Worldwide Trends in Survival From Common Childhood Brain Tumors: A Systematic Review

Ophthalmic symptoms, clinical signs and diagnostic delay in infants diagnosed with brain tumours in Denmark between 2007 and 2017

PURPOSE

To investigate ophthalmic onset manifestations and the impact of diagnostic delay on the prognosis in infants (<1 year) diagnosed with a brain tumour.

METHODS

A retrospective population-based nationwide study of infants diagnosed with a brain tumour between 2007 and 2017 in Denmark. Data was retrieved from the Danish Childhood Cancer Registry, the National Danish Health registries, and medical files. Primary outcome measures included symptoms, clinical findings, time to diagnosis and survival.

RESULTS

Thirty-seven infants were diagnosed with a brain tumour in Denmark between 2007 and 2017. In total, 19/37 infants (51%, 95% CI: 34-68) had ophthalmic manifestations at any time prior to or at diagnosis; and in 6/37 (16%, 95% CI: 6-32) ophthalmic manifestations were the initial symptom. The most common ophthalmic manifestations were strabismus (n = 7), sunset eyes (n = 6), nystagmus (n = 4), reduced pupillary light reflex (n = 4), and/or decreased vision (n = 4). The median number of symptoms per infant at the time of diagnosis was three (range 0-9). The median diagnostic delay was 26 days (range 0-283, IQR: 6;90). 5-year survival rate was 75% (95% CI: 61-90) and all children with diagnostic delay > 100 days (n = 9, 24%) were still alive at the end of follow-up (median 6.3 years, range 2.2-10.2).

CONCLUSION

We provide an overview of symptoms and clinical signs in a nation-wide series of infants with CNS tumours and demonstrate that ophthalmic manifestations are frequently observed in infants prior to diagnosis, but, often in combination with other clinical signs. The diagnostic delay was substantial for a large part of the infants, but this was not associated with increased mortality.

Discovery of Conformationally Constrained ALK2 Inhibitors

Despite decades of research on new diffuse intrinsic pontine glioma (DIPG) treatments, little or no progress has been made on improving patient outcomes. In this work, we explored novel scaffold modifications of M4K2009, a 3,5-diphenylpyridine ALK2 inhibitor previously reported by our group. Here we disclose the design, synthesis, and evaluation of a first-in-class set of 5- to 7-membered ether-linked and 7-membered amine-linked constrained inhibitors of ALK2. This rigidification strategy led us to the discovery of the ether-linked inhibitors M4K2308 and M4K2281 and the amine-linked inhibitors M4K2304 and M4K2306, each with superior potency against ALK2. Notably, M4K2304 and M4K2306 exhibit exceptional selectivity for ALK2 over ALK5, surpassing the reference compound. Preliminary studies on their in vivo pharmacokinetics, including blood-brain barrier penetration, revealed that these constrained scaffolds have favorable exposure and do open a novel chemical space for further optimization and future evaluation in orthotopic models of DIPG.

Primary central nervous system tumors survival in children in ten Colombian cities: a VIGICANCER report

Purpose

Primary central nervous system (CNS) tumors are the second most common cancer in children and adolescents, leading to premature death and disability. Population-based survival estimates aid decision-making in cancer control, however data on survival for primary CNS tumors in Latin America is lacking. We describe survival rates for children with primary CNS tumors treated in ten Colombian cities.

Methods

We analyzed data from children and adolescents newly diagnosed with cancer between 2012 and 2021, participating in the Childhood Cancer Clinical Outcomes Surveillance System (VIGICANCER) in ten cities in Colombia. VIGICANCER collects information on clinical outcomes from twenty-seven pediatric oncology units and conducts active follow-up every three months. VIGICANCER does not register craniopharyngiomas; we excluded intracranial germ cell tumors for this report. We used the Kaplan-Meier method to estimate the overall survival probability, stratified by sociodemographic variables, topography, WHO grading, receipt of radiation therapy, and type of surgical resection. We analyzed the prognostic capacity of variables using multivariate proportional Cox's regression, stratified by city and year of diagnosis.

