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1.
Cancer Epidemiol Biomarkers Prev ; 28(4): 822-825, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30642840

RESUMO

BACKGROUND: Genes regulated by breast cancer risk alleles identified through genome-wide association studies (GWAS) may harbor rare coding risk alleles. METHODS: We sequenced the coding regions for 38 genes within 500 kb of 38 lead GWAS SNPs in 13,538 breast cancer cases and 5,518 controls. RESULTS: Truncating variants in these genes were rare, and were not associated with breast cancer risk. Burden testing of rare missense variants highlighted 5 genes with some suggestion of an association with breast cancer, although none met the multiple testing thresholds: MKL1, FTO, NEK10, MDM4, and COX11. Six common alleles in COX11, MAP3K1 (two), and NEK10 (three) were associated at the P < 0.0001 significance level, but these likely reflect linkage disequilibrium with causal regulatory variants. CONCLUSIONS: There was no evidence that rare coding variants in these genes confer substantial breast cancer risks. However, more modest effect sizes could not be ruled out. IMPACT: We tested the hypothesis that rare variants in 38 genes near breast cancer GWAS loci may mediate risk. These variants do not appear to play a major role in breast cancer heritability.

2.
Cancer Res ; 78(21): 6329-6338, 2018 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-30385609

RESUMO

Genetic variants that increase breast cancer risk can be rare or common. This study tests whether the genetic risk stratification of breast cancer by rare and common variants in established loci can discriminate tumors with different biology, patient survival, and mode of detection. Multinomial logistic regression tested associations between genetic risk load [protein-truncating variant (PTV) carriership in 31 breast cancer predisposition genes-or polygenic risk score (PRS) using 162 single-nucleotide polymorphisms], tumor characteristics, and mode of detection (OR). Ten-year breast cancer-specific survival (HR) was estimated using Cox regression models. In this unselected cohort of 5,099 patients with breast cancer diagnosed in Sweden between 2001 and 2008, PTV carriers (n = 597) were younger and associated with more aggressive tumor phenotypes (ER-negative, large size, high grade, high proliferation, luminal B, and basal-like subtype) and worse outcome (HR, 1.65; 1.16-2.36) than noncarriers. After excluding 92 BRCA1/2 carriers, PTV carriership remained associated with high grade and worse survival (HR, 1.76; 1.21-2.56). In 5,007 BRCA1/2 noncarriers, higher PRS was associated with less aggressive tumor characteristics (ER-positive, PR-positive, small size, low grade, low proliferation, and luminal A subtype). Among patients with low mammographic density (<25%), non-BRCA1/2 PTV carriers were more often interval than screen-detected breast cancer (OR, 1.89; 1.12-3.21) than noncarriers. In contrast, higher PRS was associated with lower risk of interval compared with screen-detected cancer (OR, 0.77; 0.64-0.93) in women with low mammographic density. These findings suggest that rare and common breast cancer susceptibility loci are differentially associated with tumor characteristics, survival, and mode of detection.Significance: These findings offer the potential to improve screening practices for breast cancer by providing a deeper understanding of how risk variants affect disease progression and mode of detection. Cancer Res; 78(21); 6329-38. ©2018 AACR.

3.
Int J Cancer ; 2018 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-30175445

RESUMO

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.

4.
Sci Rep ; 8(1): 1508, 2018 01 24.
Artigo em Inglês | MEDLINE | ID: mdl-29367611

RESUMO

Identifying single nucleotide polymorphisms (SNPs) that influence chemotherapy disposition may help to personalize cancer treatment and limit toxicity. Genome-wide approaches are unbiased, compared with candidate gene studies, but usually require large cohorts. As most chemotherapy is given cyclically multiple blood sampling is required to adequately define drug disposition, limiting patient recruitment. We found that carboplatin and paclitaxel disposition are stable phenotypes in ovarian cancer patients and tested a genome-wide association study (GWAS) design to identify SNPs associated with chemotherapy disposition. We found highly significant SNPs in ABCC2, a known carboplatin transporter, associated with carboplatin clearance (asymptotic P = 5.2 × 106, empirical P = 1.4 × 10-5), indicating biological plausibility. We also identified novel SNPs associated with paclitaxel disposition, including rs17130142 with genome-wide significance (asymptotic P = 2.0 × 10-9, empirical P = 1.3 × 10-7). Although requiring further validation, our work demonstrated that GWAS of chemotherapeutic drug disposition can be effective, even in relatively small cohorts, and can be adopted in drug development and treatment programs.

5.
J Med Genet ; 55(2): 97-103, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28993434

RESUMO

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.

