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1.
Nat Commun ; 10(1): 1741, 2019 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-30988301

RESUMO

Genome-wide association studies (GWAS) have identified more than 170 breast cancer susceptibility loci. Here we hypothesize that some risk-associated variants might act in non-breast tissues, specifically adipose tissue and immune cells from blood and spleen. Using expression quantitative trait loci (eQTL) reported in these tissues, we identify 26 previously unreported, likely target genes of overall breast cancer risk variants, and 17 for estrogen receptor (ER)-negative breast cancer, several with a known immune function. We determine the directional effect of gene expression on disease risk measured based on single and multiple eQTL. In addition, using a gene-based test of association that considers eQTL from multiple tissues, we identify seven (and four) regions with variants associated with overall (and ER-negative) breast cancer risk, which were not reported in previous GWAS. Further investigation of the function of the implicated genes in breast and immune cells may provide insights into the etiology of breast cancer.


Assuntos
Neoplasias da Mama/genética , Predisposição Genética para Doença , Feminino , Perfilação da Expressão Gênica , Estudo de Associação Genômica Ampla , Humanos , Locos de Características Quantitativas
2.
J Gastrointestin Liver Dis ; 28(1): 15-22, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30851167

RESUMO

BACKGROUND AND AIMS: There is no literature on the role of repeat small bowel capsule endoscopy (SBCE) in patients with refractory coeliac disease (RCD) following treatment with steroids +/- immunosuppressants. METHODS: The findings on SBCEs from a group of patients with histologically proven RCD (n=23) were compared to the findings from patients with uncomplicated coeliac disease (n=48). All patients had concurrent duodenal histology and serology taken at the time of SBCE. RESULTS: Patients with RCD had a greater extent of mucosal involvement on SBCE than patients with uncomplicated CD (42.4+/-34.1% vs 9.7+/-21.7%, p=0.0001). Following treatment with steroids and / or immunosuppressants, patients with RCD had an improvement in the extent of affected small bowel mucosa (42.4+/-34.1% vs 26.4+/-28.9% p=0.012). There was no statistical difference in histology and serology taken at the time of the first and second SBCE in patients with RCD. CONCLUSIONS: Our study suggests that SBCE is valuable in documenting the extent of mucosal involvement in patients with RCD. This is the first study that delineates the value of a second look SBCE to assess improvement in the extent of disease in the small bowel following treatment.


Assuntos
Endoscopia por Cápsula , Doença Celíaca/tratamento farmacológico , Doença Celíaca/patologia , Duodeno/efeitos dos fármacos , Duodeno/patologia , Imunossupressores/uso terapêutico , Mucosa Intestinal/efeitos dos fármacos , Mucosa Intestinal/patologia , Esteroides/uso terapêutico , Adulto , Idoso , Doença Celíaca/complicações , Resistência a Medicamentos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Prospectivos , Índice de Gravidade de Doença , Fatores de Tempo , Resultado do Tratamento , Cicatrização/efeitos dos fármacos
3.
Hum Mutat ; 39(5): 729-741, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29460995

RESUMO

Although the spliceogenic nature of the BRCA2 c.68-7T > A variant has been demonstrated, its association with cancer risk remains controversial. In this study, we accurately quantified by real-time PCR and digital PCR (dPCR), the BRCA2 isoforms retaining or missing exon 3. In addition, the combined odds ratio for causality of the variant was estimated using genetic and clinical data, and its associated cancer risk was estimated by case-control analysis in 83,636 individuals. Co-occurrence in trans with pathogenic BRCA2 variants was assessed in 5,382 families. Exon 3 exclusion rate was 4.5-fold higher in variant carriers (13%) than controls (3%), indicating an exclusion rate for the c.68-7T > A allele of approximately 20%. The posterior probability of pathogenicity was 7.44 × 10-115 . There was neither evidence for increased risk of breast cancer (OR 1.03; 95% CI 0.86-1.24) nor for a deleterious effect of the variant when co-occurring with pathogenic variants. Our data provide for the first time robust evidence of the nonpathogenicity of the BRCA2 c.68-7T > A. Genetic and quantitative transcript analyses together inform the threshold for the ratio between functional and altered BRCA2 isoforms compatible with normal cell function. These findings might be exploited to assess the relevance for cancer risk of other BRCA2 spliceogenic variants.

