Treatment strategy for hepatocellular carcinoma: Expanding the indications for radiofrequency ablation

Background: Radiofrequency ablation (RFA) for hepatocellular carcinoma (HCC) is ordinarily indicated for those with three or fewer nodules, none of which exceeds 3 cm in diameter. This study investigated whether an apparent threshold exists in the diameter and number of nodules in terms of the prognosis of patients with HCC. Methods: We enrolled 663 naïve patients with HCC who were treated with RFA at our hospital between 1999 and 2005. We analyzed the patients' prognosis using multivariate Cox proportional regression with the diameter and number of nodules as covariates and Child-Pugh class as a stratification factor. The diameter and number were categorized as ≤2.0, 2.1-3.0, 3.1-.0, 4.1-5.0, and >5 cm and 1, 2-3, 4-5, and >5, respectively. Results: The adjusted hazard ratio of patients whose largest nodule was ≤2.0, 2.1-3.0, 3.1-4.0, 4.1-5.0, and >5 cm was 1, 1.51, 2.56, 2.25, and 2.71, respectively. The adjusted hazard ratio of patients with one, two or three, four or five, and more than five nodules was 1, 1.35, 1.70, and 2.12, respectively. Therefore, patients with three or fewer nodules, none of which exceeds 5 cm in diameter, have a 5-year survival of 40%. Conclusions: The prognosis of the patients worsened gradually as the diameter and number of nodules increased. No apparent threshold in the diameter or number of HCC nodules was detected. RFA can be applied beyond the conventional indications.