Platelet-to-lymphocyte ratio in the setting of liver transplantation for hepatocellular cancer: A systematic review and meta-analysis

摘要

AIM To perform a systematic review and meta-analysis on platelet-to-lymphocyte ratio(PLR) as a risk factor for post-transplant hepatocellular cancer(HCC) recurrence. METHODS A systematic literature search was performed using PubM ed. Participants of any age and sex, who underwent liver transplantation for HCC were considered following these criteria:(1) studies comparing pre-transplant low vs high PLR values;(2) studies reporting post-transplant recurrence rates; and(3) if more than one study was reported by the same institute, only the most recent was included. The primary outcome measure was set for HCC recurrence after transplantation. RESULTS A total of 5 articles, published between 2014 and 2017, fulfilled the selection criteria. As for the quality of the reported studies, all the investigated articles presented an overall high quality. A total of 899 cases were investigated: 718 cases(80.0%) were males. Three studies coming from European countries and one from Japan presented HCV as the main cause of cirrhosis. On the opposite, one Chinese study presented a greater incidence of HBV-related cirrhotic cases. In all the studies apart one, the PLR cut-off value of 150 was reported. At meta-analysis, high PLR value was associated with a significant increase in recurrence after transplantation(OR = 3.33; 95%CI: 1.78-6.25; P < 0.001). A moderate heterogeneity was observed among the identified studies according to the Higgins I^2 statistic value.CONCLUSION Pre-transplant high PLR values are connected with an increased risk of post-operative recurrence of hepatocellular cancer. More studies are needed for better clarify the biological mechanisms of this results.