Treating individual metastatic tumors with highly focused radiation or surgery did not improve progression-free or overall survival for patients with oligometastatic breast cancer receiving first-line systemic therapy, according to results from the randomized NRG-BR002 clinical trial led by Steven Chmura, M.D., Ph.D., chair of Breast Radiation Oncology. The findings provide important evidence against routinely adding metastasis-directed treatment for patients with a limited number of breast cancer metastases when effective systemic therapy is already controlling the disease. Oligometastatic cancer refers to metastatic disease that has spread beyond the original tumor but remains confined to a small number of sites. Advances in stereotactic body radiation therapy and surgery have made it possible to eradicate individual metastases, which raises the following question: Could treating every visible site of disease delay progression or extend survival? Researchers designed this trial to directly test that approach in breast cancer.
“There has been tremendous interest in whether aggressively treating every visible metastatic site could change the natural history of breast cancer for patients with only a few metastases,” Chmura said. “This randomized trial gives us important evidence that, for most patients in this setting, adding local treatment to effective systemic therapy does not improve progression-free or overall survival.”