Long-term Risk of Malignancy in Branch Duct Intraductal Papillary Mucinous Neoplasms.

During 9231 person-years of follow up, we identified 68 patients with pancreatic carcinomas (38 patients with IPMN-derived carcinomas and 30 patients with concomitant PDACs); the overall incidence rates were 3.3%, 6.6%, and 15% at 5, 10, and 15 years, respectively. Among 804 patients followed more than 5 years, overall cumulative incidence rates of pancreatic carcinoma were 3.5% at 10 years and 12% at 15 years from the initial diagnosis. The size of the IPMN and the diameter of the main pancreatic duct associated with incidence of IPMN-derived carcinoma (SHR, 1.85; 95% CI, 1.38-2.48 for a 10-mm increase in the IPMN size and SHR, 1.56; 95% CI, 1.33-1.83 for a 1-mm increase in the main pancreatic duct diameter) but not with incidence of concomitant PDAC CONCLUSIONS: In a large long-term study of patients with branch-duct IPMNs, we found the 5-year incidence rate of pancreatic malignancy to be 3.3%, reaching 15% at 15 years after IPMN diagnosis. We observed heterogeneous risk factor profiles between IPMN-derived and concomitant carcinomas.