Cancer ResearchRadiation to Metastases Cuts Cancer Progression Risk in Half in Phase II Trial
The EXTEND trial tested whether targeting individual metastases with radiation therapy, on top of standard drug treatment, could slow cancer progression in patients with a limited number of metastases (1–5). Across 334 patients and multiple cancer types, adding this metastasis-directed therapy cut the risk of cancer progression nearly in half over a median follow-up of 53 months. Benefits were clearest in pancreatic, prostate, and mixed-tumor patients. The trial also found that a blood-based marker called circulating tumor DNA could predict outcomes, and that the treatment appeared to trigger a broader immune response — potentially explaining why it works beyond just destroying visible tumors.
