Background: An appropriate timing for surgical resection of branch duct-type intraductal papillary mucinous neoplasm (BD-IPMN) to achieve sufficient postoperative survival is still unknown.
Methods: Of 80 patients with histologically proven IPMNs, 61 patients who had BD-IPMN without pancreatic cancer concomitant with IPMN were enrolled in this study. We divided BD-IPMN into four groups according to disease progression: low to intermediate grade of dysplasia (LGD/IGD-IPMN), high grade of dysplasia (HGD-IPMN), minimally invasive IPMN (MI-IPMN: T1a), and invasive IPMN (IN-IPMN: ≥T1b). Indicators of surgical resection were investigated on the basis of pathological findings and postoperative prognosis.
Results: Postoperative survival was distinctly worse for patients with IN-IPMN than for patients with MI-IPMN, HGD-IPMN, and LGD/IGD-IPMN. Postoperative disease-specific 5-year survival rate was 100 % in patients with IN-IPMN, HGD-IPMN, and LGD/IGD-IPMN, by contrast, 40 % in patients with IN-IPMN. The presence of two of the three factors (pancreatitis, serum carbohydrate antigen [CA] 19-9 levels >13 U/mL, and mural nodules) could distinguish HGD-IPMN from LGD/IGD-IPMN with a sensitivity of 92.9 %, specificity of 90.2 %, positive predictive value of 76.5 %, negative predictive value of 97.4 %, and accuracy of 90.9 %.
Conclusions: To manage patients with BD-IPMN and achieve a good postoperative prognosis, surgical resection should be performed before progression to IN-IPMN.