Prognostic Role of Neutrophil-to-Lymphocyte Ratio in Advanced Pancreatic Ductal Adenocarcinoma: Impact of Baseline Fluctuation and Changes during Chemotherapy

Abstract

Aims and background

Inflammation has been implicated in carcinogenesis and progression of pancreatic cancer. The neutrophil-to-lymphocyte ratio is an index of systemic inflammation. We examined the prognostic role of the neutrophil-to-lymphocyte ratio at baseline and the significance of intrapersonal variability of the ratio before and during chemotherapy.

Methods and study design

Advanced pancreatic adenocarcinoma patients who had received chemotherapy were included. Baseline clinical and biochemical parameters, including the neutrophil-to-lymphocyte ratio, were extracted and analyzed. The neutrophil-to-lymphocyte ratio threshold was determined via recursive partitioning and assessed at diagnosis, prior to chemotherapy and during treatment. Overall survival was estimated via the Kaplan-Meier method and compared between groups with the logrank test.

Results

Between 2005 and 2011, 85 patients with locally advanced (n = 38) and metastatic disease were identified: 68% with a neutrophil-to-lymphocyte ratio >3 had shorter median overall survival than patients with a neutrophil-to-lymphocyte ratio <3 (3.4 vs 9.4 months, P = 0.001). Pretreatment, 35% of repeat neutrophil-to-lymphocyte ratios crossed the threshold of 3. A persistently elevated neutrophil-to-lymphocyte ratio >3 suggested a worse overall survival than in patients with a decreasing, increasing or persistently low neutrophil-to-lymphocyte ratio (1.9 vs 8.2, 12.3 and 11.7 months, respectively, P <0.001). Twenty-three percent of patients had a >50% decrease in neutrophil-to-lymphocyte ratio following 4 weeks of chemotherapy, with a trend towards improvement in overall survival (12.5 vs 5.0 mo, P = 0.068).

Conclusions

The baseline neutrophil-to-lymphocyte ratio is a validated marker for a poor prognosis. Multiple assessments of the pre-treatment neutrophil-to-lymphocyte ratio might be required. Reduction in the neutrophil-to-lymphocyte ratio during chemotherapy may be associated with improved survival.