1,114 research outputs found

    Phase 2 Neoadjuvant Treatment Intensification Trials in Rectal Cancer: A Systematic Review

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    Purpose: Multiple phase 2 trials of neoadjuvant treatment intensification in locally advanced rectal cancer have reported promising efficacy signals, but these have not translated into improved cancer outcomes in phase 3 trials. Improvements in phase 2 trial design are needed to reduce these false-positive signals. This systematic review evaluated the design of phase 2 trials of neoadjuvant long-course radiation or chemoradiation therapy treatment intensification in locally advanced rectal cancer. Methods and Materials: The PubMed, EMBASE, MEDLINE, and Cochrane Library databases were searched for published phase 2 trials of neoadjuvant treatment intensification from 2004 to 2016. Trial clinical design and outcomes were assessed, with statistical design and compliance rated using a previously published system. Multivariable meta-regression analysis of pathologic complete response (pCR) was conducted. Results: We identified 92 eligible trials. Patients with American Joint Committee on Cancer stage II and III equivalent disease were eligible in 87 trials (94.6%). In 43 trials (46.7%), local staging on magnetic resonance imaging was mandated. Only 12 trials (13.0%) were randomized, with 8 having a standard-treatment control arm. Just 51 trials (55.4%) described their statistical design, with 21 trials (22.8%) failing to report their sample size derivation. Most trials (n=84, 91.3%) defined a primary endpoint, but 15 different primary endpoints were used. All trials reported pCR rates. Only 38 trials (41.3%) adequately reported trial statistical design and compliance. Meta-analysis revealed a pooled pCR rate of 17.5% (95% confidence interval, 15.7%-19.4%) across treatment arms of neoadjuvant long-course radiation or chemoradiation therapy treatment intensification and substantial heterogeneity among the reported effect sizes (I2 = 55.3%, P<.001). Multivariable meta-regression analysis suggested increased pCR rates with higher radiation therapy doses (adjusted P=.025). Conclusions: Improvement in the design of future phase 2 rectal cancer trials is urgently required. A significant increase in randomized trials is essential to overcome selection bias and determine novel schedules suitable for phase 3 testing. This systematic review provides key recommendations to guide future treatment intensification trial design in rectal cancer

    Measurement of the Higgs boson inclusive and differential fiducial production cross sections in the diphoton decay channel with pp collisions at s \sqrt{s} = 13 TeV

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    The measurements of the inclusive and differential fiducial cross sections of the Higgs boson decaying to a pair of photons are presented. The analysis is performed using proton-proton collisions data recorded with the CMS detector at the LHC at a centre-of-mass energy of 13 TeV and corresponding to an integrated luminosity of 137 fb−1^{−1}. The inclusive fiducial cross section is measured to be σfidσ_{fid}=73.4−5.3+5.4^{+5.4}_{−5.3}(stat)−2.2+2.4^{+2.4}_{−2.2}(syst) fb, in agreement with the standard model expectation of 75.4 ± 4.1 fb. The measurements are also performed in fiducial regions targeting different production modes and as function of several observables describing the diphoton system, the number of additional jets present in the event, and other kinematic observables. Two double differential measurements are performed. No significant deviations from the standard model expectations are observed

    Measurement of the B0^{0}s_{s} → ÎŒ+^{+} Ό−^{-} decay properties and search for the B0^{0} → ÎŒ+^{+}Ό−^{-} decay in proton-proton collisions at √s = 13 TeV

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    Search for top squarks in the four-body decay mode with single lepton final states in proton-proton collisions at s \sqrt{s} = 13 TeV

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    A search for the pair production of the lightest supersymmetric partner of the top quark, the top squark (t∌1), is presented. The search targets the four-body decay of the t∌1, which is preferred when the mass difference between the top squark and the lightest supersymmetric particle is smaller than the mass of the W boson. This decay mode consists of a bottom quark, two other fermions, and the lightest neutralino (χ∌01), which is assumed to be the lightest supersymmetric particle. The data correspond to an integrated luminosity of 138 fb−1 of proton-proton collisions at a center-of-mass energy of 13 TeV collected by the CMS experiment at the CERN LHC. Events are selected using the presence of a high-momentum jet, an electron or muon with low transverse momentum, and a significant missing transverse momentum. The signal is selected based on a multivariate approach that is optimized for the difference between m(t∌1) and m(χ∌01). The contribution from leading background processes is estimated from data. No significant excess is observed above the expectation from standard model processes. The results of this search exclude top squarks at 95% confidence level for masses up to 480 and 700 GeV for m(t∌1) − m(χ∌01) = 10 and 80 GeV, respectively

