Neutrophil-to-lymphocyte ratio predicts prognosis of patients with hepatocellular carcinoma: a systematic review and meta-analysis

BACKGROUND: Neutrophil-to-lymphocyte ratio (NLR) is one predictive factor for poor prognosis of patients with hepatocellular carcinoma (HCC). In response to contradictory data concerning the predictive ability of NLR, we performed a meta-analysis for the determination of its prognostic value in patients with HCC. METHODS: We systematically searched several databases including PubMed, EMBASE, Cochrane Library, Chinese National Knowledge Infrastructure and Wan Fang databases with the updated date of September 21, 2020. Inclusion criteria: RCT studies reporting the prognostic value of the serum levels of NLR in HCC patients receiving treatment were enrolled. Pooled estimates of odds ratio (OR) and diagnostic odds ratio (DOR) were used to assess the prognostic performance of NLR in HCC patients. Overall survival (OS) was the primary outcome and progression-free survival (PFS) was secondary outcomes. Data from studies reporting a hazard ratio and 95% confidence interval (CI) or a P value were pooled in a meta-analysis. Furthermore, risk of bias assessment of included studies is specified by Cochrane Risk Bias Assessment Tool. RESULTS: This analysis included 9 studies containing a total of 3,862 HCC patients. High baseline NLR was significantly correlated with poor prognosis or recurrence. The patient-based analysis of pooled estimates was as follows: sensitivity, 0.68 (95% CI: 0.58–0.77); specificity, 0.73 (95% CI: 0.61–0.82); DOR, 6.347 (95% CI: 5.450–7.391). The pooled positive likelihood ratio (PLR) and negative likelihood ratio (NLHR) were 2.5 (95% CI: 1.8–3.6) and 0.43 (95% CI: 0.33–0.57). Furthermore, the area under the curve (AUC) of summary receiver operating characteristic (SROC) reflecting the prognostic accuracy was 0.76 (95% CI: 0.72–0.80). Results obtained from subgroup meta-analyses and overall meta-analyses were accordingly consistent with each other. CONCLUSIONS: Our findings suggested that NLR is an effective prognostic factor for patients with HCC, especially for those from East Asian populations with high incidence. In the future, trials with larger sample sizes and more high-quality evidence are needed to further improve patient outcomes.