Displaying publications 1 - 20 of 39 in total

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  1. Engku Fatimah Syairah Engku Safruddin, Wan Zainira Wan Zain, Bhavaraju, Venkata Murali Krishna, Kannan, Thirumulu Ponnuraj
    MyJurnal
    Given that the germline mutations of BRCA1 and BRCA2 confer genetic susceptibility to cancer, the
    genetic variations, polymorphisms or mutations are widely analyzed in Western countries. However, in Asian
    population, the prevalence of BRCA1 and BRCA2 polymorphisms is very limited. In Asia, breast cancer occurs in
    women early with an age of onset under 50 years. This review comprises the incidence of BRCA1 and BRCA2
    polymorphisms in the Japanese, Korean and Malaysian population. Founder mutations of BRCA1 and BRCA2
    were also compared to mark the genetic difference in these populations. The mutational analysis performed to
    analyze the entire coding region of BRCA1 and BRCA2 include the next generation sequencing and full
    sequencing of all exons and intron-exon junctions. From the diagnosis of triple negative breast cancer (TNBC)
    patients, TNBC is associated with the lack of tailored therapies and the treatment option available for TNBC
    patients is mainly chemotherapy. The poor prognosis of TNBC leads to determine the predictive biomarkers in
    order to develop treatment efficacy. This review will address the current clinical therapies available to treat TNBC
    patients.
    Matched MeSH terms: BRCA2 Protein
  2. 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: BRCA2 Protein/genetics*
  3. 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: BRCA2 Protein/genetics*
  4. 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: BRCA2 Protein/genetics*
  5. Hasmad HN, Lai KN, Wen WX, Park DJ, Nguyen-Dumont T, Kang PCE, et al.
    Gynecol Oncol, 2016 05;141(2):318-322.
    PMID: 26541979 DOI: 10.1016/j.ygyno.2015.11.001
    OBJECTIVE: Despite the discovery of breast and ovarian cancer predisposition genes BRCA1 and BRCA2 more than two decades ago, almost all the available data relate to women of European ancestry, with only a handful of studies in Asian populations. In this study, we determined the frequency of germline alterations in BRCA1 and BRCA2 in ovarian cancer patients from a multi-ethnic cross-sectional cohort of Asian ovarian cancer patients from Malaysia.

    METHODS: From October 2008 to February 2015, we established a hospital-based cohort of ovarian cancer patients and the germline status of all 218 women with invasive epithelial ovarian cancer was tested using targeted amplification and sequencing of the intron-exon junctions and exonic sequences of BRCA1, BRCA2, PALB2 and TP53.

    RESULTS: BRCA1 and BRCA2 mutations were found in 8% (17 cases) and 3% (7 cases) of the ovarian cancer patients, respectively. Mutation carriers were diagnosed at a similar age to non-carriers, but were more likely to be Indian, have serous ovarian cancer, and have more relatives with breast or ovarian cancer. Nonetheless, 42% (10/24) of mutation carriers did not have any family history of breast or ovarian cancer and offering genetic counselling and genetic testing only to women with family history would mean that 35% (6/17) of BRCA1 mutation carriers and 57% (4/7) of BRCA2 mutation carriers would not be offered genetic testing.

    CONCLUSIONS: Our data suggest that, similar to Caucasians, a significant proportion of Asian ovarian cancer was attributed to germline mutations in BRCA1 and to a lesser extent in BRCA2.

    Matched MeSH terms: BRCA2 Protein/genetics
  6. Kemp Z, Turnbull A, Yost S, Seal S, Mahamdallie S, Poyastro-Pearson E, et al.
    JAMA Netw Open, 2019 05 03;2(5):e194428.
    PMID: 31125106 DOI: 10.1001/jamanetworkopen.2019.4428
    Importance: Increasing BRCA1 and BRCA2 (collectively termed herein as BRCA) gene testing is required to improve cancer management and prevent BRCA-related cancers.

    Objective: To evaluate mainstream genetic testing using cancer-based criteria in patients with cancer.

    Design, Setting, and Participants: A quality improvement study and cost-effectiveness analysis of different BRCA testing selection criteria and access procedures to evaluate feasibility, acceptability, and mutation detection performance was conducted at the Royal Marsden National Health Service Foundation Trust as part of the Mainstreaming Cancer Genetics (MCG) Programme. Participants included 1184 patients with cancer who were undergoing genetic testing between September 1, 2013, and February 28, 2017.

