| 531. |
- Aglago, Elom K., et al.
(författare)
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A Genetic Locus within the FMN1/GREM1 Gene Region Interacts with Body Mass Index in Colorectal Cancer Risk
- 2023
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Ingår i: Cancer Research. - : American Association For Cancer Research (AACR). - 0008-5472 .- 1538-7445. ; 83:15, s. 2572-2583
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Tidskriftsartikel (refereegranskat)abstract
- Colorectal cancer risk can be impacted by genetic, environmental, and lifestyle factors, including diet and obesity. Gene-environment interactions (G × E) can provide biological insights into the effects of obesity on colorectal cancer risk. Here, we assessed potential genome-wide G × E interactions between body mass index (BMI) and common SNPs for colorectal cancer risk using data from 36,415 colorectal cancer cases and 48,451 controls from three international colorectal cancer consortia (CCFR, CORECT, and GECCO). The G × E tests included the conventional logistic regression using multiplicative terms (one degree of freedom, 1DF test), the two-step EDGE method, and the joint 3DF test, each of which is powerful for detecting G × E interactions under specific conditions. BMI was associated with higher colorectal cancer risk. The two-step approach revealed a statistically significant G×BMI interaction located within the Formin 1/Gremlin 1 (FMN1/GREM1) gene region (rs58349661). This SNP was also identified by the 3DF test, with a suggestive statistical significance in the 1DF test. Among participants with the CC genotype of rs58349661, overweight and obesity categories were associated with higher colorectal cancer risk, whereas null associations were observed across BMI categories in those with the TT genotype. Using data from three large international consortia, this study discovered a locus in the FMN1/GREM1 gene region that interacts with BMI on the association with colorectal cancer risk. Further studies should examine the potential mechanisms through which this locus modifies the etiologic link between obesity and colorectal cancer.SIGNIFICANCE: This gene-environment interaction analysis revealed a genetic locus in FMN1/GREM1 that interacts with body mass index in colorectal cancer risk, suggesting potential implications for precision prevention strategies.
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| 532. |
- Albrecht, Daniel S., et al.
(författare)
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Brain glial activation in fibromyalgia - A multi-site positron emission tomography investigation
- 2019
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Ingår i: Brain, behavior, and immunity. - : Elsevier BV. - 0889-1591 .- 1090-2139. ; 75, s. 72-83
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Tidskriftsartikel (refereegranskat)abstract
- Fibromyalgia (FM) is a poorly understood chronic condition characterized by widespread musculoskeletal pain, fatigue, and cognitive difficulties. While mounting evidence suggests a role for neuroinflammation, no study has directly provided evidence of brain glial activation in FM. In this study, we conducted a Positron Emission Tomography (PET) study using [C-11]PBR28, which binds to the translocator protein (TSPO), a protein upregulated in activated microglia and astrocytes. To enhance statistical power and generalizability, we combined datasets collected independently at two separate institutions (Massachusetts General Hospital [MGH] and Karolinska Institutet [KI]). In an attempt to disentangle the contributions of different glial cell types to FM, a smaller sample was scanned at KI with [C-11]-L-deprenyl-D2 PET, thought to primarily reflect astrocytic (but not microglial) signal. Thirty-one FM patients and 27 healthy controls (HC) were examined using [C-11]PBR28 PET. 11 FM patients and 11 HC were scanned using [C-11]-L-deprenyl-D2 PET. Standardized uptake values normalized by occipital cortex signal (SUVR) and distribution volume (V-T) were computed from the [C-11]PBR28 data. [C-11]-L-deprenyl-D2 was quantified using lambda k(3). PET imaging metrics were compared across groups, and when differing across groups, against clinical variables. Compared to HC, FM patients demonstrated widespread cortical elevations, and no decreases, in [C-11]PBR28 ITT and SUVR, most pronounced in the medial and lateral walls of the frontal and parietal lobes. No regions showed significant group differences in [C-11]-L-deprenyl-Ds signal, including those demonstrating elevated [C-11] PBR28 signal in patients (p's >= 0.53, uncorrected). The elevations in [C-11]PBR28 V-T and SUVR were correlated both spatially (i.e., were observed in overlapping regions) and, in several areas, also in terms of magnitude. In exploratory, uncorrected analyses, higher subjective ratings of fatigue in FM patients were associated with higher [C-11] PBR28 SUVR in the anterior and posterior middle cingulate cortices (p's < 0.03). SUVR was not significantly associated with any other clinical variable. Our work provides the first in vivo evidence supporting a role for glial activation in FM pathophysiology. Given that the elevations in [C-11]PBR28 signal were not also accompanied by increased [C-11]-deprenyl-D2 signal, our data suggests that microglia, but not astrocytes, may be driving the TSPO elevation in these regions. Although [C-11]-L-deprenyl-D2 signal was not found to be increased in FM patients, larger studies are needed to further assess the role of possible astrocytic contributions in FM. Overall, our data support glial modulation as a potential therapeutic strategy for FM.