Results

During the study period, VIGICANCER included 989 primary CNS tumors in 879 children and 110 adolescents. The cohort median age was 9 years; 53% of patients were males, and 8% were Afro-descendants. Most common tumors were supratentorial astrocytomas (47%), astrocytic tumors (35%), medulloblastomas (20%), ependymomas (11%), and mixed and unspecified gliomas (10%). Five-year overall survival of the entire cohort was 54% (95% CI, 51-58); for supratentorial gliomas, WHO grade I was 77%, II was 62%, III-IV was 27%, respectively, and for medulloblastoma was 61%. The adjusted hazard rate ratio for patients with WHO grade III and IV, for those with subtotal resection, for brainstem location, and for those not receiving radiation therapy was 7.4 (95% CI, 4.7-11.8), 6.4 (95% CI, 4.2-9.8), 2.8 (95% 2.1-3.8), 2.0 (95% CI, 1.3-2.8) and 2.3 (95% CI, 1.7-3.0), respectively.

Conclusion

We found that half of Colombia's children and adolescents with primary CNS tumors survive five years, compared to 70% to 80% in high-income countries. In addition to tumor biology and location, gross total resection was crucial for improved survival in this cohort. Systematic monitoring of survival and its determinants provides empirical data for guiding cancer control policies.

Trends in pediatric CNS tumors in Armenia: a multicenter retrospective study

PURPOSE

Central nervous system (CNS) tumors are the most common solid malignancies in children worldwide, including in Armenia. The current study aims to analyze epidemiological data, treatment, and outcomes of children and young adults (≤25 years) with CNS tumors in Armenia during the last 26 years.

METHODS

We collected data from pediatric and young adult patients treated in selected sites in Armenia from 1st January 1995 to 31st December 2020. Incidence by sex, age at diagnosis, time from first complaints to diagnosis, histopathology results, treatment strategies, complications, and overall survival (OS) rates were calculated.

RESULTS

The multicenter data analysis revealed 149 patients with diagnosed primary CNS tumors over 26 years. Among them, 84 (56.4%) were male. The median age at diagnosis was 7 years (range, 3 months to 25 years), and the median time from the first complaints to diagnosis was 2 months (range, 1 week to 70 months). Medulloblastomas and other embryonal tumors (47), low-grade gliomas (32), and high-grade gliomas (22) were the most commonly diagnosed malignancies. Ependymomas, craniopharyngiomas, germ cell tumors, and other malignancies were observed in 22 patients. For 26 patients, no histopathological or radiological diagnosis was available. Follow-up information was available for 98 (65.8%) patients. The 5-year OS rate for the whole study group was 67.7%.

CONCLUSION

Consistent with international data, embryonal tumors, and gliomas were the most commonly diagnosed CNS malignancies in Armenia. Multimodal treatment was often not available in Armenia during the study period, especially for early cases.

Prognostic factors of pediatric ependymomas at a National Cancer Reference Center in Peru

Background

Ependymomas are central nervous system tumors that significantly impact the quality of life and carry a high mortality rate. Both the disease itself and its treatment cause significant morbidity. At a national level in Peru, there are no reports on clinical characteristics of the disease.

Methods

This retrospective study captured patient aged less than 19 years with a diagnosis of ependymoma from 2012 to 2022 at a tertiary center in Lima.

Results

85 patients were included with a median follow-up time was 51.6 months. The 5-year overall survival and progression-free survival were 55.89% (95% CI: 44.28 - 65.99) and 37.71% (95% CI: 26,21-49,16) respectively. The main prognostic factors identified were completed treatment (p=0.019), adjuvant chemotherapy (p=0.048), presence of metastasis (p=0.012), and disease recurrence (p=0.02).

