Expression of Syndecan-1 in histologically normal breast tissue from postmenopausal women with breast cancer according to mammographic density

Objective To analyze the expression of Syndecan-1 in dense and non-dense human breast tissue. Methods Specimens of histologically normal tissue were obtained from postmenopausal women undergoing surgery for breast cancer. Each tissue block was subject to radiological examination and pair-wise samples of dense and non-dense tissue were collected. Semi-quantitative assessment of immunohistochemical staining intensity for Syndecan-1 and estrogen receptor subtypes was performed. Results The expression of Syndecan-1 in all tissue compartments was significantly higher in dense than in non-dense specimens. The strongest staining was recorded in stromal tissue. There was a strong correlation between epithelial estrogen receptor alpha and stromal cell Syndecan-1 expression in dense tissue (r(s) = 0.7; p = 0.02). This association was absent in non-dense tissue. Conclusion An increase of Syndecan-1 in all tissue compartments and a redistribution from epithelium to stroma may be a characteristic feature for dense breast tissue.