BRCA1 and BRCA2 mutation status and cancer family history of Danish women affected with multifocal or bilateral breast cancer at a young age

INTRODUCTION—A small fraction of breast cancer is the result of germline mutations in the BRCA1 and BRCA2 cancer susceptibility genes. Mutation carriers frequently have a positive family history of breast and ovarian cancer, are often diagnosed at a young age, and may have a higher incidence of double or multiple primary breast tumours than breast cancer patients in general.
OBJECTIVES—To estimate the prevalence and spectrum of BRCA1 and BRCA2 mutations in young Danish patients affected with bilateral or multifocal breast cancer and to determine the relationship of mutation status to family history of cancer.
SUBJECTS—From the files of the Danish Breast Cancer Cooperative Group (DBCG), we selected 119 breast cancer patients diagnosed before the age of 46 years with either bilateral (n=59) or multifocal (n=61) disease.
METHODS—DNA from the subjects was screened for BRCA1 and BRCA2 mutations using single strand conformation analysis (SSCA) and the protein truncation test (PTT). Observed and expected cancer incidence in first degree relatives of the patients was estimated using data from the Danish Cancer Registry.
RESULTS—Twenty four mutation carriers were identified (20%), of whom 13 had a BRCA1 mutation and 11 carried a BRCA2 mutation. Two mutations in BRCA1 were found repeatedly in the material and accounted for seven of the 24 (29%) mutation carriers. The mutation frequency was about equal in patients with bilateral (22%) and multifocal breast cancer (18%). The incidence of breast and ovarian cancer was greatly increased in first degree relatives of BRCA1 and BRCA2 mutation carriers, but to a much lesser degree in relatives of non-carriers. An increased risk of cancer was also noted in brothers of non-carriers.
CONCLUSIONS—A relatively broad spectrum of germline mutations was observed in BRCA1 and BRCA2 and most of the mutations are present in other populations. Our results indicate that a diagnosis of bilateral and multifocal breast cancer is predictive of BRCA1 and BRCA2 mutation status, particularly when combined with information on the patients' age at diagnosis and family history of breast/ovarian cancer.


Keywords: breast cancer; mutations; BRCA1; BRCA2     

BRCA1/2 testing in newly diagnosed breast and ovarian cancer patients without prior genetic counselling: the DNA-BONus study

Germline BRCA1/2 testing of breast and ovarian cancer patients is growing rapidly as the result affects both treatment and cancer prevention in patients and relatives. Through the DNA-BONus study we offered BRCA1/2 testing and familial risk assessment to all new patients with breast (N=893) or ovarian (N=122) cancer diagnosed between September 2012 and April 2015, irrespective of family history or age, and without prior face-to-face genetic counselling. BRCA1/2 testing was accepted by 405 (45.4%) and 83 (68.0%) of the patients with breast or ovarian cancer, respectively. A pathogenic BRCA1/2 variant was found in 7 (1.7%) of the breast cancer patients and 19 (22.3%) of the ovarian cancer patients. In retrospect, all BRCA1/2 mutation carriers appeared to fulfill current criteria for BRCA1/2 testing. Hospital Anxiety and Depression Scale (HADS) scores showed that the mean levels of anxiety and depression were comparable to those reported for breast and gynecological cancer patients in general, with a significant drop in anxiety symptoms during a 6-month follow-up period, during which the test result was forwarded to the patients. These results show that BRCA1/2 testing is well accepted in newly diagnosed breast and ovarian cancer patients. Current test criteria based on age and family history are sufficient to identify most BRCA1/2 mutation carriers among breast cancer patients. We recommend germline BRCA1/2 testing in all patients with epithelial ovarian cancer because of the high prevalence of pathogenic BRCA1/2 variants.     

