ObjectiveTo investigate the predictive value of preoperative D-dimer, CA19-9, neutrophil-to-lymphocyte ratio (NLR) in the diagnosis of pancreatic cancer. MethodsThe clinicopathologic data of patients who underwent pancreaticoduodenectomy for pancreatic occupying lesions in the First and Fifth Affiliated Hospitals of Xinjiang Medical University from January 2016 to December 2019 were analyzed retrospectively. According to the pathological characteristics, the patients were divided into pancreatic cancer and pancreatic benign tumour. The gender, age, accompanying diseases, preoperative D-dimer, CA19-9, lymphocyte count, neutrophil count, NLR and so on were compared between them. The receiver operating characteristic (ROC) curves of preoperative D-dimer, CA19-9, and NLR for diagnosis of pancreatic cancer were draw. ResultsA total of 142 patients were collected, including 79 patients with pancreatic cancer and 63 patients with pancreatic benign tumour. Compared with the patients with pancreatic benign tumour, the age was older (P<0.05), the number of neutrophils was more (P<0.05), the number of lymphocytes was less (P<0.05), the preoperative levels of CA19-9 and D-dimer, and the preoperative NLR were higher (P<0.05) for the patients with pancreatic cancer. The multivariate analysis of logistic regression revealed that the preoperative higer CA19-9, D-dimer, and NLR increased the incidence of pancreatic cancer (P<0.05), then the optimal cut-off value of preoperative levels of CA19-9 and D-dimer, and preoperative NLR on diagnosis of pancreatic cancer was 108 U/mL, 306 μg/L and 3.2, respectively, the corresponding area under ROC curve was 0.900, 0.891, 0.768, respectively, and which of combination of preoperative CA19-9, D-dimer, and NLR was 0.931. For the pancreatic cancer patients with preoperative NLR, CA19-9, and D-dimer higher than the optimal cut-off value, the proportions of patients with pTNM stage Ⅲ and lymph node metastasis were higher than those for pancreatic cancer patients with below than optimal cut-off value (P<0.05). ConclusionFrom preliminary study results, preoperative CA19-9, D-dimer, and NLR values have certain values in diagnosis of pancreatic cancer, and diagnostic value of combined detection of 3 indexes is higher than single index.