Radiofrequency ablation for hepatocellular carcinoma measuring 2 cm or smaller: results and risk factors for local recurrence.

Objective: The purpose of this study was to evaluate the risk factors for local recurrence with radiofrequency ablation (RFA) for hepatocellular carcinoma (HCC) measuring ≤2 cm.

Methods: This study involved 234 patients with 274 HCCs measuring ≤2 cm who had undergone RFA as the initial treatment. The mean tumor diameter was 1.478 cm. The median follow-up period was 829 days. We evaluated the post-RFA cumulative local recurrence rate and analyzed the risk factors contributing to clinical outcomes.

Results: Cumulative local recurrence rates were 9, 19 and 19% at 1, 2 and 3 years, respectively. Among the 145 cases with a complete safety margin (SM) after RFA, only 4 developed local tumor recurrence and the cumulative rates of local tumor recurrence at 1, 2 and 3 years were 2, 3 and 3%, respectively. Among the 129 cases with incomplete SM, local tumor recurrence developed in 34 and the cumulative rates of local tumor progression at 1, 2 and 3 years were 14, 36 and 36%, respectively. In multivariate analysis, significant risk factors were tumor location (liver surface), irregular gross type and SM <5 mm.

Conclusion: Even with HCC measuring ≤2 cm, location and gross type of tumor should be carefully evaluated before RFA is performed.