Background: Metaplastic breast carcinoma (MBC) comprises a histologically diverse group of malignancies that seem to have characteristics different from those of invasive duct carcinoma. The objective of this study was to describe the clinicopathological appearance of MBC and the prognostic outcome of patients with this disease in order to establish proper management.
Methods: A total of 38 patients were diagnosed with MBC between 1998 and 2009, at National Cancer Institute, Egypt. Patient medical records were revised, and the overall survival and disease-free survival were estimated. Tissue samples from 30 of these 38 patients were available, and immunostaining for estrogen receptor and progesterone receptor, epidermal growth factor receptor (EGFR), and Her2/neu was performed for all samples.
Results: The most common subtype was carcinosarcoma, of which grade III was reported in 20 patients. Immunohistochemically, all patients were negative for estrogen receptor and progesterone receptor, three were positive for Her2/neu overexpression, and 53.3% were positive for EGFR. Adjuvant chemotherapy was used in 31 patients and adjuvant radiotherapy in 25 patients. The mean follow-up was 32 months (5–59 months). Seventeen patients (44.7%) failed therapy, and nine of them died of disease. Locoregional failure was reported in three patients, distant failure in 10, and both were reported in four patients. The 4-year overall survival was 59±13%, and the disease-free survival was 37±12%.
Conclusion: MBC is a rare entity among cases of breast carcinomas in Egypt. The diagnosis is difficult in some cases and requires rigorous use of immunohistochemistry. Most patients present with poor prognostic indicators. A multicenter approach for large-scale studies is recommended to analyze the tendency for EGFR expression in MBC. These findings have potential implications for the design of clinical trials involving anti-EGFR-directed therapy.