4.
Int J Epidemiol ; 47(2): 526-536, 2018 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-29315403

RESUMO

Background: Polygenic risk scores (PRS) for breast cancer can be used to stratify the population into groups at substantially different levels of risk. Combining PRS and environmental risk factors will improve risk prediction; however, integrating PRS into risk prediction models requires evaluation of their joint association with known environmental risk factors. Methods: Analyses were based on data from 20 studies; datasets analysed ranged from 3453 to 23 104 invasive breast cancer cases and similar numbers of controls, depending on the analysed environmental risk factor. We evaluated joint associations of a 77-single nucleotide polymorphism (SNP) PRS with reproductive history, alcohol consumption, menopausal hormone therapy (MHT), height and body mass index (BMI). We tested the null hypothesis of multiplicative joint associations for PRS and each of the environmental factors, and performed global and tail-based goodness-of-fit tests in logistic regression models. The outcomes were breast cancer overall and by estrogen receptor (ER) status. Results: The strongest evidence for a non-multiplicative joint associations with the 77-SNP PRS was for alcohol consumption (P-interaction = 0.009), adult height (P-interaction = 0.025) and current use of combined MHT (P-interaction = 0.038) in ER-positive disease. Risk associations for these factors by percentiles of PRS did not follow a clear dose-response. In addition, global and tail-based goodness of fit tests showed little evidence for departures from a multiplicative risk model, with alcohol consumption showing the strongest evidence for ER-positive disease (P = 0.013 for global and 0.18 for tail-based tests). Conclusions: The combined effects of the 77-SNP PRS and environmental risk factors for breast cancer are generally well described by a multiplicative model. Larger studies are required to confirm possible departures from the multiplicative model for individual risk factors, and assess models specific for ER-negative disease.

5.
J Clin Pathol ; 71(4): 316-322, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28844038

RESUMO

BACKGROUND: Faecal calprotectin (FC) measurement distinguishes patients with inflammatory bowel disease (IBD) from those with irritable bowel syndrome but evidence of its performance in primary care is limited. AIMS: To assess the yield of IBD from FC testing in primary care. METHODS: Retrospective review of hospital records to assess the outcome following FC testing in primary care. Investigations for all patients undergoing FC testing in a single laboratory for 6 months from 1 October 2013 to 28 February 2014 were reviewed. RESULTS: 410 patients (162 male; median age 42; range 16-91) were included. FC>50 µg/g was considered positive (FC+). 148/410 (36.1%; median age 44 (17-91)) were FC+ (median FC 116.5 µg/g (51-1770)). 122/148 FC-positive patients (82.4%) underwent further investigation. 97 (65.5%) underwent lower gastrointestinal endoscopy (LGIE), of which 7 (7.2%) had IBD. 49/262 (18.7%) FC-negative (FC-) patients (FC ≤50 µg/g) (median age 47 (19-76)) also underwent LGIE, of whom 3 (6.1%) had IBD.IBD was diagnosed in 11/410 (2.7%; 4 ulcerative colitis, 3 Crohn's disease, 4 microscopic colitis). 8/11 were FC+ (range 67-1170) and 3 FC-. At a 50 µg/g threshold, sensitivity for detecting IBD was 72.7%, specificity 64.9%, positive predictive value (PPV) 5.41% and negative predictive value 98.9%. Increasing the threshold to 100 µg/g reduced the sensitivity of the test for detecting IBD to 54.6%. CONCLUSIONS: FC testing in primary care has low sensitivity and specificity with poor PPV for diagnosing IBD. Its use needs to be directed to those with a higher pretest probability of disease. Local services and laboratories should advise general practitioners accordingly.


