The global burden of adolescent and young adult cancer in 2019 : a systematic analysis for the Global Burden of Disease Study 2019

Background In estimating the global burden of cancer, adolescents and young adults with cancer are often overlooked, despite being a distinct subgroup with unique epidemiology, clinical care needs, and societal impact. Comprehensive estimates of the global cancer burden in adolescents and young adults (aged 15-39 years) are lacking. To address this gap, we analysed results from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019, with a focus on the outcome of disability-adjusted life-years (DALYs), to inform global cancer control measures in adolescents and young adults. Methods Using the GBD 2019 methodology, international mortality data were collected from vital registration systems, verbal autopsies, and population-based cancer registry inputs modelled with mortality-to-incidence ratios (MIRs). Incidence was computed with mortality estimates and corresponding MIRs. Prevalence estimates were calculated using modelled survival and multiplied by disability weights to obtain years lived with disability (YLDs). Years of life lost (YLLs) were calculated as age-specific cancer deaths multiplied by the standard life expectancy at the age of death. The main outcome was DALYs (the sum of YLLs and YLDs). Estimates were presented globally and by Socio-demographic Index (SDI) quintiles (countries ranked and divided into five equal SDI groups), and all estimates were presented with corresponding 95% uncertainty intervals (UIs). For this analysis, we used the age range of 15-39 years to define adolescents and young adults. Findings There were 1.19 million (95% UI 1.11-1.28) incident cancer cases and 396 000 (370 000-425 000) deaths due to cancer among people aged 15-39 years worldwide in 2019. The highest age-standardised incidence rates occurred in high SDI (59.6 [54.5-65.7] per 100 000 person-years) and high-middle SDI countries (53.2 [48.8-57.9] per 100 000 person-years), while the highest age-standardised mortality rates were in low-middle SDI (14.2 [12.9-15.6] per 100 000 person-years) and middle SDI (13.6 [12.6-14.8] per 100 000 person-years) countries. In 2019, adolescent and young adult cancers contributed 23.5 million (21.9-25.2) DALYs to the global burden of disease, of which 2.7% (1.9-3.6) came from YLDs and 97.3% (96.4-98.1) from YLLs. Cancer was the fourth leading cause of death and tenth leading cause of DALYs in adolescents and young adults globally. Interpretation Adolescent and young adult cancers contributed substantially to the overall adolescent and young adult disease burden globally in 2019. These results provide new insights into the distribution and magnitude of the adolescent and young adult cancer burden around the world. With notable differences observed across SDI settings, these estimates can inform global and country-level cancer control efforts. Copyright (C) 2021 The Author(s). Published by Elsevier Ltd.Peer reviewe

Zeeman perturbed spin echo FT-NQR spectroscopy

An approach for the evaluation of the asymmetry parameter, η, of the electric field gradient tensor for spin I = 3 2 systems from Zeeman NQR spectroscopy of polycrystalline samples is presented. The method relies on Fourier transformation of the second half of the Zeeman-perturbed Hahn spin-echo signal, generated via a two-pulse excitation sequence. Suitable phase cycling of the RF pulses of the spin-echo sequence has been derived and implemented, for the first time in NQR spectroscopy, to retain only the echo component in the detected signal. The RF pulse phase-cycling scheme employed in this work permits the extraction of the parameters of interest with improved sensitivity. A numerical procedure for simulating the powder Zeeman spin-echo FT NQR spectra is also given. A comparison of the theoretically simulated spin-echo spectrum with that recorded experimentally is shown to permit the evaluation of η. The method has been successfully demonstrated for the two 35Cl sites in 2,4,6-trichloro-1,3,5-triazine ("cyanuric chloride")

Measurement of the tensor-asymmetry parameter of the electric-field gradient for spin-3/2 nuclei in polycrystalline specimens via Zeeman FT NQR spectroscopy

A knowledge of vQ alone is insufficient to independently determine the two structural parameters of interest, namely the nuclear quadrupole coupling constant e*qQ and the electric-field-gradient tensor-asymmetry parameter 1. Different approaches, with varying degrees of utility, have been presented in the literature (2-12) for obtaining these parameters. In situations where a highly homogeneous RF field of appreciable strength is available over the entire sample volume, Harbison et al. ( 11, 12) have recently demonstrated the elucidation of 4 from an analysis of the two-dimensional zero-field nutation NQR spectral data. Alternatively, when the inhomogeneous NQR linewidth is not very large, a simpler one-dimensional approach for the extraction of 17 involves the application of a Zeeman perturbation to lift the degeneracy of the quadrupole energy levels and a subsequent analysis of the Zeeman spectra (2-9). The signal-to-noise ratios encountered in the Zeeman NQR investigations of polycrystalline materials are often very low and signal averaging is a prerequisite for obtaining highfidelity spectral lineshape. Because of the higher sensitivity and ease with which longterm signal averaging can be effected, transient rather than steady-state techniques are obviously the method of choice for 7 determination. However, in the analysis of the Zeeman FT NQR spectra, one must take into consideration factors such as the receiver dead time and the strength of the RF field in relation to the magnitude of the Zeeman field and the resonance offset