Background: Two distinct types of epithelial cells have been found in breast tissue, epithelial (luminal) and myoepithelial (basal) cells. Recently, microarray based studies of breast cancer have suggested the existence of mutually exclusive profiles of tumor cells; the tumors with luminal cell phenotype are ER a+; ER-tumors either have a basal/myoepithelial phenotype or cerb-B2 + phenotype. To test the validity of this finding we carried out immunohistochemical staining using antibodies against cytokeratin 14 which are specific for breast basal cells. As myoepithelial differentiation is relatively frequent in high grade tumors, we selected twenty-six cases of ER+ high grade tumors for the study to explore the relationship between ER positivity and myoepithelial differentiation. These cases were examined by dual staining immunohistochemistry for the expression of estrogen receptors and CK14. The expression of ER in the normal lobules and ducts and expression of CK-14 in myoepithelial cells served as internal control. Results: Dual staining IHC confirmed the presence of ER in all the cases. CK-14 expression was limited to myoepithelial cells in normal lobules and entrapped myoepithelial cells within the tumor. None of the tumor cells were positive for Ck-14. Conclusion: Although myoepithelial differentiation has been reported in high-grade IDC, we were unable to demonstrate CK 14 reactivity in any of the 26 high-grade ductal carcinomas that were ER positive. This supports the microarray results that suggest that ER expression and myoepithelial differentiation occur in distinct, mutually exclusive cell populations.
|Original language||English (US)|
|Number of pages||1|
|Journal||Breast Cancer Research and Treatment|
|State||Published - Dec 1 2001|
ASJC Scopus subject areas
- Cancer Research