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

Aim: 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. Methods: 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. Results: 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). Conclusion: The results of this meta-analysis showed that elevated pretransplant NLR may be used as a new prognostic predictor after LT for HCC.