    Main Outcomes and Measures: Mutation rates, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratios were the primary outcomes.

    Results: Of the 1184 patients (1158 women [97.8%]) meeting simple cancer-based criteria, 117 had a BRCA mutation (9.9%). The mutation rate was similar in retrospective United Kingdom (10.2% [235 of 2294]) and prospective Malaysian (9.7% [103 of 1061]) breast cancer studies. If traditional family history criteria had been used, more than 50% of the mutation-positive individuals would have been missed. Of the 117 mutation-positive individuals, 115 people (98.3%) attended their genetics appointment and cascade to relatives is underway in all appropriate families (85 of 85). Combining with the equivalent ovarian cancer study provides 5 simple cancer-based criteria for BRCA testing with a 10% mutation rate: (1) ovarian cancer; (2) breast cancer diagnosed when patients are 45 years or younger; (3) 2 primary breast cancers, both diagnosed when patients are 60 years or younger; (4) triple-negative breast cancer; and (5) male breast cancer. A sixth criterion-breast cancer plus a parent, sibling, or child with any of the other criteria-can be added to address family history. Criteria 1 through 5 are considered the MCG criteria, and criteria 1 through 6 are considered the MCGplus criteria. Testing using MCG or MCGplus criteria is cost-effective with cost-effectiveness ratios of $1330 per discounted QALYs and $1225 per discounted QALYs, respectively, and appears to lead to cancer and mortality reductions (MCG: 804 cancers, 161 deaths; MCGplus: 1020 cancers, 204 deaths per year over 50 years). Use of MCG or MCGplus criteria might allow detection of all BRCA mutations in patients with breast cancer in the United Kingdom through testing one-third of patients. Feedback questionnaires from 259 patients and 23 cancer team members (12 oncologists, 8 surgeons, and 3 nurse specialists) showed acceptability of the process with 100% of patients pleased they had genetic testing and 100% of cancer team members confident to approve patients for genetic testing. Use of MCGplus criteria also appeared to be time and resource efficient, requiring 95% fewer genetic consultations than the traditional process.

    Conclusions and Relevance: This study suggests that mainstream testing using simple, cancer-based criteria might be able to efficiently deliver consistent, cost-effective, patient-centered BRCA testing.

    Matched MeSH terms: BRCA2 Protein/genetics*
  7. Mikropoulos C, Selkirk CGH, Saya S, Bancroft E, Vertosick E, Dadaev T, et al.
    Br J Cancer, 2018 Jan;118(2):266-276.
    PMID: 29301143 DOI: 10.1038/bjc.2017.429
    BACKGROUND: Prostate-specific antigen (PSA) and PSA-velocity (PSAV) have been used to identify men at risk of prostate cancer (PrCa). The IMPACT study is evaluating PSA screening in men with a known genetic predisposition to PrCa due to BRCA1/2 mutations. This analysis evaluates the utility of PSA and PSAV for identifying PrCa and high-grade disease in this cohort.

    METHODS: PSAV was calculated using logistic regression to determine if PSA or PSAV predicted the result of prostate biopsy (PB) in men with elevated PSA values. Cox regression was used to determine whether PSA or PSAV predicted PSA elevation in men with low PSAs. Interaction terms were included in the models to determine whether BRCA status influenced the predictiveness of PSA or PSAV.

    RESULTS: 1634 participants had ⩾3 PSA readings of whom 174 underwent PB and 45 PrCas diagnosed. In men with PSA >3.0 ng ml-l, PSAV was not significantly associated with presence of cancer or high-grade disease. PSAV did not add to PSA for predicting time to an elevated PSA. When comparing BRCA1/2 carriers to non-carriers, we found a significant interaction between BRCA status and last PSA before biopsy (P=0.031) and BRCA2 status and PSAV (P=0.024). However, PSAV was not predictive of biopsy outcome in BRCA2 carriers.

    CONCLUSIONS: PSA is more strongly predictive of PrCa in BRCA carriers than non-carriers. We did not find evidence that PSAV aids decision-making for BRCA carriers over absolute PSA value alone.

