Top Line: We have understood from some time now that oligometastatic breast cancer usually isn’t.
The Study: As opposed to several other malignancies such as lung and prostate, occult widespread metastatic breast cancer often precludes successful deceleration of overall disease trajectory with aggressive local therapy to known lesions. This prospective cohort of 207 patients with metastatic breast cancer offers a thought-provoking look at the natural history of disease when treated with first-line systemic therapy alone. At baseline, 30% had 1-5 lesions, but patterns of failure skewed distant with 61% progressing at a new versus known site. In other words, disease tended to evolve toward polymetastatic dominance portending worse survival. Most interesting is that all patients had baseline ctDNA assessment prior to first-line systemic therapy, which was analyzed retrospectively to calculate copy-number instability. It turns out higher instability independently predicted rapid progression to widespread disease (HR 3.21) while patients with lower instability more often recycled through limited-site recurrences.
TBL: Low baseline ctDNA copy-number instability may help identify which patients with metastatic breast cancer will benefit most from aggressive local therapy to oligometastic lesions. | Chang, Int J Radiat Oncol Biol Phys 2026
The Study: As opposed to several other malignancies such as lung and prostate, occult widespread metastatic breast cancer often precludes successful deceleration of overall disease trajectory with aggressive local therapy to known lesions. This prospective cohort of 207 patients with metastatic breast cancer offers a thought-provoking look at the natural history of disease when treated with first-line systemic therapy alone. At baseline, 30% had 1-5 lesions, but patterns of failure skewed distant with 61% progressing at a new versus known site. In other words, disease tended to evolve toward polymetastatic dominance portending worse survival. Most interesting is that all patients had baseline ctDNA assessment prior to first-line systemic therapy, which was analyzed retrospectively to calculate copy-number instability. It turns out higher instability independently predicted rapid progression to widespread disease (HR 3.21) while patients with lower instability more often recycled through limited-site recurrences.
TBL: Low baseline ctDNA copy-number instability may help identify which patients with metastatic breast cancer will benefit most from aggressive local therapy to oligometastic lesions. | Chang, Int J Radiat Oncol Biol Phys 2026