6.
J Med Genet ; 54(11): 732-741, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28779002

RESUMO

BACKGROUND: Breast cancer (BC) is the most common malignancy in women and has a major heritable component. The risks associated with most rare susceptibility variants are not well estimated. To better characterise the contribution of variants in ATM, CHEK2, PALB2 and XRCC2, we sequenced their coding regions in 13 087 BC cases and 5488 controls from East Anglia, UK. METHODS: Gene coding regions were enriched via PCR, sequenced, variant called and filtered for quality. ORs for BC risk were estimated separately for carriers of truncating variants and of rare missense variants, which were further subdivided by functional domain and pathogenicity as predicted by four in silico algorithms. RESULTS: Truncating variants in PALB2 (OR=4.69, 95% CI 2.27 to 9.68), ATM (OR=3.26; 95% CI 1.82 to 6.46) and CHEK2 (OR=3.11; 95% CI 2.15 to 4.69), but not XRCC2 (OR=0.94; 95% CI 0.26 to 4.19) were associated with increased BC risk. Truncating variants in ATM and CHEK2 were more strongly associated with risk of oestrogen receptor (ER)-positive than ER-negative disease, while those in PALB2 were associated with similar risks for both subtypes. There was also some evidence that missense variants in ATM, CHEK2 and PALB2 may contribute to BC risk, but larger studies are necessary to quantify the magnitude of this effect. CONCLUSIONS: Truncating variants in PALB2 are associated with a higher risk of BC than those in ATM or CHEK2. A substantial risk of BC due to truncating XRCC2 variants can be excluded.


Assuntos
Proteínas Mutadas de Ataxia Telangiectasia/genética , Neoplasias da Mama/genética , Quinase do Ponto de Checagem 2/genética , Proteínas de Ligação a DNA/genética , Proteína do Grupo de Complementação N da Anemia de Fanconi/genética , Proteínas Mutadas de Ataxia Telangiectasia/química , Quinase do Ponto de Checagem 2/química , Proteínas de Ligação a DNA/química , Proteína do Grupo de Complementação N da Anemia de Fanconi/química , Feminino , Predisposição Genética para Doença , Variação Genética , Humanos , Análise de Sequência de Proteína
7.
Cancer Epidemiol Biomarkers Prev ; 26(1): 126-135, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27697780

RESUMO

BACKGROUND: Common cancers develop through a multistep process often including inherited susceptibility. Collaboration among multiple institutions, and funding from multiple sources, has allowed the development of an inexpensive genotyping microarray, the OncoArray. The array includes a genome-wide backbone, comprising 230,000 SNPs tagging most common genetic variants, together with dense mapping of known susceptibility regions, rare variants from sequencing experiments, pharmacogenetic markers, and cancer-related traits. METHODS: The OncoArray can be genotyped using a novel technology developed by Illumina to facilitate efficient genotyping. The consortium developed standard approaches for selecting SNPs for study, for quality control of markers, and for ancestry analysis. The array was genotyped at selected sites and with prespecified replicate samples to permit evaluation of genotyping accuracy among centers and by ethnic background. RESULTS: The OncoArray consortium genotyped 447,705 samples. A total of 494,763 SNPs passed quality control steps with a sample success rate of 97% of the samples. Participating sites performed ancestry analysis using a common set of markers and a scoring algorithm based on principal components analysis. CONCLUSIONS: Results from these analyses will enable researchers to identify new susceptibility loci, perform fine-mapping of new or known loci associated with either single or multiple cancers, assess the degree of overlap in cancer causation and pleiotropic effects of loci that have been identified for disease-specific risk, and jointly model genetic, environmental, and lifestyle-related exposures. IMPACT: Ongoing analyses will shed light on etiology and risk assessment for many types of cancer. Cancer Epidemiol Biomarkers Prev; 26(1); 126-35. ©2016 AACR.


Assuntos
Predisposição Genética para Doença/epidemiologia , Variação Genética/genética , Estudo de Associação Genômica Ampla/métodos , Neoplasias/genética , Polimorfismo de Nucleotídeo Único/genética , Feminino , Genótipo , Humanos , Masculino , Neoplasias/epidemiologia , Neoplasias/fisiopatologia , Prevalência , Prognóstico , Medição de Risco , Seleção Genética
8.
J Med Genet ; 53(5): 298-309, 2016 05.
Artigo em Inglês | MEDLINE | ID: mdl-26921362

