Impact of Preoperative Neutrophil-Lymphocyte and Platelet-Lymphocyte Ratios on Long-Term Survival in Patients with Operable Pancreatic Ductal Adenocarcinoma

Background: Pancreatic ductal adenocarcinoma (PDAC) has an extremely poor prognosis. The outcomes of patients with cancer are determined not only by tumor-related factors, but also by systemic inflammatory response. The objective of study was to identify whether the preoperative neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) are associated with the prognosis of PDAC of the pancreas head after curative pancreato-duodenectomy.Materials and methods: Seventy-six patients were enrolled in this prospective observational clinical study. The optimal NLR and PLR cut-off values were calculated using a receiver operating characteristic (ROC) curve analysis. ROC curve analysis revealed an optimal NLR and PLR cut-off point of 5.41 and 205.56 respectively. Consequently, the NLR and PRL scores were classified as NLR<5.41 or >= 5.41 and PLR<205.56 or >= 205.56. The clinical outcomes of overall survival (OS) and disease-free survival (DFS) were calculated by Kaplan-Meier survival curves. Univariate and multivariate analyses were performed to analyze the prognostic value of NLR and PLR.Results: Low pre-operative NLR and PLR levels both correlated with better pathological features, including decreased depth of invasion (P<0.001), less lymph node metastasis (P<0.001), earlier stage (P<0.001), and lymphovascular invasion (P=0.004). Kaplan-Meier plots illustrated that higher preoperative NLR and PLR had does not influence OS and DFS. Univariate analysis revealed that depth of invasion, lymph node metastasis, stage, PLR and NLR are risk factors affecting OS and DFS. Multivariate analysis revealed that only stage was independently associated with OS and DFS.Conclusions: NLR and PLR measurements cannot provide important prognostic results in patients with resectable PDAC.