[Metaplastic carcinoma of the breast and the impact of the p63 and cytokeratin 5/6: experience of 40 patients].

BACKGROUND: Metaplasic carcinoma of the breast was initially described by Huvos in 1974. It is a rare and aggressive entity characterized by the presence of mesenchymal and epithelial components.

OBJECTIVE: To know the incidence and biologic behaviour of the metaplasic carcinoma of the breast at the Instituto de Enfermedades de la Mama, FUCAM, AC.

METHODS: Data on women diagnosed with metaplasic carcinoma of the breast between January 2005 and December 2014 was collected by retrospectively reviewing in FUCAM. Clinical, pathological and immunohistochemical characteristics were assessed. The five-year disease-free survival (DFS) and overall survival (OS) were evaluated.

RESULTS: a total of 4198 patients have been diagnosed with breast cancer in our institution, 40 (0.95%) of them with metaplasic carcinoma. The median age of the patients was 46 years (27-73). 60% of the patients were diagnosed with an advanced clinical stage (III) and the triple-negative subtype was the most frequently found. A mean follow-up of 24 months showed rates of overall survival and disease-free survival of 80% and 69.9%, respectively. The presence of both, cytokeratins 5/6 and p63, seems to have a negative impact in local recurrence.

CONCLUSION: this study demonstrates that metaplasic carcinoma is a rare and aggressive disease. Expression of both tumor cytokeratins was associated with a worse outcome.