Conclusions

The survival of patients with ependymoma is below that reported in high-income countries. Incomplete treatment and treatment abandonment are factors that negatively impact the prognosis. Further studies are needed to identify barriers in the referral and treatment process for patients with ependymoma.

Validation of an automated contouring and treatment planning tool for pediatric craniospinal radiation therapy

Purpose

Treatment planning for craniospinal irradiation (CSI) is complex and time-consuming, especially for resource-constrained centers. To alleviate demanding workflows, we successfully automated the pediatric CSI planning pipeline in previous work. In this work, we validated our CSI autosegmentation and autoplanning tool on a large dataset from St. Jude Children's Research Hospital.

Methods

Sixty-three CSI patient CT scans were involved in the study. Pre-planning scripts were used to automatically verify anatomical compatibility with the autoplanning tool. The autoplanning pipeline generated 15 contours and a composite CSI treatment plan for each of the compatible test patients (n=51). Plan quality was evaluated quantitatively with target coverage and dose to normal tissue metrics and qualitatively with physician review, using a 5-point Likert scale. Three pediatric radiation oncologists from 3 institutions reviewed and scored 15 contours and a corresponding composite CSI plan for the final 51 test patients. One patient was scored by 3 physicians, resulting in 53 plans scored total.

Results

The algorithm automatically detected 12 incompatible patients due to insufficient junction spacing or head tilt and removed them from the study. Of the 795 autosegmented contours reviewed, 97% were scored as clinically acceptable, with 92% requiring no edits. Of the 53 plans scored, all 51 brain dose distributions were scored as clinically acceptable. For the spine dose distributions, 92%, 100%, and 68% of single, extended, and multiple-field cases, respectively, were scored as clinically acceptable. In all cases (major or minor edits), the physicians noted that they would rather edit the autoplan than create a new plan.

Conclusions

We successfully validated an autoplanning pipeline on 51 patients from another institution, indicating that our algorithm is robust in its adjustment to differing patient populations. We automatically generated 15 contours and a comprehensive CSI treatment plan for each patient without physician intervention, indicating the potential for increased treatment planning efficiency and global access to high-quality radiation therapy.

Supporting families through paediatric brain tumour: Unmet needs and suggestions for change

OBJECTIVE

From diagnosis and beyond, a paediatric brain tumour and its treatment impact the child and their family in a myriad of ways. While it is considered best practice to offer ongoing psychosocial support for all family members, there is little scholarly investigation of both families' experiences and the practical implications of offering such care. We aimed to explore families' experiences of paediatric brain tumour and their associated psychosocial health service needs.

METHODS

Families receiving care at the Queensland Children's Hospital in Brisbane, Australia, for a child (0-18 years) who had been diagnosed with a brain tumour between 2019 and 2022 were invited to be interviewed about their experiences. Using qualitative description, we analysed these interviews to identify families' unmet psychosocial health service needs and their suggestions for improvement.

RESULTS

Twenty-three clinically and socially diverse families were represented. While parents/carers expressed gratitude for the care their child had received, most also described unmet needs for the broader family. We identified three primary needs to be addressed: (1) parents want accessible psychological/emotional support for themselves; (2) parents/carers want additional guidance to navigate the hospital setting to reduce uncertainty and loss of control; and (3) parents want support to minimise treatment-associated trauma for their child.

CONCLUSIONS

Our findings evidence the need for improved family-centred psychosocial care within paediatric brain tumour care in Queensland, Australia. We propose a counselling and care coordination intervention to support parents/carers to care for themselves, their child, and their family through an extremely challenging experience.

