Evaluation of ActD therapeutic effect by longitudinal ctDNA monitoring and a comparison between ddPCR-based and deep UMI-based amplicon panel sequencing for multi-site detection
by Chen Xiangnyu | Sun Yat-sen University
Abstract ID: 170
Event: The 3rd AsiaEvo Conference
Topic: Open category
Presenter Name: Chen Xiangnyu

The level of ctDNA in the blood cannot only reflect the occurrence of tumors and the stage of cancer, but also translate the effectiveness of treatment and predict the relapse of tumors. In order to further validate the translation of treatment effectiveness by ctDNA, we used multiplex ddPCR technology to dynamically monitor the levels of ctDNA in mice treated with ActD-based hydrogel targeting five SVs and four SNPs, as well as untreated mice. The results showed that after 14 days of treatment, the levels of ctDNA in the relapse group and the remission group exhibited completely opposite trends. The ctDNA levels in the relapse group continued to increase, while gradually decreasing to undetectable levels in the cured group. And the untreated group showed a gradual increase in ctDNA level with the growth of the tumor. Furthermore, we employed deep UMI-based amplicon sequencing (UMI-AS) to identify ctDNA in a cohort of seven cancer patients, achieving an overall patient detection rate of 100% (7/7) and an overall mutation detection rate of 57.44% (27/47), and LOD can reach 0.01%. This underscores the capability of UMI-AS to effectively pinpoint low-frequency mutation sites, rendering it more adept at the concurrent detection of multiple mutation sites compared to ddPCR with an LOD of 0.1%. As a result, UMI-AS is a highly promising option for clinical cancer diagnosis.