Synapse - Massively parallel sequencing analysis of synchronous fibroepithelial lesions supports the concept of progression from fibroadenoma to phyllodes tumor

Massively parallel sequencing analysis of synchronous fibroepithelial lesions supports the concept of progression from fibroadenoma to phyllodes tumor Journal Article

Authors:	Piscuoglio, S.; Geyer, F. C.; Burke, K. A.; Murray, M. P.; Ng, C. K. Y.; Mota, A.; Marchio, C.; Berman, S. H.; Norton, L.; Brogi, E.; Weigelt, B.; Reis-Filho, J. S.
Article Title:	Massively parallel sequencing analysis of synchronous fibroepithelial lesions supports the concept of progression from fibroadenoma to phyllodes tumor
Abstract:	Phyllodes tumors (PTs) and fibroadenomas (FAs) are fibroepithelial lesions (FELs) of the breast. Although mutations affecting exon 2 of MED12 are highly recurrent in FAs and PTs, TERT promoter hotspot mutations are frequently found in PTs but are vanishingly rare in FAs. Malignant transformation of benign PTs is well-documented, but the progression from FA to PT remains a matter of contention. Here we report on the somatic genetic alterations in multiple ipsilateral synchronous FELs (three FAs, one benign PT, and one malignant PT) occurring in the same patient. DNA samples extracted from each tumor and matched normal tissue were subjected to targeted massively parallel sequencing using the Memorial Sloan Kettering-Integrated Mutation Profiling of Actionable Cancer Targets (MSK-IMPACT) assay. This analysis revealed MED12 mutations in all lesions. One FA and the benign PT harbored a MED12(Gly44Val) mutation, whereas another FA and the malignant PT displayed a MED12(Gly44Asp) mutation. The remaining FA had an independent distinct MED12(Gly44Cys) mutation. A formal clonality analysis suggested a clonal relationship between the FELs with identical MED12 mutations (P < 0.05). A clonal TERT promoter hotspot mutation was identified exclusively in the malignant PT. The identification of distinct MED12 mutations in multifocal ipsilateral and synchronous FELs supports the notion that co-existing mammary fibroepithelial tumors can arise independently. Conversely, the co-existence of identical MED12 mutations indicates clonal relatedness among FAs and PTs, corroborating the hypothesis that FAs may constitute the substrate from which PTs develop. Our findings also support the notion that acquisition of TERT promoter mutations may drive the progression of FELs.
Keywords:	breast; frequent med12 mutations
Journal Title:	npj Breast Cancer
Volume:	2
ISSN:	2374-4677
Publisher:	Nature Publishing Group
Date Published:	2016-11-16
Start Page:	16035
Language:	English
ACCESSION:	WOS:000411078100001
DOI:	10.1038/npjbcancer.2016.35
PROVIDER:	wos
PMCID:	PMC5515337
PUBMED:	28721388
Notes:	Article -- Source: Wos