    Matched MeSH terms: BRCA2 Protein/genetics
  8. Phelan CM, Kuchenbaecker KB, Tyrer JP, Kar SP, Lawrenson K, Winham SJ, et al.
    Nat Genet, 2017 May;49(5):680-691.
    PMID: 28346442 DOI: 10.1038/ng.3826
    To identify common alleles associated with different histotypes of epithelial ovarian cancer (EOC), we pooled data from multiple genome-wide genotyping projects totaling 25,509 EOC cases and 40,941 controls. We identified nine new susceptibility loci for different EOC histotypes: six for serous EOC histotypes (3q28, 4q32.3, 8q21.11, 10q24.33, 18q11.2 and 22q12.1), two for mucinous EOC (3q22.3 and 9q31.1) and one for endometrioid EOC (5q12.3). We then performed meta-analysis on the results for high-grade serous ovarian cancer with the results from analysis of 31,448 BRCA1 and BRCA2 mutation carriers, including 3,887 mutation carriers with EOC. This identified three additional susceptibility loci at 2q13, 8q24.1 and 12q24.31. Integrated analyses of genes and regulatory biofeatures at each locus predicted candidate susceptibility genes, including OBFC1, a new candidate susceptibility gene for low-grade and borderline serous EOC.
    Matched MeSH terms: BRCA2 Protein/genetics
  9. Wen WX, Leong CO
    PLoS One, 2019;14(4):e0215381.
    PMID: 31022191 DOI: 10.1371/journal.pone.0215381
    Immune checkpoint inhibitors have demonstrated effective anti-tumour response in cancer types with high mutation burden (e.g. melanoma) and in subset of cancers with features of genomic instability (e.g. mismatch-repair deficiency). One possible explanation for this effect is the increased expression of immune checkpoint molecules and pre-existing adaptive immune response in these cancers. Given that BRCA1 and BRCA2 are integral in maintaining genomic integrity, we hypothesise that the inactivation of these genes may give rise to breast cancers with such immunogenic phenotype. Therefore, using two large series of publicly available breast cancer datasets, namely that from The Cancer Genome Atlas and Wellcome Trust Institute, we sought to investigate the association between BRCA1- and BRCA2-deficiency with features of genomic instability, expression of PD-L1 and PD-1, landscape of inferred tumour-infiltrating immune cells, and T-cell inflamed signature in breast cancers. Here, we report that BRCA1 and BRCA2-deficient breast cancers were associated with features of genomic instability including increased mutation burden. Interestingly, BRCA1-, but not BRCA2-, deficient breast cancers were associated with increased expression of PD-L1 and PD-1, higher abundance of tumour-infiltrating immune cells, and enrichment of T cell-inflamed signature. The differences in immunophenotype between BRCA1- and BRCA2-deficient breast cancers can be attributed, in part, to PTEN gene mutation. Therefore, features of genomic instability such as that mediated by BRCA1- and BRCA2- deficiency in breast cancer were necessary, but not always sufficient, for yielding T cell-inflamed tumour microenvironment, and by extension, predicting clinical benefit from immunotherapy.
    Matched MeSH terms: BRCA2 Protein/deficiency*; BRCA2 Protein/genetics
  10. 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: BRCA2 Protein/genetics
  11. Dörk T, Peterlongo P, Mannermaa A, Bolla MK, Wang Q, Dennis J, et al.
    Sci Rep, 2019 08 29;9(1):12524.
    PMID: 31467304 DOI: 10.1038/s41598-019-48804-y
    Fanconi anemia (FA) is a genetically heterogeneous disorder with 22 disease-causing genes reported to date. In some FA genes, monoallelic mutations have been found to be associated with breast cancer risk, while the risk associations of others remain unknown. The gene for FA type C, FANCC, has been proposed as a breast cancer susceptibility gene based on epidemiological and sequencing studies. We used the Oncoarray project to genotype two truncating FANCC variants (p.R185X and p.R548X) in 64,760 breast cancer cases and 49,793 controls of European descent. FANCC mutations were observed in 25 cases (14 with p.R185X, 11 with p.R548X) and 26 controls (18 with p.R185X, 8 with p.R548X). There was no evidence of an association with the risk of breast cancer, neither overall (odds ratio 0.77, 95%CI 0.44-1.33, p = 0.4) nor by histology, hormone receptor status, age or family history. We conclude that the breast cancer risk association of these two FANCC variants, if any, is much smaller than for BRCA1, BRCA2 or PALB2 mutations. If this applies to all truncating variants in FANCC it would suggest there are differences between FA genes in their roles on breast cancer risk and demonstrates the merit of large consortia for clarifying risk associations of rare variants.
    Matched MeSH terms: BRCA2 Protein/genetics
  12. Qian F, Wang S, Mitchell J, McGuffog L, Barrowdale D, Leslie G, et al.
    J Natl Cancer Inst, 2019 Apr 01;111(4):350-364.
    PMID: 30312457 DOI: 10.1093/jnci/djy132
    BACKGROUND: BRCA1/2 mutations confer high lifetime risk of breast cancer, although other factors may modify this risk. Whether height or body mass index (BMI) modifies breast cancer risk in BRCA1/2 mutation carriers remains unclear.

