Background: The mammary stroma is important for modulating epithelial breast cell response to sex steroid hormones. Proteoglycans, such as syndecan-1, promote the integration of cellular signals.
Materials and methods: The immunohistochemical expression of syndecan-1 and of the androgen receptor (AR) was analyzed in paired samples of cancer and adjacent normal tissue from postmenopausal women.
Results: Normal and cancer tissue showed dramatic differences in the expression of syndecan-1. In malignant breast stroma, mean values were more than 10-fold higher than in normal tissue (p<0.001). There was also a marked redistribution from the epithelium to the stroma. The expression of AR was on average 2-fold higher in cancerous than in normal tissue (p<0.01).
Conclusion: Breast cancer patients have very different prognoses. Syndecan-1 and the AR may be new molecular markers relevant to clinical outcome. The redistribution from the epithelium and the dramatic increase of syndecan-1 in cancerous stroma may be related to the natural history of the disease.