Immunohistochemical features of claudin-low intrinsic subtype in metaplastic breast carcinomas.

Breast, 2012

[Epub ahead of print] Immunohistochemical features of claudin-low intrinsic subtype in metaplastic breast carcinomas.
Abstract PURPOSE: The claudin-low molecular subtype of breast cancer includes triple negative invasive carcinomas, with a high frequency of metaplastic and medullary features.
The aim of this study was to evaluate the immunohistochemistry expression of claudins in a series of metaplastic breast carcinomas.
We also assessed other claudin-low features, such as the cancer stem cell-like and epithelial-to-mesenchymal transition phenotypes.
RESULTS: The majority of the cases showed weak or negative staining for membrane claudins expression.
We found 76.9% (10/13) low expressing cases for claudin-1, 84.6% (11/13) for claudin-3 and claudin-4, and 92.3% (12/13) for claudin-7.
We also showed that the majority of the cases presented a CD44()CD24(-/low) phenotype, positivity for vimentin and lack of E-cadherin expression.
Interestingly, these claudin-low molecular features were specific of the mesenchymal component of metaplastic breast carcinomas, since its frequency was very low in other breast cancer molecular subtypes, as luminal, HER2-overexpressing and non-metaplastic triple negative tumors.
CONCLUSIONS: The negative/low expression of claudins and E-cadherin, high levels of vimentin, and the breast cancer stem cell phenotype suggests that metaplastic breast carcinomas have similar features to the ones included in the claudin-low molecular subtype, specially their mesenchymal components.
PMID: 22464177 [PubMed - as supplied by publisher] Full Text Sources