Evaluation of the Dutch BRCA1/2 clinical genetic center referral criteria in an unselected early breast cancer population

In this study, we evaluated the diagnostic value of the Dutch Clinical Genetic Center (CGC) referral guidelines for BRCA1/2 mutation testing in 903 early breast cancer patients, unselected for family history, diagnosed in a cancer hospital before the age of 50 years in 1974–2002; most prevalent Dutch pathogenic BRCA1/2 mutations had been analyzed on coded DNA in a research setting. Forty-nine (5.4%) of the patients were proven to be BRCA1/2 mutation carriers. We found that 78% and 69% of BRCA1 and BRCA2 mutation carriers identified met the criteria for referral to the CGC based on age, family history and synchronous multiple tumors; reflected by a combined sensitivity of 75.5% and specificity of 63.2%. More than half of the BRCA1 mutation carriers, that is, 58% had a triple-negative tumor. The highest AUC was obtained by shifting the age at diagnosis threshold criterion from 40 to 35 years and by adding a ‘triple-negative breast cancer'' criterion with an age threshold of 45 years; the specificity increased to 71.2%, whereas the sensitivity remained the same; that is, a referral of fewer patients will lead to the identification of at least the same number of BRCA1/2 mutation carriers. Two-thirds of the BRCA1/2 mutation carriers identified in this research setting had been referred for counseling and testing. Our results indicate that, awaiting a possibly more extended mutation screening of all breast cancer patients, the triple-negative status of a breast cancer should be added to the CGC referral criteria.     

Angiogenetic axis angiopoietins/Tie2 and VEGF in familial breast cancer

Angiogenesis leads to the formation of blood vessels from pre-existing ones, allowing tumor growth. Vascular endothelial growth factor (VEGF) and Angiopoietins (Ang-1, Ang-2) have a pivotal role in tumor angiogenesis but few data regarding their role in hereditary breast cancer are available. The aim of the present study was to analyze Ang-1, Ang-2, tyrosine-protein kinase receptor Tie2 and VEGF expression and their correlation in a cohort of familial and sporadic breast cancers in order to verify whether the presence of germline mutations in BRCA may have a role in tumor microenvironment regulation. Tumor samples from a cohort of 41 patients with a first diagnosis and a family history of breast cancer and 19 patients with sporadic breast cancers were enrolled. The expression of Tie2, Ang-1, Ang-2 and VEGF were analyzed by quantitative real-time PCR. Patients harboring BRCA mutations had higher levels of Ang-1 (P=0.05), Ang-2 (P=0.02) and VEGF (P=0.04) mRNA compared with those without BRCA mutations (BRCAX). The same was observed in triple-negative breast cancer (TNBC). Moreover, a positive correlation between Ang-2 and VEGF was found in both the familial breast cancer group (BRCA carriers: r=0.83; P<0.0001 and BRCAX: r=0.58; P=0.008) and in TNBC (r=0.62; P=0.007). The higher levels of Ang-1, Ang-2 and VEGF mRNA found in BRCA carriers and TNBCs suggest that they could be attractive angiogenic therapeutic targets in these breast cancers.     

海南西部地区乳腺癌患者 BRCA1 / 2 基因突变状态分析

目的 不同的区域及种族的 BRCA1 / 2 基因突变频率差异较大, 着重分析海南西部地区乳腺癌患 者 BRCA1 / 2 基因的突变状态及对患者预后的影响。 方法 选取 2015 年 10 月 ~ 2020 年 12 月在海南西部中 心医院住院并确诊为原发性乳腺癌的 256 例患者为研究对象, 采用变性高效液相色谱法 ( denaturing high performance liquid chromatography, DHPLC) 筛查乳腺癌患者是否存在 BRCA1 / 2 基因突变, 分析 BRCA1 / 2 基 因突变状态及 BRCA1 / 2 基因突变患者的临床特征, 并随访分析患者 5 年生存情况, COX 回归分析影响患者 预后的因素。 结果 256 例乳腺癌患者中共检出 53 例患者发生 BRCA1 / 2 基因突变, 其中 BRCA1 突变率 12. 11 % (31 / 256), BRCA2 突变率 8. 59 % (22 / 256), 其中有害变异率为 7. 03 % (18 / 256)。 BRCA1 / 2 基 因突变患者家族病史、 妇科疾病史、 乳腺疾病史、 雌激素受体 (estrogen receptor, ER)、 原癌基因 (CerbB2) 蛋白阳性比例以及临床病理分级、 临床分期与未突变患者比较差异有统计学意义 (P< 0. 05)。 患者总 体生存率为 83. 59 % , BRCA1 / 2 基因突变者生存率低于未突变者 (P< 0. 05), COX 回归分析显示, BRCA1 / 2 基因突变、 乳腺疾病史、 临床分期、 CerbB-2 阳性、 CEA、 CA199 均是影响乳腺癌患者生存的危险因素 (P< 0. 05)。 结论 通过 DHPLC 可有效筛查海南西部地区乳腺癌患者 BRCA1 / 2 基因的有害变异, BRCA1 / 2 基因突变与临床病理特征及预后密切相关。     

