Polyunsaturated fatty acids and risk of melanoma: A Mendelian randomisation analysis

Melanoma is the deadliest form of skin cancer, mainly affecting populations of European ancestry. Some observational studies suggest that particular diets reduce melanoma risk, putatively through an increase in polyunsaturated fatty acid (PUFA) consumption. However, interpretation of these observational findings is difficult due to residual confounding or reverse causality. To date, a randomized controlled trial has not been carried out to examine the relationship between PUFAs and melanoma. Hence, we performed a Mendelian randomisation (MR) study to evaluate the link between PUFAs and melanoma. To perform MR, we used summary results from the largest risk genome‐wide association study (GWAS) meta‐analysis of melanoma, consisting of 12,874 cases and 23,203 controls. As instrumental variables we selected SNPs associated with PUFA levels from a GWAS meta‐analysis of PUFA levels, from the CHARGE consortium. We used the inverse variance weighted method to estimate a causal odds ratio. To aid interpretation, we established a benchmark “large” predicted change in PUFAs in which, for example, an increase in docosahexaenoic acid (DPA) of 0.17 units (equal to 1 standard deviation) moves a person from the 17th percentile to the median. Raising PUFA levels by a large amount (increasing DPA by 0.17 units) only negligibly changed melanoma risk: odds ratio [OR] = 1.03 (95% confidence interval [CI] = 0.96–1.10). Other PUFAs yielded similar results as DPA. Our MR analysis suggests that the effect of PUFA levels on melanoma risk is either zero or very small

Is there a causal relationship between vitamin D and melanoma risk? : A Mendelian randomization study.

BACKGROUND: Several pre-clinical studies have identified the anti-proliferative effects of 25-hydroxyvitamin D (25(OH) D; vitamin D). Ultraviolet radiation (UVR) is essential for vitamin D synthesis yet increases the risk of melanoma. Observational studies on the association of vitamin D levels with melanoma risk have reported inconclusive results, and are difficult to interpret due to the potential confounding from the dual role of UVR. OBJECTIVES: Our objective was to determine whether there is a causal association between genetically predicted 25(OH) D concentrations and melanoma using a Mendelian randomization (MR) approach. METHODS: We performed MR using summary data from a large genome-wide association study (GWAS) meta-analysis of melanoma risk, consisting of 12,874 cases and 23,203 controls. Five SNPs that are associated with 25(OH) D concentration rs12785878, rs10741657, rs2282679, rs6013897 and rs116970203 were selected as instrumental variables (IVs). Inverse variance weighted method was used to access the evidence for causality. MR results from the melanoma meta-analysis were combined with results from an MR study based on a melanoma risk GWAS using UK Biobank data. RESULTS: A 20 nmol/L decrease in 25(OH) D was not associated with melanoma risk (OR = 1.06, 95% CI = 0.94 - 1.19). Results from the UK Biobank were concordant with this, with meta-analysis of our and UK Biobank derived MR causal estimates showing no association (OR = 1.02, 95% CI = 0.92 - 1.13 for a 20nmol/L decrease). CONCLUSIONS: Our study results suggest that the genetically vitamin D levels may not be causally associated with the risk of melanoma. This article is protected by copyright. All rights reserved

Search for narrow resonances in the b-tagged dijet mass spectrum in proton-proton collisions at 1as=13 TeV

Abstract: A search is performed for narrow resonances decaying to final states of two jets, with at least one jet ffiffioriginating from a b quark, in proton-proton collisions at p s = 13 TeV. The data set corresponds to an integrated luminosity of 138 fb-1 collected with the CMS detector at the LHC. Jets originating from energetic b hadrons are identified through a b-tagging algorithm that utilizes a deep neural network or the presence of a muon inside a jet. The invariant mass spectrum of jet pairs is well described by a smooth parametrization and no evidence for the production of new particles is observed. Upper limits on the production cross section are set for excited b quarks and other resonances decaying to dijet final states containing b quarks. These limits exclude at 95% confidence level models of Z' bosons with masses from 1.8 TeV to 2.4 TeV and of excited b quarks with masses from 1.8 TeV to 4.0 TeV. This is the most stringent exclusion of excited b quarks to date

Measurements of inclusive and differential cross sections for the Higgs boson production and decay to four-leptons in proton-proton collisions at 1as=13 TeV

Abstract: Measurements of the inclusive and differential fiducial cross sections for the Higgs boson production in the H -> ZZ -> 4 l ( l = e, mu) decay channel are presented. The results are obtained from the analysis of proton-proton collision data recorded by the CMS experiment at the CERN LHC at a center-of-mass energy of 13TeV, corresponding to an integrated luminosity of 138 fb(-1). The measured inclusive fiducial cross section is 2.73 +/- 0.26 fb, in agreement with the standard model expectation of 2.86 +/- 0.1 fb. Differential cross sections are measured as a function of several kinematic observables sensitive to the Higgs boson production and decay to four leptons. A set of double-differential measurements is also performed, yielding a comprehensive characterization of the four leptons final state. Constraints on the Higgs boson trilinear coupling and on the bottom and charm quark coupling modifiers are derived from its transverse momentum distribution. All results are consistent with theoretical predictions from the standard model

Search for Higgs boson pairs decaying to WW*WW*, WW*\u3c4\u3c4, and \u3c4\u3c4\u3c4\u3c4 in proton-proton collisions at 1as =13 TeV

Abstract: The results of a search for Higgs boson pair (HH) production in the (WWWW*)-W-*, WW*tau tau, and tau tau tau tau decay modes are presented. The search uses 138 fb(-1) of proton-proton collision data recorded by the CMS experiment at the LHC at a center-of-mass energy of 13 TeV from 2016 to 2018. Analyzed events contain two, three, or four reconstructed leptons, including electrons, muons, and hadronically decaying tau leptons. No evidence for a signal is found in the data. Upper limits are set on the cross section for nonresonant HH production, as well as resonant production in which a new heavy particle decays to a pair of Higgs bosons. For nonresonant production, the observed (expected) upper limit on the cross section at 95% confidence level (CL) is 21.3 (19.4) times the standard model (SM) prediction. The observed (expected) ratio of the trilinear Higgs boson self-coupling to its value in the SM is constrained to be within the interval -6.9 to 11.1 (-6.9 to 11.7) at 95% CL, and limits are set on a variety of new-physics models using an effective field theory approach. The observed (expected) limits on the cross section for resonant HH production range from 0.18 to 0.90 (0.08 to 1.06) pb at 95% CL for new heavy-particle masses in the range 250-1000 GeV