Further evidence that E-cadherin is not a tumour suppressor gene in invasive ductal carcinoma of the breast: an immunohistochemical study.
OBJECTIVE
E-cadherin is a cell adhesion molecule expressed in normal breast tissue; it is used generally as a phenotypical marker in breast cancer, with the absence of its expression observed frequently in lobular tumours. We have reported E-cadherin expression previously in 1516 ductal breast carcinoma using tissue microarray (TMA), where 7% of cases showed a complete absence of membrane staining. In this study, we investigated further the existence of E-cadherin-negative ductal carcinoma and evaluated the status of the E-cadherin-catenin complex in this subgroup.


METHODS
Full-face sections from excision specimens of 72 ductal breast carcinomas reported previously as E-cadherin-negative were assessed morphologically using haematoxylin and eosin staining, and immunohistochemically using two E-cadherin antibodies (HECD-1 and CDH1/4A2C7) and antibodies recognizing β-catenin and p120 proteins. Only membrane expression was considered.


RESULTS
Forty-seven ductal carcinomas were assessed after the exclusion of inappropriate cases; 34 of these showed positive E-cadherin (HECD-1) membrane expression which was focal and weak and seen mainly in invasion fronts. Ten cases showed E-cadherin (4A2C7) staining. Staining for p120 and β-catenin showed membrane staining in all cases for both antibodies, which was variable in both intensity and the proportion of positive cells.


CONCLUSIONS
These results demonstrate that E-cadherin-negative ductal carcinoma is rare, and in these cases p120 and β-catenin maintained their membranous localization, suggesting a functional E-cadherin-membrane complex.
Department of Histopathology, University of Nottingham, Nottingham, UK. emadrakha@yahoo.com
Emad A
EA
Rakha
Tsu K
TK
Teoh
Andrew H S
AH
Lee
Chris C
CC
Nolan
Ian O
IO
Ellis
Andrew R
AR
Green
D000368:Aged; D014408:Biomarkers, Tumor / Q000235:genetics / Q000378:metabolism; D001943:Breast Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D015820:Cadherins / Q000235:genetics* / Q000378:metabolism*; D018270:Carcinoma, Ductal, Breast / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D018275:Carcinoma, Lobular / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D002462:Cell Membrane / Q000378:metabolism / Q000473:pathology; D005260:Female; D016147:Genes, Tumor Suppressor; D006801:Humans; D046912:Multiprotein Complexes / Q000235:genetics / Q000378:metabolism; D009367:Neoplasm Staging; D051176:beta Catenin / Q000235:genetics / Q000378:metabolism
D014408:Biomarkers, Tumor; D015820:Cadherins; D046912:Multiprotein Complexes; D051176:beta Catenin