Abstract
Adenoid cystic carcinoma (AdCC) is a rare form of triple-negative and basal-like breast cancer that has an indolent clinical behaviour. Four breast AdCCs were recently shown to harbour the recurrent chromosomal translocation t(6;9)(q22-23;p23-24), which leads to the formation of the MYB-NFIB fusion gene. Our aims were (i) to determine the prevalence of the MYB-NFIB fusion gene in AdCCs of the breast; (ii) to characterize the gene copy number aberrations found in AdCCs; and (iii) to determine whether AdCCs are genomically distinct from histological grade-matched or triple-negative and basal-like invasive ductal carcinomas of no special type (IDC-NSTs). The presence of the MYB-NFIB fusion gene was investigated in 13 AdCCs of the breast by fluorescence in situ hybridization (FISH) and reverse transcriptase-PCR (RT-PCR), and MYB and BRCA1 RNA expression was determined by quantitative RT-PCR. Fourteen AdCCs, 14 histological grade-matched IDC-NSTs, and 14 IDC-NSTs of triple-negative and basal-like phenotype were microdissected and subjected to high-resolution microarray-based comparative genomic hybridization (aCGH). The MYB-NFIB fusion gene was detected in all but one AdCC. aCGH analysis demonstrated a relatively low number of copy number aberrations and a lack of recurrent amplifications in breast AdCCs. Contrary to grade-matched IDC-NSTs, AdCCs lacked 1q gains and 16q losses, and in contrast with basal-like IDC-NSTs, AdCCs displayed fewer gene copy number aberrations and expressed MYB and BRCA1 at significantly higher levels. Breast AdCCs constitute an entity distinct from grade-matched and triple-negative and basal-like IDC-NSTs, emphasizing the importance of histological subtyping of triple-negative and basal-like breast carcinomas.
Original language | English |
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Pages (from-to) | 84-96 |
Number of pages | 13 |
Journal | Journal of Pathology |
Volume | 226 |
Issue number | 1 |
DOIs | |
Publication status | Published - Jan 2012 |
Keywords
- Breast Neoplasms
- Carcinoma, Adenoid Cystic
- Carcinoma, Ductal, Breast
- Female
- Gene Dosage
- Gene Expression Profiling
- Humans
- Immunohistochemistry
- In Situ Hybridization, Fluorescence
- Microdissection
- Oncogene Proteins, Fusion
- Receptor, ErbB-3
- Receptors, Estrogen
- Receptors, Progesterone
- Reverse Transcriptase Polymerase Chain Reaction
- Tissue Array Analysis
- Journal Article
- Research Support, Non-U.S. Gov't