Evolving Diagnostic and Treatment Strategies for Pediatric CNS Tumors: The Impact of Lipid Metabolism

Pediatric neurological tumors are a heterogeneous group of cancers, many of which carry a poor prognosis and lack a "standard of care" therapy. While they have similar anatomic locations, pediatric neurological tumors harbor specific molecular signatures that distinguish them from adult brain and other neurological cancers. Recent advances through the application of genetics and imaging tools have reshaped the molecular classification and treatment of pediatric neurological tumors, specifically considering the molecular alterations involved. A multidisciplinary effort is ongoing to develop new therapeutic strategies for these tumors, employing innovative and established approaches. Strikingly, there is increasing evidence that lipid metabolism is altered during the development of these types of tumors. Thus, in addition to targeted therapies focusing on classical oncogenes, new treatments are being developed based on a broad spectrum of strategies, ranging from vaccines to viral vectors, and melitherapy. This work reviews the current therapeutic landscape for pediatric brain tumors, considering new emerging treatments and ongoing clinical trials. In addition, the role of lipid metabolism in these neoplasms and its relevance for the development of novel therapies are discussed.

National and subnational burden of brain and central nervous system cancers in Iran, 1990-2019: Results from the global burden of disease study 2019

INTRODUCTION

Central nervous system cancers (CNS cancers) impose a significant burden upon healthcare systems worldwide. Currently, the lack of a comprehensive study to assess various epidemiological indexes of CNS cancers on national and subnational scales in Iran can hamper healthcare planning and resource allocation in this regard. This study aims to fill this gap by providing estimates of CNS cancer epidemiological measures on national and subnational levels in Iran from 1990 to 2019.

MATERIALS AND METHODS

This study is a part of Global Burden of Disease (GBD) 2019 that contains epidemiological measures including prevalence, incidence, mortality, Disability-Adjusted Life Years (DALYs), Years Lived with Disability (YLDs), and Years of Life Lost (YLLs) of CNS cancers. Age standardization was utilized for comparing different provinces.

RESULTS

In 2019, 5811 (95% Uncertainty Interval: 2942-7046) national new cases and 3494 (1751-4173) deaths due to CNS cancers were reported. National age-standardized incidence (ASIR), deaths (ASDR), and DALYs rates were 7.3 (3.7-8.8), 4.6 (2.3-5.5), and 156.4 (82.0-187.0) per 100,000 in 2019, respectively. Subnational results revealed that ASDR and ASIR have increased in the past 30 years in all provinces. Although incidence rates have increased in all age groups and genders since 1990, death rates have remained the same for most age groups and genders except for young patients aged under 15, where a decrease in mortality and YLLs can be observed.

CONCLUSION

The incidence, deaths, and DALYs of CNS cancers increased at national and subnational levels. These findings should be considered for planning and resource allocation.

Evaluating preclinical evidence for clinical translation in childhood brain tumours: Guidelines from the CONNECT, PNOC, and ITCC brain networks

Clinical outcomes for many childhood brain tumours remain poor, despite our increasing understanding of the underlying disease biology. Advances in molecular diagnostics have refined our ability to classify tumour types and subtypes, and efforts are underway across multiple international paediatric neuro-oncology consortia to take novel biological insights in the worst prognosis entities into innovative clinical trials. Whilst for the first time we are designing such studies on the basis of disease-specific biological data, the levels of preclincial evidence in appropriate model systems on which these trials are initiated is still widely variable. We have considered these issues between CONNECT, PNOC and ITCC-Brain, and developed a framework in which we can assess novel concepts being brought forward for possible clinical translation. Whilst not intended to be proscriptive for every possible circumstance, these criteria provide a basis for self-assessment of evidence by laboratory scientists, and a platform for discussion and rational decision-making prior to moving forward clinically.

Interventions to improve neurocognitive late-effects in pediatric and adolescent CNS tumor patients and survivors - a systematic review

Introduction

Survival of children and adolescents diagnosed with central nervous system (CNS) tumors massively improved over the last decades due to better diagnostics, treatment, and supportive care. However, morbidity is still the highest of all cancer entities in this age group with neurocognitive late-effects being one of the most severe.

Aim

With this systematic review, we aim to summarize interventions designed to prevent or improve neurocognitive late-effects in CNS tumor patients.

