The pretransplant neutrophil-lymphocyte ratio as a new prognostic predictor after liver transplantation for hepatocellular cancer: a systematic review and meta-analysis

Recently, many reports showed that the pretransplant neutrophil-lymphocyte ratio (NLR) may be correlated with the prognosis of patients undergoing liver transplantation (LT) for hepatocellular cancer (HCC). However, their results still remained controversial. Thus we performed a meta-analysis of 13 studies to estimate the prognostic value of pretransplant NLR. Databases including PubMed, Embase, Cochrane Library and Web of Science were searched to September 2017. Hazard ratio (HR) or odds ratio (OR) with its 95% CI was used to evaluate the association between elevated NLR and the prognosis or clinical features of liver cancer patients. A total of 13 studies including 1936 patients were included in this meta-analysis. Elevated pretransplant NLR had a close association with the overall survival (HR: 2.22; 95% CI: 1.34-3.68), recurrence-free survival (HR: 3.77; 95% CI: 2.01-7.06) and disease-free survival (HR: 2.51; 95% CI: 1.22-5.15) of patients undergoing LT for HCC, respectively. In addition, elevated NLR was associated with the presence of vascular invasion (OR: 2.39; 95% CI: 1.20-4.77) and Milan criteria (OR: 0.26; 95% CI: 0.17-0.40). The results of this meta-analysis showed that elevated pretransplant NLR may be used as a new prognostic predictor after LT for HCC.