RESUMO

BACKGROUND: BRCA1 interacting protein C-terminal helicase 1 (BRIP1) is one of the Fanconi Anaemia Complementation (FANC) group family of DNA repair proteins. Biallelic mutations in BRIP1 are responsible for FANC group J, and previous studies have also suggested that rare protein truncating variants in BRIP1 are associated with an increased risk of breast cancer. These studies have led to inclusion of BRIP1 on targeted sequencing panels for breast cancer risk prediction. METHODS: We evaluated a truncating variant, p.Arg798Ter (rs137852986), and 10 missense variants of BRIP1, in 48 144 cases and 43 607 controls of European origin, drawn from 41 studies participating in the Breast Cancer Association Consortium (BCAC). Additionally, we sequenced the coding regions of BRIP1 in 13 213 cases and 5242 controls from the UK, 1313 cases and 1123 controls from three population-based studies as part of the Breast Cancer Family Registry, and 1853 familial cases and 2001 controls from Australia. RESULTS: The rare truncating allele of rs137852986 was observed in 23 cases and 18 controls in Europeans in BCAC (OR 1.09, 95% CI 0.58 to 2.03, p=0.79). Truncating variants were found in the sequencing studies in 34 cases (0.21%) and 19 controls (0.23%) (combined OR 0.90, 95% CI 0.48 to 1.70, p=0.75). CONCLUSIONS: These results suggest that truncating variants in BRIP1, and in particular p.Arg798Ter, are not associated with a substantial increase in breast cancer risk. Such observations have important implications for the reporting of results from breast cancer screening panels.


Assuntos
Neoplasias da Mama/metabolismo , Proteínas de Ligação a DNA/genética , Predisposição Genética para Doença , Mutação , RNA Helicases/genética , Adulto , Idoso , Neoplasias da Mama/epidemiologia , Neoplasias da Mama/genética , Estudos de Coortes , Grupo com Ancestrais do Continente Europeu/genética , Proteínas de Grupos de Complementação da Anemia de Fanconi , Feminino , Estudos de Associação Genética , Humanos , Pessoa de Meia-Idade , Risco
9.
Radiother Oncol ; 111(2): 178-85, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24785509

RESUMO

BACKGROUND AND PURPOSE: This study was designed to identify common single nucleotide polymorphisms (SNPs) associated with toxicity 2years after radiotherapy. MATERIALS AND METHODS: A genome wide association study was performed in 1850 patients from the RAPPER study: 1217 received adjuvant breast radiotherapy and 633 had radical prostate radiotherapy. Genotype associations with both overall and individual endpoints of toxicity were tested via univariable and multivariable regression. Replication of potentially associated SNPs was carried out in three independent patient cohorts who had radiotherapy for prostate (516 RADIOGEN and 862 Gene-PARE) or breast (355 LeND) cancer. RESULTS: Quantile-quantile plots show more associations at the P<5×10(-7) level than expected by chance (164 vs. 9 for the prostate cases and 29 vs. 4 for breast cases), providing evidence that common genetic variants are associated with risk of toxicity. Strongest associations were for individual endpoints rather than an overall measure of toxicity in all patients. However, in general, significant associations were not validated at a nominal 0.05 level in the replication cohorts. CONCLUSIONS: This largest GWAS to date provides evidence of true association between common genetic variants and toxicity. Associations with toxicity appeared to be tumour site-specific. Future GWAS require higher statistical power, in particular in the validation stage, to test clinically relevant effect sizes of SNP associations with individual endpoints, but the required sample sizes are achievable.


Assuntos
Neoplasias da Mama/genética , Neoplasias da Mama/radioterapia , Variação Genética , Neoplasias da Próstata/genética , Neoplasias da Próstata/radioterapia , Lesões por Radiação/genética , Radioterapia de Intensidade Modulada/efeitos adversos , Relação Dose-Resposta à Radiação , Feminino , Frequência do Gene , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Genótipo , Humanos , Masculino , Polimorfismo de Nucleotídeo Único , Estudos Prospectivos , Radioterapia Adjuvante/efeitos adversos
10.
Am J Hum Genet ; 92(4): 489-503, 2013 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-23540573

RESUMO

Analysis of 4,405 variants in 89,050 European subjects from 41 case-control studies identified three independent association signals for estrogen-receptor-positive tumors at 11q13. The strongest signal maps to a transcriptional enhancer element in which the G allele of the best candidate causative variant rs554219 increases risk of breast cancer, reduces both binding of ELK4 transcription factor and luciferase activity in reporter assays, and may be associated with low cyclin D1 protein levels in tumors. Another candidate variant, rs78540526, lies in the same enhancer element. Risk association signal 2, rs75915166, creates a GATA3 binding site within a silencer element. Chromatin conformation studies demonstrate that these enhancer and silencer elements interact with each other and with their likely target gene, CCND1.


