[Prognostic value of pretreatment neutrophil-to-lymphocyte ratio (NLR) in locally advanced non-small cell lung cancer patients treated with thoracic radiation]

Objective: The aim of this retrospective study was to evaluate the prognostic significance of pretreatment Neutrophil-to-Lymphocyte Ratio(NLR) in locally advanced non-small cell lung cancer(NSCLC) patients treated with thoracic radiotherapy. Methods: We retrospectively analyze 420 patients who received thoracic radiotherapy alone, sequential chemoraiotherapy or concurrent chemoradiotherapy for locally advanced stage NSCLC from January 2007 to December 2010 of our hospital. The patients were divided into two groups (high NLR group and low NLR group) with appropriate cutoff point using the receiver operating characteristic (ROC) curve method. The survival curve was established by Kaplan-Meier method. The Log-rank test was used to compare the survival of the two NLR groups and the multivariate analysis was carried out by Cox regression model. Results: Among the 420 patients, 99 received radiotherapy alone, 139 received sequential chemoradiotherapy and 182 received concurrent chemoradiotherapy. 345 patients died and 75 were still alive. The median follow-up time was 5.2 years and the median overall survival was 22 months. The cut-off value of pretreatment NLR was 2.1. The 5-year PFS and OS rates in high NLR group and low NLR group were 10.6% vs 15.7% (P=0.033) and 15.5% vs 22.7% (P=0.012). Multivariate analysis confirmed that pretreatment NLR (hazard ratio 1.06, P=0.041) was independent prognostic factor of OS. Conclusions: Our study revealed that the pretreatment NLR is the independent prognostic factor of OS in patients with locally advanced stage NSCLC treated with thoracic radiotherapy. However, NLR is still greatly influenced by patient's condition and treatment which needs further research.