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Metaplastic breast carcinoma
Metaplastic breast carcinoma (MBC) is a rare (<1% of breast cancers) poorly differentiated breast cancer. MBC is characterized by coexistence of ductal carcinoma with areas of matrix producing, spindle-cell, sarcomatous, or squamous differentiation; ER/PR/HER2 negativity; and a reputation for poor outcome. From one patient to another, the proportion of the MBC that demonstrates the metaplastic component can vary widely from very little to almost the entire tumor. We compared the presentation, treatment and outcome of our 24 MBC cases identified in the Swedish Cancer Institute prospective breast cancer database (1990–2005) with 72 typical breast cancer cases matched for age, date of diagnosis, stage and ER/PR/HER2 (3:1 match). Five-year survival of MBC cases was 83% (95% confidence interval, 66–100%). There was no major significant difference in multidisciplinary treatment patterns, recurrence, or survival compared with the matched typical breast cancer cases. In conclusion, MBC is associated with poor prognostic indicators, but outcomes comparable with matched typical breast cancer cases can be achieved with routine aggressive multidisciplinary care. In practical clinical terms, we recommend careful work-up of metaplastic breast cancer (MBC) patients for extent of disease in the breast and regional nodes, evaluation of standard breast tumor markers (ER/PR/HER2), and multidisciplinary treatment appropriate for typical breast cancer of the same stage and marker status. In addition, increased expression of EGFR (HER1) in MBC tumor provides an opportunity to explore targeted tumor therapy for these rare tumors.
Bibliographical reference:
J. David Beatty Breast Cancer Program, Swedish Cancer Institute, Seattle, WA, USA
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