Assuntos
Neoplasias da Mama/genética , Cromossomos Humanos Par 11/genética , Ciclina D1/genética , Elementos Facilitadores Genéticos/genética , Polimorfismo de Nucleotídeo Único/genética , Sítios de Ligação , Estudos de Casos e Controles , Linhagem Celular Tumoral , Cromatina/química , Cromatina/genética , Imunoprecipitação da Cromatina , Ciclina D1/metabolismo , Ensaio de Desvio de Mobilidade Eletroforética , Feminino , Fator de Transcrição GATA3/antagonistas & inibidores , Fator de Transcrição GATA3/genética , Fator de Transcrição GATA3/metabolismo , Regulação Neoplásica da Expressão Gênica , Humanos , Luciferases/metabolismo , Regiões Promotoras Genéticas/genética , RNA Mensageiro/genética , RNA Interferente Pequeno/genética , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Elementos Silenciadores Transcricionais/genética , Proteínas Elk-4 do Domínio ets/antagonistas & inibidores , Proteínas Elk-4 do Domínio ets/genética , Proteínas Elk-4 do Domínio ets/metabolismo
11.
Nat Genet ; 45(4): 385-91, 391e1-2, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23535732

RESUMO

Prostate cancer is the most frequently diagnosed cancer in males in developed countries. To identify common prostate cancer susceptibility alleles, we genotyped 211,155 SNPs on a custom Illumina array (iCOGS) in blood DNA from 25,074 prostate cancer cases and 24,272 controls from the international PRACTICAL Consortium. Twenty-three new prostate cancer susceptibility loci were identified at genome-wide significance (P < 5 × 10(-8)). More than 70 prostate cancer susceptibility loci, explaining ∼30% of the familial risk for this disease, have now been identified. On the basis of combined risks conferred by the new and previously known risk loci, the top 1% of the risk distribution has a 4.7-fold higher risk than the average of the population being profiled. These results will facilitate population risk stratification for clinical studies.


Assuntos
Loci Gênicos/genética , Predisposição Genética para Doença , Polimorfismo de Nucleotídeo Único/genética , Neoplasias da Próstata/etiologia , Estudos de Casos e Controles , Comportamento Cooperativo , Estudo de Associação Genômica Ampla , Genótipo , Humanos , Masculino , Metanálise como Assunto , Análise de Sequência com Séries de Oligonucleotídeos , Neoplasias da Próstata/patologia , Fatores de Risco
12.
Hum Mol Genet ; 22(12): 2520-8, 2013 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-23535824

RESUMO

Associations between single nucleotide polymorphisms (SNPs) at 5p15 and multiple cancer types have been reported. We have previously shown evidence for a strong association between prostate cancer (PrCa) risk and rs2242652 at 5p15, intronic in the telomerase reverse transcriptase (TERT) gene that encodes TERT. To comprehensively evaluate the association between genetic variation across this region and PrCa, we performed a fine-mapping analysis by genotyping 134 SNPs using a custom Illumina iSelect array or Sequenom MassArray iPlex, followed by imputation of 1094 SNPs in 22 301 PrCa cases and 22 320 controls in The PRACTICAL consortium. Multiple stepwise logistic regression analysis identified four signals in the promoter or intronic regions of TERT that independently associated with PrCa risk. Gene expression analysis of normal prostate tissue showed evidence that SNPs within one of these regions also associated with TERT expression, providing a potential mechanism for predisposition to disease.


Assuntos
Cromossomos Humanos Par 5/genética , Predisposição Genética para Doença , Neoplasias da Próstata/enzimologia , Neoplasias da Próstata/genética , Telomerase/genética , Adulto , Estudos de Casos e Controles , Mapeamento Cromossômico , Genótipo , Humanos , Desequilíbrio de Ligação , Masculino , Polimorfismo de Nucleotídeo Único , Regiões Promotoras Genéticas , Telomerase/metabolismo
13.
BMC Med Genomics ; 5: 19, 2012 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-22647440