Method

We searched PubMed on August 16^th 2022 and included publications studying interventions for neurocognitive late-effects in pediatric and adolescent patients and survivors diagnosed with a CNS tumor. We included any form of neurocognitive intervention during treatment or following treatment completion. We considered all types of studies except for expert opinions and case reports.

Results

The literature search resulted in 735 publications. We included 43 publications in the full text screening and 14 met our inclusion criteria. Of those, two assessed the impact of pharmacological interventions, three of exercise interventions, five of online cognitive training, and four assessed behavioral interventions. Different neuropsychological test batteries and imaging were used to measure the impact of the respective interventions. Most studies showed a positive impact of the interventions in single to several of the subtests used.

Conclusion

We found several intervention studies indicating improvement of neurocognitive problems in children and adolescent CNS tumor survivors. In this population exercise interventions or online cognitive training might mitigate or improve neurocognitive late-effects.

Disability or Death: A Focused Review of Informed Consent in Pediatric Neurosurgery

The management of pediatric neurosurgical disease often requires families to choose between long-term disability and premature death. This decision-making is codified by informed consent. In practice, decision-making is heavily weighted toward intervening to prevent death, often with less consideration of the realities of long-term disability. We analyze long-term disability in pediatric neurosurgical disease from the perspectives of patients, families, and society. We then present a pragmatic framework and conversational approach for addressing informed consent discussions when the outcome is expected to be death or disability. We performed a focused review of literature regarding informed consent in pediatric neurosurgery by searching PubMed and Google Scholar with search terms including "pediatric neurosurgery," "informed consent," and "disability." The literature was focused on patients with diagnoses including spina bifida, neuro-oncology, trauma, and hydrocephalus. Patient perspective elements were physical/mental disability, lack of autonomy, and role in community/society. The family perspective involves caregiver burden, emotional toll, and financial impact. Societal considerations include the availability of public resources for disabled children, large-scale financial cost, and impacts on global health. Practical conversational steps with patients/caregivers include opening the discussion, information provision and acknowledgement of uncertainty, assessment of understanding and clarifying questions, decision-making, and decision maintenance, all while remaining sensitive to the emotional burden commensurate with these decisions. The "death or disability" paradigm represents a common challenge to informed consent in pediatric neurosurgery. Patient, family, and societal factors that inform surrogate decisions vary and sometimes conflict. Pediatric neurosurgeons must use a comprehensive approach to address the informational and relational needs of caregivers during the informed consent process.

Prospective Evaluation of Kidney Function in Long-Term Survivors of Pediatric CNS Tumors

Purpose: Numerous acute effects of chemotherapeutics on kidney function are well described. However, data on the long-term effects of chemotherapy in the growing population of childhood central nervous system (CNS) tumor survivors is limited. We aimed to evaluate the kidney function of a cohort of long-term CNS tumor survivors treated with different standard chemotherapeutic regimens. Methods: Patients treated for a CNS tumor were prospectively evaluated up to 12 years after completion of their therapy. Examination of kidney function was performed during routine follow-up visits. Blood pressure and blood and urine parameters were analyzed for kidney function evaluation. Glomerular function was assessed by calculating the estimated glomerular filtration rate (eGFR), tubular functions were analyzed by measuring serum electrolytes, bicarbonate and phosphate reabsorption, and proteinuria was assessed by calculating the protein/creatinine ratio and phosphate reabsorption. Results: None of the 65 patients evaluated suffered from clinically relevant kidney impairment (eGFR < 90 mL/min/L, 73 m2). There was no association between chemotherapy dose and eGFR. Only two patients showed mild signs of tubulopathy and 11 patients were diagnosed with elevated blood pressure. Conclusion: With adequate supportive measures, such as sufficient hydration according to chemotherapy protocol guidelines, as well as avoidance or close monitoring of additional nephrotoxic medication, impaired kidney function is rare in CNS tumor survivors treated with standard chemotherapy. Nonetheless, long-term follow-up is essential for early detection of mild impairment of kidney function.

