Germline investigation in male breast cancer of DNA repair genes by next-generation sequencing
In order to better define the breast cancer (BC) genetic risk factors in men, a germline investigation was carried out on 81 Male BC cases by screening the 24 genes involved in BC predisposition, genome stability maintenance and DNA repair mechanisms by next-generation sequencing.
Germline DNAs were tested in a custom multi-gene panel focused on all coding exons and exon–intron boundaries of 24 selected genes using two amplicon-based assays on PGM-Ion Torrent (ThermoFisher Scientific) and MiSeq (Illumina) platforms. All variants were recorded and classified by using a custom pipeline.
Clinical pathological data and the family history of 81 Male BC cases were gathered and analysed, revealing the average age of onset to be 61.3 years old and that in 35 cases there was a family history of BC. Our genetic screening allowed us to identify a germline mutation in 22 patients (23%) in 4 genes: BRCA2, BRIP1, MUTYH and PMS2. Moreover, 12 variants of unknown clinical significance (VUS) in 9 genes (BARD1, BRCA1, BRIP1, CHEK2, ERCC1, NBN, PALB2, PMS1, RAD50) were predicted as potentially pathogenic by in silico analysis bringing the mutation detection rate up to 40%.
As expected, a positive family history is a strong predictor of germline BRCA2 mutations in male BC. Understanding the potential pathogenicity of VUS represents an extremely urgent need for the management of BC risk in Male BC cases and their own families.
KeywordsMale breast cancer Next-generation sequencing DNA repair genes Familial breast cancer Breast cancer risk in men
The authors would like to acknowledge all the patients that were involved in this study.
This study was supported by Grants from the Istituto Toscano Tumori (ITT) Grant 2010 and from the Fondazione Pisa Grant 2016 (prog.127/16 and prog.148/16), and from research funding Susan G. Komen Italia onlus 2017.
Compliance with ethical standards
Conflict of interest
M.A. Caligo was supported by Grant 2016 (prog.127/16) from the Fondazione Pisa and by research funding 2017 from the Susan G. Komen Italia onlus. A. G. Naccarato was supported by Grant 2016 (prog.148/16) from the Fondazione Pisa. D. Palli was supported by Grant 2010 from the Istituto Toscano Tumori (ITT). All authors declare that there are no conflicts of interest.
All the procedures performed in studies involving human participants were in accordance with the Ethical Standards of the Institutional and/or National Research Committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards.
Informed consent was obtained from all individual participants included in the study.
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