods: This study analysed IPMN patients enrolled between 2015–2017 in the prospective observational multicentric registry PANcreatic CYsts (PANCY), focusing on brunch duct (BD). Extension of surveillance until December 31st, 2021 was proposed to the recruited patients. Relevant changes were defined as: worrisome features/high risk stigmata/pancreatic cancer, pancreatectomy, death due to IPMN/pancreatic cancer. Results: At diagnosis, from 647 IPMNs, 547 (60%) were BD, 87 (9%) mixed type, and 13 (1%) main duct. 57 (8.8%) underwent immediate surgery and 590 (91.2%) active surveillance. Of them 34 (5.7%) underwent surgery with 2/3 malignancy. Malignancy rates for BD- and mixed-IPMNs under surveillance were 2.7% and 12.5%. Smoking (OR 2.2) and cyst size >15 mm at diagnosis (OR 7.1) were independent risk factors for relevant changes at multivariate analysis. The combination of cyst size ≤15 mm & age >65 was a protective factor at univariate analysis (OR 0.1), mainly in no smokers (OR 0.2, p < 0.01). Conclusions: BD-IPMN progression risk is low for lesions <15 mm in non-smokers, >65 years patients. Surgery and follow-up criteria are still imperfect, leading to inappropriate utilization of resources.