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| 533. |
- Anney, Richard, et al.
(författare)
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Individual common variants exert weak effects on the risk for autism spectrum disorders.
- 2012
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Ingår i: Human Molecular Genetics. - : Oxford University Press (OUP). - 0964-6906 .- 1460-2083. ; 21:21, s. 4781-92
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Tidskriftsartikel (refereegranskat)abstract
- While it is apparent that rare variation can play an important role in the genetic architecture of autism spectrum disorders (ASD), the contribution of common variation to ASD risk is less clear. To produce a more comprehensive picture, we report Stage 2 of the Autism Genome Project genome-wide association study, adding 1301 ASD families and bringing the total to 2705 families analysed (Stages 1 and 2). In addition to evaluating association of individual SNPs, we also sought evidence that common variants, en masse, might affect risk. Despite genotyping over a million SNPs covering the genome, no single SNP shows significant association with ASD or selected phenotypes at a genome-wide level. The SNP that achieves the smallest p-value from secondary analyses is rs1718101. It falls in CNTNAP2, a gene previously implicated in susceptibility for ASD. This SNP also shows modest association with age of word/phrase acquisition in ASD subjects, of interest because features of language development are also associated with other variation in CNTNAP2. By contrast, allele-scores derived from the transmission of common alleles to Stage 1 cases significantly predict case-status in the independent Stage 2 sample. Despite being significant, the variance explained by these allele scores was small (Vm< 1%). Based on results from individual SNPs and their en masse effect on risk, as inferred from the allele-score results, it is reasonable to conclude that common variants affect ASD risk but their individual effects are modest.
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| 534. |
- Armstrong, Ben, et al.
(författare)
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The Role of Humidity in Associations of High Temperature with Mortality : A Multicountry, Multicity Study
- 2019
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Ingår i: Journal of Environmental Health Perspectives. - : The National Institute of Environmental Health Sciences. - 0091-6765 .- 1552-9924. ; 127:9
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Tidskriftsartikel (refereegranskat)abstract
- Background: There is strong experimental evidence that physiologic stress from high temperatures is greater if humidity is higher. However, heat indices developed to allow for this have not consistently predicted mortality better than dry-bulb temperature.Objectives: We aimed to clarify the potential contribution of humidity an addition to temperature in predicting daily mortality in summer by using a large multicountry dataset.Methods: In 445 cities in 24 countries, we fit a time-series regression model for summer mortality with a distributed lag nonlinear model (DLNM) for temperature (up to lag 3) and supplemented this with a range of terms for relative humidity (RH) and its interaction with temperature. City-specific associations were summarized using meta-analytic techniques.Results: Adding a linear term for RH to the temperature term improved fit slightly, with an increase of 23% in RH (the 99th percentile anomaly) associated with a 1.1% [95% confidence interval (CI): 0.8, 1.3] decrease in mortality. Allowing curvature in the RH term or adding terms for interaction of RH with temperature did not improve the model fit. The humidity-related decreased risk was made up of a positive coefficient at lag 0 outweighed by negative coefficients at lags of 1–3 d. Key results were broadly robust to small model changes and replacing RH with absolute measures of humidity. Replacing temperature with apparent temperature, a metric combining humidity and temperature, reduced goodness of fit slightly.Discussion:The absence of a positive association of humidity with mortality in summer in this large multinational study is counter to expectations from physiologic studies, though consistent with previous epidemiologic studies finding little evidence for improved prediction by heat indices. The result that there was a small negative average association of humidity with mortality should be interpreted cautiously; the lag structure has unclear interpretation and suggests the need for future work to clarify.
