24 Efficacy of Pre-Operative Neutrophil-to-Lymphocyte Ratio (NLR) in Predicting Recurrence in Pancreatic Ductal Adenocarcinoma (PDAC)

Abstract Aim Neutrophil-to-lymphocyte ratio’s (NLR) role in predicting PDAC recurrence has not been widely explored. This study aims to investigate the effect of pre-operative NLR on PDAC recurrence. Method A retrospective analysis of patients who underwent surgery with curative intent for PDAC between 2015 and 2024 was performed. Patients were divided into two groups (high and low) using an NLR cutoff of 3. Primary outcome was disease recurrence. The predictive value of NLR was compared using receiver operating characteristic curves, univariate binary logistic regression and multivariate cox regression. Results 132 patients were included; high NLR group n=57 and low NLR group n=75. Both groups were statistically matched across all baseline characteristics. NLR is a strong predictor of recurrence compared to platelet-to-lymphocyte ratio (PLR) and CA19-9 (AUC: NLR 0.712 vs PLR 0.599, CA19-9 0.553; p=0.046, p=0.009 respectively). High NLR group had a significantly greater recurrence rate compared to low NLR group (58.1% vs 34.7%, p<0.001) and a significantly greater local recurrence rate (45.6% vs 21.3%, p=0.003). Across various NLR cutoffs (2.5 to 5.5) high NLR was associated with significantly greater recurrence rates suggesting that regardless of NLR cutoff, comparable results would have been observed. High NLR group remains a significant negative prognosticator for recurrence in both univariate (HR 3.231, p=0.001) and multivariate analysis (HR 3.312, p=0.014). Conclusions A pre-operative high NLR (>3) is associated with a significantly greater risk of recurrence, especially local recurrence. NLR is one of few pre-operative factors that may be used to identify, and risk stratify PDAC patients.