Metaplastic breast cancer: clinical features and outcomes

Metaplastic carcinoma of the breast, a neoplasm with both epithelial and mesenchymal elements, represents less than 1 per cent of all breast cancer. We reviewed the records of all patients diagnosed with localized metaplastic breast cancer from 1991 to 2003 at our institution. We identified 21 patients. Mean primary tumor size was 4.62 cm. Eight patients (38%) had axillary node involvement at presentation. All the tumors were high grade. Only two (10%) of the tumors were hormone receptor positive. Seventeen (81%) of the patients received adjuvant chemotherapy, and 12 (57%) of the patients received radiation. Ten (29%) patients suffered a local recurrence. With a mean follow-up of 46 months, the 5-year disease-free and overall survival was 42 per cent (95% CI: 20% to 65%) and 71 per cent (95% CI: 46% to 96%), respectively. Stage-specific overall survival was 100 per cent, 83 per cent, and 53 per cent for stages I, II, and III, respectively. By multivariate analysis, there was no impact on recurrence or survival with regard to size, age, menopausal status, nodal status, histologic subtype, adjuvant therapy, or extent of surgery. Metaplastic breast cancer is a unique neoplasm that tends to present at an advanced stage and has a propensity for local recurrence. When stratified by stage, however, survival appears similar to that of adenocarcinoma of the breast, and these tumors should be treated as such.