Purpose: Metaplastic carcinoma of the breast represents a rare and heterogeneous group of malignancies that accounts for less than 1% of all breast cancers. The purpose of this study is to better characterize the clinical management of this disease including the role of radiation therapy after surgery. We compared patients that have been treated with either modified radical mastectomy (MRM) or breast-conserving surgery (BCS).
Methods and materials: We performed a retrospective review of 43 patients with metaplastic breast cancer who were evaluated in our regional radiation oncology department between 1987 and 2002. Twenty-one patients were treated with an MRM and 22 with BCS. Five patients from the MRM group received adjuvant radiation, as did 19 patients from the BCS group. Univariate and multivariate analysis of pathologic and treatment-related factors was performed. Local control, disease-free, and overall survival rates were calculated by the Kaplan-Meier method and compared for the two groups.
Results: Mean follow-up for all patients was 44.2 months. Mean tumor size was 3.4 cm. Four patients (9%) had positive estrogen receptors and 20 (25%) had positive nodes. The overall 5-year projected local recurrence-free (88% vs. 85%, p = 0.86), disease-free (55% vs. 84%, p = 0.13), and overall survivals (80% vs. 89%, p = 0.58) were not significantly different for both groups. The only tumor parameter significantly associated with overall survival was nodal status.
Conclusion: Our study suggests that breast conservation appears to be a reasonable treatment option for women with metaplastic breast cancer, achieving equal survival to mastectomy. The use of adjuvant radiation seems essential for achieving high local control rates after conservation therapy. Further studies will be needed to determine the impact of chemotherapy on survival outcomes.