Application of a Tissue-Free Epigenomic Assay to Improve MRD Detection in Previously Treated CRC - Episode 5

Concluding Remarks for the Current Use of ctDNA Testing for Treatment Decisions in stage II-III CRC

Yoshiaki Nakamura, MD, PhD, discusses the quantification threshold for tissue-free ctDNA in detecting residual tumor fractions, highlights additional mutations and hypermethylated loci identified by epigenomic assays, and examines how these assays complement current radiographic monitoring in stage II to III CRC while also considering their evolving role in identifying MRD to enhance recurrence-free survival.

1. What is the quantification threshold of tissue-free ctDNA in detecting residual tumor fractions?

2. In addition to APC, KRAS G12C, and PIKC3A tumor fractions, what other lower-frequency mutations and hypermethylated gene loci can a tissue-free ctDNA epigenomic assay detect?

3. How well does tissue-free ctDNA complement current postoperative radiographic monitoring in patients with stage II to III CRC?

4. Looking ahead, please briefly discuss the evolving position of minimally invasive, tissue-free ctDNA to detect methylation andgenomic alterations in postoperative/post-ACT patients with early-stage CRC to rapidly identifyMRD and contribute to an extended RFS?