Establishment of an insufficient radiofrequency ablation orthotopic nude mouse model of hepatocellular carcinoma to study the invasiveness and metastatic potential of residual cancer.

In order to assess the metastatic potential of residual hepatocellular carcinoma (HCC) following insufficient radiofrequency ablation (RFA) and to improve the current animal model, an insufficient RFA orthotopic nude mouse model of HCC was developed in the present study. A human HCC orthotopic nude mouse model was established using HCCLM3 cells, which has a high metastatic potential, labeled with green fluorescent protein. A total of 12 nude mice within the RFA group received insufficient RFA and 12 mice in the control group received RFA needle electrode puncture of the tumor without ablation, 3 weeks after implantation. To investigate tumor growth and metastasis, 4 weeks after RFA, six mice in each group were sacrificed and the remaining mice in each group were maintained until death to evaluate their life span. No mice died following insufficient RFA and the success rate was 100%. Compared with the control group, the intrahepatic and lung metastasis rates were higher in the RFA group, despite the mice having smaller tumor volumes and longer survival times. Lung and intrahepatic metastasis rates in the insufficient RFA group were 100% (6/6) and 66.67% (4/6), respectively, compared with 33.33% (2/6) and 0% (0/6), respectively, in the control group. As part of the study, a safe and reliable method to establish an insufficient RFA orthotopic nude mouse model was developed. The present study revealed that residual cancer following insufficient RFA had exhibited increased invasiveness and metastatic potential.