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

• Published in: Breast (Edinburgh) Vol. 21; no. 3; pp. 354 - 360
• Main Authors: Gerhard, Renê, Ricardo, Sara, Albergaria, André, Gomes, Madalena, Silva, Alfredo Ribeiro, Logullo, Ângela Flavia, Cameselle-Teijeiro, Jorge F, Paredes, Joana, Schmitt, Fernando
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Ltd 01.06.2012
• Subjects: Adult; Aged; Aged, 80 and over; Analysis of Variance; Biomarkers, Tumor - metabolism; Breast cancer; Breast Neoplasms - metabolism; Breast Neoplasms - pathology; Carcinoma - metabolism; Carcinoma - pathology; Claudin-1; Claudin-3; Claudin-4; Claudin-low subtype; Claudins; Claudins - metabolism; Female; Hematology, Oncology and Palliative Medicine; Humans; Immunohistochemistry; Membrane Proteins - metabolism; Metaplasia - metabolism; Metaplasia - pathology; Metaplastic breast carcinoma; Middle Aged; Young Adult; Claudins; Breast cancer; Claudin-low subtype; Metaplastic breast carcinoma
• ISSN: 0960-9776; 1532-3080
• DOI: 10.1016/j.breast.2012.03.001

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. Regarding the cancer stem cell marker ALDH1, 30.8% (4/13) showed positive staining. 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.