Researchers at MD Anderson reported Phase 2 EXTEND trial data showing circulating tumor DNA (ctDNA) can enhance treatment monitoring in patients undergoing metastasis-directed therapy for early metastatic cancers. The study supports ctDNA as a non-invasive biomarker to track disease dynamics and refine clinical decision-making. By focusing on non-invasive monitoring, the trial design aims to address gaps between imaging-based assessments and biological response timing. The results are intended to strengthen correlative endpoints and help clinicians anticipate outcomes earlier in the treatment course.