    METHODS: We used Mendelian randomization approaches to evaluate the association of height and BMI on breast cancer risk, using data from the Consortium of Investigators of Modifiers of BRCA1/2 with 14 676 BRCA1 and 7912 BRCA2 mutation carriers, including 11 451 cases of breast cancer. We created a height genetic score using 586 height-associated variants and a BMI genetic score using 93 BMI-associated variants. We examined both observed and genetically determined height and BMI with breast cancer risk using weighted Cox models. All statistical tests were two-sided.

    RESULTS: Observed height was positively associated with breast cancer risk (HR = 1.09 per 10 cm increase, 95% confidence interval [CI] = 1.0 to 1.17; P = 1.17). Height genetic score was positively associated with breast cancer, although this was not statistically significant (per 10 cm increase in genetically predicted height, HR = 1.04, 95% CI = 0.93 to 1.17; P = .47). Observed BMI was inversely associated with breast cancer risk (per 5 kg/m2 increase, HR = 0.94, 95% CI = 0.90 to 0.98; P = .007). BMI genetic score was also inversely associated with breast cancer risk (per 5 kg/m2 increase in genetically predicted BMI, HR = 0.87, 95% CI = 0.76 to 0.98; P = .02). BMI was primarily associated with premenopausal breast cancer.

    CONCLUSION: Height is associated with overall breast cancer and BMI is associated with premenopausal breast cancer in BRCA1/2 mutation carriers. Incorporating height and BMI, particularly genetic score, into risk assessment may improve cancer management.

