Postchemoradiotherapy Neutrophil-to-Lymphocyte Ratio Predicts Distant Metastasis and Survival Results in Locally Advanced Pancreatic Cancers

Abstract

Background and Objectives. In the absence of similar research, we endeavored to investigate the prognostic usefulness of posttreatment neutrophil-to-lymphocyte ratio (NLR) in patients treated with definitive concurrent chemoradiotherapy (CCRT) for locally advanced pancreatic adenocarcinoma (LAPAC). Materials and Methods. Our retrospective research included a sum of 126 LAPAC patients who received CCRT. The NLR was calculated for each patient based on the complete blood count test results obtained on the last day of the CCRT. The availability of optimal cutoff(s) that might dichotomize the whole cohort into two groups with significantly different clinical outcomes was searched using receiver operating characteristic (ROC) curve analysis. Primary and secondary endpoints were the potential association between the post-CCRT NLR measures and distant metastasis-free survival (DMFS) and overall survival (OS) outcomes. Results. The median follow-up duration was 14.7 months (range: 2.4–94.5). The median and 3-year OS and DMFS rates for the whole group were 15.3 months (95% confidence interval: 12.4–18.2) and 14.5%, and 8.7 months (95% CI: 6.7–10.7) and 6.3% separately. The ROC curve analysis findings separated the patients into two groups on a rounded NLR cutoff of 3.1 (area under the curve (AUC): 75.4%; sensitivity: 74.2%; specificity: 73.9%) for OS and DMFS: NLR <3.1 (N = 62) and NLR ≥3.1 (N = 64), respectively. Comparisons between the NLR groups displayed that the median OS (11.4 vs. 21.4 months; $P<0.001$ ) and DMFS (6.0 vs. 16.0 months; $P<0.001$ ) lengths were significantly shorter in the NLR ≥3.1 group than its NLR <3.1 counterparts, as well as the 3-year actuarial DM rate (79.7% vs. 50.0%; $P=0.003$ ). The N1-2 nodal stage, CA 19–9>90 U/mL, and NLR >3.1 were found to be independent predictors of poor prognosis in the multivariate analysis. Conclusion. The present study found that the posttreatment NLR ≥3.1 was independently linked with a higher risk of DM and subsequent degraded survival outcomes in unresectable LAPAC patients managed with exclusive CCRT.