Twelve-month observational study of children with cancer in 41 countries during the COVID-19 pandemic

Introduction Childhood cancer is a leading cause of death. It is unclear whether the COVID-19 pandemic has impacted childhood cancer mortality. In this study, we aimed to establish all-cause mortality rates for childhood cancers during the COVID-19 pandemic and determine the factors associated with mortality. Methods Prospective cohort study in 109 institutions in 41 countries. Inclusion criteria: children <18 years who were newly diagnosed with or undergoing active treatment for acute lymphoblastic leukaemia, non-Hodgkin's lymphoma, Hodgkin lymphoma, retinoblastoma, Wilms tumour, glioma, osteosarcoma, Ewing sarcoma, rhabdomyosarcoma, medulloblastoma and neuroblastoma. Of 2327 cases, 2118 patients were included in the study. The primary outcome measure was all-cause mortality at 30 days, 90 days and 12 months. Results All-cause mortality was 3.4% (n=71/2084) at 30-day follow-up, 5.7% (n=113/1969) at 90-day follow-up and 13.0% (n=206/1581) at 12-month follow-up. The median time from diagnosis to multidisciplinary team (MDT) plan was longest in low-income countries (7 days, IQR 3-11). Multivariable analysis revealed several factors associated with 12-month mortality, including low-income (OR 6.99 (95% CI 2.49 to 19.68); p<0.001), lower middle income (OR 3.32 (95% CI 1.96 to 5.61); p<0.001) and upper middle income (OR 3.49 (95% CI 2.02 to 6.03); p<0.001) country status and chemotherapy (OR 0.55 (95% CI 0.36 to 0.86); p=0.008) and immunotherapy (OR 0.27 (95% CI 0.08 to 0.91); p=0.035) within 30 days from MDT plan. Multivariable analysis revealed laboratory-confirmed SARS-CoV-2 infection (OR 5.33 (95% CI 1.19 to 23.84); p=0.029) was associated with 30-day mortality. Conclusions Children with cancer are more likely to die within 30 days if infected with SARS-CoV-2. However, timely treatment reduced odds of death. This report provides crucial information to balance the benefits of providing anticancer therapy against the risks of SARS-CoV-2 infection in children with cancer

دراسة بتروجرافية وكيميائية لصخور الدولوميت غير المتجانس الواحات البحرية - مصر

Dolomite samples from the lower member of the El-Hafhuf Formation (Turonian-Santonian) possess noticeable petrographic and chemical heterogeneity among their fabric components. Petrographically, the study samples can be subdivided into three types of dolomite: 1) main dolomite intraclasts embedded in 2) dolomite matrix and bounded by 3) laminated dolomite. Dolomite intraclasts are the more stoichiometric having 8I8O values that range from (-0.5 to -3.2%o PDB) and enriched 8I3C signatures (+2.0 to +6.0%o PDB). They possess nonplanar crystal boundaries and polymodal crystal size distributions. The dolomite matrix shows the lowest Sr2+ (av. 80 ppm) and Na+(av. 320 ppm) values and the highest Mn2+ (av. 1150 ppm) content. They exhibit narrow5I8O and 8I3C ranges (-3.5 to -4.7 and 0.0 to -1.8%o PDB, respectively). Crystals comprising this matrix have dominantly euhedral planar forms possessing polymodal distribution. Laminated dolomites exhibit the highest Sr2+ (av. 230 ppm) and Na+ (av. 470 ppm) values and depleted SI8O (-5.1 to -6.4%o PDB) and 5I3C (-2.5 to -5.\%o PDB) signatures. Their crystal boundaries are nonplanar while crystal size distribution is polymodal. Such petrographic and chemical heterogeneity among the investigated dolomite types within the studied samples are related primarily to the variable origins of these dolomites and their diagenetic stabilization pathways.أوضحت دراسة صخور الدولوميت للعضو السفلي بمتكون الحفوف وجود عدم . تجانس في الخواص الصخرية والجيوكيميائية ، وقد بينت الدراسة البتروجرافية أن صخر الدولوميت يشتمل على ثلاثة أنواع هي : . 1 ‏- فتات الدولوميت الأساسي 2. أرضية دولوميتية 3‏- دولوميت رقائقي ‏وتتميز هذه الأنواع بوجود تفاوت في محتوى نظائر الاكسجين والكربون المستقر وكذلك في نسبة تواجد العناصر الرئيسية ( كالسيوم - ماغنسيوم - حديد ) والعناصر الشحيحة (استرانشيوم - صوديوم - منجنيز) . ويعزى هذا الاختلاف في التركيب الصخري والكيميائي لأنواع الدولوميت سالفة الذكر إلى اختلاف نشأتها الأولية وكذلك اختلاف الظروف الثانوية التي أثرت عليها وأدت إلى وجودها في حالة ثبات