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| 535. |
- Ayyer, Kartik, et al.
(författare)
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3D diffractive imaging of nanoparticle ensembles using an x-ray laser
- 2021
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Ingår i: Optica. - : Optical Society of America. - 2334-2536. ; 8:1, s. 15-23
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Tidskriftsartikel (refereegranskat)abstract
- Single particle imaging at x-ray free electron lasers (XFELs) has the potential to determine the structure and dynamics of single biomolecules at room temperature. Two major hurdles have prevented this potential from being reached, namely, the collection of sufficient high-quality diffraction patterns and robust computational purification to overcome structural heterogeneity. We report the breaking of both of these barriers using gold nanoparticle test samples, recording around 10 million diffraction patterns at the European XFEL and structurally and orientationally sorting the patterns to obtain better than 3-nm-resolution 3D reconstructions for each of four samples. With these new developments, integrating advancements in x-ray sources, fast-framing detectors, efficient sample delivery, and data analysis algorithms, we illuminate the path towards sub-nano meter biomolecular imaging. The methods developed here can also be extended to characterize ensembles that are inherently diverse to obtain their full structural landscape. Published by The Optical Society under the terms of the Creative Commons Attribution 4.0 License.
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| 536. |
- Backes, Claudia, et al.
(författare)
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Production and processing of graphene and related materials
- 2020
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Ingår i: 2D Materials. - : IOP Publishing. - 2053-1583. ; 7:2
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Tidskriftsartikel (refereegranskat)abstract
- We present an overview of the main techniques for production and processing of graphene and related materials (GRMs), as well as the key characterization procedures. We adopt a 'hands-on' approach, providing practical details and procedures as derived from literature as well as from the authors' experience, in order to enable the reader to reproduce the results. Section I is devoted to 'bottom up' approaches, whereby individual constituents are pieced together into more complex structures. We consider graphene nanoribbons (GNRs) produced either by solution processing or by on-surface synthesis in ultra high vacuum (UHV), as well carbon nanomembranes (CNM). Production of a variety of GNRs with tailored band gaps and edge shapes is now possible. CNMs can be tuned in terms of porosity, crystallinity and electronic behaviour. Section II covers 'top down' techniques. These rely on breaking down of a layered precursor, in the graphene case usually natural crystals like graphite or artificially synthesized materials, such as highly oriented pyrolythic graphite, monolayers or few layers (FL) flakes. The main focus of this section is on various exfoliation techniques in a liquid media, either intercalation or liquid phase exfoliation (LPE). The choice of precursor, exfoliation method, medium as well as the control of parameters such as time or temperature are crucial. A definite choice of parameters and conditions yields a particular material with specific properties that makes it more suitable for a targeted application. We cover protocols for the graphitic precursors to graphene oxide (GO). This is an important material for a range of applications in biomedicine, energy storage, nanocomposites, etc. Hummers' and modified Hummers' methods are used to make GO that subsequently can be reduced to obtain reduced graphene oxide (RGO) with a variety of strategies. GO flakes are also employed to prepare three-dimensional (3d) low density structures, such as sponges, foams, hydro- or aerogels. The assembly of flakes into 3d structures can provide improved mechanical properties. Aerogels with