From genes to guidance: How ctDNA and MRD shape treatment choices
February 18, 2026 • Season 4: Episode 6
A drop of blood can change the course of cancer care. Speaking of Women's Health Podcast host Holly Thacker, MD sits down with variant curator Stetson Thacker, PhD to unpack how circulating tumor DNA and tumor‑informed minimal residual disease testing help clinicians see recurrence months before imaging, tailor adjuvant therapy, and track response in real time. Together, they translate complex genomics into clear choices: when a negative MRD result supports de‑escalation, when a persistent positive argues for chemotherapy and how colorectal and breast cancers have led the way in clinical validation.
They also cover the guardrails. Not everyone has banked tissue for a tumor‑informed assay, and sensitivity and specificity vary by platform and cancer type. Early multi‑cancer detection tests promise a lot but risk overdiagnosis and anxiety if used without clear indications. The smarter path is matching the right test to the right person at the right time, ideally within guidelines and with an oncologist who can synthesize genomics, imaging, pathology, and patient goals. From colorectal screening shifts to balancing overtreatment in prostate and thyroid cancers, we focus on practical decisions that protect both survival and quality of life.
If this deep dive helped you make sense of liquid biopsies and MRD, subscribe, share the episode with someone navigating cancer decisions and leave a review so more listeners can find the show.
