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Fulltext Male breast cancer in BRCA1 and BRCA2 mutation carriers: pathology data from the Consortium of Investigators of Modifiers of BRCA1/2

Silvestri V, Barrowdale D, Mulligan AM, Neuhausen SL, Fox S, Karlan BY, et al.

Breast Cancer Res, 2016 Feb 09;18(1):15.
PMID: 26857456 DOI: 10.1186/s13058-016-0671-y

BACKGROUND: BRCA1 and, more commonly, BRCA2 mutations are associated with increased risk of male breast cancer (MBC). However, only a paucity of data exists on the pathology of breast cancers (BCs) in men with BRCA1/2 mutations. Using the largest available dataset, we determined whether MBCs arising in BRCA1/2 mutation carriers display specific pathologic features and whether these features differ from those of BRCA1/2 female BCs (FBCs).
METHODS: We characterised the pathologic features of 419 BRCA1/2 MBCs and, using logistic regression analysis, contrasted those with data from 9675 BRCA1/2 FBCs and with population-based data from 6351 MBCs in the Surveillance, Epidemiology, and End Results (SEER) database.
RESULTS: Among BRCA2 MBCs, grade significantly decreased with increasing age at diagnosis (P = 0.005). Compared with BRCA2 FBCs, BRCA2 MBCs were of significantly higher stage (P for trend = 2 × 10(-5)) and higher grade (P for trend = 0.005) and were more likely to be oestrogen receptor-positive [odds ratio (OR) 10.59; 95 % confidence interval (CI) 5.15-21.80] and progesterone receptor-positive (OR 5.04; 95 % CI 3.17-8.04). With the exception of grade, similar patterns of associations emerged when we compared BRCA1 MBCs and FBCs. BRCA2 MBCs also presented with higher grade than MBCs from the SEER database (P for trend = 4 × 10(-12)).
CONCLUSIONS: On the basis of the largest series analysed to date, our results show that BRCA1/2 MBCs display distinct pathologic characteristics compared with BRCA1/2 FBCs, and we identified a specific BRCA2-associated MBC phenotype characterised by a variable suggesting greater biological aggressiveness (i.e., high histologic grade). These findings could lead to the development of gender-specific risk prediction models and guide clinical strategies appropriate for MBC management.

Matched MeSH terms: BRCA1 Protein/genetics*
KSR1 regulates BRCA1 degradation and inhibits breast cancer growth

Stebbing J, Zhang H, Xu Y, Lit LC, Green AR, Grothey A, et al.

Oncogene, 2015 Apr 16;34(16):2103-14.
PMID: 24909178 DOI: 10.1038/onc.2014.129

Kinase suppressor of Ras-1 (KSR1) facilitates signal transduction in Ras-dependent cancers, including pancreatic and lung carcinomas but its role in breast cancer has not been well studied. Here, we demonstrate for the first time it functions as a tumor suppressor in breast cancer in contrast to data in other tumors. Breast cancer patients (n>1000) with high KSR1 showed better disease-free and overall survival, results also supported by Oncomine analyses, microarray data (n=2878) and genomic data from paired tumor and cell-free DNA samples revealing loss of heterozygosity. KSR1 expression is associated with high breast cancer 1, early onset (BRCA1), high BRCA1-associated ring domain 1 (BARD1) and checkpoint kinase 1 (Chk1) levels. Phospho-profiling of major components of the canonical Ras-RAF-mitogen-activated protein kinases pathway showed no significant changes after KSR1 overexpression or silencing. Moreover, KSR1 stably transfected cells formed fewer and smaller size colonies compared to the parental ones, while in vivo mouse model also demonstrated that the growth of xenograft tumors overexpressing KSR1 was inhibited. The tumor suppressive action of KSR1 is BRCA1 dependent shown by 3D-matrigel and soft agar assays. KSR1 stabilizes BRCA1 protein levels by reducing BRCA1 ubiquitination through increasing BARD1 abundance. These data link these proteins in a continuum with clinical relevance and position KSR1 in the major oncoprotein pathways in breast tumorigenesis.

Matched MeSH terms: BRCA1 Protein/metabolism*
Fulltext Identification of six new susceptibility loci for invasive epithelial ovarian cancer

Kuchenbaecker KB, Ramus SJ, Tyrer J, Lee A, Shen HC, Beesley J, et al.