a highly open structure, with interconnected hierarchical pores, can enhance the accessibility to the whole surface area, as relevant for a number of applications, such as energy storage. The main recipes to yield graphite intercalation compounds (GICs) are also discussed. GICs are suitable precursors for covalent functionalization of graphene, but can also be used for the synthesis of uncharged graphene in solution. Degradation of the molecules intercalated in GICs can be triggered by high temperature treatment or microwave irradiation, creating a gas pressure surge in graphite and exfoliation. Electrochemical exfoliation by applying a voltage in an electrolyte to a graphite electrode can be tuned by varying precursors, electrolytes and potential. Graphite electrodes can be either negatively or positively intercalated to obtain GICs that are subsequently exfoliated. We also discuss the materials that can be amenable to exfoliation, by employing a theoretical data-mining approach. The exfoliation of LMs usually results in a heterogeneous dispersion of flakes with different lateral size and thickness. This is a critical bottleneck for applications, and hinders the full exploitation of GRMs produced by solution processing. The establishment of procedures to control the morphological properties of exfoliated GRMs, which also need to be industrially scalable, is one of the key needs. Section III deals with the processing of flakes. (Ultra)centrifugation techniques have thus far been the most investigated to sort GRMs following ultrasonication, shear mixing, ball milling, microfluidization, and wet-jet milling. It allows sorting by size and thickness. Inks formulated from GRM dispersions can be printed using a number of processes, from inkjet to screen printing. Each technique has specific rheological requirements, as well as geometrical constraints. The solvent choice is critical, not only for the GRM stability, but also in terms of optimizing printing on different substrates, such as glass, Si, plastic, paper, etc, all with different surface energies. Chemical modifications of such substrates is also a key step. Sections IV-VII are devoted to the growth of GRMs on various substrates and their processing after growth to place them on the surface of choice for specific applications. The substrate for graphene growth is a key determinant of the nature and quality of the resultant film. The lattice mismatch between graphene and substrate influences the resulting crystallinity. Growth on insulators, such as SiO2, typically results in films with small crystallites, whereas growth on the close-packed surfaces of metals yields highly crystalline films. Section IV outlines the growth of graphene on SiC substrates. This satisfies the requirements for electronic applications, with well-defined graphene-substrate interface, low trapped impurities and no need for transfer. It also allows graphene structures and devices to be measured directly on the growth substrate. The flatness of the substrate results in graphene with minimal strain and ripples on large areas, allowing spectroscopies and surface science to be performed. We also discuss the surface engineering by intercalation of the resulting graphene, its integration with Si-wafers and the production of nanostructures with the desired shape, with no need for patterning. Section V deals with chemical vapour deposition (CVD) onto various transition metals and on insulators. Growth on Ni results in graphitized polycrystalline films. While the thickness of these films can be optimized by controlling the deposition parameters, such as the type of hydrocarbon precursor and temperature, it is difficult to attain single layer graphene (SLG) across large areas, owing to the simultaneous nucleation/growth and solution/precipitation mechanisms. The differing characteristics of polycrystalline Ni films facilitate the growth of graphitic layers at different rates, resulting in regions with differing numbers of graphitic layers. High-quality films can be grown on Cu. Cu is available in a variety of shapes and forms, such as foils, bulks, foams, thin