Assuntos
Fezes/química , Doenças Inflamatórias Intestinais/diagnóstico , Complexo Antígeno L1 Leucocitário/análise , Atenção Primária à Saúde/métodos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Sensibilidade e Especificidade , Adulto Jovem
6.
Int J Epidemiol ; 46(6): 1814-1822, 2017 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-29232439

RESUMO

Background: There is increasing evidence that elevated body mass index (BMI) is associated with reduced survival for women with breast cancer. However, the underlying reasons remain unclear. We conducted a Mendelian randomization analysis to investigate a possible causal role of BMI in survival from breast cancer. Methods: We used individual-level data from six large breast cancer case-cohorts including a total of 36 210 individuals (2475 events) of European ancestry. We created a BMI genetic risk score (GRS) based on genotypes at 94 known BMI-associated genetic variants. Association between the BMI genetic score and breast cancer survival was analysed by Cox regression for each study separately. Study-specific hazard ratios were pooled using fixed-effect meta-analysis. Results: BMI genetic score was found to be associated with reduced breast cancer-specific survival for estrogen receptor (ER)-positive cases [hazard ratio (HR) = 1.11, per one-unit increment of GRS, 95% confidence interval (CI) 1.01-1.22, P = 0.03). We observed no association for ER-negative cases (HR = 1.00, per one-unit increment of GRS, 95% CI 0.89-1.13, P = 0.95). Conclusions: Our findings suggest a causal effect of increased BMI on reduced breast cancer survival for ER-positive breast cancer. There is no evidence of a causal effect of higher BMI on survival for ER-negative breast cancer cases.


Assuntos
Índice de Massa Corporal , Neoplasias da Mama/genética , Neoplasias da Mama/mortalidade , Grupo com Ancestrais do Continente Europeu/estatística & dados numéricos , Receptores Estrogênicos/genética , Causalidade , Europa (Continente)/epidemiologia , Feminino , Variação Genética , Humanos , Análise da Randomização Mendeliana , Metanálise como Assunto , Polimorfismo de Nucleotídeo Único , Medição de Risco , Fatores de Risco , Análise de Sobrevida
7.
Oncotarget ; 8(61): 102769-102782, 2017 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-29262523

RESUMO

Most non-BRCA1/2 breast cancer families have no identified genetic cause. We used linkage and haplotype analyses in familial and sporadic breast cancer cases to identify a susceptibility locus on chromosome 6q. Two independent genome-wide linkage analysis studies suggested a 3 Mb locus on chromosome 6q and two unrelated Swedish families with a LOD >2 together seemed to share a haplotype in 6q14.1. We hypothesized that this region harbored a rare high-risk founder allele contributing to breast cancer in these two families. Sequencing of DNA and RNA from the two families did not detect any pathogenic mutations. Finally, 29 SNPs in the region were analyzed in 44,214 cases and 43,532 controls from BCAC, and the original haplotypes in the two families were suggested as low-risk alleles for European and Swedish women specifically. There was also some support for one additional independent moderate-risk allele in Swedish familial samples. The results were consistent with our previous findings in familial breast cancer and supported a breast cancer susceptibility locus at 6q14.1 around the PHIP gene.

8.
Breast Cancer Res ; 19(1): 119, 2017 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-29116004

RESUMO

BACKGROUND: Previous studies have shown that reproductive factors are differentially associated with breast cancer (BC) risk by subtypes. The aim of this study was to investigate associations between reproductive factors and BC subtypes, and whether these vary by age at diagnosis. METHODS: We used pooled data on tumor markers (estrogen and progesterone receptor, human epidermal growth factor receptor-2 (HER2)) and reproductive risk factors (parity, age at first full-time pregnancy (FFTP) and age at menarche) from 28,095 patients with invasive BC from 34 studies participating in the Breast Cancer Association Consortium (BCAC). In a case-only analysis, we used logistic regression to assess associations between reproductive factors and BC subtype compared to luminal A tumors as a reference. The interaction between age and parity in BC subtype risk was also tested, across all ages and, because age was modeled non-linearly, specifically at ages 35, 55 and 75 years. RESULTS: Parous women were more likely to be diagnosed with triple negative BC (TNBC) than with luminal A BC, irrespective of age (OR for parity = 1.38, 95% CI 1.16-1.65, p = 0.0004; p for interaction with age = 0.076). Parous women were also more likely to be diagnosed with luminal and non-luminal HER2-like BCs and this effect was slightly more pronounced at an early age (p for interaction with age = 0.037 and 0.030, respectively). For instance, women diagnosed at age 35 were 1.48 (CI 1.01-2.16) more likely to have luminal HER2-like BC than luminal A BC, while this association was not significant at age 75 (OR = 0.72, CI 0.45-1.14). While age at menarche was not significantly associated with BC subtype, increasing age at FFTP was non-linearly associated with TNBC relative to luminal A BC. An age at FFTP of 25 versus 20 years lowered the risk for TNBC (OR = 0.78, CI 0.70-0.88, p < 0.0001), but this effect was not apparent at a later FFTP. CONCLUSIONS: Our main findings suggest that parity is associated with TNBC across all ages at BC diagnosis, whereas the association with luminal HER2-like BC was present only for early onset BC.