BRCA1 and BRCA2 unclassified variants and missense polymorphisms in Algerian breast/ovarian cancer families

Background: BRCA1 and BRCA2 germline mutations predispose heterozygous carriers to hereditary breast/ovarian cancer. However, unclassified variants (UVs) (variants with unknown clinical significance) and missense polymorphisms in BRCA1 and BRCA2 genes pose a problem in genetic counseling, as their impact on risk of breast and ovarian cancer is still unclear. The objective of our study was to identify UVs and missense polymorphisms in Algerian breast/ovarian cancer patients and relatives tested previously for BRCA1 and BRCA2 genes germline mutations analysis. Methods: We analyzed 101 DNA samples from 79 breast/ovarian cancer families. The approach used is based on BRCA1 and BRCA2 sequence variants screening by SSCP or High-Resolution Melting (HRM) curve analysis followed by direct sequencing. In silico analyses have been performed using different bioinformatics programs to individualize genetics variations that can disrupt the BRCA1 and BRCA2 genes function. Results: Among 80 UVs and polymorphisms detected in BRCA1/2 genes (33 BRCA2 and 47 BRCA2), 31 were new UVs (10 BRCA2 and 21 BRCA2), 7 were rare UVs (4 BRCA2 and 3 BRCA2) and 42 were polymorphic variants (19 BRCA2 and 23 BRCA2). Moreover, 8 new missense UVs identified in this study: two BRCA1 (c.4066C>A/p.Gln1356Lys, c.4901G>T/p.Arg1634Met) located respectively in exons 11 and 16, and six BRCA2 (c.1099G>A/p.Asp367Asn, c.2636C>A/p.Ser879Tyr, c.3868T>A/p.Cys1290Ser, c.5428G>T/p.Val1810Phe, c.6346C>G/p.His2116Asp and c.9256G>A/p.Gly3086Arg) located respectively in exons 10, 11 and 24, show a damaging PSIC score yielded by PolyPhen2 program and could be pathogenic. In addition, 5 new BRCA2 missense UVs out of six that were found to be damaging by PolyPhen2 program, also were deleterious according to SIFT program. The rare BRCA2 UV c.5332G>A/p.Asp1778Asn was found here for the first time in co-occurrence in trans with the deleterious BRCA1 mutation c.798_799delTT/p.Ser267LysfsX19 in young breast cancer patient. Moreover, 10 new identified intronic variants with unknown clinical significance (3 BRCA1 and 7 BRCA2) in the present study, could be considered as benign, because GeneSplicer, SpliceSiteFinder and MaxEntScan prediction programs show no splice site alteration for these variants. Several missense polymorphisms of BRCA1 c.2612C>T/p.Pro871Leu, c.3548A>G/p.Lys1183Arg, c.4837A>G/p.Ser1613Gly and BRCA2 c.865A>C/p.Asn289His, c.1114A>C/p.Asn372His, c.2971A>G/p.Asn991Asp, c.7150C>A/p.Gly2384Lys have been identified with high frequency in patients who were tested negative for BRCA1 and BRCA2 mutations. These missense polymorphisms could have a role as susceptibility breast cancer markers in Algerian breast/ovarian cancer families where pathological BRCA1 and BRCA2 mutations were not present. Conclusions: For the first time, UVs and missense polymorphisms in BRCA1 and BRCA2 genes have been identified in Algerian breast/ovarian cancer families. Evaluation of breast/ovarian cancer risk induced by the eight new missense UVs and common polymorphisms detected in our present work is on going in a larger study.     

