title: Immunohistochemical expression of internal and external ErbB-2 domains in invasive breast cancer.
abstract: We tested three ErbB-2 monoclonal antibodies (MoAbs) specific to the intracytoplasmic internal domain (clone CB 11) and the extracellular glycosylated peptide domain (clones CBE1 and Tab250) in 351 primary invasive breast carcinomas. ErbB-2 immunodetection allowed us to differentiate three main groups: group 1 (62.7%) lacked both MoAb ErbB-2 domains (erb -/-); group 2 stained for both domains (erb +/+) (26.5%); group 3 stained for the internal domain only (erb +/-) (10.8%). The relationships among these groups and nodal status (N) were statistically significant, with N+ cases reaching the highest value (89.2%) in the erb +/- group. Lack of immunostaining in the external domain thus seems to be associated with increased metastatic spread. At variance analysis the difference in hormonal receptor content between groups 1 and 3 was not significant; while between groups 1 and 2 it was. The growth fraction of groups 2 and 3 was significantly higher than that of group 1. Our results showed that anti-ErbB-2 MoAb clone CB 11 was able to detect a higher number of ErbB-2 expressing cases than the two that are specific for the external domain (clones Tab 250 and CBE1). Due to the strong association between group 3 cases and the highest metastatic potential, this aggressive group could be identified only with the use of an internal-domain specific MoAb CB 11, which thus seems to present a better discriminative power as a diagnostic marker in the biopathological characterization of breast carcinoma.
authors.affiliation: Second Service of Pathologic Anatomy and Hematopathology Section, Bologna University, Policlinico S. Orsola, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Ceccarelli
authors.forename: D
authors.initials: D
authors.lastname: Santini
authors.forename: M
authors.initials: M
authors.lastname: Gamberini
authors.forename: M
authors.initials: M
authors.lastname: Taffurelli
authors.forename: P
authors.initials: P
authors.lastname: Chieco
authors.forename: S
authors.initials: S
authors.lastname: Piana
authors.forename: S
authors.initials: S
authors.lastname: Pileri
authors.forename: D
authors.initials: D
authors.lastname: Marrano
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000911:Antibodies, Monoclonal / Q000276:immunology; D001943:Breast Neoplasms / Q000378:metabolism* / Q000473:pathology; D018270:Carcinoma, Ductal, Breast / Q000378:metabolism* / Q000473:pathology; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry; D016014:Linear Models; D008207:Lymphatic Metastasis; D008875:Middle Aged; D017434:Protein Structure, Tertiary; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000276:immunology / Q000378:metabolism*
chemical_list: D000911:Antibodies, Monoclonal; D018719:Erb-b2 Receptor Tyrosine Kinases