Addition of Metastasis-Directed Therapy to Standard of Care for Oligometastatic Disease: Primary Aggregated Analysis of All Baskets from the Phase II Randomized EXTEND Trial

Adding metastasis-directed therapy (MDT — radiotherapy in 98% of lesions) to standard-of-care systemic therapy improved progression-free survival in oligometastatic disease: HR 0.54 (95% CI 0.41-0.72; P<.001) in the randomized phase 2 EXTEND trial (334 patients in the per-protocol analysis, median follow-up 53 months). The benefit persisted after excluding the two prostate baskets (HR 0.60; 95% CI 0.40-0.89). Superiority was seen in the pancreas, prostate and 'other' baskets, whereas the breast and kidney baskets were inconclusive. This is a phase 2 trial with progression-free survival as the primary endpoint, so the authors frame it as a basis for phase 3 testing rather than as definitive evidence.