Advances in brain tumour classification and therapy

Trends, age shifts, and potential delayed peaks post-pandemic of early-onset brain and central nervous system cancers in individuals aged 20-49: a cross-sectional study

BACKGROUND

Central nervous system (CNS) cancers are highly lethal and increasingly affect younger populations aged 20-49, posing significant challenges to global healthcare systems. Current research on early-onset CNS cancer trends is limited and outdated, with uncertain impacts from the COVID-19 pandemic. This study explores the epidemiology of early-onset CNS cancer and the pandemic's effects.

METHODS

We analyzed incidence, mortality, and disability-adjusted life years (DALYs) rates for early-onset CNS cancer (age 20-49) from 2019 to 2021 using GBD 2021 data. The global data were categorized into five regions based on the Socio-Demographic Index (SDI), reflecting income, education, and fertility rates. Trends over the past 30 years were examined using estimated annual percentage change (EAPC), average annual percentage change (AAPC), and joinpoint analysis, with a focus on 2019-2021. The Bayesian age-period-cohort (BAPC) model predicted post-pandemic impacts on CNS cancer metrics.

RESULTS

In 2021, global cases of early-onset CNS cancer rose to 50 201.7 (95% UI, 42 864.1-58 187.5), with deaths increasing to 25 023.1 (95% UI, 20 973.8-29 670.8) and DALYs reaching 1 483 019.4 (95% UI, 1 240 923.4-1 756 043.3). The incidence rate increased to 2.1 (95% UI, 1.8-2.5), while mortality rates remained stable at 1.1 (95% UI, 0.9-1.2), and DALY rates decreased to 62.6 (95% UI, 52.4-74.1). Over the past two decades, the incidence of early-onset CNS cancer has steadily increased, particularly in regions with a high SDI and in emerging economies. Although there was a decline in early-onset CNS cancer-related metrics during the pandemic, it is anticipated that global incidence rates will peak between 2035 and 2040.

CONCLUSION

This study provides a comprehensive overview of early-onset CNS cancer trends. Despite stable mortality rates, the increasing incidence suggests a growing global burden, with a delayed peak expected due to the pandemic. These findings highlight the need for preventive and control policies targeting early-onset CNS cancer.

Innovation in Non-Invasive Diagnosis and Disease Monitoring for Meningiomas

Meningiomas are tumors of the central nervous system that vary in their presentation, ranging from benign and slow-growing to highly aggressive. The standard method for diagnosing and classifying meningiomas involves invasive surgery and can fail to provide accurate prognostic information. Liquid biopsy methods, which exploit circulating tumor biomarkers such as DNA, extracellular vesicles, micro-RNA, proteins, and more, offer a non-invasive and dynamic approach for tumor classification, prognostication, and evaluating treatment response. Currently, a clinically approved liquid biopsy test for meningiomas does not exist. This review provides a discussion of current research and the challenges of implementing liquid biopsy techniques for advancing meningioma patient care.

International patterns and trends in the brain cancer incidence and mortality: An observational study based on the global burden of disease

BACKGROUND

Brain cancer is a serious issue in the global burden of diseases. This observational research aimed to assess trends of the brain cancer incidence and mortality in the world in the period 1990-2019.

METHODS

Brain cancer incidence and mortality data were retrieved from the Global Burden of Disease 2019 study database. The joinpoint regression analysis was done to assess the brain cancer indicence and mortality trends: the average annual percent change (AAPC) along with its 95% confidence interval (95% CI) was calculated.

RESULTS

In both sexes, the highest age-standardized rates of incidence and mortality were found in high-income regions (Europe and America), while the lowest were observed in the African Region. A significant rise in brain cancer incidence rates both in males and females was observed in all regions, with one exception of a significantly decreased trend only among males in the South-East Asia Region. Among countries with increased trends in incidence and mortality from brain cancer, Cuba experienced the most marked increase in both incidence (AAPC = +5.7% in males and AAPC = +5.4% in females) and mortality rates (AAPC = +5.5% in males and AAPC = +5.1% in females). Among countries that experienced a decline in brain cancer incidence and mortality, Hungary and Greenland showed the most marked decline in both sexes (equally by -1.0%).

CONCLUSION

Brain cancer shows increasing global incidence rates in both sexes and represents a priority for prevention and further research.

ctDNA-Based Liquid Biopsy of Cerebrospinal Fluid in Brain Cancer

The correct characterisation of central nervous system (CNS) malignancies is crucial for accurate diagnosis and prognosis and also the identification of actionable genomic alterations that can guide the therapeutic strategy. Surgical biopsies are performed to characterise the tumour; however, these procedures are invasive and are not always feasible for all patients. Moreover, they only provide a static snapshot and can miss tumour heterogeneity. Currently, monitoring of CNS cancer is performed by conventional imaging techniques and, in some cases, cytology analysis of the cerebrospinal fluid (CSF); however, these techniques have limited sensitivity. To overcome these limitations, a liquid biopsy of the CSF can be used to obtain information about the tumour in a less invasive manner. The CSF is a source of cell-free circulating tumour DNA (ctDNA), and the analysis of this biomarker can characterise and monitor brain cancer. Recent studies have shown that ctDNA is more abundant in the CSF than plasma for CNS malignancies and that it can be sequenced to reveal tumour heterogeneity and provide diagnostic and prognostic information. Furthermore, analysis of longitudinal samples can aid patient monitoring by detecting residual disease or even tracking tumour evolution at relapse and, therefore, tailoring the therapeutic strategy. In this review, we provide an overview of the potential clinical applications of the analysis of CSF ctDNA and the challenges that need to be overcome in order to translate research findings into a tool for clinical practice.