Assuntos
Neoplasias da Mama/epidemiologia , Neoplasias da Mama/etiologia , História Reprodutiva , Adulto , Idoso , Biomarcadores Tumorais , Neoplasias da Mama/diagnóstico , Estudos de Coortes , Feminino , Humanos , Pessoa de Meia-Idade , Razão de Chances , Medição de Risco , Fatores de Risco , Neoplasias de Mama Triplo Negativas/diagnóstico , Neoplasias de Mama Triplo Negativas/epidemiologia , Neoplasias de Mama Triplo Negativas/etiologia , Adulto Jovem
9.
Cancer Res ; 77(11): 2789-2799, 2017 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-28283652

RESUMO

Breast cancer risks conferred by many germline missense variants in the BRCA1 and BRCA2 genes, often referred to as variants of uncertain significance (VUS), have not been established. In this study, associations between 19 BRCA1 and 33 BRCA2 missense substitution variants and breast cancer risk were investigated through a breast cancer case-control study using genotyping data from 38 studies of predominantly European ancestry (41,890 cases and 41,607 controls) and nine studies of Asian ancestry (6,269 cases and 6,624 controls). The BRCA2 c.9104A>C, p.Tyr3035Ser (OR = 2.52; P = 0.04), and BRCA1 c.5096G>A, p.Arg1699Gln (OR = 4.29; P = 0.009) variant were associated with moderately increased risks of breast cancer among Europeans, whereas BRCA2 c.7522G>A, p.Gly2508Ser (OR = 2.68; P = 0.004), and c.8187G>T, p.Lys2729Asn (OR = 1.4; P = 0.004) were associated with moderate and low risks of breast cancer among Asians. Functional characterization of the BRCA2 variants using four quantitative assays showed reduced BRCA2 activity for p.Tyr3035Ser compared with wild-type. Overall, our results show how BRCA2 missense variants that influence protein function can confer clinically relevant, moderately increased risks of breast cancer, with potential implications for risk management guidelines in women with these specific variants. Cancer Res; 77(11); 2789-99. ©2017 AACR.


Assuntos
Proteína BRCA2/genética , Neoplasias da Mama/genética , Idoso , Substituição de Aminoácidos , Animais , Estudos de Casos e Controles , Feminino , Genótipo , Mutação em Linhagem Germinativa , Humanos , Camundongos , Mutação de Sentido Incorreto , Risco
10.
Genet Med ; 19(5): 599-603, 2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-27711073

RESUMO

PURPOSE: CHEK2*1100delC is a founder variant in European populations that confers a two- to threefold increased risk of breast cancer (BC). Epidemiologic and family studies have suggested that the risk associated with CHEK2*1100delC is modified by other genetic factors in a multiplicative fashion. We have investigated this empirically using data from the Breast Cancer Association Consortium (BCAC). METHODS: Using genotype data from 39,139 (624 1100delC carriers) BC patients and 40,063 (224) healthy controls from 32 BCAC studies, we analyzed the combined risk effects of CHEK2*1100delC and 77 common variants in terms of a polygenic risk score (PRS) and pairwise interaction. RESULTS: The PRS conferred odds ratios (OR) of 1.59 (95% CI: 1.21-2.09) per standard deviation for BC for CHEK2*1100delC carriers and 1.58 (1.55-1.62) for noncarriers. No evidence of deviation from the multiplicative model was found. The OR for the highest quintile of the PRS was 2.03 (0.86-4.78) for CHEK2*1100delC carriers, placing them in the high risk category according to UK NICE guidelines. The OR for the lowest quintile was 0.52 (0.16-1.74), indicating a lifetime risk close to the population average. CONCLUSION: Our results confirm the multiplicative nature of risk effects conferred by CHEK2*1100delC and the common susceptibility variants. Furthermore, the PRS could identify carriers at a high lifetime risk for clinical actions.Genet Med advance online publication 06 October 2016.