RESUMO

BACKGROUND: The increasing trend for incorporation of biological sample collection within clinical trials requires sample collection procedures which are convenient and acceptable for both patients and clinicians. This study investigated the feasibility of using saliva-extracted DNA in comparison to blood-derived DNA, across two genotyping platforms: Applied Biosystems Taqman™ and Illumina Beadchip™ genome-wide arrays. METHOD: Patients were recruited from the Pharmacogenetics of Breast Cancer Chemotherapy (PGSNPS) study. Paired blood and saliva samples were collected from 79 study participants. The Oragene DNA Self-Collection kit (DNAgenotek®) was used to collect and extract DNA from saliva. DNA from EDTA blood samples (median volume 8 ml) was extracted by Gen-Probe, Livingstone, UK. DNA yields, standard measures of DNA quality, genotype call rates and genotype concordance between paired, duplicated samples were assessed. RESULTS: Total DNA yields were lower from saliva (mean 24 µg, range 0.2-52 µg) than from blood (mean 210 µg, range 58-577 µg) and a 2-fold difference remained after adjusting for the volume of biological material collected. Protein contamination and DNA fragmentation measures were greater in saliva DNA. 78/79 saliva samples yielded sufficient DNA for use on Illumina Beadchip arrays and using Taqman assays. Four samples were randomly selected for genotyping in duplicate on the Illumina Beadchip arrays. All samples were genotyped using Taqman assays. DNA quality, as assessed by genotype call rates and genotype concordance between matched pairs of DNA was high (>97%) for each measure in both blood and saliva-derived DNA. CONCLUSION: We conclude that DNA from saliva and blood samples is comparable when genotyping using either Taqman assays or genome-wide chip arrays. Saliva sampling has the potential to increase participant recruitment within clinical trials, as well as reducing the resources and organisation required for multicentre sample collection.


Assuntos
DNA/sangue , Técnicas de Genotipagem/métodos , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Saliva/metabolismo , Alelos , Feminino , Genótipo , Humanos , Polimorfismo de Nucleotídeo Único/genética
14.
Nat Genet ; 44(3): 312-8, 2012 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-22267197

RESUMO

Breast cancer is the most common cancer among women. To date, 22 common breast cancer susceptibility loci have been identified accounting for ∼8% of the heritability of the disease. We attempted to replicate 72 promising associations from two independent genome-wide association studies (GWAS) in ∼70,000 cases and ∼68,000 controls from 41 case-control studies and 9 breast cancer GWAS. We identified three new breast cancer risk loci at 12p11 (rs10771399; P = 2.7 × 10(-35)), 12q24 (rs1292011; P = 4.3 × 10(-19)) and 21q21 (rs2823093; P = 1.1 × 10(-12)). rs10771399 was associated with similar relative risks for both estrogen receptor (ER)-negative and ER-positive breast cancer, whereas the other two loci were associated only with ER-positive disease. Two of the loci lie in regions that contain strong plausible candidate genes: PTHLH (12p11) has a crucial role in mammary gland development and the establishment of bone metastasis in breast cancer, and NRIP1 (21q21) encodes an ER cofactor and has a role in the regulation of breast cancer cell growth.


Assuntos
Neoplasias da Mama/genética , Cromossomos Humanos Par 12/genética , Cromossomos Humanos Par 21/genética , Loci Gênicos/genética , Predisposição Genética para Doença/genética , Grupo com Ancestrais do Continente Europeu/genética , Feminino , Estudo de Associação Genômica Ampla , Humanos , Modelos Logísticos , Polimorfismo de Nucleotídeo Único/genética , Análise de Componente Principal
15.
Lancet Oncol ; 13(1): 65-77, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22169268

RESUMO

BACKGROUND: Several studies have reported associations between radiation toxicity and single nucleotide polymorphisms (SNPs) in candidate genes. Few associations have been tested in independent validation studies. This prospective study aimed to validate reported associations between genotype and radiation toxicity in a large independent dataset. METHODS: 92 (of 98 attempted) SNPs in 46 genes were successfully genotyped in 1613 patients: 976 received adjuvant breast radiotherapy in the Cambridge breast IMRT trial (ISRCTN21474421, n=942) or in a prospective study of breast toxicity at the Christie Hospital, Manchester, UK (n=34). A further 637 received radical prostate radiotherapy in the MRC RT01 multicentre trial (ISRCTN47772397, n=224) or in the Conventional or Hypofractionated High Dose Intensity Modulated Radiotherapy for Prostate Cancer (CHHiP) trial (ISRCTN97182923, n=413). Late toxicity was assessed 2 years after radiotherapy with a validated photographic technique (patients with breast cancer only), clinical assessment, and patient questionnaires. Association tests of genotype with overall radiation toxicity score and individual endpoints were undertaken in univariate and multivariable analyses. At a type I error rate adjusted for multiple testing, this study had 99% power to detect a SNP, with minor allele frequency of 0·35, associated with a per allele odds ratio of 2·2. FINDINGS: None of the previously reported associations were confirmed by this study, after adjustment for multiple comparisons. The p value distribution of the SNPs tested against overall toxicity score was not different from that expected by chance. INTERPRETATION: We did not replicate previously reported late toxicity associations, suggesting that we can essentially exclude the hypothesis that published SNPs individually exert a clinically relevant effect. Continued recruitment of patients into studies within the Radiogenomics Consortium is essential so that sufficiently powered studies can be done and methodological challenges addressed. FUNDING: Cancer Research UK, The Royal College of Radiologists, Addenbrooke's Charitable Trust, Breast Cancer Campaign, Cambridge National Institute of Health Research (NIHR) Biomedical Research Centre, Experimental Cancer Medicine Centre, East Midlands Innovation, the National Cancer Institute, Joseph Mitchell Trust, Royal Marsden NHS Foundation Trust, Institute of Cancer Research NIHR Biomedical Research Centre for Cancer.


