Prognostic value of pre-treatment neutrophil-to-lymphocyte ratio in patients with brain metastasis from cancer: a meta-analysis.

Evidence shows that inflammatory responses play an essential role in the development of brain metastases (BM). The goal of this meta-analysis was to critically evaluate the literature regarding the use of the neutrophil to lymphocyte ratio (NLR) to predict the prognosis of patients with BM to help clinicians institute early interventions and improve outcomes. We conducted systematic review and meta-analysis, utilizing data from prominent databases, including PubMed, Cochrane Library and China National Knowledge Infrastructure databases. Our inclusion criteria encompassed studies investigating the studies that assessed the association between NLR and overall survival (OS). We included 11 articles, with 2629 eligible patients, to evaluate the association between NLR and OS. High NLR was significantly associated with shorter OS, with a pooled hazard ratio (HR) of 1.82 (95% CI 1.57-2.11). Subgroup analysis revealed that this association was consistent across different regions, with HRs of 2.03 (95% CI 1.67-2.46) in Asian populations and 1.58 (95% CI 1.35-1.84) in non-Asian populations. Additionally, in a subgroup analysis based on NLR cut-off values, patients with NLR ≥ 3 had an HR of 1.69 (95% CI 1.46-1.96), while those with NLR < 3 had an HR of 2.26 (95% CI 1.64-3.11). Sensitivity analysis confirmed that no single study significantly influenced the pooled effect size. Our meta-analysis confirmed the prognostic value of NLR in patients with brain metastasis.