Assuntos
Neoplasias da Mama/genética , Quinase do Ponto de Checagem 2/genética , Deleção de Sequência , Feminino , Genes Modificadores , Predisposição Genética para Doença , Humanos , Razão de Chances , Penetrância
11.
Gut ; 66(9): 1563-1572, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-27605538

RESUMO

BACKGROUND: Seronegative villous atrophy (SNVA) is commonly attributed to coeliac disease (CD). However, there are other causes of SNVA. More recently angiotensin-2-receptor-blockers (A2RBs) have been reported as an association but data on SNVA have been limited to centres evaluating complex case referrals and not SNVA in general. OBJECTIVES: To provide clinical outcomes and associations in a large prospective study overseeing all newcomers with SNVA. DESIGN: Over a 15-year period (2000-2015) we evaluated 200 adult patients with SNVA at a UK centre. A diagnosis of either seronegative CD (SNCD) or seronegative non-CD (SN-non-CD) was reached. Baseline comparisons were made between the groups, with 343 seropositive CD subjects serving as controls. RESULTS: Of the 200 SNVA cases, SNCD represented 31% (n=62) and SN-non-CD 69% (n=138). The human leucocyte antigen (HLA)-DQ2 and/or DQ8 genotype was present in 61%, with a 51% positive predictive value for SNCD. The breakdown of identifiable causes in the SN-non-CD group comprised infections (27%, n=54), inflammatory/immune-mediated disorders (17.5%, n=35) and drugs (6.5%, n=13; two cases related to A2RBs). However, no cause was found in 18% (n=36) and of these 72% (n=26/36) spontaneously normalised duodenal histology while consuming a gluten-enriched diet. Following multivariable logistic regression analysis an independent factor associated with SN-non-CD was non-white ethnicity (OR 10.8, 95% CI 2.2 to 52.8); in fact, 66% of non-whites had GI infections. On immunohistochemistry all groups stained positive for CD8-T-cytotoxic intraepithelial lymphocytes. However, additional CD4-T helper intraepithelial lymphocytes were occasionally seen in SN-non-CD mimicking the changes associated with refractory CD. CONCLUSIONS: Most patients with SNVA do not have CD, in particular those who are not white. Furthermore, a subgroup with no obvious aetiology will show spontaneous histological resolution while consuming gluten. These findings suggest caution in empirically prescribing a gluten-free diet without investigation.


Assuntos
Doença Celíaca , Dieta Livre de Glúten/métodos , Antígenos HLA-DQ/imunologia , Mucosa Intestinal , Transglutaminases/imunologia , Adulto , Idoso , Atrofia , Autoanticorpos/sangue , Biópsia/métodos , Doença Celíaca/dietoterapia , Doença Celíaca/epidemiologia , Doença Celíaca/imunologia , Doença Celíaca/patologia , Feminino , Humanos , Mucosa Intestinal/imunologia , Mucosa Intestinal/patologia , Masculino , Microvilosidades/imunologia , Microvilosidades/patologia , Pessoa de Meia-Idade , Estudos Prospectivos , Testes Sorológicos/métodos , Estatística como Assunto , Reino Unido/epidemiologia
12.
Sci Rep ; 6: 36874, 2016 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-27845421

RESUMO

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.


Assuntos
Neoplasias da Mama/genética , Proteínas de Ciclo Celular/genética , MicroRNAs/metabolismo , Proteínas Nucleares/genética , Regiões 3' não Traduzidas , Alelos , Proteína BRCA1/genética , Proteína BRCA2/genética , Sítios de Ligação , Neoplasias da Mama/patologia , Feminino , Predisposição Genética para Doença , Genótipo , Humanos , Razão de Chances , Polimorfismo de Nucleotídeo Único , Fatores de Risco
14.
Oncotarget ; 7(49): 80140-80163, 2016 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-27792995

