Microvascular Invasion in Small-sized Hepatocellular Carcinoma: Significance for Outcomes Following Hepatectomy and Radiofrequency Ablation

Abstract

Background/aim: The significance of microvascular invasion (MVI) of hepatocellular carcinoma (HCC) after radiofrequency ablation (RFA) is unknown.

Patients and methods: We studied 149 patients with solitary small-sized HCC (≤3 cm) who underwent hepatectomy, and developed a predictive model of MVI using independent factors related to the presence of MVI. The predictive model was applied to 159 patients who underwent RFA, and their outcomes were examined.

Results: A multivariate analysis revealed that α-fetoprotein ≥15 ng/ml (relative risk (RR) 3.05, p=0.02), des-γ-carboxy prothrombin ≥100 mAU/ml (RR 4.19, p=0.003), and tumor size ≥2 cm (RR 3.37, p=0.03) were independent risk factors of MVI. Among the patients who underwent RFA, the survival in patients with risk factors 2-3 was significantly worse, and local recurrence was more frequently obserbed than those with 0-1.

Conclusion: When an HCC tumor is expected to display MVI, RFA may not be suitable in terms of poorer survival and local disease-control rates.

Keywords: Hepatocellular carcinoma; local recurrence; microvascular invasion; predictive model; radiofrequency ablation.