Why is radiofrequency ablation therapy applied for hepatocellular carcinoma up to 3 nodules and smaller than 3 cm in tumor size?

Background/aims: Radiofrequency ablation (RFA) has been applied for hepatocellular carcinoma (HCC) up to 3 nodules, within 3 cm in size. However, the scientific rationale of the treatment criteria for RFA has not been well analyzed. We compared the number and size of tumors with recurrence rates and survival rates.

Methodology: The study participants retrospectively were enrolled 625 consecutive cases of naïve HCC treated with RFA. We analyzed recurrence rates and survival of 472 for the patients with HCC ≤ 3 nodules, ≤ 3 cm in size (Group A), and 153 for the patients exceeding limits (Group B).

Results: Median follow-up was 2.97 years. The survival rate of Group A was significantly higher than that of Group B (5 years: 55.6% vs. 44.2%, 10 years: 27.4% vs. 15.7%; P<0.05). Multivariate analysis of predictors for prognostic factors demonstrated that meeting the RFA criteria, Child-Pugh score A, and lower levels of des-gamma carboxy prothrombin (DCP) were independent factors significantly affecting prognosis.

Conclusions: The present study is the firstto elucidate the scientific rationale for RFA treatment criteria for HCC regarding tumor number and size. We confirmed that the RFA treatment criteria select patients who stand to gain the most from RFA.