RESUMO

There are significant inter-individual differences in the levels of gene expression. Through modulation of gene expression, cis-acting variants represent an important source of phenotypic variation. Consequently, cis-regulatory SNPs associated with differential allelic expression are functional candidates for further investigation as disease-causing variants. To investigate whether common variants associated with differential allelic expression were involved in breast cancer susceptibility, a list of genes was established on the basis of their involvement in cancer related pathways and/or mechanisms. Thereafter, using data from a genome-wide map of allelic expression associated SNPs, 313 genetic variants were selected and their association with breast cancer risk was then evaluated in 46,451 breast cancer cases and 42,599 controls of European ancestry ascertained from 41 studies participating in the Breast Cancer Association Consortium. The associations were evaluated with overall breast cancer risk and with estrogen receptor negative and positive disease. One novel breast cancer susceptibility locus on 4q21 (rs11099601) was identified (OR = 1.05, P = 5.6x10-6). rs11099601 lies in a 135 kb linkage disequilibrium block containing several genes, including, HELQ, encoding the protein HEL308 a DNA dependant ATPase and DNA Helicase involved in DNA repair, MRPS18C encoding the Mitochondrial Ribosomal Protein S18C and FAM175A (ABRAXAS), encoding a BRCA1 BRCT domain-interacting protein involved in DNA damage response and double-strand break (DSB) repair. Expression QTL analysis in breast cancer tissue showed rs11099601 to be associated with HELQ (P = 8.28x10-14), MRPS18C (P = 1.94x10-27) and FAM175A (P = 3.83x10-3), explaining about 20%, 14% and 1%, respectively of the variance inexpression of these genes in breast carcinomas.


Assuntos
Biomarcadores Tumorais/genética , Neoplasias da Mama/genética , Cromossomos Humanos Par 4 , Polimorfismo de Nucleotídeo Único , Neoplasias da Mama/patologia , Canadá , Proteínas de Transporte/genética , Estudos de Casos e Controles , DNA Helicases/genética , Europa (Continente) , Feminino , Frequência do Gene , Estudos de Associação Genética , Predisposição Genética para Doença , Humanos , Desequilíbrio de Ligação , Proteínas Mitocondriais/genética , Razão de Chances , Fenótipo , Locos de Características Quantitativas , Medição de Risco , Fatores de Risco
15.
Sci Rep ; 6: 32512, 2016 09 07.
Artigo em Inglês | MEDLINE | ID: mdl-27600471

RESUMO

Genome-wide association studies have found SNPs at 17q22 to be associated with breast cancer risk. To identify potential causal variants related to breast cancer risk, we performed a high resolution fine-mapping analysis that involved genotyping 517 SNPs using a custom Illumina iSelect array (iCOGS) followed by imputation of genotypes for 3,134 SNPs in more than 89,000 participants of European ancestry from the Breast Cancer Association Consortium (BCAC). We identified 28 highly correlated common variants, in a 53 Kb region spanning two introns of the STXBP4 gene, that are strong candidates for driving breast cancer risk (lead SNP rs2787486 (OR = 0.92; CI 0.90-0.94; P = 8.96 × 10(-15))) and are correlated with two previously reported risk-associated variants at this locus, SNPs rs6504950 (OR = 0.94, P = 2.04 × 10(-09), r(2) = 0.73 with lead SNP) and rs1156287 (OR = 0.93, P = 3.41 × 10(-11), r(2) = 0.83 with lead SNP). Analyses indicate only one causal SNP in the region and several enhancer elements targeting STXBP4 are located within the 53 kb association signal. Expression studies in breast tumor tissues found SNP rs2787486 to be associated with increased STXBP4 expression, suggesting this may be a target gene of this locus.


Assuntos
Neoplasias da Mama/genética , Predisposição Genética para Doença , Locos de Características Quantitativas/genética , Proteínas de Transporte Vesicular/genética , Neoplasias da Mama/patologia , Mapeamento Cromossômico , Cromossomos Humanos Par 17/genética , Grupo com Ancestrais do Continente Europeu , Feminino , Estudo de Associação Genômica Ampla , Genótipo , Humanos , Polimorfismo de Nucleotídeo Único/genética
17.
PLoS Med ; 13(8): e1002105, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27551723