Changes in Korean National Healthcare Insurance Policy and Breast Cancer Surgery Trend in Korea

BackgroundSince April 2015, the Korean National Health Insurance (NHI) has reimbursed breast cancer patients, approximately 50% of the cost of the breast reconstruction (BR) procedure. We aimed to investigate NHI reimbursement policy influence on the rate of immediate BR (IBR) following total mastectomy (TM).MethodsWe retrospectively analyzed breast cancer data between April 2011 and June 2016. We divided patients who underwent IBR following TM for primary breast cancer into “uninsured” and “insured” groups using their NHI statuses at the time of surgery. Univariate analyses determined the insurance influence on the decision to undergo IBR.ResultsOf 2,897 breast cancer patients, fewer uninsured patients (n = 625) underwent IBR compared with those insured (n = 325) (30.0% vs. 39.8%, P < 0.001). Uninsured patients were younger than those insured (median age [range], 43 [38–48] vs. 45 [40–50] years; P < 0.001). Pathologic breast cancer stage did not differ between the groups (P = 0.383). More insured patients underwent neoadjuvant chemotherapy (P = 0.011), adjuvant radiotherapy (P < 0.001), and IBR with tissue expander insertion (P = 0.005) compared with those uninsured.ConclusionIBR rate in patients undergoing TM increased after NHI reimbursement.     

Decreased HCRP1 expression is associated with poor prognosis in breast cancer patients

Background: Downregulation of hepatocellular carcinoma related protein 1 (HCRP1) has been reported to be associated with a poor prognosis in a variety of malignant tumors. The purpose of this study was to assess HCRP1 expression in breast cancer and to examine its possible correlation with commonly used prognostic factors, particularly epidermal growth factor receptor (EGFR). Methods: Immunohistochemical analysis was performed on tumors from 194 patients with primary breast cancer. HCRP1 expression was analyzed along with major clinicopathological variables. Results: HCRP1 protein expression was shown to be correlated with age (P = 0.001), histological grade (P = 0.005), tumor progression (P = 0.013), and death (P = 0.001), but not with tumor size, lymph-node metastasis, or Ki67 status. Kaplan-Meier survival curves showed that lower HCRP1 expression was significantly correlated with increased short-term survival (P < 0.001), and both univariate and multivariate analyses revealed that HCRP1, tumor size, lymph-node metastasis, and human epidermal growth factor receptor-2 (HER-2) were independent prognostic factors (all P < 0.05). In addition, low HCRP1 expression was much more frequent in triple negative breast cancer (TNBC; 63.89%) than in luminal (16.95%) and HER-2 overexpression phenotypes (7.5%; P < 0.001), and significant correlations between HCRP1 and survival time were observed for the TNBC group (P < 0.004). Furthermore, an inverse relationship between HCRP1 and EGFR expression was found both for the complete set of all cases (P < 0.001), and for each phenotype analyzed individually (P < 0.05). Conclusion: Our results suggest that HCRP1 may play an important role in EGFR regulation and that its decreased expression is an independent predictor of breast cancer, especially in TNBC patients.     

Effect of EME1 exon variant Ile350Thr on risk and early onset of breast cancer in southern Chinese women

