Locoregional Therapy for the Primary Tumor in Stage IV Breast Cancer

Abstract

Locoregional therapy, comprising surgery and radiation, has traditionally been reserved for managing symptoms from the primary tumor in women with stage IV breast cancer. However, in recent years, there has been significant interest in expanding the indications of local therapy in women with metastatic breast cancer beyond palliation to prolonging survival. In this review, we first discuss biological hypotheses of breast cancer metastasis that support the use of locoregional therapy in stage IV breast cancer. Second, we summarize the data from the key retrospective studies of locoregional therapy in stage IV breast cancer. Although many of these studies demonstrated a survival advantage over women who received systemic therapy alone, a number of key questions remained unanswered, including the timing, extent, and type of locoregional therapy that would provide maximal benefit to patients with metastatic disease while preserving quality of life. Lastly, three recently completed prospective trials have reported inconsistent results, with two demonstrating no survival advantage over systemic therapy alone and the third showing an increased overall survival after longer follow-up. Three other prospective trials are ongoing and attempt to address the limitations of the retrospective review and determine which class of patients would benefit most from additional intervention. This review contains 8 figures, 4 tables, and 44 references. Key words: axillary surgery, biology of breast cancer metastasis, breast surgery, clinical trials, locoregional therapy, margin status, quality of life, radiation therapy, stage IV breast cancer