Neutrophil-to-lymphocyte Ratio as a Predictor of Malignancy of Intraductal Papillary Mucinous Neoplasms

Background: Intraductal papillary mucinous neoplasm (IPMN) can lead, via the adenoma–carcinoma sequence, to invasive adenocarcinoma, which has a poor prognosis. Most IPMNs do not meet the indications for surgery and instead are monitored regularly, but no biomarkers of malignant transformation during surveillance have been established. Patients and Methods: A total of 50 patients with IPMN who underwent pancreatectomy were evaluated retrospectively. Clinicopathological parameters during the surveillance period before surgery were assessed to explore biomarkers for predicting malignancy. Results: The serum level of carbohydrate antigen 19-9 was significantly higher in IPMN-derived invasive adenocarcinoma. The neutrophil-to-lymphocyte ratio was significantly lower in low-grade IPMN than high-grade and Inv-IPMN cases by univariate and multivariate analysis. Disease-free survival was significantly shorter in patients with high-grade and invasive IPMN compared with those with low-grade IPMN. In patients whose preoperative surveillance was performed for more than 12 months, the neutrophil-to-lymphocyte ratio was significantly higher in those with high-grade and invasive IPMNs compared with patients with low-grade IPMN in the year before surgery. Conclusion: The NLR is a useful biomarker for distinguishing between low-grade and high-grade IPMN and thus should be monitored during surveillance.