Researchers from China have reported that thermal ablation with radiofrequency thermal ablation (RFA) or microwave ablation (MWA) is effective treatment for hepatocellular carcinomas (HCC) measuring between 3 and 7 centimeters. The details of this study appeared in the May 1, 2009 issue of Cancer.[1]

Hepatocellular carcinoma is increasing in incidence, primarily as a result of alcoholism and chronic hepatitis B and C. Depending on the stage of disease, there are a variety of approaches for curative or palliative treatment of hepatocellular carcinoma, including surgical resection, intravenous chemotherapy, intra-arterial chemotherapy, interferon alfa, conformal radiation therapy, radioactive lipitiol, liver transplantation, embolization, chemoembolization, cryosurgery, RFA, and MWA. However, for patients with unresectable hepatocellular cancer, there is no standard treatment.

Radiofrequency ablation is applied via an electrode inserted percutaneously into the tumor using CT or MRI imaging for guidance. Cell death is due to thermal destruction. Microwave ablation is similar to RFA except an antenna is placed percutaneously in the tumor and microwaves applied. Cell death from MWA is also due to thermal destruction.  Radiofrequency ablation and MWA are often used to effectively treat relatively small HCC (for instance, smaller than 3 centimeters). The effect of thermal ablation on larger tumors is less well documented. In patients with larger HCC, chemoembolization and RFA have been combined for more effectiveness than RFA alone.

The current study included 89 patients with HCC measuring 3-5 centimeters and 20 patients with HCC measuring 5-7 centimeters. All were treated with RFA or MWA. There were no treatment-related deaths. Complete ablation was achieved in 93% of patients. The local recurrence rate was 22%, and the distant relapse rate was 53%. The one-year survival rate was 76%, the two-year survival rate was 31%, and the five-year survival rate was 15%. Adverse risk factors for long-term survival included incomplete ablation, posthepatectomy recurrence, and elevated alfa-fetal protein.

Comments: These data suggest the thermal ablation can provide significant palliation for most patients with medium to large HCC, with 15% of patients benefiting for five or more years.

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