    Matched MeSH terms: BRCA2 Protein/genetics*
  13. Liu J, Lončar I, Collée JM, Bolla MK, Dennis J, Michailidou K, et al.
    Sci Rep, 2016 Nov 15;6:36874.
    PMID: 27845421 DOI: 10.1038/srep36874
    NBS1, also known as NBN, plays an important role in maintaining genomic stability. Interestingly, rs2735383 G > C, located in a microRNA binding site in the 3'-untranslated region (UTR) of NBS1, was shown to be associated with increased susceptibility to lung and colorectal cancer. However, the relation between rs2735383 and susceptibility to breast cancer is not yet clear. Therefore, we genotyped rs2735383 in 1,170 familial non-BRCA1/2 breast cancer cases and 1,077 controls using PCR-based restriction fragment length polymorphism (RFLP-PCR) analysis, but found no association between rs2735383CC and breast cancer risk (OR = 1.214, 95% CI = 0.936-1.574, P = 0.144). Because we could not exclude a small effect size due to a limited sample size, we further analyzed imputed rs2735383 genotypes (r2 > 0.999) of 47,640 breast cancer cases and 46,656 controls from the Breast Cancer Association Consortium (BCAC). However, rs2735383CC was not associated with overall breast cancer risk in European (OR = 1.014, 95% CI = 0.969-1.060, P = 0.556) nor in Asian women (OR = 0.998, 95% CI = 0.905-1.100, P = 0.961). Subgroup analyses by age, age at menarche, age at menopause, menopausal status, number of pregnancies, breast feeding, family history and receptor status also did not reveal a significant association. This study therefore does not support the involvement of the genotype at NBS1 rs2735383 in breast cancer susceptibility.
    Matched MeSH terms: BRCA2 Protein/genetics
  14. Patel VL, Busch EL, Friebel TM, Cronin A, Leslie G, McGuffog L, et al.
    Cancer Res, 2020 Feb 01;80(3):624-638.
    PMID: 31723001 DOI: 10.1158/0008-5472.CAN-19-1840
    Pathogenic sequence variants (PSV) in BRCA1 or BRCA2 (BRCA1/2) are associated with increased risk and severity of prostate cancer. We evaluated whether PSVs in BRCA1/2 were associated with risk of overall prostate cancer or high grade (Gleason 8+) prostate cancer using an international sample of 65 BRCA1 and 171 BRCA2 male PSV carriers with prostate cancer, and 3,388 BRCA1 and 2,880 BRCA2 male PSV carriers without prostate cancer. PSVs in the 3' region of BRCA2 (c.7914+) were significantly associated with elevated risk of prostate cancer compared with reference bin c.1001-c.7913 [HR = 1.78; 95% confidence interval (CI), 1.25-2.52; P = 0.001], as well as elevated risk of Gleason 8+ prostate cancer (HR = 3.11; 95% CI, 1.63-5.95; P = 0.001). c.756-c.1000 was also associated with elevated prostate cancer risk (HR = 2.83; 95% CI, 1.71-4.68; P = 0.00004) and elevated risk of Gleason 8+ prostate cancer (HR = 4.95; 95% CI, 2.12-11.54; P = 0.0002). No genotype-phenotype associations were detected for PSVs in BRCA1. These results demonstrate that specific BRCA2 PSVs may be associated with elevated risk of developing aggressive prostate cancer. SIGNIFICANCE: Aggressive prostate cancer risk in BRCA2 mutation carriers may vary according to the specific BRCA2 mutation inherited by the at-risk individual.
    Matched MeSH terms: BRCA2 Protein/genetics*
  15. Karin BR, Das I, Jackman TR, Bauer AM
    PeerJ, 2017;5:e3762.
    PMID: 29093993 DOI: 10.7717/peerj.3762
    Episodic sea level changes that repeatedly exposed and inundated the Sunda Shelf characterize the Pleistocene. Available evidence points to a more xeric central Sunda Shelf during periods of low sea levels, and despite the broad land connections that persisted during this time, some organisms are assumed to have faced barriers to dispersal between land-masses on the Sunda Shelf. Eutropis rugifera is a secretive, forest adapted scincid lizard that ranges across the Sunda Shelf. In this study, we sequenced one mitochondrial (ND2) and four nuclear (BRCA1, BRCA2, RAG1, and MC1R) markers and generated a time-calibrated phylogeny in BEAST to test whether divergence times between Sundaic populations of E. rugifera occurred during Pleistocene sea-level changes, or if they predate the Pleistocene. We find that E. rugifera shows pre-Pleistocene divergences between populations on different Sundaic land-masses. The earliest divergence within E. rugifera separates the Philippine samples from the Sundaic samples approximately 16 Ma; the Philippine populations thus cannot be considered conspecific with Sundaic congeners. Sundaic populations diverged approximately 6 Ma, and populations within Borneo from Sabah and Sarawak separated approximately 4.5 Ma in the early Pliocene, followed by further cladogenesis in Sarawak through the Pleistocene. Divergence of peninsular Malaysian populations from the Mentawai Archipelago occurred approximately 5 Ma. Separation among island populations from the Mentawai Archipelago likely dates to the Pliocene/Pleistocene boundary approximately 3.5 Ma, and our samples from peninsular Malaysia appear to coalesce in the middle Pleistocene, about 1 Ma. Coupled with the monophyly of these populations, these divergence times suggest that despite consistent land-connections between these regions throughout the Pleistocene E. rugifera still faced barriers to dispersal, which may be a result of environmental shifts that accompanied the sea-level changes.
    Matched MeSH terms: BRCA2 Protein
  16. Ng PS, Wen WX, Fadlullah MZ, Yoon SY, Lee SY, Thong MK, et al.
    Clin Genet, 2016 10;90(4):315-23.
    PMID: 26757417 DOI: 10.1111/cge.12735
    Although an association between protein-truncating variants and breast cancer risk has been established for 11 genes, only alterations in BRCA1, BRCA2, TP53 and PALB2 have been reported in Asian populations. Given that the age of onset of breast cancer is lower in Asians, it is estimated that inherited predisposition to breast cancer may be more significant. To determine the potential utility of panel testing, we investigated the prevalence of germline alterations in 11 established and 4 likely breast cancer genes in a cross-sectional hospital-based cohort of 108 moderate to high-risk breast cancer patients using targeted next generation sequencing. Twenty patients (19%) were identified to carry deleterious mutations, of whom 13 (12%) were in the BRCA1 or BRCA2, 6 (6%) were in five other known breast cancer predisposition genes and 1 patient had a mutation in both BRCA2 and BARD1. Our study shows that BRCA1 and BRCA2 account for the majority of genetic predisposition to breast cancer in our cohort of Asian women. Although mutations in other known breast cancer genes are found, the functional significance and breast cancer risk have not yet been determined, thus limiting the clinical utility of panel testing in Asian populations.
    Matched MeSH terms: BRCA2 Protein/genetics; BRCA2 Protein/chemistry
  17. 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 (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: BRCA2 Protein/genetics*
  18. Wen WX, Allen J, Lai KN, Mariapun S, Hasan SN, Ng PS, et al.
    J Med Genet, 2018 02;55(2):97-103.
    PMID: 28993434 DOI: 10.1136/jmedgenet-2017-104947
    BACKGROUND: Genetic testing for BRCA1 and BRCA2 is offered typically to selected women based on age of onset and family history of cancer. However, current internationally accepted genetic testing referral guidelines are built mostly on data from cancer genetics clinics in women of European descent. To evaluate the appropriateness of such guidelines in Asians, we have determined the prevalence of germ line variants in an unselected cohort of Asian patients with breast cancer and healthy controls.

