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Basal‐like breast cancers: More than just triple negatives
Author(s) -
Beyer Ginine,
Yeh ITien
Publication year - 2008
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.22.1_supplement.898.18
Subject(s) - breast cancer , immunohistochemistry , basal (medicine) , medicine , pathology , staining , keratin 5 , breast carcinoma , myoepithelial cell , oncology , cancer , insulin
Basal‐like breast carcinomas are aggressive tumors that are typically ER‐, PR‐ and HER2‐ (known as “triple‐negative”, TN), and EGFR+. This study compares breast cancer expression of basal keratins and the TN phenotype. Methods: We reviewed immunomarkers on invasive breast carcinoma biopsies from 9/06 to 10/07, including ER, PR, and HER2. Immunohistochemistry (IHC) for CK5/6 was performed on all breast cancers. CK14 and EGFR were performed on CK5/6 + cases and TN cases. Proportion and intensity of staining for CK5/6 and CK14 were evaluated with the Allred score. EGFR staining was graded as 0–3+. Results: 24 basal‐like breast carcinomas were identified by IHC, representing 16% of the total cases of invasive breast cancer. H&Es demonstrated tumors to be high grade with poor tubule formation, prominent necrosis and high mitotic count. Cases included 19 TNs and 5 that marked with CK5/6 but were not TN. Of the TNs, only 11 were CK5+. All cases were + with CK14. CK14 scores were on average higher than CK5/6 scores (5.4 vs. 3.9). EGFR was + in all but 3 cases, 2 of which were CK5/6 +. Conclusions: Not all breast cancers expressing basal keratins are TN. CK14 marked all TN breast cancers and all CK5/6 positive cases. EGFR marked the vast majority of basal‐like breast cancers. Keratin identifies more basal‐like breast cancers than the TN profile.