Nat Genet, 2015 Feb;47(2):164-71.
PMID: 25581431 DOI: 10.1038/ng.3185

Genome-wide association studies (GWAS) have identified 12 epithelial ovarian cancer (EOC) susceptibility alleles. The pattern of association at these loci is consistent in BRCA1 and BRCA2 mutation carriers who are at high risk of EOC. After imputation to 1000 Genomes Project data, we assessed associations of 11 million genetic variants with EOC risk from 15,437 cases unselected for family history and 30,845 controls and from 15,252 BRCA1 mutation carriers and 8,211 BRCA2 mutation carriers (3,096 with ovarian cancer), and we combined the results in a meta-analysis. This new study design yielded increased statistical power, leading to the discovery of six new EOC susceptibility loci. Variants at 1p36 (nearest gene, WNT4), 4q26 (SYNPO2), 9q34.2 (ABO) and 17q11.2 (ATAD5) were associated with EOC risk, and at 1p34.3 (RSPO1) and 6p22.1 (GPX6) variants were specifically associated with the serous EOC subtype, all with P < 5 × 10(-8). Incorporating these variants into risk assessment tools will improve clinical risk predictions for BRCA1 and BRCA2 mutation carriers.

Matched MeSH terms: BRCA1 Protein/genetics*
Fulltext Haplotype analysis of the 185delAG BRCA1 mutation in ethnically diverse populations

Laitman Y, Feng BJ, Zamir IM, Weitzel JN, Duncan P, Port D, et al.

Eur J Hum Genet, 2013 Feb;21(2):212-6.
PMID: 22763381 DOI: 10.1038/ejhg.2012.124

The 185delAG* BRCA1 mutation is encountered primarily in Jewish Ashkenazi and Iraqi individuals, and sporadically in non-Jews. Previous studies estimated that this is a founder mutation in Jewish mutation carriers that arose before the dispersion of Jews in the Diaspora ~2500 years ago. The aim of this study was to assess the haplotype in ethnically diverse 185delAG* BRCA1 mutation carriers, and to estimate the age at which the mutation arose. Ethnically diverse Jewish and non-Jewish 185delAG*BRCA1 mutation carriers and their relatives were genotyped using 15 microsatellite markers and three SNPs spanning 12.5 MB, encompassing the BRCA1 gene locus. Estimation of mutation age was based on a subset of 11 markers spanning a region of ~5 MB, using a previously developed algorithm applying the maximum likelihood method. Overall, 188 participants (154 carriers and 34 noncarriers) from 115 families were included: Ashkenazi, Iraq, Kuchin-Indians, Syria, Turkey, Iran, Tunisia, Bulgaria, non-Jewish English, non-Jewish Malaysian, and Hispanics. Haplotype analysis indicated that the 185delAG mutation arose 750-1500 years ago. In Ashkenazim, it is a founder mutation that arose 61 generations ago, and with a small group of founder mutations was introduced into the Hispanic population (conversos) ~650 years ago, and into the Iraqi-Jewish community ~450 years ago. The 185delAG mutation in the non-Jewish populations in Malaysia and the UK arose at least twice independently. We conclude that the 185delAG* BRCA1 mutation resides on a common haplotype among Ashkenazi Jews, and arose about 61 generations ago and arose independently at least twice in non-Jews.

Matched MeSH terms: BRCA1 Protein/genetics*
Fulltext Comparable frequency of BRCA1, BRCA2 and TP53 germline mutations in a multi-ethnic Asian cohort suggests TP53 screening should be offered together with BRCA1/2 screening to early-onset breast cancer patients

Lee DS, Yoon SY, Looi LM, Kang P, Kang IN, Sivanandan K, et al.

Breast Cancer Res, 2012;14(2):R66.
PMID: 22507745

Germline TP53 mutations cause an increased risk to early-onset breast cancer in Li-Fraumeni syndrome (LFS) families and the majority of carriers identified through breast cancer cohorts have LFS or Li-Fraumeni-like (LFL) features. However, in Asia and in many low resource settings, it is challenging to obtain accurate family history and we, therefore, sought to determine whether the presence of early-onset breast cancer is an appropriate selection criteria for germline TP53 testing.

Matched MeSH terms: BRCA1 Protein/genetics*
Large BRCA1 and BRCA2 genomic rearrangements in Malaysian high risk breast-ovarian cancer families

Kang P, Mariapun S, Phuah SY, Lim LS, Liu J, Yoon SY, et al.