    METHODS: Germ line DNA from a hospital-based study of 2575 unselected patients with breast cancer and 2809 healthy controls were subjected to amplicon-based targeted sequencing of exonic and proximal splice site junction regions of BRCA1 and BRCA2 using the Fluidigm Access Array system, with sequencing conducted on a Illumina HiSeq2500 platform. Variant calling was performed with GATK UnifiedGenotyper and were validated by Sanger sequencing.

    RESULTS: Fifty-five (2.1%) BRCA1 and 66 (2.6%) BRCA2 deleterious mutations were identified among patients with breast cancer and five (0.18%) BRCA1 and six (0.21%) BRCA2 mutations among controls. One thousand one hundred and eighty-six (46%) patients and 97 (80%) carriers fulfilled the National Comprehensive Cancer Network guidelines for genetic testing.

    CONCLUSION: Five per cent of unselected Asian patients with breast cancer carry deleterious variants in BRCA1 or BRCA2. While current referral guidelines identified the majority of carriers, one in two patients would be referred for genetic services. Given that such services are largely unavailable in majority of low-resource settings in Asia, our study highlights the need for more efficient guidelines to identify at-risk individuals in Asia.

    Matched MeSH terms: BRCA2 Protein/genetics*
  19. Li J, Wen WX, Eklund M, Kvist A, Eriksson M, Christensen HN, et al.
    Int J Cancer, 2019 03 01;144(5):1195-1204.
    PMID: 30175445 DOI: 10.1002/ijc.31841
    Breast cancer patients with BRCA1/2-driven tumors may benefit from targeted therapy. It is not clear whether current BRCA screening guidelines are effective at identifying these patients. The purpose of our study was to evaluate the prevalence of inherited BRCA1/2 pathogenic variants in a large, clinically representative breast cancer cohort and to estimate the proportion of BRCA1/2 carriers not detected by selectively screening individuals with the highest probability of being carriers according to current clinical guidelines. The study included 5,122 unselected Swedish breast cancer patients diagnosed from 2001 to 2008. Target sequence enrichment (48.48 Fluidigm Access Arrays) and sequencing were performed (Illumina Hi-Seq 2,500 instrument, v4 chemistry). Differences in patient and tumor characteristics of BRCA1/2 carriers who were already identified as part of clinical BRCA1/2 testing routines and additional BRCA1/2 carriers found by sequencing the entire study population were compared using logistic regression models. Ninety-two of 5,099 patients with valid variant calls were identified as BRCA1/2 carriers by screening all study participants (1.8%). Only 416 study participants (8.2%) were screened as part of clinical practice, but this identified 35 out of 92 carriers (38.0%). Clinically identified carriers were younger, less likely postmenopausal and more likely to be associated with familiar ovarian cancer compared to the additional carriers identified by screening all patients. More BRCA2 (34/42, 81.0%) than BRCA1 carriers (23/50, 46%) were missed by clinical screening. In conclusion, BRCA1/2 mutation prevalence in unselected breast cancer patients was 1.8%. Six in ten BRCA carriers were not detected by selective clinical screening of individuals.
    Matched MeSH terms: BRCA2 Protein/genetics*
  20. 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: BRCA2 Protein/genetics*
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