P2-15-07: The Need for Additional Surgeries to Adequately Excise Early Breast Cancers May Have a Negative Impact on Local Recurrence.

Abstract

Abstract Background: Breast conservation surgery (BCS) is considered the standard of care for the treatment of early stage breast cancer (ESBC, AJCC stage 1 and 2). 20 to 50% of patients will require further surgery for positive or close margins. There is recent data suggesting that re-operation can have a negative impact on local and distant recurrences. Our aim is to examine the effects of multiple surgeries to obtain adequate margins on breast cancer recurrence, metastatic disease and survival. Methods: We reviewed a prospectively maintained breast cancer database at the University Health Network and included all women who had BCS for their first diagnosis of ESBC between January 2004 and December 2007. Patients with neoadjuvant chemotherapy were excluded. We collected patient demographics, surgical pathology, adjuvant therapy and follow up outcome data, which included local recurrence, distant recurrence, cancer-specific survival and overall survival. Clinical and pathologic features were compared using chi-square analyses. Patients who had one lumpectomy were compared to those who had multiple surgeries by using Kaplan-Meier survival curves and log rank test. Results: Of a total of 744 patients (8 patients had bilateral cancer) 577 (77.6%) had one lumpectomy only (Group 1). 167 (22.4%) patients required further surgery (group 2 = LR+LM+LRM): 83 (11.1%) had a re-excision (LR), 69 (9.3%) had mastectomy (LM) and 15 (2%) had a re-excision followed by a mastectomy (LRM). Thus, a total of 85 (11.4%) patients had mastectomy to achieve adequate margins. All clinicopathologic factors and adjuvant systemic treatments were similar between the two groups except for age and use of adjuvant radiotherapy, which was related to that fact that many of those in group 2 had mastectomy. We observed a difference in disease-free survival favoring patients with lumpectomy only (group 1–3.4% vs. group 2–8.1%, p= 0.01) but there was no difference in distant metastasis (4.5% vs. 5.6%, p=0.56), cancer-specific survival (97.6% vs. 95.6%, p=0.20) and overall survival (6.9% vs 6.3%, p= 0.76) at a median follow up of 4.54 years. Conclusion: Despite having similar stage, grade, receptor status and adjuvant systemic therapies, having multiple surgeries for primary breast cancer appeared to be associated with decreased disease-free survival but had no difference in rates of distant metastatic disease, cancer-specific survival and overall survival. Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P2-15-07.