TY - JOUR
T1 - MED12 somatic mutations in fibroadenomas and phyllodes tumours of the breast
AU - Piscuoglio, Salvatore
AU - Murray, Melissa
AU - Fusco, Nicola
AU - Marchiò, Caterina
AU - Loo, Florence L.
AU - Martelotto, Luciano G.
AU - Schultheis, Anne M.
AU - Akram, Muzaffar
AU - Weigelt, Britta
AU - Brogi, Edi
AU - Reis-Filho, Jorge S.
PY - 2015/11/1
Y1 - 2015/11/1
N2 - Aims: Somatic mutations in exon 2 of the mediator complex subunit 12 (MED12) gene have been identified in 60% of breast fibroadenomas (FAs). The aim of this study was to define whether phyllodes tumours (PTs) would harbour MED12 somatic mutations in a way akin to FAs. Methods and results: A collection of 73 fibroepithelial tumours (including 26 FAs, 25 benign PTs, nine borderline PTs and 13 malignant PTs) from 64 patients was retrieved from the authors' institution. Sections from formalin-fixed paraffin-embedded (FFPE) blocks were microdissected to ensure an enrichment in neoplastic stromal elements of >70%. DNA samples extracted from tumour and matched normal tissues were subjected to Sanger sequencing of exon 2 of the MED12 gene. MED12 exon 2 somatic mutations, including 28 somatic single nucleotide variants and 19 insertions and deletions, were found in 65%, 88%, 78% and 8% of FAs, benign PTs, borderline PTs and malignant PTs, respectively. Malignant PTs harboured MED12 exon 2 somatic mutations significantly less frequently than FAs, benign and borderline PTs. Conclusions: Although MED12 exon 2 somatic mutations probably constitute the driver genetic event of most FAs, benign and borderline PTs, our results suggest that the majority of malignant PTs may be driven by other genetic/epigenetic alterations.
AB - Aims: Somatic mutations in exon 2 of the mediator complex subunit 12 (MED12) gene have been identified in 60% of breast fibroadenomas (FAs). The aim of this study was to define whether phyllodes tumours (PTs) would harbour MED12 somatic mutations in a way akin to FAs. Methods and results: A collection of 73 fibroepithelial tumours (including 26 FAs, 25 benign PTs, nine borderline PTs and 13 malignant PTs) from 64 patients was retrieved from the authors' institution. Sections from formalin-fixed paraffin-embedded (FFPE) blocks were microdissected to ensure an enrichment in neoplastic stromal elements of >70%. DNA samples extracted from tumour and matched normal tissues were subjected to Sanger sequencing of exon 2 of the MED12 gene. MED12 exon 2 somatic mutations, including 28 somatic single nucleotide variants and 19 insertions and deletions, were found in 65%, 88%, 78% and 8% of FAs, benign PTs, borderline PTs and malignant PTs, respectively. Malignant PTs harboured MED12 exon 2 somatic mutations significantly less frequently than FAs, benign and borderline PTs. Conclusions: Although MED12 exon 2 somatic mutations probably constitute the driver genetic event of most FAs, benign and borderline PTs, our results suggest that the majority of malignant PTs may be driven by other genetic/epigenetic alterations.
KW - Breast
KW - Fibroepithelial tumours
KW - MED12
KW - Sequencing
KW - Somatic mutations
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U2 - 10.1111/his.12712
DO - 10.1111/his.12712
M3 - Article
AN - SCOPUS:84943352974
VL - 67
SP - 719
EP - 729
JO - Histopathology
JF - Histopathology
SN - 0309-0167
IS - 5
ER -