The diagnostic role of the neutrophil-to-lymphocyte ratio in predicting pancreatic ductal adenocarcinoma in patients with pancreatic diseases

Accurately diagnosing pancreatic ductal adenocarcinomas (PDACs) is challenging because of the loss of vascularity and poor imaging. The neutrophil-to-lymphocyte ratio (NLR) has been reported to predict poor prognosis in several types of malignancy including PDAC; however, the diagnostic role of NLR in PDAC has never been addressed. This study retrospectively assessed 297 patients who underwent curative pancreatic resection for pancreatic tumors from 1995-2015, including 140 with PDACs, 58 with pancreatic neuroendocrine tumors (PNETs), 76 with intraductal papillary mucinous neoplasms (IPMNs), 13 with mucinous/serous cyst neoplasms, 7 with solid pseudopapillary neoplasms, and 3 with tumor-forming pancreatitis. The role of preoperative NLR in predicting PDACs was investigated. Preoperative NLR was significantly higher in patients with PDACs (2.52 +/- A 1.34) than in patients with PNETs (1.93 +/- A 0.68, P = 0.0004) and IPMNs (2.17 +/- A 0.79, P = 0.0253). Only eight patients with PDACs (5.7 %) had NLR > 5; of these, three had normal carcinoembyronic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9) levels. Multivariate analysis revealed that abnormal CA19-9 levels, abnormal CEA levels, age > 67 years, and NLR > 5 were independent predictors of PDACs. Both the specificity and the positive predictive value of NLR > 5 for predicting PDACs were 100 %; however, the sensitivity was 4.6 % and the negative predictive value was 43.8 %. NLR > 5 could independently predict the occurrence of PDACs in pancreatic neoplastic disease irrespective of other tumor markers, CEA and CA19-9, in pancreatic disease.