Clinicopathological and prognostic value of preoperative lymphocyte to monocyte ratio for hepatocellular carcinoma following curative resection: A meta-analysis including 4,092 patients

BACKGROUND: Previous studies have reported that lymphocyte-to-monocyte ratio (LMR) had novel prognostic value in hepatocellular carcinoma (HCC). The purpose of this meta-analysis was to synthetically evaluate the prognostic role of preoperative LMR in HCC patients following curative resection. METHODS: Eligible studies were acquired through searching Pubmed, Web of Science, Cochrane Library and EMbase update to September 2019. Merged hazard ratios (HRs) and 95% confidence intervals (CIs) were applied as effect sizes. RESULTS: A total of ten studies containing 4,092 patients following liver resection were enrolled in this meta-analysis. The pooled results demonstrated that preoperative elevated LMR indicated superior survival outcome (HR: 0.58, 95% CI: 0.34–0.96, P = .035) and recurrence-free survival (RFS)/disease-free survival/time to recurrence (HR = 0.76, 95% CI: 0.58–0.98, P = .034). The significant prognostic role of preoperative LMR was detected in the subgroup of all publication year, country of origin, sample sizes <300, TNM stage of I–IV and LMR cut-off value ≤4. Furthermore, high LMR was significantly associated with male, high AFP, large tumor size, incomplete tumor capsule, advanced TNM stage and BCLC stage, and presence of PVTT. CONCLUSION: Elevated preoperative LMR indicated superior survival outcome in HCC patients following curative resection, and might serve as a novel prognostic biomarker.