1,138 research outputs found

    How should we discuss genetic testing with women newly diagnosed with breast cancer? Design and implementation of a randomized controlled trial of two models of delivering education about treatment-focused genetic testing to younger women newly diagnosed with breast cancer

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    BACKGROUND: Germline BRCA1 and BRCA2 mutation testing offered shortly after a breast cancer diagnosis to inform women's treatment choices - treatment-focused genetic testing 'TFGT' - has entered clinical practice in specialist centers and is likely to be soon commonplace in acute breast cancer management, especially for younger women. Yet the optimal way to deliver information about TFGT to younger women newly diagnosed with breast cancer is not known, particularly for those who were not suspected of having a hereditary breast cancer syndrome prior to their cancer diagnosis. Also, little is known about the behavioral and psychosocial impact or cost effectiveness of educating patients about TFGT. This trial aims to examine the impact and efficiency of two models of educating younger women newly diagnosed with breast cancer about genetic testing in order to provide evidence for a safe and effective future clinical pathway for this service. DESIGN/METHODS: In this non-inferiority randomized controlled trial, 140 women newly diagnosed with breast cancer (aged less than 50 years) are being recruited from nine cancer centers in Australia. Eligible women with either a significant family history of breast and/or ovarian cancer or with other high risk features suggestive of a mutation detection rate of > 10% are invited by their surgeon prior to mastectomy or radiotherapy. After completing the first questionnaire, participants are randomized to receive either: (a) an educational pamphlet about genetic testing (intervention) or (b) a genetic counseling appointment at a family cancer center (standard care). Each participant is offered genetic testing for germline BRCA mutations. Decision-related and psychosocial outcomes are assessed over 12 months and include decisional conflict (primary outcome);uptake of bilateral mastectomy and/or risk-reducing salpingo-oophorectomy; cancer-specific- and general distress; family involvement in decision making; and decision regret. A process-oriented retrospective online survey will examine health professionals' attitudes toward TFGT; a health economic analysis will determine the cost effectiveness of the intervention. DISCUSSION: This trial will provide crucial information about the impact, efficiency and cost effectiveness of an educational pamphlet designed to inform younger women newly diagnosed with breast cancer about genetic testing. Issues regarding implementation of the trial are discussed

    T and F asymmetries in π0 photoproduction on the proton

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    The γp→π0p reaction was studied at laboratory photon energies from 425 to 1445 MeV with a transversely polarized target and a longitudinally polarized beam. The beam-target asymmetry F was measured for the first time and new high precision data for the target asymmetry T were obtained. The experiment was performed at the photon tagging facility of the Mainz Microtron (MAMI) using the Crystal Ball and TAPS photon spectrometers. The polarized cross sections were expanded in terms of associated Legendre functions and compared to recent predictions from several partial-wave analyses. The impact of the new data on our understanding of the underlying partial-wave amplitudes and baryon resonance contributions is discussed

    Photoproduction of π0-pairs off protons and off neutrons

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    Total cross sections, angular distributions, and invariant-mass distributions have been measured for the photoproduction of π0π0 pairs off free protons and off nucleons bound in the deuteron. The experiments were performed at the MAMI accelerator facility in Mainz using the Glasgow photon tagging spectrometer and the Crystal Ball/TAPS detector. The accelerator delivered electron beams of 1508 and 1557MeV, which produced bremsstrahlung in thin radiator foils. The tagged photon beam covered energies up to 1400MeV. The data from the free proton target are in good agreement with previous measurements and were only used to test the analysis procedures. The results for differential cross sections (angular distributions and invariant-mass distributions) for free and quasi-free protons are almost identical in shape, but differ in absolute magnitude up to 15%. Thus, moderate final-state interaction effects are present. The data for quasi-free neutrons are similar to the proton data in the second resonance region (final-state invariant masses up to ≈1550 MeV), where both reactions are dominated by the N(1520)3/2−→Δ(1232)3/2+π decay. At higher energies, angular and invariant-mass distributions are different. A simple analysis of the shapes of the invariant-mass distributions in the third resonance region is consistent with strong contributions of an N⋆→Nσ decay for the proton, while the reaction is dominated by a sequential decay via a Δπ intermediate state for the neutron. The data are compared to predictions from the Two-Pion-MAID model and the Bonn-Gatchina coupled-channel analysis

