Radiofrequency thermal ablation vs. percutaneous ethanol injection for small hepatocellular carcinoma in cirrhosis: Meta-analysis of randomized controlled trials

OBJECTIVES: Radiofrequency thermal ablation (RF) and percutaneous ethanol injection (PEI) have been employed in the treatment of small hepatocellular carcinoma (HCC) as curative treatments. The aim of the study was to review the available evidence comparing RF to PEI for small HCC. METHODS: Search strategy: Cochrane, MEDLINE, CANCERLIT, and ENBASE databases were used. Selection criteria: randomized clinical trials evaluating RF vs. PEI. Data were extracted from each randomized controlled trial (RCT). Primary outcomes were overall survival and local recurrence. Meta-analysis software was used and risk differences (RDs) and their 95% confidence intervals and Q-test for heterogeneity were calculated. RESULTS: Five RCTs were identified including 701 patients. The overall survival was significantly higher in patients treated with RF than in those treated with PEI (RD 0.116, 95% CI 0.173/0.060; heterogeneity not present). Local recurrence rate is significantly higher in patients treated with PEI than in those treated with RF. In the RF group the 1, 2, and 3 years cancer-free survival rates were significantly better than in the PEI-treated patients (respectively: RD 0.098 - 95% CI 0.006/0.189; heterogeneity P=0.57; RD 0.187, 95% CI 0.082/0.293; heterogeneity P=0.98; RD 0.210, 95% CI 0.095/0.325; heterogeneity P = 0.78). A small number of adverse events were reported in the two treatments. CONCLUSIONS: RF ablation is superior to PEI in the treatment of small HCC with respect to overall survival, 1, 2, and 3 years survival rates, 1, 2, and 3 cancer-free survival rates, and tumor response. RF shows a significantly smaller risk of local recurrence.