RESUMO

BACKGROUND: Observational epidemiological studies have shown that high body mass index (BMI) is associated with a reduced risk of breast cancer in premenopausal women but an increased risk in postmenopausal women. It is unclear whether this association is mediated through shared genetic or environmental factors. METHODS: We applied Mendelian randomization to evaluate the association between BMI and risk of breast cancer occurrence using data from two large breast cancer consortia. We created a weighted BMI genetic score comprising 84 BMI-associated genetic variants to predicted BMI. We evaluated genetically predicted BMI in association with breast cancer risk using individual-level data from the Breast Cancer Association Consortium (BCAC) (cases = 46,325, controls = 42,482). We further evaluated the association between genetically predicted BMI and breast cancer risk using summary statistics from 16,003 cases and 41,335 controls from the Discovery, Biology, and Risk of Inherited Variants in Breast Cancer (DRIVE) Project. Because most studies measured BMI after cancer diagnosis, we could not conduct a parallel analysis to adequately evaluate the association of measured BMI with breast cancer risk prospectively. RESULTS: In the BCAC data, genetically predicted BMI was found to be inversely associated with breast cancer risk (odds ratio [OR] = 0.65 per 5 kg/m2 increase, 95% confidence interval [CI]: 0.56-0.75, p = 3.32 × 10-10). The associations were similar for both premenopausal (OR = 0.44, 95% CI:0.31-0.62, p = 9.91 × 10-8) and postmenopausal breast cancer (OR = 0.57, 95% CI: 0.46-0.71, p = 1.88 × 10-8). This association was replicated in the data from the DRIVE consortium (OR = 0.72, 95% CI: 0.60-0.84, p = 1.64 × 10-7). Single marker analyses identified 17 of the 84 BMI-associated single nucleotide polymorphisms (SNPs) in association with breast cancer risk at p < 0.05; for 16 of them, the allele associated with elevated BMI was associated with reduced breast cancer risk. CONCLUSIONS: BMI predicted by genome-wide association studies (GWAS)-identified variants is inversely associated with the risk of both pre- and postmenopausal breast cancer. The reduced risk of postmenopausal breast cancer associated with genetically predicted BMI observed in this study differs from the positive association reported from studies using measured adult BMI. Understanding the reasons for this discrepancy may reveal insights into the complex relationship of genetic determinants of body weight in the etiology of breast cancer.


Assuntos
Índice de Massa Corporal , Neoplasias da Mama/genética , Grupo com Ancestrais do Continente Europeu/genética , Neoplasias da Mama/etiologia , Grupo com Ancestrais do Continente Europeu/estatística & dados numéricos , Feminino , Predisposição Genética para Doença/genética , Humanos , Análise da Randomização Mendeliana , Menopausa , Pessoa de Meia-Idade , Modelos Estatísticos , Polimorfismo de Nucleotídeo Único/genética , Fatores de Risco
18.
PLoS One ; 11(7): e0160174, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27463681

RESUMO

Triple negative breast cancer is typically an aggressive and difficult to treat subtype. It is often associated with loss of function of the BRCA1 gene, either through mutation, loss of heterozygosity or methylation. This study aimed to measure methylation of the BRCA1 gene promoter at individual CpG sites in blood, tumour and normal breast tissue, to assess whether levels were correlated between different tissues, and with triple negative receptor status, histopathological scoring for BRCA-like features and BRCA1 protein expression. Blood DNA methylation levels were significantly correlated with tumour methylation at 9 of 11 CpG sites examined (p<0.0007). The levels of tumour DNA methylation were significantly higher in triple negative tumours, and in tumours with high BRCA-like histopathological scores (10 of 11 CpG sites; p<0.01 and p<0.007 respectively). Similar results were observed in blood DNA (6 of 11 CpG sites; p<0.03 and 7 of 11 CpG sites; p<0.02 respectively). This study provides insight into the pattern of CpG methylation across the BRCA1 promoter, and supports previous studies suggesting that tumours with BRCA1 promoter methylation have similar features to those with BRCA1 mutations, and therefore may be suitable for the same targeted therapies.


Assuntos
Proteína BRCA1/genética , Metilação de DNA , Neoplasias de Mama Triplo Negativas/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/sangue , Biomarcadores Tumorais/genética , Ilhas de CpG , DNA de Neoplasias/sangue , DNA de Neoplasias/genética , Feminino , Humanos , Pessoa de Meia-Idade , Regiões Promotoras Genéticas , Neoplasias de Mama Triplo Negativas/sangue , Neoplasias de Mama Triplo Negativas/patologia
19.
J Clin Oncol ; 34(23): 2750-60, 2016 08 10.
Artigo em Inglês | MEDLINE | ID: mdl-27269948

