Primary tumor resection improves the survival of younger patients with metastatic breast cancer.

Current treatments for metastatic breast cancer (MBC) include palliation with chemotherapy and/or hormone therapy, neither of which has the effect of adequately improving survival. Local surgery to remove the primary breast tumor is performed to improve local control and prevent uncontrolled chest wall disease (UCD). From June 1962 to February 2007, 344 patients with MBC were treated at National Cancer Center Hospital. In our review of these cases, we evaluated the prognostic impact of local surgery and other clinicopathological features. One hundred and sixty patients (47%) underwent resection of primary breast tumor, while 184 (53%) patients were treated without surgery. Overall survival (OS) was prolonged in patients treated with surgery (p=0.049), younger patients (age <50, p=0.023), and patients with bone or soft tissue metastases (p=0.013). While surgery significantly improved OS in young patients (p=0.021), it did not increase OS in older patients (age >51, p=0.665) or patients with visceral metastasis (p=0.797). This study demonstrated that local surgery improved OS of patients with MBC; local surgery should therefore be considered, especially in young patients. Prospective studies are required to validate these findings and evaluate the impact of surgical intervention.