films on other materials and powders, making it attractive for industrial production of large area graphene films. The push to use CVD graphene in applications has also triggered a research line for the direct growth on insulators. The quality of the resulting films is lower than possible to date on metals, but enough, in terms of transmittance and resistivity, for many applications as described in section V. Transfer technologies are the focus of section VI. CVD synthesis of graphene on metals and bottom up molecular approaches require SLG to be transferred to the final target substrates. To have technological impact, the advances in production of high-quality large-area CVD graphene must be commensurate with those on transfer and placement on the final substrates. This is a prerequisite for most applications, such as touch panels, anticorrosion coatings, transparent electrodes and gas sensors etc. New strategies have improved the transferred graphene quality, making CVD graphene a feasible option for CMOS foundries. Methods based on complete etching of the metal substrate in suitable etchants, typically iron chloride, ammonium persulfate, or hydrogen chloride although reliable, are time- and resource-consuming, with damage to graphene and production of metal and etchant residues. Electrochemical delamination in a low-concentration aqueous solution is an alternative. In this case metallic substrates can be reused. Dry transfer is less detrimental for the SLG quality, enabling a deterministic transfer. There is a large range of layered materials (LMs) beyond graphite. Only few of them have been already exfoliated and fully characterized. Section VII deals with the growth of some of these materials. Amongst them, h-BN, transition metal tri- and di-chalcogenides are of paramount importance. The growth of h-BN is at present considered essential for the development of graphene in (opto) electronic applications, as h-BN is ideal as capping layer or substrate. The interesting optical and electronic properties of TMDs also require the development of scalable methods for their production. Large scale growth using chemical/physical vapour deposition or thermal assisted conversion has been thus far limited to a small set, such as h-BN or some TMDs. Heterostructures could also be directly grown. Section VIII discusses advances in GRM functionalization. A broad range of organic molecules can be anchored to the sp(2) basal plane by reductive functionalization. Negatively charged graphene can be prepared in liquid phase (e.g. via intercalation chemistry or electrochemically) and can react with electrophiles. This can be achieved both in dispersion or on substrate. The functional groups of GO can be further derivatized. Graphene can also be noncovalently functionalized, in particular with polycyclic aromatic hydrocarbons that assemble on the sp(2) carbon network by pi-pi stacking. In the liquid phase, this can enhance the colloidal stability of SLG/FLG. Approaches to achieve noncovalent on-substrate functionalization are also discussed, which can chemically dope graphene. Research efforts to derivatize CNMs are also summarized, as well as novel routes to selectively address defect sites. In dispersion, edges are the most dominant defects and can be covalently modified. This enhances colloidal stability without modifying the graphene basal plane. Basal plane point defects can also be modified, passivated and healed in ultra-high vacuum. The decoration of graphene with metal nanoparticles (NPs) has also received considerable attention, as it allows to exploit synergistic effects between NPs and graphene. Decoration can be either achieved chemically or in the gas phase. All LMs,
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| 537. |
- Baumbach, Andreas, et al.
(författare)
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LANDMARK comparison of early outcomes of newer-generation Myval transcatheter heart valve series with contemporary valves (Sapien and Evolut) in real-world individuals with severe symptomatic native aortic stenosis: a randomised non-inferiority trial.