Essential meiotic endonuclease 1 homolog 1 (EME1) is a key DNA repair protein that participates in the recognition and repair of DNA double-strand breaks. Deficiency of the EME1 gene can lead to spontaneous genomic instability and thus contribute to tumorgenesis. We hypothesized that the exon variants of EME1 confer genetic susceptibility to breast cancer. In a case-control study of 748 breast cancer patients and 778 normal controls, we analyzed the association between two exon variants of EME1 (i.e.,Ile350Thr: rs12450550T > C and Glu69Asp: rs3760413T > G) and breast cancer risk. We found that compared to the common Ile/Ile genotype, the Thr variant genotypes (Thr/Ile + Thr/Thr) conferred a 1.47-fold increased risk of breast cancer (OR=1.47, 95% CI=1.13-1.92). The variant Ile350Thr was also associated with early onset of breast cancer (r = -0.116, P = 0.002). The mean age of onset was 44.4 years for Thr/Thr genotype carriers and 46.5 years for Thr/Ile genotype carriers, which was significantly lower than that (49.4 years) for Ile/Ile genotype carriers (P = 0.006). Moreover, no significant association was observed between the Glu69Asp variant and breast cancer risk. Our findings suggest that the EME1 variant Ile350Thr contributes to an increased risk and early onset of breast cancer.     

Functional characterization of BRCA1 gene variants by mini-gene splicing assay

Mutational screening of the breast cancer susceptibility gene BRCA1 leads to the identification of numerous pathogenic variants such as frameshift and nonsense variants, as well as large genomic rearrangements. The screening moreover identifies a large number of variants, for example, missense, silent, and intron variants, which are classified as variants of unknown clinical significance owing to the lack of causal evidence. Variants of unknown clinical significance can potentially have an impact on splicing and therefore functional examinations are warranted to classify whether these variants are pathogenic or benign. Here we validate a mini-gene splicing assay by comparing the results of 24 variants with previously published data from RT-PCR analysis on RNA from blood samples/lymphoblastoid cell lines. The analysis showed an overall concordance of 100%. In addition, we investigated 13 BRCA1 variants of unknown clinical significance or putative variants affecting splicing by in silico analysis and mini-gene splicing assay. Both the in silico analysis and mini-gene splicing assay classified six BRCA1 variants as pathogenic (c.80+1G>A, c.132C>T (p.=), c.213−1G>A, c.670+1delG, c.4185+1G>A, and c.5075−1G>C), whereas six BRCA1 variants were classified as neutral (c.-19-22_-19-21dupAT, c.302−15C>G, c.547+14delG, c.4676−20A>G, c.4987−21G>T, and c.5278−14C>G) and one BRCA1 variant remained unclassified (c.670+16G>A). In conclusion, our study emphasizes that in silico analysis and mini-gene splicing assays are important for the classification of variants, especially if no RNA is available from the patient. This knowledge is crucial for proper genetic counseling of patients and their family members.     

Novel nonsense mutation of BRCA2 gene in a Moroccan man with familial breast cancer

Background

Breast cancer is the most common cancer in women worldwide. About 5 to 10% of cases are due to an inherited predisposition in two major genes, BRCA1 and BRCA2, transmitted as an autosomal dominant form. Male breast cancer is rare and is mainly due to BRCA2 than BRCA1 germline mutations.

Objective

Molecular study of BRCA2 gene in man with familial breast cancer.

Methods

PCR and direct sequencing of BRCA2 gene.

Results

Identification of novel heterozygous germline mutation c.6428C>A ; p.Ser2143Stop of BRCA2 gene.     

Expression of ALDH1 and TGFβ2 in benign and malignant breast tumors and their prognostic implications

The specific mechanism underlying the role of putative stem cell marker aldehyde dehydrogenase 1 (ALDH1) playing in development and progression of breast cancer is currently unclear. Transforming growth factor β (TGFβ) signaling pathway is reported to be activated in most cancers. Thus a study was initiated to explore possible differences and correlation of ALDH1 and TGFβ2 expression in the most common malignant and benign tumors of the breast in Chinese women. Samples of 75 breast cancer tissues, 30 paracancerous normal tissues, and 39 fibroadenoma breast tissues were investigated for the expression of ALDH1 and TGFβ2 using immunohistochemistry. The positive rates of ALDH1 and TGFβ2 protein were 62.67% and 66.67%, respectively, in breast cancer tissues, which were significantly higher than that in normal fibroadenoma breast (P<0.05) and paracancerous tissues (P<0.01). ALDH1 and TGFβ2 status were significantly associated with tumor histological grade and receptor status (P<0.05). Expression of ALDH1 was found to be positively correlative to TGFβ2 in breast cancer (r = 0.33, P<0.01). Expression of both proteins remained significantly associated with reduced overall survival (OS) by univariate analysis (P<0.05). Multivariate Cox regression analysis showed that ALDH1 expression, tumor stage, and lymph node status are independent prognostic factors in invasive breast cancer patients. Thus ALDH1 and TGFβ2 play important roles in the development of breast cancer. The ALDH1 phenotype is an independent predictor of poor prognosis, and TGFβ2 signaling pathway activation might be involved in the pathological regulation of ALDH1 in breast cancer.     

