Does resection of an intact breast primary improve survival in metastatic breast cancer?

The recommended primary treatment approach for women with metastatic breast cancer and an intact primary tumor is the use of systemic therapy. Local therapy of the primary tumor is recommended only for palliation of symptoms. However, a series of retrospective studies examining practice patterns for this problem show that about half the women presenting with de novo metastatic disease undergo resection of the primary tumor, and suggest that women so treated survive longer than those who do not undergo resection of the intact primary. In analyses that adjust for tumor burden (number of metastatic sites), types of metastases (visceral, nonvisceral), and the use of systemic therapy, the hazard ratio for death is reduced by 40% to 50% in women receiving surgical treatment of the primary tumor. The benefit of surgical treatment appears to be confined to women whose tumors were resected with free margins. However, these results may simply reflect a selection bias (ie, younger, healthier women with a smaller tumor burden are more likely to receive surgical treatment). In addition, the role of other locoregional therapy such as axillary dissection and radiotherapy is not addressed in these studies. In view of these data, the role of local therapy in women with stage IV breast cancer needs to be reevaluated, and local therapy plus systemic therapy should be compared to systemic therapy alone in a randomized trial.