Prognostic Impact of Monocyte to Lymphocyte Ratio in Clinical Outcome for Patients with Hepatocellular Carcinoma: A Systematic Review and Meta-Analysis

Background Lymphocyte to monocyte ratio (LMR) is a surrogate marker of systemic inflammation which is shown to be related to the patient's survival in multiple malignancies. An important implication of this marker potentially is neoplasms in which there is no correlation between prognosis and histopathological staging and also has no reliable chemical markers associated with prognosis. Herein, this meta-analysis aimed to investigate the prognostic role of LMR in patients with hepatocellular carcinoma (HCC). Materials and Methods In the current systemic review and meta-analysis, we conducted a systemic search of databases and indexing sources, including PubMed, EMBASE, Cochrane, Scopus, and ProQuest up to May 2019 toinclude studies on the prognostic significance of LMR on patients with HCC. Overall survival (OS), disease-free survival (DFS) and recurrence-free survival (RFS) values were extracted from the studies and analyzed. The pooled hazard ratio with a 95% confidence interval was explored to identify the prognostic value of the LMR in the survival of the patients with HCC. Results A total of 12 studies with a total sample size of 3750 cases were included. There was significant heterogeneity among the studies; therefore, subgroup analysis was also performed. Overall analysis regarding OS showed an insignificant relationship between LMR and patient's prognosis, dividing to subgroups based on LMR cut-offs did not yield any significant result, subgroup analysis for RFS founded statistically significant results and LMR was significantly related to DFS. Conclusion High LMR was associated with increased DFS and RFS, in return this association was not observed for OS.