Circular and Fusion RNAs in Medulloblastoma Development

Simple Summary

Expression of circular RNAs is known to be deregulated in cancer. Here the most comprehensive set of differentially expressed RNA circles in medulloblastoma compared to cerebellum is provided. Additionally, fusion RNAs are also identified in both cancerous and normal cerebellar tissue. Some of the fusions detected in medulloblastoma are generated by genomic rearrangements that link different genes. However, fusion RNAs are also detected in normal cerebellum. In fact, there are cases where the same fusion RNA is also found in medulloblastoma. This observation underscores that the formation of fusion transcripts may not be limited to chromosomal events but could also result from mechanisms that act at the RNA level. These include read-through transcription of neighboring genes and intermolecular splicing of pre-mRNAs from different genes Importantly, these RNA “recombination” events occur not only in normal but also in cancerous tissue.

Abstract

Background. The cerebellar cancer medulloblastoma is the most common childhood cancer in the brain. Methods. RNA sequencing of 81 human biospecimens of medulloblastoma using pipelines to detect circular and fusion RNAs. Validation via PCR and Sanger sequencing. Results. 27, 56, 28 and 11 RNA circles were found to be uniquely up-regulated, while 149, 7, 20 and 15 uniquely down-regulated in the SHH, WNT, Group 3, and Group 4 medulloblastoma subtypes, respectively. Moreover, linear and circular fusion RNAs containing exons from distinct genes joined at canonical splice sites were also identified. These were generally expressed less than the circular RNAs, however the expression of both the linear and the circular fusions was comparable. Importantly, the expression of the fusions in medulloblastoma was also comparable to that of cerebellum. Conclusions. A significant number of fusions in tumor may be generated by mechanisms similar to the ones generating fusions in normal tissue. Some fusions could be rationalized by read-through transcription of two neighboring genes. However, for other fusions, e.g., a linear fusion with an exon from a downstream gene joined 5′ to 3′ with an exon from an upstream gene, more complicated splicing mechanisms, e.g., trans-splicing, have to be postulated.

The Road to CAR T-Cell Therapies for Pediatric CNS Tumors: Obstacles and New Avenues

Pediatric central nervous system (CNS) tumors are the most common solid tumors diagnosed in children and are the leading cause of pediatric cancer-related death. Those who do survive are faced with the long-term adverse effects of the current standard of care treatments of chemotherapy, radiation, and surgery. There is a pressing need for novel therapeutic strategies to treat pediatric CNS tumors more effectively while reducing toxicity - one of these novel modalities is chimeric antigen receptor (CAR) T-cell therapy. Currently approved for use in several hematological malignancies, there are promising pre-clinical and early clinical data that suggest CAR-T cells could transform the treatment of pediatric CNS tumors. There are, however, several challenges that must be overcome to develop safe and effective CAR T-cell therapies for CNS tumors. Herein, we detail these challenges, focusing on those unique to pediatric patients including antigen selection, tumor immunogenicity and toxicity. We also discuss our perspective on future avenues for CAR T-cell therapies and potential combinatorial treatment approaches.

Web-Based Research Trends on Child and Adolescent Cancer Survivors Over the Last 5 Years: Text Network Analysis and Topic Modeling Study

Background

Being diagnosed with cancer during childhood or adolescence can disrupt important periods in an individual’s physical, psychosocial, and spiritual development and potentially reduce the quality of life (QOL) after treatment. Research is urgently required to improve the QOL for child and adolescent cancer survivors, and it is necessary to analyze the trends in prior research reported in international academic journals to identify knowledge structures.

Objective

This study aims to identify the main keywords based on network centrality, subgroups (clusters) of keyword networks by using a cohesion analysis method, and the main theme of child and adolescent cancer survivor–related research abstracts through topic modeling. This study also aims to label the subgroups by comparing the results of the cohesion and topic modeling.

