Expression of c-erb B-2 protein and DNA ploidy in breast carcinogenesis.
OBJECTIVE
to examine the c-erb B-2 expression and nuclear DNA content in samples of breast lesions to ascertain any relationship between c-erb B-2 expression and aneuploidy in the different types of proliferative breast lesions and in intraductal and invasive carcinomas.


METHODS
Immunohistochemical analysis of c-erb B-2 expression and cytometric nuclear DNA assessment were performed in a series of 39 cases of intraductal hyperplasia without atypia, 7 cases of intraductal hyperplasia with atypia, 64 cases of intraductal carcinoma, and 85 cases of invasive breast carcinoma (30 of which had extensive intraductal component).


RESULTS
Overexpression of c-erb B-2 was seen only in cases of carcinoma: 28 (43.7%) intraductal carcinomas and 15 (17.6%) invasive carcinomas. Aneuploidy was demonstrated in 3 (43.0%) cases of intraductal hyperplasia with atypia, in 54 (84.4%) cases of intraductal carcinoma, and in 63 (74.2%) cases of invasive carcinoma. All cases of intraductal hyperplasia without atypia were euploid and none expressed c-erb B-2. Among the carcinomas (intraductal and invasive) there was a strong relationship between aneuploidy and c-erb B-2 expression. In most instances, the intraductal and invasive components of the 30 invasive carcinomas with extensive intraductal component displayed similar DNA content and c-erb B-2 immunoreactivity; whenever there was a difference, the intraductal component tended to be aneuploid (five out of six cases) and c-erb B-2 positive (one case), in contrast to the respective invasive component.


CONCLUSIONS
The higher frequency of aneuploidy and c-erb B-2 expression in intraductal carcinomas in comparison with invasive carcinomas suggests there is not a linear relationship between DNA content abnormalities and neoplastic progression and that some invasive breast carcinomas evolve without an identifiable intraductal phase or are unrelated to disturbances at the c-erb B-2 locus.
Schmitt
F C
FC
Department of Pathology, Botucatu School of Medicine, Universidade Estadual Paulista, São Paulo, Brazil.
Figueiredo
P
P
Lacerda
M
M
D014408:Biomarkers, Tumor / Q000032:analysis*; D001943:Breast Neoplasms / Q000737:chemistry* / Q000235:genetics / Q000473:pathology; D004273:DNA, Neoplasm / Q000032:analysis*; D006801:Humans; D006965:Hyperplasia / Q000473:pathology; D007150:Immunohistochemistry; D011003:Ploidies; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000032:analysis*
D014408:Biomarkers, Tumor; D004273:DNA, Neoplasm; D018719:Erb-b2 Receptor Tyrosine Kinases