Assuntos
Neoplasias da Mama/genética , Neoplasias da Mama/radioterapia , Fracionamento da Dose de Radiação , Polimorfismo de Nucleotídeo Único , Neoplasias da Próstata/genética , Neoplasias da Próstata/radioterapia , Lesões por Radiação/genética , Radioterapia de Intensidade Modulada/efeitos adversos , Relação Dose-Resposta à Radiação , Feminino , Frequência do Gene , Predisposição Genética para Doença , Humanos , Modelos Lineares , Masculino , Razão de Chances , Estudos Prospectivos , Lesões por Radiação/patologia , Radioterapia Adjuvante/efeitos adversos , Medição de Risco , Fatores de Risco , Fatores de Tempo , Reino Unido
16.
Cancer Epidemiol Biomarkers Prev ; 20(6): 1255-8, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21527579

RESUMO

BACKGROUND: The gene encoding the phase I enzyme cytochrome P4502D6 (CYP2D6) has been previously investigated for its potential predictive role in the efficacy of breast cancer treatments such as tamoxifen, but its role in breast cancer susceptibility is unclear. This study aims to evaluate the association between germ line variations in CYP2D6 and breast cancer susceptibility. METHODS: DNA samples from 13,472 cases and controls were genotyped for seven known functional variants [minor allele frequency (MAF) ≥ 0.01] and five single nucleotide polymorphisms (SNP) that tag common genetic variation (MAF > 0.05) in CYP2D6. RESULTS: One relatively rare functional variant, CYP2D6*6, (MAF = 0.01) showed a modest increased association with breast cancer susceptibility (P(trend) = 0.02; OR = 1.32; 95% CI = 1.04-1.68). All other functional and tagSNPs showed no association with breast cancer susceptibility. CONCLUSIONS: Common variants of CYP2D6 do not play a significant role in breast cancer susceptibility. However, this study raises questions regarding the role of rare variants, such as CYP2D6*6, in breast cancer susceptibility which merit further investigation. IMPACT: This large case-control study, involving 13,472 women, found no evidence of any association between common CYP2D6 gene variants and breast cancer susceptibility. However, one relatively rare functional variant CYP2D6*6 showed a modest association with breast cancer susceptibility, indicating that the role of rare CYP2D6 variants in breast cancer risk is unclear and requires further investigation in an adequately powered study.


Assuntos
Neoplasias da Mama/genética , Citocromo P-450 CYP2D6/genética , Predisposição Genética para Doença , Polimorfismo de Nucleotídeo Único/genética , Mama/metabolismo , Mama/patologia , Estudos de Casos e Controles , DNA de Neoplasias/genética , Feminino , Genótipo , Humanos , Reação em Cadeia da Polimerase , Prognóstico , Fatores de Risco
17.
Cancer Epidemiol Biomarkers Prev ; 20(6): 1112-9, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21527583

