Dr. Trent on the Utility of ctDNA to Understand Primary Mutations in GIST

Jonathan C. Trent, MD, PhD, professor and associate director for Clinical Research at the Sylvester Comprehensive Cancer Center, University of Miami Health System, discusses the utility of circulating tumor DNA (ctDNA) to understand primary driver mutations in gastrointestinal stromal tumor (GIST).

ctDNA testing is noninvasive and has a rapid turnaround time of about 1 week, explains Trent. The results of ctDNA testing can shed light on primary driver mutations, as well as resistance mutations that could arise following treatment with imatinib (Gleevec).

GIST comprises about 10 subtypes with different driver mutations, including KIT, PDGFRα, neurofibromatosis type 1, RAS, and succinate dehydrogenase deficiency, Trent says. Understanding what mutation is driving the disease can inform treatment selection for patients, Trent explains. For example, patients with RAS-driven GIST will benefit from a RAS inhibitor rather than a KIT inhibitor, Trent concludes.