Meta-analysis of percutaneous radiofrequency ablation versus ethanol injection in hepatocellular carcinoma

Abstract

Background: Percutaneous radiofrequency ablation (RFA) has gained popularity in the treatment of hepatocellular carcinoma (HCC). However, its role versus other conventional minimally invasive therapies is still a matter of debate. The purpose of this work is to analyse the efficacy and safety of RFA versus that of ethanol injection (PEI), the percutaneous standard approach to treat nonsurgical HCC.

Methods: Systematic review and meta-analysis of randomised or quasi-randomised controlled trials published up to August 2008 in PubMed, ISI Web of Science and The Cochrane Library. Overall survival, local recurrence rate and adverse effects were considered as primary outcomes. Studies were critically appraised and estimates of effect were calculated according to the random-effects model. Inconsistency across studies was evaluated using the I2 statistic. Sensitivity analyses were conducted to explore statistical heterogeneity.

Results: Six studies were eligible. The studies reported data on 396 patients treated by RFA and 391 treated by PEI. In general, subjects were in Child-Pugh class A (74%) and had unresectable HCC (mean size 2.5 cm). Mean follow-up was 25 +/- 11 months. The survival rate showed a significant benefit for RFA over PEI at one, two, three and four years. The advantage in survival increased with time with Relative Risk values of: 1.28 (95%CI:1.12-1.45) and 1.24 (95%CI:1.05-1.48) for RFA versus PEI at 3- and 4-years respectively. Likewise, RFA achieved significantly lower rates of local recurrence (RR: 0.37, 95%CI: 0.23-0.59). The overall rate of adverse events was higher with RFA (RR:2.55, 95%CI: 1.8-3.6) yet no significant differences were found concerning major complications (RR:1.85, 95%CI: 0.68-5.01). There was not enough evidence supporting a better cost-effectiveness ratio for RFA compared to PEI.

Conclusion: Available evidence from adequate quality controlled studies support the superiority of RFA versus PEI, in terms of better survival and local control of the disease, for the treatment of patients with relatively preserved liver function and early-stage non-surgical HCC. However, the higher rate of adverse events displayed is something that will have to be tested with appropriate weighting of the possible benefits in each individual case. Overall cost-effectiveness of RFA needs further evaluation.

Figure 1

Flow diagram for study selection and inclusion.

Figure 2

RFA vs. PEI: Results of the meta-analysis on overall survival at 3 years. CI: Confidence interval. All based on a random-effects meta-analysis.

Figure 3

RFA vs. PEI: Results of the meta-analysis on local recurrence rate. CI: Confidence interval. All based on a random-effects meta-analysis.