P63 expression in normal, hyperplastic and malignant breast tissues
p63 is a homologue of the p53 tumor suppressor gene and its protein is selectively expressed in the basal cells of a variety of epithelial tissues. It has recently been confirmed that p63 is expressed in the basal cells of normal prostate glands but not in prostatic carcinomas. Whether expression of p63 in breast correlates with tumor progression is the focus of this study.
Forty cases, which all contained normal breast tissue, ductal hyperplasia, ductal carcinomain situ and invasive ductal carcinoma in the same patient were included in this investigation using an indirect immunohistochemical method and double staining.
p63 was exclusively expressed in the myoepithelial cells of normal breast, partially expressed in ductal hyperplasia, rarely expressed in carcinomain situ and not expressed in invasive carcinomas.
The results suggest an association between loss of p63 expression and progression of breast ductal carcinoma. p63 immunostaining might be of assistance for distinguishing invasive ductal carcinoma from ductal carcinomain situ or rare questionable ductal hyperplastic lesions, leading to correct therapy clinically.
Key wordsp63 Ductal intraepithelial neoplasia Intraductal hyperplasia Atypical ductal hyperplasia Ductal carcinomain situ Breast cancer Immunohistochemistry
Ductal carcinomain situ
Smooth muscle actin
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