Abstract
Background:
With the increasing importance of thermal ablation (TA) in hepatocellular carcinoma (HCC) treatment, local tumor progression (LTP) has become a nonignorable recurrence type after ablation.
Purposes:
To analyze the influence of peritumoral liver parenchyma on LTP and to explore the possible reasons for this influence
Methods:
Ablated HCCs with peritumoral parenchymal biopsy and ablation margins greater than 5 mm were included from two hospitals. The grade of necroinflammatory activity (G) and stage of fibrosis (S) of the parenchyma were evaluated by Scheuer staging system. Univariate/multivariate Cox model was used to analyze the possible factors influencing LTP. Peritumoral satellite focus rate, ablation energy, ablation volume after treatment, ablation volume after one-month, and volume reduction rate were collected and analyzed to explore the possible reasons for influence. Propensity score matching (PSM) was used to balance baselines across different groups.
Results:
346 HCCs (64 with LTP, 282 without LTP) were enrolled from January 2013 to June 2022, with a median follow-up of 27 months. Univariate/multivariate analysis showed fibrosis was a protective factor in LTP (HR=0.70, 95%CI: 0.55-0.89). The low-fibrosis group exhibited higher satellite focus rate (15.6% vs. 8.4%, p=0.048), lower ablation energy (22637 ± 9424J vs. 33352 ± 13779J, p<0.001) and higher volume reduction rate (0.33±0.06 vs. 0.25±0.06, p<0.001) than the high-fibrosis group. Therefore, we speculated that the protective effect of fibrosis was due to its blocking of tumor invasion and reduction of sublethal zones.
Conclusion:
Fibrosis of the peritumoral liver parenchyma is a stable protective factor in LTP occurrence.