RESUMO

PURPOSE: CHEK2*1100delC is a well-established breast cancer risk variant that is most prevalent in European populations; however, there are limited data on risk of breast cancer by age and tumor subtype, which limits its usefulness in breast cancer risk prediction. We aimed to generate tumor subtype- and age-specific risk estimates by using data from the Breast Cancer Association Consortium, including 44,777 patients with breast cancer and 42,997 controls from 33 studies genotyped for CHEK2*1100delC. PATIENTS AND METHODS: CHEK2*1100delC genotyping was mostly done by a custom Taqman assay. Breast cancer odds ratios (ORs) for CHEK2*1100delC carriers versus noncarriers were estimated by using logistic regression and adjusted for study (categorical) and age. Main analyses included patients with invasive breast cancer from population- and hospital-based studies. RESULTS: Proportions of heterozygous CHEK2*1100delC carriers in controls, in patients with breast cancer from population- and hospital-based studies, and in patients with breast cancer from familial- and clinical genetics center-based studies were 0.5%, 1.3%, and 3.0%, respectively. The estimated OR for invasive breast cancer was 2.26 (95%CI, 1.90 to 2.69; P = 2.3 × 10(-20)). The OR was higher for estrogen receptor (ER)-positive disease (2.55 [95%CI, 2.10 to 3.10; P = 4.9 × 10(-21)]) than it was for ER-negative disease (1.32 [95%CI, 0.93 to 1.88; P = .12]; P interaction = 9.9 × 10(-4)). The OR significantly declined with attained age for breast cancer overall (P = .001) and for ER-positive tumors (P = .001). Estimated cumulative risks for development of ER-positive and ER-negative tumors by age 80 in CHEK2*1100delC carriers were 20% and 3%, respectively, compared with 9% and 2%, respectively, in the general population of the United Kingdom. CONCLUSION: These CHEK2*1100delC breast cancer risk estimates provide a basis for incorporating CHEK2*1100delC into breast cancer risk prediction models and into guidelines for intensified screening and follow-up.


Assuntos
Neoplasias da Mama/epidemiologia , Neoplasias da Mama/genética , Quinase do Ponto de Checagem 2/genética , Predisposição Genética para Doença/genética , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Neoplasias da Mama/química , Estudos de Casos e Controles , Feminino , Heterozigoto , Homozigoto , Humanos , Pessoa de Meia-Idade , Razão de Chances , Receptores Estrogênicos/análise , Receptores de Progesterona/análise , Medição de Risco , Deleção de Sequência
20.
Int J Cancer ; 139(6): 1303-1317, 2016 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-27087578

RESUMO

Previous genome-wide association studies among women of European ancestry identified two independent breast cancer susceptibility loci represented by single nucleotide polymorphisms (SNPs) rs13281615 and rs11780156 at 8q24. A fine-mapping study across 2.06 Mb (chr8:127,561,724-129,624,067, hg19) in 55,540 breast cancer cases and 51,168 controls within the Breast Cancer Association Consortium was conducted. Three additional independent association signals in women of European ancestry, represented by rs35961416 (OR = 0.95, 95% CI = 0.93-0.97, conditional p = 5.8 × 10(-6) ), rs7815245 (OR = 0.94, 95% CI = 0.91-0.96, conditional p = 1.1 × 10(-6) ) and rs2033101 (OR = 1.05, 95% CI = 1.02-1.07, conditional p = 1.1 × 10(-4) ) were found. Integrative analysis using functional genomic data from the Roadmap Epigenomics, the Encyclopedia of DNA Elements project, the Cancer Genome Atlas and other public resources implied that SNPs rs7815245 in Signal 3, and rs1121948 in Signal 5 (in linkage disequilibrium with rs11780156, r(2) = 0.77), were putatively functional variants for two of the five independent association signals. The results highlighted multiple 8q24 variants associated with breast cancer susceptibility in women of European ancestry.


Assuntos
Neoplasias da Mama/epidemiologia , Neoplasias da Mama/genética , Mapeamento Cromossômico , Cromossomos Humanos Par 8/genética , Variação Genética , Locos de Características Quantitativas , Alelos , Estudos de Casos e Controles , Grupo com Ancestrais do Continente Europeu/genética , Feminino , Estudo de Associação Genômica Ampla , Genótipo , Haplótipos , Humanos , Desequilíbrio de Ligação , Razão de Chances , Polimorfismo de Nucleotídeo Único , Risco
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