In situ and invasive components of mammary adenocarcinoma: comparison of Her-2/neu status.
OBJECTIVE
To compare the relationship between Her-2/neu in the invasive and in situ components of carcinoma.


METHODS
Using immunohistochemistry, this study compares the Her-2/neu status in the in situ and invasive components of 200 cases of ductal carcinoma of the breast. A 0-3+ grading scale was used to semiquantitate Her-2/neu protein expression.


RESULTS
Twenty-five cases (12.5%) demonstrated a difference of 2 or more grades between the in situ and invasive components. The in situ component always showed higher expression of Her-2/neu than did the invasive component when protein expression was discordant. Comedo carcinoma was the in situ component in 12 of the 25 discordances in Her-2/neu expression.


CONCLUSIONS
Significant heterogeneity exists between Her-2/neu expression in the in situ component and invasive components of adenocarcinoma of the breast. When discordance exists, the in situ component shows higher levels of expression.
Layfield
Lester J
LJ
Department of Pathology, University of Utah School of Medicine, 50 North Medical Drive, Salt Lake City, Utah 84132, USA. layfiel@aruplab.com
Lewis
Cameron
C
D014408:Biomarkers, Tumor / Q000378:metabolism*; D001943:Breast Neoplasms / Q000378:metabolism / Q000473:pathology*; D018270:Carcinoma, Ductal, Breast / Q000378:metabolism / Q000473:pathology*; D002285:Carcinoma, Intraductal, Noninfiltrating / Q000378:metabolism / Q000473:pathology*; D005260:Female; D006801:Humans; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism*; D015203:Reproducibility of Results
D014408:Biomarkers, Tumor; D018719:Erb-b2 Receptor Tyrosine Kinases; C508053:ERBB2 protein, human