The Roles of 2-Hydroxyglutarate

2-Hydroxyglutarate (2-HG) is structurally similar to α-ketoglutarate (α-KG), which is an intermediate product of the tricarboxylic acid (TCA) cycle; it can be generated by reducing the ketone group of α-KG to a hydroxyl group. The significant role that 2-HG plays has been certified in the pathophysiology of 2-hydroxyglutaric aciduria (2HGA), tumors harboring mutant isocitrate dehydrogenase 1/2 (IDH1/2mt), and in clear cell renal cell carcinoma (ccRCC). It is taken as an oncometabolite, raising much attention on its oncogenic mechanism. In recent years, 2-HG has been verified to accumulate in the context of hypoxia or acidic pH, and there are also researches confirming the vital role that 2-HG plays in the fate decision of immune cells. Therefore, 2-HG not only participates in tumorigenesis. This text will also summarize 2-HG’s identities besides being an oncometabolite and will discuss their enlightenment for future research and clinical treatment.

Global, regional, and national burden of brain and other CNS cancer, 1990-2016: a systematic analysis for the Global Burden of Disease Study 2016

BACKGROUND

Brain and CNS cancers (collectively referred to as CNS cancers) are a source of mortality and morbidity for which diagnosis and treatment require extensive resource allocation and sophisticated diagnostic and therapeutic technology. Previous epidemiological studies are limited to specific geographical regions or time periods, making them difficult to compare on a global scale. In this analysis, we aimed to provide a comparable and comprehensive estimation of the global burden of brain cancer between 1990 and 2016.

METHODS

We report means and 95% uncertainty intervals (UIs) for incidence, mortality, and disability-adjusted life-years (DALYs) estimates for CNS cancers (according to the International Classification of Diseases tenth revision: malignant neoplasm of meninges, malignant neoplasm of brain, and malignant neoplasm of spinal cord, cranial nerves, and other parts of CNS) from the Global Burden of Diseases, Injuries, and Risk Factors Study 2016. Data sources include vital registration and cancer registry data. Mortality was modelled using an ensemble model approach. Incidence was estimated by dividing the final mortality estimates by mortality to incidence ratios. DALYs were estimated by summing years of life lost and years lived with disability. Locations were grouped into quintiles based on the Socio-demographic Index (SDI), a summary indicator of income per capita, years of schooling, and total fertility rate.

FINDINGS

In 2016, there were 330 000 (95% UI 299 000 to 349 000) incident cases of CNS cancer and 227 000 (205 000 to 241 000) deaths globally, and age-standardised incidence rates of CNS cancer increased globally by 17·3% (95% UI 11·4 to 26·9) between 1990 and 2016 (2016 age-standardised incidence rate 4·63 per 100 000 person-years [4·17 to 4·90]). The highest age-standardised incidence rate was in the highest quintile of SDI (6·91 [5·71 to 7·53]). Age-standardised incidence rates increased with each SDI quintile. East Asia was the region with the most incident cases of CNS cancer for both sexes in 2016 (108 000 [95% UI 98 000 to 122 000]), followed by western Europe (49 000 [37 000 to 54 000]), and south Asia (31 000 [29 000 to 37 000]). The top three countries with the highest number of incident cases were China, the USA, and India. CNS cancer was responsible for 7·7 million (95% UI 6·9 to 8·3) DALYs globally, a non-significant change in age-standardised DALY rate of -10·0% (-16·4 to 2·6) between 1990 and 2016. The age-standardised DALY rate decreased in the high SDI quintile (-10·0% [-27·1 to -0·1]) and high-middle SDI quintile (-10·5% [-18·4 to -1·4]) over time but increased in the low SDI quintile (22·5% [11·2 to 50·5]).

INTERPRETATION

CNS cancer is responsible for substantial morbidity and mortality worldwide, and incidence increased between 1990 and 2016. Significant geographical and regional variation in the incidence of CNS cancer might be reflective of differences in diagnoses and reporting practices or unknown environmental and genetic risk factors. Future efforts are needed to analyse CNS cancer burden by subtype.

FUNDING

Bill & Melinda Gates Foundation.

Epigenetic Regulation of Telomere Maintenance for Therapeutic Interventions in Gliomas

High-grade astrocytoma of WHO grade 4 termed glioblastoma multiforme (GBM) is a common human brain tumor with poor patient outcome. Astrocytoma demonstrates two known telomere maintenance mechanisms (TMMs) based on telomerase activity (TA) and on alternative lengthening of telomeres (ALT). ALT is associated with lower tumor grades and better outcome. In contrast to ALT, regulation of TA in tumors by direct mutation and epigenetic activation of the hTERT promoter is well established. Here, we summarize the genetic background of TMMs in non-malignant cells and in cancer, in addition to clinical and pathological features of gliomas. Furthermore, we present new evidence for epigenetic mechanisms (EMs) involved in regulation of ALT and TA with special emphasis on human diffuse gliomas as potential therapeutic drug targets. We discuss the role of TMM associated telomeric chromatin factors such as DNA and histone modifying enzymes and non-coding RNAs including microRNAs and long telomeric TERRA transcripts.