RESUMO

BACKGROUND: TGF-ß acts as a suppressor of primary tumor initiation but has been implicated as a promoter of the later malignant stages. Here associations with risk of invasive breast cancer are assessed for single-nucleotide polymorphisms (SNP) tagging 17 genes in the canonical TGF-ß ALK5/SMADs 2&3 and ALK1/SMADs 1&5 signaling pathways: LTBP1, LTBP2, LTBP4, TGFB1, TGFB2, TGFB3, TGFBR1(ALK5), ALK1, TGFBR2, Endoglin, SMAD1, SMAD2, SMAD3, SMAD4, SMAD5, SMAD6, and SMAD7 [Approved Human Gene Nomenclature Committee gene names: ACVRL1 (for ALK1) and ENG (for Endoglin)]. METHODS: Three-hundred-fifty-four tag SNPs (minor allele frequency > 0.05) were selected for genotyping in a staged study design using 6,703 cases and 6,840 controls from the Studies of Epidemiology and Risk Factors in Cancer Heredity (SEARCH) study. Significant associations were meta-analyzed with data from the NCI Polish Breast Cancer Study (PBCS; 1,966 cases and 2,347 controls) and published data from the Breast Cancer Association Consortium (BCAC). RESULTS: Associations of three SNPs, tagging TGFB1 (rs1982073), TGFBR1 (rs10512263), and TGFBR2 (rs4522809), were detected in SEARCH; however, associations became weaker in meta-analyses including data from PBCS and BCAC. Tumor subtype analyses indicated that the TGFB1 rs1982073 association may be confined to increased risk of developing progesterone receptor negative (PR(-)) tumors [1.18 (95% CI: 1.09-1.28), 4.1 × 10(-5) (P value for heterogeneity of ORs by PR status = 2.3 × 10(-4))]. There was no evidence for breast cancer risk associations with SNPs in the endothelial-specific pathway utilizing ALK1/SMADs 1&5 that promotes angiogenesis. CONCLUSION: Common variation in the TGF-ß ALK5/SMADs 2&3 signaling pathway, which initiates signaling at the cell surface to inhibit cell proliferation, might be related to risk of specific tumor subtypes. IMPACT: The subtype specific associations require very large studies to be confirmed.


Assuntos
Neoplasias da Mama/etiologia , Suscetibilidade a Doenças , Polimorfismo de Nucleotídeo Único/genética , Transdução de Sinais , Fator de Crescimento Transformador beta/genética , Idoso , Estudos de Casos e Controles , Feminino , Humanos , Pessoa de Meia-Idade , Invasividade Neoplásica , Estadiamento de Neoplasias , Prognóstico , Estudos Prospectivos
18.
Breast Cancer Res ; 12(4): R64, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20731819

RESUMO

INTRODUCTION: Tamoxifen is one of the most effective adjuvant breast cancer therapies available. Its metabolism involves the phase I enzyme, cytochrome P4502D6 (CYP2D6), encoded by the highly polymorphic CYP2D6 gene. CYP2D6 variants resulting in poor metabolism of tamoxifen are hypothesised to reduce its efficacy. An FDA-approved pre-treatment CYP2D6 gene testing assay is available. However, evidence from published studies evaluating CYP2D6 variants as predictive factors of tamoxifen efficacy and clinical outcome are conflicting, querying the clinical utility of CYP2D6 testing. We investigated the association of CYP2D6 variants with breast cancer specific survival (BCSS) in breast cancer patients receiving tamoxifen. METHODS: This was a population based case-cohort study. We genotyped known functional variants (n = 7; minor allele frequency (MAF) > 0.01) and single nucleotide polymorphisms (SNPs) (n = 5; MAF > 0.05) tagging all known common variants (tagSNPs), in CYP2D6 in 6640 DNA samples from patients with invasive breast cancer from SEARCH (Studies of Epidemiology and Risk factors in Cancer Heredity); 3155 cases had received tamoxifen therapy. There were 312 deaths from breast cancer, in the tamoxifen treated patients, with over 18000 years of cumulative follow-up. The association between genotype and BCSS was evaluated using Cox proportional hazards regression analysis. RESULTS: In tamoxifen treated patients, there was weak evidence that the poor-metaboliser variant, CYP2D6*6 (MAF = 0.01), was associated with decreased BCSS (P = 0.02; HR = 1.95; 95% CI = 1.12-3.40). No other variants, including CYP2D6*4 (MAF = 0.20), previously reported to be associated with poorer clinical outcomes, were associated with differences in BCSS, in either the tamoxifen or non-tamoxifen groups. CONCLUSIONS: CYP2D6*6 may affect BCSS in tamoxifen-treated patients. However, the absence of an association with survival in more frequent variants, including CYP2D6*4, questions the validity of the reported association between CYP2D6 genotype and treatment response in breast cancer. Until larger, prospective studies confirming any associations are available, routine CYP2D6 genetic testing should not be used in the clinical setting.