    Measurement of the transverse target and beam-target asymmetries in η\eta meson photoproduction at MAMI

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    We present new data for the transverse target asymmetry T and the very first data for the beam-target asymmetry F in the γpηp\vec \gamma \vec p\to\eta p reaction up to a center-of-mass energy of W=1.9 GeV. The data were obtained with the Crystal-Ball/TAPS detector setup at the Glasgow tagged photon facility of the Mainz Microtron MAMI. All existing model predictions fail to reproduce the new data indicating a significant impact on our understanding of the underlying dynamics of η\eta meson photoproduction. The peculiar nodal structure observed in existing T data close to threshold is not confirmed.Comment: 5 pages, 3 figures, accepted for publication in PR

    Photoproduction of pi0-mesons off neutrons in the nucleon resonance region

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    Precise angular distributions have been measured for the first time for the photoproduction of π0\pi^{0}-mesons off neutrons bound in the deuteron. The effects from nuclear Fermi motion have been eliminated by a complete kinematic reconstruction of the final state. The influence of final-state-interaction effects has been estimated by a comparison of the reaction cross section for quasi-free protons bound in the deuteron to the results for free protons and then applied as a correction to the quasi-free neutron data. The experiment was performed at the tagged photon facility of the Mainz Microtron MAMI with the Crystal Ball and TAPS detector setup for incident photon energies between 0.450.45~GeV and 1.41.4~GeV. The results are compared to the predictions from reaction models and partial-wave analyses based on data from other isospin channels. The model predictions show large discrepancies among each other and the present data will provide much tighter constraints. This is demonstrated by the results of a new analysis in the framework of the Bonn-Gatchina coupled-channel analysis which included the present data.Comment: accepted for publication in Phys; Rev. Let

    Measurements of double-polarized compton scattering asymmetries and extraction of the proton spin polarizabilities

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    The spin polarizabilities of the nucleon describe how the spin of the nucleon responds to an incident polarized photon. The most model-independent way to extract the nucleon spin polarizabilities is through polarized Compton scattering. Double-polarized Compton scattering asymmetries on the proton were measured in the Δ(1232) region using circularly polarized incident photons and a transversely polarized proton target at the Mainz Microtron. Fits to asymmetry data were performed using a dispersion model calculation and a baryon chiral perturbation theory calculation, and a separation of all four proton spin polarizabilities in the multipole basis was achieved. The analysis based on a dispersion model calculation yields γE1E1=−3.5±1.2, γM1M1=3.16±0.85, γE1M2=−0.7±1.2, and γM1E2=1.99±0.29, in units of 10−4  fm4

    Measurement of pi^0 photoproduction on the proton at MAMI C

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    Differential cross sections for the gamma p -> pi^0 p reaction have been measured with the A2 tagged-photon facilities at the Mainz Microtron, MAMI C, up to the center-of-mass energy W=1.9 GeV. The new results, obtained with a fine energy and angular binning, increase the existing quantity of pi^0 photoproduction data by ~47%. Owing to the unprecedented statistical accuracy and the full angular coverage, the results are sensitive to high partial-wave amplitudes. This is demonstrated by the decomposition of the differential cross sections in terms of Legendre polynomials and by further comparison to model predictions. A new solution of the SAID partial-wave analysis obtained after adding the new data into the fit is presented.Comment: 13 pages, 12 figures, 1 tabl

    Helicity-dependent cross sections and double-polarization observable E in η photoproduction from quasifree protons and neutrons

