Abstract
BACKGROUND: Neutrophil-to-lymphocyte ratio (NLR) is related to prognosis in non-small cell lung cancer (NSCLC). However, no consensus on the relationship of pretreatment NLR and survival outcomes of systemic therapy in NSCLC exists. This meta-analysis investigated the prognostic role of pretreatment NLR during systemic therapy for NSCLC, including chemotherapy, immunotherapy and targeted therapy. METHODS: PubMed, Web of Science and Cochrane Library databases were systematically searched up to April 09, 2019. Hazard ratios (HRs) with their 95% confidence intervals (CIs) were pooled to investigate the association of pretreatment NLR with progression-free survival (PFS) and overall survival (OS). RESULTS: In total, 27 articles with 4,298 participants were selected. The pooled results showed that elevated pretreatment NLR was associated with inferior PFS (HR, 1.45, 95% CI, 1.28-1.66) and OS (HR, 1.63, 95% CI, 1.43-1.84) during systemic therapy. Subgroup analyses according to the treatment strategy suggested that higher pretreatment NLR was significantly associated with shorter survival in all therapies, including chemotherapy (PFS HR, 1.74, 95% CI, 1.39-2.17; OS HR, 1.73, 95% CI, 1.26-2.36), immunotherapy (PFS HR, 1.53, 95% CI, 1.27-1.84; OS HR, 2.50, 95% CI, 1.60-3.89) and targeted therapy (PFS HR, 1.53, 95% CI, 1.04-2.25; OS HR, 1.92, 95% CI, 1.14-3.24). CONCLUSIONS: Pretreatment NLR is a promising prognostic indicator for NSCLC patients receiving systemic therapy, including chemotherapy, immunotherapy and targeted therapy.