The melanoma-specific graded prognostic assessment does not adequately discriminate prognosis in a modern population with brain metastases from malignant melanoma

The melanoma-specific graded prognostic assessment (msGPA) assigns patients with brain metastases from malignant melanoma to 1 of 4 prognostic groups. It was largely derived using clinical data from patients treated in the era that preceded the development of newer therapies such as BRAF, MEK and immune checkpoint inhibitors. Therefore, its current relevance to patients diagnosed with brain metastases from malignant melanoma is unclear. This study is an external validation of the msGPA in two temporally distinct British populations.Performance of the msGPA was assessed in Cohort I (1997-2008, n=231) and Cohort II (2008-2013, n=162) using Kaplan-Meier methods and Harrell's c-index of concordance. Cox regression was used to explore additional factors that may have prognostic relevance.The msGPA does not perform well as a prognostic score outside of the derivation cohort, with suboptimal statistical calibration and discrimination, particularly in those patients with an intermediate prognosis. Extra-cerebral metastases, leptomeningeal disease, age and potential use of novel targeted agents after brain metastases are diagnosed, should be incorporated into future prognostic models.An improved prognostic score is required to underpin high-quality randomised controlled trials in an area with a wide disparity in clinical care

Eta photoproduction on the neutron at GRAAL: Measurement of the differential cross section

In this contribution, we will present our first preliminary measurement of the differential cross section for the reaction gamma+n->eta+n. Comparison of the reactions gamma+p->eta+p for free and bound proton (D2 target) will also be discussed.Comment: 6 pages, 4 figures, Proceedings of the 10th International Symposium on Meson-Nucleon Physics and the Structure of the Nucleon, August 29-September 4 2004, Beijing, Chin

Eta photoproduction off the neutron at GRAAL: Evidence for a resonant structure at W=1.67 GeV

New (preliminary) data on eta photoproduction off the neutron are presented. These data reveal a resonant structure at W=1.67 GeV.Comment: 8 pages, 4 figures. Published in Proceedings of Workshop on the Physics of Excited Nucleons NSTAR2004, Grenoble, France, March 24 - 27, pg.19

Eta photoproduction off the neutron at GRAAL

The gamma n -> eta n quasi-free cross section reveals a resonant structure at W ~ 1.675 GeV. This structure may be a manifestation of a baryon resonance. A priori its properties, the possibly narrow width and the strong photocoupling to the neutron, look surprising. This structure may also signal the existence of a narrow state.Comment: To appear in Proceedings of Workshop on the Physics of Excited Nucleons NSTAR2005, 12 - 15 October 2005, Tallahassee, Florida, US

Lowering the Light Speed Isotropy Limit: European Synchrotron Radiation Facility Measurements

The measurement of the Compton edge of the scattered electrons in GRAAL facility in European Synchrotron Radiation Facility (ESRF) in Grenoble with respect to the Cosmic Microwave Background dipole reveals up to 10 sigma variations larger than the statistical errors. We now show that the variations are not due to the frequency variations of the accelerator. The nature of Compton edge variations remains unclear, thus outlining the imperative of dedicated studies of light speed anisotropy

A new limit on the light speed isotropy from the GRAAL experiment at the ESRF

When the electrons stored in the ring of the European Synchrotron Radiation Facility (ESRF, Grenoble) scatter on a laser beam (Compton scattering in flight) the lower energy of the scattered electron spectra, the Compton Edge (CE), is given by the two body photon-electron relativistic kinematics and depends on the velocity of light. A precision measurement of the position of this CE as a function of the daily variations of the direction of the electron beam in an absolute reference frame provides a one-way test of Relativistic Kinematics and the isotropy of the velocity of light. The results of GRAAL-ESRF measurements improve the previously existing one-way limits, thus showing the efficiency of this method and the interest of further studies in this direction.Comment: Proceed. MG12 meeting, Paris, July, 200

Estimating survival in patients with gastrointestinal cancers and brain metastases: An update of the graded prognostic assessment for gastrointestinal cancers (GI-GPA).

BackgroundPatients with gastrointestinal cancers and brain metastases (BM) represent a unique and heterogeneous population. Our group previously published the Diagnosis-Specific Graded Prognostic Assessment (DS-GPA) for patients with GI cancers (GI-GPA) (1985-2007, n = 209). The purpose of this study is to update the GI-GPA based on a larger contemporary database.MethodsAn IRB-approved consortium database analysis was performed using a multi-institutional (18), multi-national (3) cohort of 792 patients with gastrointestinal (GI) cancers, with newly-diagnosed BM diagnosed between 1/1/2006 and 12/31/2017. Survival was measured from date of first treatment for BM. Multiple Cox regression was used to select and weight prognostic factors in proportion to their hazard ratios. These factors were incorporated into the updated GI-GPA.ResultsMedian survival (MS) varied widely by primary site and other prognostic factors. Four significant factors (KPS, age, extracranial metastases and number of BM) were used to formulate the updated GI-GPA. Overall MS for this cohort remains poor; 8 months. MS by GPA was 3, 7, 11 and 17 months for GPA 0-1, 1.5-2, 2.5-3.0 and 3.5-4.0, respectively. >30% present in the worst prognostic group (GI-GPA of ≤1.0).ConclusionsBrain metastases are not uncommon in GI cancer patients and MS varies widely among them. This updated GI-GPA index improves our ability to estimate survival for these patients and will be useful for therapy selection, end-of-life decision-making and stratification for future clinical trials. A user-friendly, free, on-line app to calculate the GPA score and estimate survival for an individual patient is available at brainmetgpa.com

Limits on light-speed anisotropies from Compton scattering of high-energy electrons

The possibility of anisotropies in the speed of light relative to the limiting speed of electrons is considered. The absence of sidereal variations in the energy of Compton-edge photons at the ESRF's GRAAL facility constrains such anisotropies representing the first non-threshold collision-kinematics study of Lorentz violation. When interpreted within the minimal Standard-Model Extension, this result yields the two-sided limit of 1.6 x 10^{-14} at 95% confidence level on a combination of the parity-violating photon and electron coefficients kappa_{o+} and c. This new constraint provides an improvement over previous bounds by one order of magnitude.Comment: 4 pages, 4 figure

Precise Measurement of Sigma Beam Asymmetry for Positive Pion Photoproduction on the Proton from 800 to 1500 Mev

The Sigma beam asymmetry for positive pion photoproduction on the proton has been measured over an angular range of 40-170 deg at photon energies from 0.8 to 1.5 GeV. The resulting data set includes 237 accurate points, 136 of these belonging to an almost unexplored domain above 1.05 GeV. Data of such high precision provide severe constraints for partial wave analyses. The influence of this experiment on the GW multipole analysis is demonstrated. Significant changes are found in multipoles connected to the S31(1620) and P13(1720) resonances. Comparisons using the MAID analysis are also presented.Comment: 11 pages, 4 eps figures. to be published in Physics Letters

Differential cross section measurement of eta photoproduction on the proton from threshold to 1100 MeV

The differential cross section for the reaction p(gamma, eta p) has been measured from threshold to 1100 MeV photon laboratory energy. For the first time, the region of the S11(1535) resonance is fully covered in a photoproduction experiment and allows a precise extraction of its parameters at the photon point. Above 1000 MeV, S-wave dominance vanishes while a P-wave contribution is observed whose nature will have to be clarified. These high precision data together with the already measured beam asymmetry data will provide stringent constraints on the extraction of new couplings of baryon resonances to the eta meson.Comment: 10 pages, 5 figures, submitted to Phys. Letters B. Typos corrected. Some more information on the S11(1535) parameter