Assuntos
Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/genética , Citocromo P-450 CYP2D6/genética , Polimorfismo de Nucleotídeo Único , Tamoxifeno/uso terapêutico , Adulto , Idoso , Antineoplásicos Hormonais/metabolismo , Antineoplásicos Hormonais/uso terapêutico , Neoplasias da Mama/patologia , Quimioterapia Adjuvante/estatística & dados numéricos , Estudos de Coortes , Citocromo P-450 CYP2D6/metabolismo , Feminino , Frequência do Gene , Genótipo , Humanos , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Análise de Sobrevida , Tamoxifeno/metabolismo , Resultado do Tratamento , Reino Unido , Adulto Jovem
19.
BMC Bioinformatics ; 10: 180, 2009 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-19523221

RESUMO

BACKGROUND: In moderate-throughput SNP genotyping there was a gap in the workflow, between choosing a set of SNPs and submitting their sequences to proprietary assay design software, which was not met by existing software. Retrieval and formatting of sequences flanking each SNP, prior to assay design, becomes rate-limiting for more than about ten SNPs, especially if annotated for repetitive regions and adjacent variations. We routinely process up to 50 SNPs at once. IMPLEMENTATION: We created Seq4SNPs, a web-based, walk-away software that can process one to several hundred SNPs given rs numbers as input. It outputs a file of fully annotated sequences formatted for one of three proprietary design softwares: TaqMan's Primer-By-Design FileBuilder, Sequenom's iPLEX or SNPstream's Autoprimer, as well as unannotated fasta sequences. We found genotyping assays to be inhibited by repetitive sequences or the presence of additional variations flanking the SNP under test, and in multiplexes, repetitive sequence flanking one SNP adversely affects multiple assays. Assay design software programs avoid such regions if the input sequences are appropriately annotated, so we used Seq4SNPs to provide suitably annotated input sequences, and improved our genotyping success rate. Adjacent SNPs can also be avoided, by annotating sequences used as input for primer design. CONCLUSION: The accuracy of annotation by Seq4SNPs is significantly better than manual annotation (P < 1e-5).Using Seq4SNPs to incorporate all annotation for additional SNPs and repetitive elements into sequences, for genotyping assay designer software, minimizes assay failure at the design stage, reducing the cost of genotyping. Seq4SNPs provides a rapid route for replacement of poor test SNP sequences. We routinely use this software for assay sequence preparation. Seq4SNPs is available as a service at (http://moya.srl.cam.ac.uk/oncology/bio/s4shome.html) and (http://moya.srl.cam.ac.uk/cgi-bin/oncology/srl/ncbi/seq4snp1.pl), currently for human SNPs, but easily extended to include any species in dbSNP.


Assuntos
Biologia Computacional/métodos , Polimorfismo de Nucleotídeo Único , Análise de Sequência de DNA/métodos , Software , Sequência de Bases , Bases de Dados Genéticas , Genótipo
20.
Cancer Res ; 66(2): 1225-33, 2006 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-16424062

RESUMO

It is generally believed that the initiation of breast cancer is a consequence of cumulative genetic damage leading to genetic alterations and provoking uncontrolled cellular proliferation and/or aberrant programmed cell death, or apoptosis. Reactive oxygen species have been related to the etiology of cancer as they are known to be mitogenic and therefore capable of tumor promotion. The aim of this study was to assess the role of common variation in 10 polymorphic genes coding for antioxidant defense enzymes in modulating individual susceptibility to breast cancer using a case-control study (N cases = 4,474 and N controls = 4,580). Both cases and controls were from the East Anglian region of the United Kingdom. We have identified a set of 54 single nucleotide polymorphisms (SNPs) that efficiently tag all the known SNPs in the 10 genes and are also expected to tag any unknown SNPs in each gene. We found no evidence for association of common variants in SOD1, SOD2, GPX1, GPX4, GSR, TXNRD1, and TXN2. There was borderline evidence for association of variants in CAT g27168a {P [2 degrees of freedom (df)] = 0.05}, TXN t2715c [P (2 df) = 0.007], and TXNRD2 A66S and TXNRD2 g23524a (P(trend) = 0.074 and 0.046, respectively). For TXNRD2 A66S [AS versus AA: odds ratio (OR), 1.05; 95% confidence intervals (95% CI), 0.96-1.15; SS versus AA: OR, 1.12; 95% CI, 0.98-1.29], there are bioinformatics data to suggest that it is functional but confirmation in independent data sets is required before they can be regarded as definitive breast cancer susceptibility alleles. Even if confirmed, these four alleles would account for just 0.32% of the excess familial risk of breast cancer.


Assuntos
Neoplasias da Mama/genética , Predisposição Genética para Doença , Oxirredutases/genética , Polimorfismo de Nucleotídeo Único , Adulto , Idoso , Idoso de 80 Anos ou mais , Antioxidantes/metabolismo , Estudos de Casos e Controles , Inglaterra , Feminino , Humanos , Pessoa de Meia-Idade , Razão de Chances , Oxirredutases/metabolismo , Espécies Reativas de Oxigênio
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