Changes in Mutations of Cell-Free DNA and Liver Tumor Tissue in Patients with Advanced Hepatocellular Carcinoma before and after Introduction of Lenvatinib.

Introduction: Cell-free DNA (cfDNA) is expected to contribute to the decision for treatment and prediction of effects with minimally invasion. We investigated the correlation between gene mutations before and after lenvatinib (LEN) treatment and its effectiveness, in order to find advanced hepatocellular carcinoma (HCC) patients who would benefit greatly from the therapy.

Methods: We analyzed cfDNA before and 6-8 weeks after the start of treatment in 20 advanced HCC patients who started LEN. A next-generation sequencer was used for CTNNB1 and TP53. Concerning TERT promoter, -124C>T and -146C>T mutations are researched using digital PCR. In addition, we examined liver tumor biopsy tissues by the same method. Computerized tomography evaluation was performed at 6-8 weeks and 3-4 months to assess the efficacy.

Results: Frequencies of TERT promoter, CTNNB1, and TP53 mutations in pretreatment cfDNA were 45%, 65%, and 65%, but 53%, 41%, and 47% in HCC tissues, respectively. There were no clear correlations between these gene mutations and the disease-suppressing effect or progression-free survival. Overall, there were many cases showing a decrease in mutations after LEN treatment. Integrating the reduction of CTNNB1 and TP53 genetic mutations increased the potential for disease suppression.

Conclusion: This study suggests that analysis of cfDNA in advanced HCC patients may be useful for identifying LEN responders and determining therapeutic efficacy. Furthermore, it has potential for selecting responders for other molecular-targeted drugs.