Breast Cancer Res Treat, 2010 Nov;124(2):579-84.
PMID: 20617377 DOI: 10.1007/s10549-010-1018-5

Early studies of genetic predisposition due to the BRCA1 and BRCA2 genes have focused largely on sequence alterations, but it has now emerged that 4-28% of inherited mutations in the BRCA genes may be due to large genomic rearrangements of these genes. However, to date, there have been relatively few studies of large genomic rearrangements in Asian populations. We have conducted a full sequencing and large genomic rearrangement analysis (using Multiplex Ligation-dependent Probe Amplification, MLPA) of 324 breast cancer patients who were selected from a multi-ethnic hospital-based cohort on the basis of age of onset of breast cancer and/or family history. Three unrelated individuals were found to have large genomic rearrangements: 2 in BRCA1 and 1 in BRCA2, which accounts for 2/24 (8%) of the total mutations detected in BRCA1 and 1/23 (4%) of the mutations in BRCA2 detected in this cohort. Notably, the family history of the individuals with these mutations is largely unremarkable suggesting that family history alone is a poor predictor of mutation status in Asian families. In conclusion, this study in a multi-ethnic (Malay, Chinese, Indian) cohort suggests that large genomic rearrangements are present at a low frequency but should nonetheless be included in the routine testing for BRCA1 and BRCA2.

Matched MeSH terms: BRCA1 Protein/genetics*
Fulltext Identification of novel large genomic rearrangements at the BRCA1 locus in Malaysian women with breast cancer

Sharifah NA, Nurismah MI, Lee HC, Aisyah AN, Clarence-Ko CH, Naqiyah I, et al.

Cancer Epidemiol, 2010 Aug;34(4):442-7.
PMID: 20451485 DOI: 10.1016/j.canep.2010.04.010

The incidence of breast cancer has been on the rise in Malaysia. It is suggested that a subset of breast cancer cases were associated with germline mutation in breast cancer susceptibility (BRCA) genes. Most of the BRCA mutations reported in Malaysia were point mutations, small deletions and insertions. Here we report the first study of BRCA large genomic rearrangements (LGRs) in Malaysia. We aimed to detect the presence of LGRs in the BRCA genes of Malaysian patients with breast cancer.

Matched MeSH terms: BRCA1 Protein/genetics*
Fulltext BRCA1 and BRCA2 germline mutations in Malaysian women with early-onset breast cancer without a family history

Toh GT, Kang P, Lee SS, Lee DS, Lee SY, Selamat S, et al.

PLoS One, 2008;3(4):e2024.
PMID: 18431501 DOI: 10.1371/journal.pone.0002024

BACKGROUND: In Asia, breast cancer is characterised by an early age of onset: In Malaysia, approximately 50% of cases occur in women under the age of 50 years. A proportion of these cases may be attributable, at least in part, to genetic components, but to date, the contribution of genetic components to breast cancer in many of Malaysia's ethnic groups has not been well-characterised.
METHODOLOGY: Given that hereditary breast carcinoma is primarily due to germline mutations in one of two breast cancer susceptibility genes, BRCA1 and BRCA2, we have characterised the spectrum of BRCA mutations in a cohort of 37 individuals with early-onset disease (BRCA1 and BRCA2 was conducted by full sequencing of all exons and intron-exon junctions.
CONCLUSIONS: Here, we report a total of 14 BRCA1 and 17 BRCA2 sequence alterations, of which eight are novel (3 BRCA1 and 5 BRCA2). One deleterious BRCA1 mutation and 2 deleterious BRCA2 mutations, all of which are novel mutations, were identified in 3 of 37 individuals. This represents a prevalence of 2.7% and 5.4% respectively, which is consistent with other studies in other Asian ethnic groups (4-9%).
Study site: University Malaya Medical Centre (UMMC), Kuala Lumpur, Malaysia

Matched MeSH terms: BRCA1 Protein/genetics*
A new BRCA1 germline mutation (E879X) in a Malaysian breast cancer patient of Chinese descent

Khoo AS, Balraj P, Volpi L, Nair S

Hum Mutat, 2000 May;15(5):485.
PMID: 10790221
Matched MeSH terms: BRCA1 Protein/genetics*