Bridging locoregional treatment prior to liver transplantation for cirrhotic patients with hepatocellular carcinoma within the Milan criteria: a systematic review and meta-analysis

Background We performed a meta-analysis to assess the benefit of bridging locoregional treatment (LRT) before liver transplantation for cirrhotic patients with hepatocellular carcinoma (HCC) already within the Milan criteria at diagnosis. Methods We included original studies with HCC cases within the Milan criteria at diagnosis, comparing patients with and without bridging LRT before liver transplantation. Results Twenty-six retrospective original studies were included. Out of the 9068 patients within the Milan criteria, 6435 (71%) received bridging LRT and 2633 (29%) did not. The most frequent LRTs were transarterial chemoembolization, radiofrequency ablation, and microwave ablation. Most of the patient and tumor characteristics were similar between the 2 groups. Maximum tumor diameter on scans was slightly larger in the LRT arm (mean difference: 0.36 cm, 95% confidence interval [CI] 0.11-0.61; I2=79%). The LRT group also had multifocal disease slightly more frequently (risk ratio [RR] 1.21, 95%CI 1.04-1.41; I2=0%) and disease extent outside the Milan criteria (RR 1.3, 95%CI 1.03-1.66; I2=0%) on pathological examination of explanted livers. There was no difference between the 2 arms in the waiting time for transplant, dropout rates, disease free survival at 1, 3, 5 years after transplant, or overall survival at 3 and 5 years after transplant. However, cases with LRT had better overall survival at 1 year after transplant (hazard ratio 0.54, 95%CI 0.35-0.86; I2=0%). Conclusions The precise benefit of bridging LRT for cirrhotic patients with HCC within the Milan criteria at diagnosis is unclear. There may be an advantage regarding short-term overall survival after liver transplantation.