I read with great interest the article by Roayaie et al. published in HEPATOLOGY. The investigators stated that the survival outcomes of patients in two Western centers were comparable to those reported in the Asian series, and that resection should continue to be considered a primary treatment modality in patients with small hepatocellular carcinoma (HCC) and well-preserved liver function. I appreciate the investigators' efforts to achieve this positive surgical outcome. However, I would like to comment on the role of surgical resection and radiofrequency ablation (RFA) in very early-stage HCC by comparing the results of Roayaie et al.'s study with those of a recent Italian multicenter study of RFA.
First, in Roayaie et al.'s study, only 67% of patients had cirrhosis, whereas all patients in the Italian multicenter ablation study had cirrhosis.[1, 2] Second, in the ablation study, approximately one fourth of the patients had portal hypertension (PH). In contrast, no patients with clinical PH were included in Roayaie et al.'s study. Therefore, in the Italian ablation study, the proportion of clinical PH might have been much higher than in this study. Third, the proportion of patients with serum bilirubin level >1.5 mg/dL was 32.5% in the Italian ablation study, which seems much higher than in Roayaie et al.'s study (mean ± standard deviation: 0.9 ± 0.5 mg/dL). It is well known that clinical PH and hyperbilirubinemia are two important indicators of adverse survival outcomes of patients with early-stage HCC after hepatectomy. Fourth, the investigators unduly compared the survival outcomes of resected patients without thrombocytopenia with those of ablated patients with or without thrombocytopenia (5-year survival rates: 74% vs. 68%). Finally, in Roayaie et al.'s study, the mean size of arterial enhancement on imaging (1.9 cm) was greater than that reported in the Italian ablation study, in which all tumors were ≤2 cm. This may explain why the incidence of microvascular invasion or microsatellite formation was so high in that study.
In conclusion, based on these two nonrandomized studies, it would be very difficult to ascertain the superiority of one treatment modality over the other for very early-stage HCC in terms of overall survival. In my opinion, resection and RFA seem to have advantages and disadvantages and both deserve primary treatments for single, small HCCs ≤2 cm.
Yun Ku Cho, M.D.
Department of Radiology VHS Medical Center Seoul, Korea