Limitation of repeated radiofrequency ablation in hepatocellular carcinoma: proposal of a three (times) × 3 (years) index

Percutaneous radiofrequency ablation (RFA) has been shown to be a highly effective treatment for hepatocellular carcinoma (HCC). We investigated the controllability of HCC and explored the algorithm of therapeutic strategy for HCC in patients who met the RFA criteria.We enrolled 472 patients with HCC who met the RFA criteria (≤ 3 nodules, ≤ 3 cm) and underwent RFA for initial therapy. Patients who underwent repeated RFA were evaluated retrospectively when HCC exceeded the RFA criteria, or the functional hepatic reserve progressed to Child-Pugh grade C.Overall survival rates were: 1 year, 96%; 3 years, 79%; and 5 years, 56%. In 5 years, 14% of patients progressed to Child-Pugh grade C. Meanwhile, 47% of patients exceeded the RFA criteria. Annually, 8% of patients deviated from the RFA criteria. The percentage of patients who were able to receive RFA significantly decreased at the fourth session compared with up to the third session. The survival rates decreased at the rate of 7% annually until the third year after the initial RFA. Afterwards, it shifted to a decrease at the rate of 12% annually. In a multivariate analysis, the presence of hepatitis C virus infection and the existence of a single tumor were identified as significant independent factors contributing to probabilities exceeding the RFA criteria.HCC was controlled by RFA up to three RFA treatments and 3 years from the initial therapy. On this basis, we propose a "three (times) × 3 (years) index" for considering a shift from RFA to other treatment modalities.