BRCA1 and BRCA2 Germline Mutations Screening in Algerian Breast/Ovarian Cancer Families

Background: Breast cancer is the leading cause of cancer death in women in Algeria. The contribution of BRCA1 and BRCA2 mutations to hereditary breast/ovarian cancer in Algerian population is largely unknown. Here, we describe analysis of BRCA1 and BRCA2 genes in 86 individuals from 70 families from an Algerian cohort with a personal and family history suggestive of genetic predisposition to breast cancer. Methods: The approach used is based on BRCA1 and BRCA2 mutations screening by High-Resolution Melting (HRM) curve analysis followed by direct sequencing. All samples for which no pathogenic mutation was found were analyzed by MLPA for large deletions or duplications. Results: Three distinct pathogenic mutations c.83_84delTG, c.181T>G, c.798_799delTT and two large rearrangements involving deletion of exon 2 and exon 8 respectively, were detected in BRCA1 gene. Moreover 17 unclassified variants and polymorphisms were detected in BRCA1 gene (6 described for the first time). Two pathogenic mutations, c.1310_1313delAAGA and c.5722_5723delCT and 40 unclassified variants and polymorphisms (14 never described before) were identified in BRCA2 gene. Conclusions: For the first time, we used HRM and MLPA to identify BRCA1 and BRCA2 mutations in Algerian patients with a personal and family history suggestive of genetic predisposition to breast cancer. The implications of these new findings in regard to genetic testing and counseling are substantial for the Algerian population.     

CHEK2*1100delC homozygosity in the Netherlands—prevalence and risk of breast and lung cancer

The 1100delC mutation in the CHEK2 gene has a carrier frequency of up to 1.5% in individuals from North-West Europe. Women heterozygous for 1100delC have an increased breast cancer risk (odds ratio 2.7). To explore the prevalence and clinical consequences of 1100delC homozygosity in the Netherlands, we genotyped a sporadic breast cancer hospital-based cohort, a group of non-BRCA1/2 breast cancer families, and breast tumors from a tumor tissue bank. Three 1100delC homozygous patients were found in the cohort of 1434 sporadic breast cancer patients, suggesting an increased breast cancer risk for 1100delC homozygotes (odds ratio 3.4, 95% confidence interval 0.4–32.6, P=0.3). Another 1100delC homozygote was found in 592 individuals from 108 non-BRCA1/2 breast cancer families, and two more were found after testing 1706 breast tumors and confirming homozygosity on their wild-type DNA. Follow-up data was available for five homozygous patients, and remarkably, three of them had developed contralateral breast cancer. A possible relationship between 1100delC and lung cancer risk was investigated in 457 unrelated lung cancer patients but could not be confirmed. Due to the small number of 1100delC homozygotes identified, the breast cancer risk estimate associated with this genotype had limited accuracy but is probably higher than the risk in heterozygous females. Screening for CHEK2 1100delC could be beneficial in countries with a relatively high allele frequency.     

