Nestin and CD146 expression in metaplastic breast cancer: stem-cell therapy in need? Lessons reported from a male patient.

OBJECTIVE

Metaplastic breast carcinomas represent a rare subtype of breast cancer exhibiting aggressive clinical features. They appear as highly chemoresistant tumors, therefore showing poor outcome and high rates of local recurrence or distant metastasis.

CASE REPORT

A 37-year-old greek man was referred to our hospital for evaluation of a locally advanced, ulcerated, fixed, irregular and hard in consistency mass covering his left breast and chest wall. Further work out with CT and biopsy of the tumor revealed a triple negative metaplastic breast cancer classified as cT4cN3cM1. The patient received first line chemotherapy and afterward a palliative resection of the tumor. The histology revealed the presence of a combined triple negative adenocarcinoma with a predominant metaplastic squamous carcinoma and a spindle cell (sarcomatoid) carcinoma of the breast. In the tissue sample stem cell markers, nestin and CD146 (MCAM) were expressed, enhancing the theory that cancer cells of this tumor could possibly harbor stem cell properties. The patient received several chemotherapy regimens but died 6 months after the initiation of treatment.

CONCLUSIONS

Metaplastic breast cancer consists of cells with stem cell properties. New targeted therapies are warranted in the view of the tumor's high resistance to conventional chemotherapy. Targeting nestin and CD146 might be a promising therapy as they seem to be implicated in the EMT pathway.