Neutrophil-to-lymphocyte ratio for the prognostic assessment of hepatocellular carcinoma: A systematic review and meta-analysis of observational studies

BACKGROUND AND AIMS Neutrophil to lymphocyte ratio (NLR) is an inflammatory-based marker. A systematic review and meta-analysis was performed to explore the prognostic role of NLR in patients with hepatocellular carcinoma (HCC). RESULTS Overall, 598 papers were identified, of which 90 papers including 20,475 HCC patients were finally included. Low baseline NLR was significantly associated with better overall survival (HR = 1.80, 95% CI: 1.59-2.04, p < 0.00001) and recurrence-free or disease-free survival (HR = 2.23, 95% CI: 1.80-2.76, p < 0.00001). Low post- treatment NLR was significantly associated with better overall survival (HR = 1.90, 95% CI: 1.22-2.94, p = 0.004). Decreased NLR was significantly associated with overall survival (HR = 2.23, 95%CI: 1.83-2.72, p < 0.00001) and recurrence-free or disease-free survival (HR = 2.23, 95% CI: 1.83-2.72, p < 0.00001). The findings from most of subgroup meta-analyses were consistent with those from the overall meta-analyses. MATERIALS AND METHODS All relevant literatures were identified via PubMed, EMBASE, and Cochrane library databases. Hazard ratio (HR) with 95% confidence interval (95%CI) was calculated. Subgroup meta-analyses were performed according to the treatment options, NLR cut-off value ranges, and regions. CONCLUSIONS NLR should be a major prognostic factor for HCC patients. NLR might be further incorporated into the prognostic model of HCC.