Dr. Ahn on the Growing Role of ctDNA as a Biomarker in CRC

Daniel H. Ahn, DO, an oncologist, internist, and assistant professor of medicine at Mayo Clinic, discusses the growing role of circulating tumor DNA (ctDNA) in colorectal cancer (CRC).

The roles of ctDNA and minimal residual disease (MRD) are becoming more understood in CRC, as well as across all solid malignancies, says Ahn. Although additional investigation is warranted, MRD has the potential to be a prognostic and predictive biomarker for patient outcomes. Ultimately, MRD positivity confers a worse prognosis compared with MRD negativity, but questions remain as to how that influences treatment selection in patients with low-risk disease and in those who will receive adjuvant chemotherapy, Ahn explains.

Findings from a study, which were presented during the 2021 Gastrointestinal Cancers Symposium, showed that postoperative ctDNA positivity was more strongly associated with relapse-free survival compared with carcinoembryonic antigen (CEA). Ultimately, the results showed that ctDNA analysis can better predict the risk of recurrence compared with CEA and offers a reliable biomarker for treatment response monitoring.