Neutrophil-Lymphocyte Ratio and Platelet-Lymphocyte Ratio as Prognostic Factors for Locally Advanced Pancreatic Cancer Patients

Abstract

It is well known that locally advanced pancreatic cancer patients have a poor prognosis. Outcomes of these patients are not only determined by tumor characteristics but also by host-related factors. Recently, hematologic markers showing systemic inflammatory status such as neutrophil-lymphocyte ratio (NLR) and platelet-lymphocyte ratio (PLR) have aroused much attention due to its potential to predict patient survival. In this study, we investigated whether pre-treatment NLR and PLR independently and combination of NLR and PLR would be significant prognostic factors for survival in locally advanced pancreatic cancer patients. A total of 497 locally advanced (borderline resectable and unresectable) pancreatic cancer patients who received neoadjuvant or definitive chemoradiotherapy (CCRT) between January 2005 and December 2015 were included in this study. NLR and PLR prior to the start of treatment within 2 weeks were defined as pre-treatment NLR and PLR. We divided the patients with the median values of pre-treatment NLR and PLR; NLR < 2.44 group (n = 248), NLR ≥ 2.44 group (n = 249), PLR < 149 group (n = 248) and PLR ≥ 149 (n = 249) group. Overall survival (OS) and progression-free survival (PFS) were compared between each group for NLR and PLR. Additionally, we grouped the patients into 3 groups concerning both factors. Patients with NLR < 2.44 and PLR < 149 (n = 175), either NLR ≥ 2.44 or PLR ≥ 149 (n = 146), and NLR ≥ 2.44 and PLR ≥ 149 (n = 176) were evaluated for OS and PFS. Median overall survival was 15.7 months (range, 2.3-128.5 months). For NLR, the OS, PFS rates were significantly lower in the NLR ≥ 2.44 group, with 1-year OS rates of 67.9% and 61.5% (p = 0.003) and 1-year PFS rates of 38.1% and 32.4% (p = 0.003), for NLR < 2.44 and ≥ 2.44 group, respectively. The PLR ≥ 149 group also showed significantly poorer OS and PFS than PLR < 149 group. The 1-year OS rates were 68.1% and 61.3% (p = 0.029) and 1-year PFS rates were 37.9% and 32.5% (p = 0.027), for PLR < 149 and ≥ 149 group, respectively. When multivariate analysis was performed, NLR ≥ 2.44 remained as a significant adverse factor for OS (p=0.007) and PFS (p=0.026). PLR > 149 also proved to be a significant factor for poorer OS (p=0.03) and PFS (0.007). When both NLR and PLR were taken into account, NLR ≥ 2.44 and PLR ≥ 149 group showed the worst OS (p=0.008) and PFS (p=0.002) compared to the other two groups and remained significant after multivariate analysis for both OS (p=0.003) and PFS (p=0.003). Elevated pre-treatment NLR and PLR independently and in combination significantly predicted poor OS and PFS. The NLR or PLR can be easily measured using peripheral blood samples. Pre-treatment NLR and PLR could be useful prognostic factors for OS and PFS in locally advanced pancreatic cancer patients.