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; I(2)=79%). The LRT group also had multifocal disease slightly more frequently (risk ratio [RR] 1.21, 95%CI 1.04-1.41; I(2)=0%) and disease extent outside the Milan criteria (RR 1.3, 95%CI 1.03-1.66; I(2)=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; I(2)=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.