LAUSR

We read with great interest the study by Moran and colleagues, entitled ‘‘Revisiting breast cancer patients who previously tested negative for BRCA mutations using a 12gene panel’’ recently published in this journal [1]. Using next generation sequencing (NGS) technologies, the authors re-assessed women affected by breast cancer who had previously tested negative for mutations in the large BRCA1 exon 11 and BRCA2 exons 10–11 by the protein truncation test (PTT). Specifically, they evaluated the prevalence of mutations in 12 breast cancer susceptibility genes, including BRCA1 and BRCA2, in 190 female breast cancer cases with a strong family history of breast cancer. Six mutations were detected in BRCA1 and BRCA2; in particular, one of these mutations (c.893_899delCAGTTGTinsTACTTCAG, p.Thr298fs) was detected in BRCA2 exon 10, previously screened by PTT. Overall, six women who had previously received a negative test result for BRCA1 and BRCA2 mutations using the PTT were found to carry pathogenic mutations in these two highpenetrance genes. BRCA2 and, to a less extent, BRCA1 germ-line mutations are associated with increased risk of male breast cancer (MBC), a rare disease accounting for by 1% of all breast cancer. BRCA2 mutations are found in about 12% of MBC cases and BRCA1 mutations in about 1% [2]. Thus, much of the genetic contribution to MBC risk still remains to be elucidated. To better define the fraction of MBC cases due to genetic predisposition, we screened by NGS a large series of MBC cases selected within the ongoing Italian Multicenter Study on MBC and previously tested negative for BRCA1 and BRCA2 mutations [3]. Genomic screening was performed in 200 MBC cases by a custom panel of 50 genes, including BRCA1 and BRCA2, using MiniSeq platform (Illumina, San Diego CA). MBC cases had previously been screened for mutations in BRCA1 and BRCA2 using PTT, single-strand conformation polymorphism (SSCP), Denaturing HighPerformance Liquid Chromatography (DHPLC) or Sanger sequencing. All MBC cases included in the study had received a negative test result for BRCA1/BRCA2 mutations. For each case, information about personal and family history of cancer was available. Notably, 51% of MBC cases had a first-degree family history of breast and/or ovarian cancer and 16.5% a personal history of cancers other than breast. By NGS, we identified BRCA1 and BRCA2 germ-line pathogenic mutations in five of the 200 (2.5%) MBC cases. In particular, one mutation (c.5329dupC) was detected in BRCA1 exon 20, and four mutations (c.632-2A[G, c.7681C[T, c.8878C[T, and c.9007delG) were detected in BRCA2 intron 7, exons 16, 22, and 23, respectively (Table 1). Mutations were confirmed by Sanger sequencing. Four of the five MBC cases harboring BRCA1/BRCA2 mutations had a strong family history of breast cancer (Table 1). All five MBC cases found to be mutation carriers had previously been tested negative for BRCA1/ BRCA2 mutations using PTT, SSCP, or DHPLC. Overall, our results showed that pre-sequencing screening methods such as PTT, SSCP, and DHPLC may lead to false negative results for BRCA1 and BRCA2 mutations, and that NGS is more sensitive in detecting sequence variants. Indeed, examining by NGS a large series of MBC cases previously tested negative for BRCA1 & Laura Ottini [email protected]