Management of the intact breast primary in the setting of metastatic disease

Due to advancements in diagnostic and multimodality therapy, patients with stage IV breast cancer can achieve long-term survival. For women with asymptomatic primary tumors, the mainstay of therapy remains systemic and has been quite effective in controlling disease. However, the concept of elective resection of the intact primary has become a topic of interest in the past few decades. Biological explanations such as the role of cancer stem cells and immunosuppression in the presence of a primary tumor suggest a possible role for locoregional therapy. Retrospective data from multiple large population databases and single institutions suggest a benefit for a subset of patients with favorable features and low metastatic burden. However, the only published randomized trial from Tata Memorial shows local therapy for the primary does not improve overall survival, although there is a benefit to local progression-free survival. There is some conflict in the results illustrated in the retrospective studies and the Tata trial, hence the remaining ongoing trials will provide clarification on the role, extent, and timing of locoregional therapy for stage IV breast cancer. The present indication for locoregional therapy for the primary tumor in the setting of metastases continues to be the presence of a symptomatic tumor and should only be offered to patients with the explanation that there is no evidence of improvement in survival.