    Search for Higgs Boson Decay to a Charm Quark-Antiquark Pair in Proton-Proton Collisions at √s = 13 TeV

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    A search for the standard model Higgs boson decaying to a charm quark-antiquark pair, H→cÂŻc, produced in association with a leptonically decaying V (W or Z) boson is presented. The search is performed with proton-proton collisions at √s=13  TeV collected by the CMS experiment, corresponding to an integrated luminosity of 138  fb−1. Novel charm jet identification and analysis methods using machine learning techniques are employed. The analysis is validated by searching for Z→cÂŻc in VZ events, leading to its first observation at a hadron collider with a significance of 5.7 standard deviations. The observed (expected) upper limit on σ(VH)B(H→cÂŻc) is 0.94 (0.50+0.22−0.15)pb at 95% confidence level (C.L.), corresponding to 14 (7.6+3.4−2.3) times the standard model prediction. For the Higgs-charm Yukawa coupling modifier, Îșc, the observed (expected) 95% C.L. interval is 1.1<|Îșc|<5.5 (|Îșc|<3.4), the most stringent constraint to date

    Measurement of the cross section of top quark-antiquark pair production in association with a W boson in proton-proton collisions at s \sqrt{s} = 13 TeV

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    The production of a top quark-antiquark pair in association with a W boson (ttˉW)(t\bar{t}W) is measured in proton-proton collisions at a center-of-mass energy of 13 TeV. The analyzed data was recorded by the CMS experiment at the CERN LHC and corresponds to an integrated luminosity of 138 fb−1^{−1}. Events with two or three leptons (electrons and muons) and additional jets are selected. In events with two leptons, a multiclass neural network is used to distinguish between the signal and background processes. Events with three leptons are categorized based on the number of jets and of jets originating from b quark hadronization, and the lepton charges. The inclusive (ttˉW)(t\bar{t}W) production cross section in the full phase space is measured to be 868 ± 40(stat) ± 51(syst) fb. The (ttˉW)+(t\bar{t}W)+ and (ttˉW)−(t\bar{t}W)− cross sections are also measured as 553 ± 30(stat) ± 30(syst) and 343 ± 26(stat) ± 25(syst) fb, respectively, and the corresponding ratio of the two cross sections is found to be 1.61±0.15(stat)−0.05+0.07^{+0.07}_{−0.05}(syst). The measured cross sections are larger than but consistent with the standard model predictions within two standard deviations, and represent the most precise measurement of these cross sections to date

    Measurement of the Dependence of the Hadron Production Fraction Ratios fs/fuf_s / f_u and fd/fuf_d / f_u on BB Meson Kinematic Variables in Proton-Proton Collisions at s=13TeV\sqrt{s} = 13 TeV

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    The dependence of the ratio between the Bs0B^0_s and B+B^+ hadron production fractions, fs/fuf_s/f_u, on the transverse momentum (pT)(p_T) and rapidity of the BB mesons is studied using the decay channels Bs0→J/ψϕB^0_s→J/ψϕ and B+→J/ψK+B^+→J/ψK^+. The analysis uses a data sample of proton-proton collisions at a center-of-mass energy of 13 TeV, collected by the CMS experiment in 2018 and corresponding to an integrated luminosity of 61.6  fb−161.6  fb^{−1}. The fs/fuf_s/f_u ratio is observed to depend on the BB pTp_T and to be consistent with becoming asymptotically constant at large pTp_T. No rapidity dependence is observed. The ratio of the B0B^0 to B+B^+ meson production fractions, fd/fuf_d/f_u, is also measured, for the first time in proton-proton collisions, using the B0→J/ψK∗0B^0→J/ψK^{*0} decay channel. The result is found to be within 1 standard deviation of unity and independent of pTpT and rapidity, as expected from isospin invariance

    Search for top squark pair production in a final state with at least one hadronically decaying tau lepton in proton-proton collisions at s \sqrt{s} = 13 TeV

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    Search for high-mass exclusive γγ → WW and γγ → ZZ production in proton-proton collisions at s \sqrt{s} = 13 TeV

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