- 2024
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Ingår i: Lancet (London, England). - 1474-547X. ; 403:10445, s. 2695-2708
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Tidskriftsartikel (refereegranskat)abstract
- Transcatheter aortic valve implantation is an established, guideline-endorsed treatment for severe aortic stenosis. Precise sizing of the balloon-expandable Myval transcatheter heart valve (THV) series with the aortic annulus is facilitated by increasing its diameter in 1·5 mm increments, compared with the usual 3 mm increments in valve size. The LANDMARK trial aimed to show non-inferiority of the Myval THV series compared with the contemporary THVs Sapien Series (Edwards Lifesciences, Irvine, CA, USA) or Evolut Series (Medtronic, Minneapolis, MN, USA).In this prospective, multinational, randomised, open-label, non-inferiority trial across 31 hospitals in 16 countries (Germany, France, Sweden, the Netherlands, Italy, Spain, New Zealand, Portugal, Greece, Hungary, Poland, Slovakia, Slovenia, Croatia, Estonia, and Brazil), 768 participants with severe symptomatic native aortic stenosis were randomly assigned (1:1) to the Myval THV or a contemporary THV. Eligibility was primarily decided by the heart team in accordance with 2021 European Society of Cardiology guidelines. As per the criteria of the third Valve Academic Research Consortium, the primary endpoint at 30 days was a composite of all-cause mortality, all stroke, bleeding (types 3 and 4), acute kidney injury (stages 2-4), major vascular complications, moderate or severe prosthetic valve regurgitation, and conduction system disturbances resulting in a permanent pacemaker implantation. Non-inferiority of the study device was tested in the intention-to-treat population using a non-inferiority margin of 10·44% and assuming an event rate of 26·10%. This trial is registered with ClinicalTrials.gov, NCT04275726, and EudraCT, 2020-000137-40, and is closed to new participants.Between Jan 6, 2021, and Dec 5, 2023, 768 participants with severe symptomatic native aortic stenosis were randomly assigned, 384 to the Myval THV and 384 to a contemporary THV. 369 (48%) participants had their sex recorded as female, and 399 (52%) as male. The mean age of participants was 80·0 years (SD 5·7) for those treated with the Myval THV and 80·4 years (5·4) for those treated with a contemporary THV. Median Society of Thoracic Surgeons scores were the same in both groups (Myval 2·6% [IQR 1·7-4·0] vs contemporary 2·6% [1·7-4·0]). The primary endpoint showed non-inferiority of the Myval (25%) compared with contemporary THV (27%), with a risk difference of -2·3% (one-sided upper 95% CI 3·8, pnon-inferiority<0·0001). No significant difference was seen in individual components of the primary composite endpoint.In individuals with severe symptomatic native aortic stenosis, the Myval THV met its primary endpoint at 30 days.Meril Life Sciences.
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| 538. |
- Biswas, Rahul, et al.
(författare)
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Two c's in a pod : cosmology-independent measurement of the Type Ia supernova colour-luminosity relation with a sibling pair
- 2022
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Ingår i: Monthly notices of the Royal Astronomical Society. - : Oxford University Press (OUP). - 0035-8711 .- 1365-2966. ; 509:4, s. 5340-5356
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Tidskriftsartikel (refereegranskat)abstract
- Using Zwicky Transient Facility (ZTF) observations, we identify a pair of ‘sibling’ Type Ia supernovae (SNe Ia), i.e. hosted by the same galaxy at z = 0.0541. They exploded within 200 d from each other at a separation of 0.6arcsec0.6arcsec corresponding to a projected distance of only 0.6 kpc. Performing SALT2 light-curve fits to the gri ZTF photometry, we show that for these equally distant ‘standardizable candles’, there is a difference of 2 mag in their rest-frame B-band peaks, and the fainter supernova (SN) has a significantly red SALT2 colour c = 0.57 ± 0.04, while the stretch values x1 of the two SNe are similar, suggesting that the fainter SN is attenuated by dust in the interstellar medium of the host galaxy. We use these measurements to infer the SALT2 colour standardization parameter, β = 3.5 ± 0.3, independent of the underlying cosmology and Malmquist bias. Assuming the colour excess is entirely due to dust, the result differs by 2σ from the average Milky Way total-to-selective extinction ratio, but is in good agreement with the colour–brightness corrections empirically derived from the most recent SN Ia Hubble–Lemaitre diagram fits. Thus we suggest that SN ‘siblings’, which will increasingly be discovered in the coming years, can be used to probe the validity of the colour and light-curve shape corrections using in SN Ia cosmology while avoiding important systematic effects in their inference from global multiparameter fits to inhomogeneous data sets, and also help constrain the role of interstellar dust in SN Ia cosmology.
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| 539. |
- Calvert, Clara, et al.
