Neutrophil-lymphocyte ratio is a predictor of prognosis in patients with castration-resistant prostate cancer: a meta-analysis

Background: The prognostic value of neutrophil-lymphocyte ratio (NLR) in patients with castration-resistant prostate cancer (CRPC) had been investigated in previous studies; however, the results remain inconsistent. This study was aimed to investigate the prognostic value of NLR in CRPC patients. Materials and methods: Literature was identified from PubMed, Embase, Web of Science, and Cochrane, which investigated the relationship between pretreatment NLR and prognosis in CRPC patients. HRs for overall survival (OS) and progression-free survival (PFS) were extracted from eligible studies. Heterogeneity was assessed using the I-2 value. The fixed-effects model was used if there was no evidence of heterogeneity; otherwise, the random-effects model was used. Publication bias was evaluated using Begg's funnel plot test. Results: A total of 5,705 patients from 16 studies were included in this analysis. The pooled results showed that an elevated NLR predict poor OS (pooled HR=1.52, 95% CI: 1.41-1.63, P<0.001) and PFS (pooled HR=1.50, 95% CI: 1.21-1.85, P<0.001) in patients with CRPC. Subgroup analysis revealed that an elevated NLR significantly predicted poor OS in Asian studies group (HR=2.43, 95% CI: 1.47-4.01, P=0.001). The elevated NLR also significantly predicted poor PFS in Asian studies group (HR=1.99, 95% CI: 1.30-3.06, P=0.002). Conclusion: This study suggests that an elevated NLR predict poor prognosis in patients with CRPC.