P2-15-05: Excision of the Primary Tumour in Patients with Metastatic Breast Cancer – Will E2108 Provide the Definitive Answer?

Abstract Background: Approximately 10% of new breast cancer patients will present with overt synchronous metastatic disease. Controversy exists about the optimal local management of these patients. While several series suggest that removal of primary tumour is associated with a survival benefit, the retrospective nature of these studies raises considerable methodological challenges. We decided to evaluate the experience at our centre around the impact of surgery in patients with synchronous metastasis. Method: Case records of all patients seen with primary breast cancer and concurrent distant metastases between 2005 to 2007 were reviewed. Demographic and treatment data was collected. The study endpoints compared both overall survival and symptomatic local progression rates between patients who had breast surgery and those who did not. RESULTS: 111 patients were identified. Median follow-up 40 months (0.6-71 months). Patients were divided into two groups: those patients who underwent breast surgery (n=48; 29/48 had surgery immediate prior to metastatic diagnosis) and those that did not have surgery(n = 63). The surgical group were less likely to present with T4 tumours (20% vs 36%), N3 nodal disease (8% vs 19%) and visceral metastasis (67% vs 73%)when compared with non-surgical group. Improved overall survival (49 months vs 33 months; p=0.01) and less symptomatic local progression rates ( 15% vs 43%, p < 0.001 ) were seen in the surgical group compared to the non-surgical group. CONCLUSIONS: The optimal local management of patients with metastatic breast cancer is unknown. Despite the surgery group demonstrating an improved overall survival and symptomatic local control, this group had less aggressive disease at presentation. These results confirm the need for prospective randomized studies. E2108, an ongoing Phase III Trial, was designed to assess the effect of breast surgery in metastatic patients responding to first line systemic therapy. If excision of the primary tumour is associated with a survival benefit, then the pre-selected subgroup of patients that have responded to initial systemic therapy is the desired population to put this hypothesis to test. Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P2-15-05.