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    Precise helicity-dependent cross sections and the double-polarization observable E were measured for η photoproduction from quasifree protons and neutrons bound in the deuteron. The η → 2γ and η → 3π0 → 6γ decay modes were used to optimize the statistical quality of the data and to estimate systematic uncertainties. The measurement used the A2 detector setup at the tagged photon beam of the electron accelerator MAMI in Mainz. A longitudinally polarized deuterated butanol target was used in combination with a circularly polarized photon beam from bremsstrahlung of a longitudinally polarized electron beam. The reaction products were detected with the electromagnetic calorimeters Crystal Ball and TAPS, which covered 98% of the full solid angle. The results show that the narrow structure observed earlier in the unpolarized excitation function of η photoproduction off the neutron appears only in reactions with antiparallel photon and nucleon spin (σ1/2). It is absent for reactions with parallel spin orientation (σ3/2) and thus very probably related to partial waves with total spin 1/2. The behavior of the angular distributions of the helicity-dependent cross sections was analyzed by fitting them with Legendre polynomials. The results are in good agreement with a model from the Bonn-Gatchina group, which uses an interference of P11 and S11 partial waves to explain the narrow structure

    Factors related with symptom duration until diagnosis and treatment of symptomatic colorectal cancer

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    BACKGROUND: Colorectal cancer (CRC) survival depends mostly on stage at the time of diagnosis. However, symptom duration at diagnosis or treatment have also been considered as predictors of stage and survival. This study was designed to: 1) establish the distinct time-symptom duration intervals; 2) identify factors associated with symptom duration until diagnosis and treatment. METHODS: This is a cross-sectional study of all incident cases of symptomatic CRC during 2006–2009 (795 incident cases) in 5 Spanish regions. Data were obtained from patients’ interviews and reviews of primary care and hospital clinical records. Measurements: CRC symptoms, symptom perception, trust in the general practitioner (GP), primary care and hospital examinations/visits before diagnosis, type of referral and tumor characteristics at diagnosis. Symptom Diagnosis Interval (SDI) was calculated as time from first CRC symptoms to date of diagnosis. Symptom Treatment Interval (STI) was defined as time from first CRC symptoms until start of treatment. Nonparametric tests were used to compare SDI and STI according to different variables. RESULTS: Symptom to diagnosis interval for CRC was 128 days and symptom treatment interval was 155. No statistically significant differences were observed between colon and rectum cancers. Women experienced longer intervals than men. Symptom presentation such as vomiting or abdominal pain and the presence of obstruction led to shorter diagnostic or treatment intervals. Time elapsed was also shorter in those patients that perceived their first symptom/s as serious, disclosed it to their acquaintances, contacted emergencies services or had trust in their GPs. Primary care and hospital doctor examinations and investigations appeared to be related to time elapsed to diagnosis or treatment. CONCLUSIONS: Results show that gender, symptom perception and help-seeking behaviour are the main patient factors related to interval duration. Health service performance also has a very important role in symptom to diagnosis and treatment interval. If time to diagnosis is to be reduced, interventions and guidelines must be developed to ensure appropriate examination and diagnosis during both primary and hospital care

    Photoproduction of ηπ pairs off nucleons and deuterons

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    Quasi-free photoproduction of πηπη -pairs has been investigated from threshold up to incident photon energies of 1.4 GeV, respectively up to photon-nucleon invariant masses up to 1.9 GeV. Total cross sections, angular distributions, invariant-mass distributions of the πηπη and meson-nucleon pairs, and beam-helicity asymmetries have been measured for the reactions γp→pπ0ηγp→pπ0η , γn→nπ0ηγn→nπ0η , γp→nπ+ηγp→nπ+η , and γn→pπ−ηγn→pπ−η from nucleons bound inside the deuteron. For the γpγp initial-state data for free protons have also been analyzed. Finally, the total cross sections for quasi-free production of π0ηπ0η pairs from nucleons bound in 3 He nuclei have been investigated in view of final state interaction (FSI) effects. The experiments were performed at the tagged photon beam facility of the Mainz MAMI accelerator using an almost 4 ππ covering electromagnetic calorimeter composed of the Crystal Ball and TAPS detectors. The shapes of all differential cross section data and the asymmetries are very similar for protons and neutrons and agree with the conjecture that the reactions are dominated by the sequential Δ⋆3/2−→ηΔ(1232)→πηNΔ⋆3/2−→ηΔ(1232)→πηN decay chain, mainly with Δ(1700)3/2−Δ(1700)3/2− and Δ(1940)3/2−Δ(1940)3/2− . The ratios of the magnitude of the total cross sections also agree with this assumption. However, the absolute magnitudes of the cross sections are reduced by FSI effects with respect to fre
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