Systematic review of randomized trials for hepatocellular carcinoma treated with percutaneous ablation therapies

According to the American Association for the Study of Liver Diseases guidelines, percutaneous ethanol injection (PEI) is a safe and highly effective treatment for small hepatocellular carcinomas (HCC) and should be the standard against which any new therapy is compared. The primary purpose of this study was to identify survival benefit of any percutaneous ablation therapy as compared with PEI in the treatment of patients with unresectable HCC. The secondary endpoints were initial tumor response, local tumor progression, and complications. Randomized controlled trials that compared pecutaneous ablative therapies with PEI were included. MEDLINE, the Cochrane Library, CANCERLIT, and manual search from 1978 to July 2008 were used. To control the potential heterogeneity, the random effects model of DerSimonian and Laird was used for a meta-analysis. Egger's test was performed to test a potential publication bias. We identified seven randomized controlled trials (RCTs), but only four RCTs including 652 patients that compared radiofrequency ablation (RFA) with PEI met the inclusion criteria to perform a meta-analysis assessing 3-year survival. A meta-analysis of the four RCTs demonstrated a significant improvement in 3-year survival favoring RFA over PEI (odds ratio 0.477, 95% confidence interval 0.340-0.670; P < 0.001). Heterogeneity among the four trials was not significant (Q = 4.586; P= 0.205). Egger's test revealed that the publication bias was not significant (P = 0.647). However, the number of patients included in the analysis was insufficient for a robust meta-analysis of initial tumor response. The definition of local tumor progression or major complication was not unified among the trials included in the meta-analysis.

RFA demonstrated significantly improved 3-year survival status for patients with HCC, when compared to PEI.