De novo recurrent germline mutation of the BRCA2 gene in a patient with early onset breast cancer

Germline mutations in either of the two major breast cancer predisposition genes, BRCA1 and BRCA2, account for a significant proportion of hereditary breast/ovarian cancer. Identification of breast cancer patients carrying mutations of these genes is primarily based on a positive family history of breast/ovarian cancer or early onset of the disease or both. In the course of mutation screening of the BRCA1 and BRCA2 genes in a hospital based series of patients with risk factors for hereditary breast/ovarian cancer, we identified a germline mutation in the BRCA2 gene (3034del4) in a patient with early onset breast cancer and no strong family history of the disease. Subsequent molecular analysis in her parents showed that neither of them carried the mutation. Paternity was confirmed using a set of highly polymorphic markers, showing that the proband carried a de novo germline mutation in the BRCA2 gene. Interestingly, 3034del4 is a recurrent mutation occurring in a putative mutation prone region of the BRCA2 gene. Our study presents the first case in which a de novo germline mutation in the BRCA2 gene has been identified, and supports previous results of haplotype studies, confirming that the 3034del4 mutation has multiple independent origins.


Keywords: breast cancer; BRCA2 gene; de novo mutation     

BRCA1/2 mutations and FMR1 alleles are randomly distributed: a case control study

BRCA mutation carriers were reported to display a skewed distribution of FMR1 genotypes, predominantly within the low normal range (CGG repeat number <26). This observation led to the interpretation that BRCA1/2 mutations are embryo-lethal, unless rescued by ‘low FMR1 alleles''. We undertook to re-explore the distribution of FMR1 alleles subdivided into low, normal and high (<26, 26–34, and >34 CGG repeats, respectively) subgenotypes, on a cohort of 125 Ashkenazi women, carriers of a BRCA1/2 founder mutation. Ashkenazi healthy females (n=368), tested in the frame of the Israeli screening population program, served as controls. BRCA1/2 carriers and controls demonstrated a comparable and non-skewed FMR1 subgenotype distribution. Taken together, using a homogeneous ethnic group of Ashkenazi BRCA1/2 mutation carriers, we could not confirm the reported association between FMR1 low genotypes and BRCA1/2 mutations. The notion that BRCA1/2 mutations are embryo-lethal unless rescued by the low FMR1 subgenotypes is hereby refuted.     

Mutation Screening of the BRCA1 Gene in Early Onset and Familial Breast/Ovarian Cancer in Moroccan Population

Worldwide variation in the distribution of BRCA mutations is well recognised, and for the Moroccan population no comprehensive studies about BRCA mutation spectra or frequencies have been published. We therefore performed mutation analysis of the BRCA1 gene in 121 Moroccan women diagnosed with breast cancer. All cases completed epidemiology and family history questionnaires and provided a DNA sample for BRCA testing. Mutation analysis was performed by direct DNA sequencing of all coding exons and flanking intron sequences of the BRCA1 gene. 31.6 % (6/19) of familial cases and 1 % (1/102) of early-onset sporadic (< 45 years) were found to be associated with BRCA1 mutations. The pathogenic mutations included two frame-shift mutations (c.798_799delTT, c.1016dupA), one missense mutation (c.5095C>T), and one nonsense mutation (c.4942A>T). The c.798_799delTT mutation was also observed in Algerian and Tunisian BC families, suggesting the first non-Jewish founder mutation to be described in Northern Africa. In addition, ten different unclassified variants were detected in BRCA1, none of which were predicted to affect splicing. Most unclassified variants were placed in Align-GVGD classes suggesting neutrality. c.5117G>C involves a highly conserved amino acid suggestive of interfering with function (Align-GVGD class C55), but has been observed in conjunction with a deleterious mutation in a Tunisian family. These findings reflect the genetic heterogeneity of the Moroccan population and are relevant to genetic counselling and clinical management. The role of BRCA2 in BC is also under study.     

