Prognostic value of pre-treatment red blood cell distribution width in lung cancer: a meta-analysis

Objective: In recent years, increasing studies found that pre-treatment red blood cell distribution width (RDW) could predict clinical outcomes in various cancers. However, the prognostic value of pre-treatment RDW in lung cancer was inconsistent. Therefore, we performed a meta-analysis to determine prognostic value of pre-treatment RDW in lung cancer.Methods: We performed a search in PubMed, The Cochrane Library, EMBASE (via OVID), Web of Science, CNKI, Wanfang, VIP, SinoMed databases, then we identified all records up to February 15, 2019. Outcomes of interest were overall survival (OS) and disease-free survival (DFS). Hazard ratios (HRs) and corresponding 95% confidence intervals (95% CIs) were calculated to assess the relevance of pre-treatment RDW to OS in lung cancer.Results: We included ten articles in total. Pooled results revealed that elevated pre-treatment RDW was significantly associated with poor OS (HR = 1.55, 95% CI: 1.26-1.92, p < 0.001) and DFS (HR = 1.53, 95% Cl: 1.15-2.05; p = 0.004) in lung cancer. Further subgroup analysis manifested that lung cancer patients with elevated pre-treatment RDW had worse prognosis.Conclusions: A higher value of pre-treatment RDW indicated worse survival of patients with lung cancer. RDW may serve as a reliable and economical marker for prediction of lung cancer prognosis.