Dr. Cohen on the Use of ctDNA for Chemotherapy Decisions in CRC

Stacey A. Cohen, MD, associate professor, the Clinical Research Division, Fred Hutchinson Cancer Center, assistant professor, the Division of Oncology, the University of Washington, discusses the evaluation of the role of circulating tumor DNA (ctDNA) to determine the benefit of chemotherapy in colorectal cancer (CRC).

At the 2022 ESMO Congress, investigators presented real-world data from a retrospective analysis evaluating whether ctDNA is a reliable predictor of cancer recurrence in patients with resected stage I to III CRC.

Investigators observed the relationship between ctDNA status and the use of chemotherapy to evaluate the role of ctDNA as a prognostic and predictive factor, Cohen says. In patients who were ctDNA negative, there was not a clear benefit from chemotherapy; however, this was not a large pool of patients, and it remains too early to determine whether patients who are ctDNA negative require chemotherapy, Cohen explains.

Further investigation of ctDNA’s role in making chemotherapy decisions in required, particularly in patients with stage II CRC, Cohen adds. Additional research will aim to answer questions about chemotherapy and longitudinal ctDNA monitoring, Cohen continues. More robust conclusions can be made as datasets grow, and studying ctDNA in a real-world setting will better reflect a larger variety of patients and the heterogeneity of CRC, Cohen concludes.