MSH3 rs26279 polymorphism increases cancer risk: a meta-analysis

Previous studies have investigated the association of mutS homolog 3 (MSH3) rs26279 G > A polymorphism with the risk of different types of cancers including colorectal cancer, breast cancer, prostate cancer, bladder cancer, thyroid cancer, ovarian cancer and oesophageal cancer. However, its association with cancer remains conflicting. We performed a comprehensive meta-analysis to derive a more precise estimation of the relationship between MSH3 rs26279 G > A polymorphism and cancer susceptibility. Systematically searching the PubMed and EMBASE databases yielded 11 publications with 12 studies of 3282 cases and 6476 controls. The strength of the association was determined by crude odds ratios (OR) and 95% confidence intervals (CI). Overall, pooled risk estimates demonstrated that MSH3 rs26279 G > A was significantly associated with an increased overall cancer risk under all the genetic models (GG vs. AA: OR = 1.27, 95% CI = 1.09-1.48, P = 0.002; AG vs. AA: OR = 1.10, 95% CI = 1.00-1.21, P = 0.045; GG vs. AG + AA: OR = 1.23, 95% CI = 1.06-1.42, P = 0.005; AG + GG vs. AA: OR = 1.13, 95% CI = 1.04-1.24, P = 0.006; G vs. A: OR = 1.13, 95% CI = 1.05-1.20, P = 0.001). The association was more evident for colorectal cancer and breast cancer. Moreover, the significant association was also observed in the following subgroups: Europeans, Asians, population-based studies, hospital-based studies, and studies comprising relatively large sample size (≥ 200). Our meta-analysis results demonstrated that MSH3 rs26279 G > A polymorphism is associated with an increased risk of overall cancer, especially for the colorectal cancer and breast cancer.     

Novel BRCA1/2 mutations in Serbian breast and breast-ovarian cancer patients with hereditary predisposition

Mutations in breast cancer susceptibility (BRCA) genes lead to defects in DNA repair processes resulting in elevated genome instability and predisposing to breast and ovarian cancer. The study was designed to detect mutational spectra of BRCA1/2 genes in a Serbian population. Using automated DNA sequencing, we tested individuals for BRCA mutations, based on positive family history of either breast or ovarian cancer or both. Two novel mutations (c.4765_4784del in BRCA1 exon 15 and c.4367_4368dupTT in BRCA2 exon 11) were detected, in three probands from two different families. These mutations have not been reported previously in the BIC or LOVD databases. Protein products of these mutated alleles lack domains necessary for their DNA repair functions, an indicator that these are deleterious mutations. Neither mutation was found in any proband from 50 other families with hereditary predisposition, so the two mutations are likely family-specific rather than population-specific. Although BRCA1-associated tumors are typically negative for estrogen receptor (ER), progesterone receptor (PR), and ERBB2, the novel BRCA1 mutation identified in this study was detected in a proband with ER- and PR-positive breast cancer. Steroid receptor-positive BRCA-related breast cancer in this proband supports the idea of characteristic pathological features and older age of onset among BRCA1-mutated ER-positive breast cancers.     

High expression of REGγ is associated with metastasis and poor prognosis of patients with breast cancer

REGgamma (REGγ) has been recently found in several types of human cancer, however, its clinical significance in metastasis and prognosis of breast cancer remains unknown. In this study, immunohistochemical staining and western blot analysis were performed to evaluate REGγ expression in both mouse and human breast cancer specimens. We found that in MMTV-PyMT mice, 14 out of 20 (70%) mouse mammary carcinomas were REGγ positive, which was significantly higher than control (0/20, 0%, P < 0.001) and lower than metastatic lung tumour (20/20, 100%, P = 0.027). Further investigation for REGγ expression in 136 human breast cancer tissues with the paired peritumoural normal breast tissues and 140 breast benign disease tissue samples showed that REGγ was undetectable in normal breast tissues and nonmetastatic axillary lymph nodes (ALNs), whereas 111 out of 136 (81.6%) breast cancer tissue samples were REGγ positive, which was significantly higher than breast benign disease tissues (9/140, 6.4%, P < 0.001) and lower than metastatic ALNs (116/116, 100%, P < 0.001). The 5-year disease-free and overall survivals of patients with negative/low level of REGγ were significantly higher than those of patients with high level of REGγ (P < 0.05). Cox regression analyses further indicated that REGγ could serve as a novel independent prognostic factor for breast cancer (OR = 4.369, P = 0.008). Our results suggest that the high expression of REGγ might predict metastasis and poor prognosis in breast cancer.