Dr. Raghav on the Utilization of ctDNA in mCRC

Kanwal P.S. Raghav, MBBS, MD, associate professor, Department of Gastrointestinal Medical Oncology, Division of Cancer Medicine, medical director, Division of Ambulatory Treatment Centers, The University of Texas MD Anderson Cancer Center, discusses on the utilization of circulating tumor DNA (ctDNA) in metastatic colorectal cancer (mCRC).

Clinics have already integrated the use of ctDNA to determine treatment decisions for patients with mCRC, Raghav says. For example, if a patient received an anti-EGFR therapy before developing a different mutation, that patient could be rechallenged with panitumumab (Vectibix), if they were previously on cetuximab (Erbitux), Raghav explains.

However, ctDNA should not be used indiscriminately in all settings, Raghav adds. For example, if ctDNA in the first-line setting revealed KRAS mutations, but in a third-line setting, no KRAS mutation was found after anti-EGRF therapy, those are 2 different types of tumor biology, Raghav explains. This is common in the first-line setting, but less common in a third-line setting, Raghav concludes.