Abstract

21 ductal epithelial proliferative lesions selected from 72 cases of fibrocystic disease and 10 invasive ductal carcinoma with large areas of ductal carcinoma insitu (DCI) were studied for c-erb oncoprotein and p53 protein expression by immunohistochemistry. As a result, 5 out of 11 epithelial hyperplasia, 2 out of 10 atypical intraductal hyperplasia and 5 out of 10 invasive and DCI cases vvere shown to contain p53 protein. 2 out of 11 epithelial hyperplasia, 3 out of atypic intraductal hyperplasia and 7 out of 10 invasive and DCI cases were stained positive for c-erb protein. In addition 2 cases out of 7 cases with apocrine metaplasia showed strong positive staining for both p53 and c-erb protein in metaplastic epithelial cells. The presence of p53 and c-erb positivity in some apocrine metaplastic cells may further be investigated in order to determine any clinical significance of this finding.