title: A new rabbit monoclonal E-cadherin antibody [EP700Y] shows higher sensitivity than mouse monoclonal E-cadherin [HECD-1] antibody in breast ductal carcinomas and does not stain breast lobular carcinomas.
abstract: Immunohistochemical studies have shown E-cadherin to be expressed in breast carcinomas showing a ductal histology, with a corresponding loss of expression in tumors with a lobular histology. As a result, mouse monoclonal anti-E-cadherin [HECD-1] has been used by pathologists to differentiate between ductal and lobular carcinomas, with currently published sensitivity and specificity rates of approximately 90%. Rabbit monoclonal antibodies may combine the best properties of both mouse monoclonal antibodies and rabbit antisera. Therefore, this study compares the staining sensitivity and specificity of a new rabbit monoclonal E-cadherin and the standard mouse monoclonal E-cadherin [HECD-1] in breast ductal carcinomas, and evaluates a cocktail of rabbit monoclonal E-cadherin and p120 catenin in the discrimination of ductal from lobular carcinomas. The rabbit E-cadherin showed sharper staining and increased sensitivity (80/81, 99%) than the mouse E-cadherin (75/81, 93%). The rabbit E-cadherin achieved a score of 3+ in 85.2% (69/81) of cases as compared with a 3+ in only 21.0% (17/81) of cases stained with mouse E-cadherin. All lobular carcinomas (n=37) were confirmed by the absence of E-cadherin and the diffuse cytoplasmic expression of p120 catenin. Although both the single mouse E-cadherin and dual stain can differentiate ductal from lobular lesions, the dual stain is helpful in challenging cases because of its bright pink p120 catenin and dark brown rabbit E-cadherin staining. The highly sensitive rabbit E-cadherin antibody is the preferred antibody for evaluating ductal carcinomas and for distinguishing ductal versus lobular lesions, and the dual stain was superior to the single E-cadherin stain.
authors.affiliation: *Department of Research and Development, Biocare Medical LLC, Concord, CA †University of Rochester Medical Center, Rochester, NY ‡Mercy Health System, Janesville, WI.
authors.forename: Laura L
authors.initials: LL
authors.lastname: Hoang
authors.forename: Ping
authors.initials: P
authors.lastname: Tang
authors.forename: David G
authors.initials: DG
authors.lastname: Hicks
authors.forename: Huijiao
authors.initials: H
authors.lastname: Chen
authors.forename: Qi
authors.initials: Q
authors.lastname: Yang
authors.forename: Thomas S
authors.initials: TS
authors.lastname: Haas
authors.forename: Ryan E
authors.initials: RE
authors.lastname: Bremer
authors.forename: David
authors.initials: D
authors.lastname: Tacha
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000276:immunology; D015820:Cadherins / Q000276:immunology*; D044584:Carcinoma, Ductal / Q000175:diagnosis* / Q000276:immunology; D018275:Carcinoma, Lobular / Q000175:diagnosis* / Q000276:immunology; D005260:Female; D006801:Humans; D051379:Mice; D011817:Rabbits; D012680:Sensitivity and Specificity
chemical_list: D000911:Antibodies, Monoclonal; D015820:Cadherins