التقييم المعدني والجيوكيميائي لصخور الطفلة السوداء بعصر الطباشيري العلوي في سفاجا بمصر

Lithologic and compositional properties of black shale and pyrite from the Upper Cretaceous phosphorite/black shale deposits (Duwi Formation) of Eastern Desert of Egypt indicate similarity in mineralogy, geochemical characters and carbon isotopic ratios with those inferred for modern organic-carbon-rich sediments. Components of the black shale include various clay minerals, silt(grade quartz, organic matter, pyrite, calcareous foraminifera shells and phosphatic nodules. The clay mineralogy of the black shale does not differ significantly from typical Cretaceous black shale (dominance of smectite and illite with minor amounts of kaolinite and chlorite). The trace-element concentrations (Zn, Cu, Ni, Co, U and Pb) show a general enrichment pattern and seem to correlate with enrichment of organic matter. The stable carbon-isotope cratios (from- 22% to - 28.7 %) suggest that the organic matter is of continental and marine origin. The relationship between the total organic carbon and sulfur contents of black shale samples is similar to that of marine sediments, but the pyrite content is probably controlled by the Fe +contents.بدراسة الخصائص الصخرية والتركيبية لصخور الطفلة السوداء والبريت (متكون حنوى) بالصحراء الشرقية – مصر وجد أن تركيبها المعدني والجيوكيميائي وكذلك نسبة نظائر الكربون المستقرة بهذه الصخور مثابه لمثيلتها من الرواسب الحديثة الغنية بالمواد العضوية . حيث أن الطفلة السوداء تحتوي علي المكونات التالية : معادن طينية ، كوارتز ، مواد عضوية ، بيريت ، أصداف الفورامينفرا الجيرية وكذلك عقد فوسفاتية . واتضح من الدراسة أن معادن الطين المكونة لطفلة متكون حنوى لا تختلف عن مثيلتها من صخور الطفلة السوداء المنتمية للعصر الطباشيري العلوي حيث أن معدني السمكثيت والاليت . كذلك توجد تركيزات عالية من العناصر الشحيحة التي ترتبط بالتركيزات العالية للمواد العضوية . ومن دراسة نسب نظائر الكربون المستقر اتضح أن هذه المواد العضوية ذات أصل قاري وبحري . وتوضح العلاقة ما بين الكربون العضوي الكلي وتحتوي الكبريت تشابه بين صخور الطفلة السوداء والرواسب البحرية حيث أن عنصر الحديد يعتبر أحد العوامل المتحكمة في تكوين معدني البيريت المصاحب للطفلة السوداء

Impact of the COVID-19 pandemic on patients with paediatric cancer in low-income, middle-income and high-income countries: a multicentre, international, observational cohort study

OBJECTIVES: Paediatric cancer is a leading cause of death for children. Children in low-income and middle-income countries (LMICs) were four times more likely to die than children in high-income countries (HICs). This study aimed to test the hypothesis that the COVID-19 pandemic had affected the delivery of healthcare services worldwide, and exacerbated the disparity in paediatric cancer outcomes between LMICs and HICs. DESIGN: A multicentre, international, collaborative cohort study. SETTING: 91 hospitals and cancer centres in 39 countries providing cancer treatment to paediatric patients between March and December 2020. PARTICIPANTS: Patients were included if they were under the age of 18 years, and newly diagnosed with or undergoing active cancer treatment for Acute lymphoblastic leukaemia, non-Hodgkin's lymphoma, Hodgkin lymphoma, Wilms' tumour, sarcoma, retinoblastoma, gliomas, medulloblastomas or neuroblastomas, in keeping with the WHO Global Initiative for Childhood Cancer. MAIN OUTCOME MEASURE: All-cause mortality at 30 days and 90 days. RESULTS: 1660 patients were recruited. 219 children had changes to their treatment due to the pandemic. Patients in LMICs were primarily affected (n=182/219, 83.1%). Relative to patients with paediatric cancer in HICs, patients with paediatric cancer in LMICs had 12.1 (95% CI 2.93 to 50.3) and 7.9 (95% CI 3.2 to 19.7) times the odds of death at 30 days and 90 days, respectively, after presentation during the COVID-19 pandemic (p<0.001). After adjusting for confounders, patients with paediatric cancer in LMICs had 15.6 (95% CI 3.7 to 65.8) times the odds of death at 30 days (p<0.001). CONCLUSIONS: The COVID-19 pandemic has affected paediatric oncology service provision. It has disproportionately affected patients in LMICs, highlighting and compounding existing disparities in healthcare systems globally that need addressing urgently. However, many patients with paediatric cancer continued to receive their normal standard of care. This speaks to the adaptability and resilience of healthcare systems and healthcare workers globally