(författare)
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Changes in preterm birth and stillbirth during COVID-19 lockdowns in 26 countries
- 2023
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Ingår i: Nature Human Behaviour. - : Springer Nature. - 2397-3374. ; 7:4, s. 529-544
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Tidskriftsartikel (refereegranskat)abstract
- Preterm birth (PTB) is the leading cause of infant mortality worldwide. Changes in PTB rates, ranging from -90% to +30%, were reported in many countries following early COVID-19 pandemic response measures ('lockdowns'). It is unclear whether this variation reflects real differences in lockdown impacts, or perhaps differences in stillbirth rates and/or study designs. Here we present interrupted time series and meta-analyses using harmonized data from 52 million births in 26 countries, 18 of which had representative population-based data, with overall PTB rates ranging from 6% to 12% and stillbirth ranging from 2.5 to 10.5 per 1,000 births. We show small reductions in PTB in the first (odds ratio 0.96, 95% confidence interval 0.95-0.98, P value <0.0001), second (0.96, 0.92-0.99, 0.03) and third (0.97, 0.94-1.00, 0.09) months of lockdown, but not in the fourth month of lockdown (0.99, 0.96-1.01, 0.34), although there were some between-country differences after the first month. For high-income countries in this study, we did not observe an association between lockdown and stillbirths in the second (1.00, 0.88-1.14, 0.98), third (0.99, 0.88-1.12, 0.89) and fourth (1.01, 0.87-1.18, 0.86) months of lockdown, although we have imprecise estimates due to stillbirths being a relatively rare event. We did, however, find evidence of increased risk of stillbirth in the first month of lockdown in high-income countries (1.14, 1.02-1.29, 0.02) and, in Brazil, we found evidence for an association between lockdown and stillbirth in the second (1.09, 1.03-1.15, 0.002), third (1.10, 1.03-1.17, 0.003) and fourth (1.12, 1.05-1.19, <0.001) months of lockdown. With an estimated 14.8 million PTB annually worldwide, the modest reductions observed during early pandemic lockdowns translate into large numbers of PTB averted globally and warrant further research into causal pathways.
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| 540. |
- Canzian, Federico, et al.
(författare)
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Comprehensive analysis of common genetic variation in 61 genes related to steroid hormone and insulin-like growth factor-I metabolism and breast cancer risk in the NCI breast and prostate cancer cohort consortium.
- 2010
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Ingår i: Human Molecular Genetics. - : Oxford University Press (OUP). - 0964-6906 .- 1460-2083. ; 19:19, s. 3873-84
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Tidskriftsartikel (refereegranskat)abstract
- There is extensive evidence that increases in blood and tissue concentrations of steroid hormones and of insulin-like growth factor I (IGF-I) are associated with breast cancer risk. However, studies of common variation in genes involved in steroid hormone and IGF-I metabolism have yet to provide convincing evidence that such variants predict breast cancer risk. The Breast and Prostate Cancer Cohort Consortium (BPC3) is a collaboration of large US and European cohorts. We genotyped 1416 tagging single nucleotide polymorphisms (SNPs) in 37 steroid hormone metabolism genes and 24 IGF-I pathway genes in 6292 cases of breast cancer and 8135 controls, mostly Caucasian, postmenopausal women from the BPC3. We also imputed 3921 additional SNPs in the regions of interest. None of the SNPs tested was significantly associated with breast cancer risk, after correction for multiple comparisons. The results remained null when cases and controls were stratified by age at diagnosis/recruitment, advanced or nonadvanced disease, body mass index, with or without in situ cases; or restricted to Caucasians. Among 770 estrogen receptor-negative cases, an SNP located 3' of growth hormone receptor (GHR) was marginally associated with increased risk after correction for multiple testing (P(trend) = 1.5 × 10(-4)). We found no significant overall associations between breast cancer and common germline variation in 61 genes involved in steroid hormone and IGF-I metabolism in this large, comprehensive study. Although previous studies have shown that variations in these genes can influence endogenous hormone levels, the magnitude of the effect of single SNPs does not appear to be sufficient to alter breast cancer risk.
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