Background: 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.
Methods: 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.
Results: Preoperative NLR was significantly higher in patients with PDACs (2.52 ± 1.34) than in patients with PNETs (1.93 ± 0.68, P = 0.0004) and IPMNs (2.17 ± 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 %.
Conclusions: 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.
Keywords: Diagnosis; Neutrophil-to-lymphocyte ratio; Pancreatic ductal adenocarcinoma.