Methods

A text network analysis method and topic modeling were used to explore the main trends in child and adolescent cancer survivor research by structuring a network of keyword (semantic morphemes) co-occurrence in the abstracts of articles published in 5 major web-based databases from 2016 to 2020. A total of 1677 child and adolescent cancer survivor–related studies were used for data analyses. Data selection, processing, and analyses were also conducted.

Results

The top 5 keywords in terms of degree and eigenvector centrality were risk, control interval, radiation, childhood cancer treatment, and diagnosis. Of the 1677 studies used for data analyses, cluster 1 included 780 (46.51%) documents under risk management, cluster 2 contained 557 (33.21%) articles under health-related QOL and supportive care, and cluster 3 consisted of 340 (20.27%) studies under cancer treatment and complications.

Conclusions

This study is significant in that it confirms the knowledge structure based on the main keywords and cross-disciplinary trends in child and adolescent cancer survivor research published in the last 5 years worldwide. The primary goal of child and adolescent cancer survivor research is to prevent and manage the various aspects of the problems encountered during the transition to a normal life and to improve the overall QOL. To this end, it is necessary to further revitalize the study of the multidisciplinary team approach for the promotion of age-specific health behaviors and the development of intervention strategies with increased feasibility for child and adolescent cancer survivors.

High expression of Toll-like receptor 7 is a survival factor in pediatric medulloblastoma

PURPOSE

Medulloblastoma is an embryonal brain tumor that predominantly occurs in childhood with a wide histological and molecular variability. Our aim was to investigate the expression of Toll-like receptors (TLRs), their association with the infiltration of immune cells and with the histological subgroups, and, also, with the overall survival of patients.

METHODS

Fifty-six paraffin-preserved biopsies from children with medulloblastoma of the classic, desmoplastic, and anaplastic subtypes were included. Microarrays of tissues were performed, and the infiltration of T and NK cells was quantified, as well as the expression of TLR7, TLR8, and TLR9. For all statistical analyses, significance was p < 0.05.

RESULTS

CD4 + and CD8 + T lymphocytes and NK cells were found infiltrating the tumor. The infiltration of NK and CD4 + cells was greater in the classic and desmoplastic subtypes than in anaplastic. We found an important expression of TLRs in all medulloblastomas, but TLR7 and TLR8 were considerably higher in classic and desmoplastic subtypes than in anaplastic. Importantly, we observed that TLR7 was a prognostic factor for survival.

CONCLUSIONS

Medulloblastomas present cellular infiltration and a differential expression of TLRs depending on the histological subtype. TLR7 is a prognostic factor of survival that is dependent on treatment and age.

Tick bite induced α-gal syndrome highlights anticancer effect of allergy

Tick bite induced α-gal syndrome (AGS) following consumption of mammalian meat is a recently described intriguing disease occurring worldwide. Here we argue that AGS and delayed allergy in general is an adaptive defence method against cancer. Our hypothesis synthesizes two lines of supporting evidence. First, allergy has been shown to have direct anti-cancer effects with unknown mechanism. Second, eating processed meat was shown to be linked to developing cancer. Humans lost their genes encoding molecules α-gal 30 MYA and Neu5Gc 2 MYA, the latter co-occurring with the start of using fire. These molecules are acquired from external sources, as tick bite for α-gal and mammalian meat for Neu5Gc, the latter accumulating in tumors. The resulting specific delayed allergic response is a molecular adaptation to fight cancer. By further testing and applying our hypothesis, new avenues in cancer research and therapy will open that might save lives and decrease human suffering.

Incidence and survival of childhood central nervous system tumors in Denmark, 1997-2019

BACKGROUND

Incidence rates in Denmark of central nervous system (CNS) tumors remain among the highest in the world. Survival rates, however, have improved in the past decades in high-income countries.

METHODS

We analyzed incidence and survival of childhood CNS tumors in Denmark diagnosed from 1997 to 2019 based on data from the Danish Childhood Cancer Registry and information on histological types, tumor localization, and treatment from medical records.

RESULTS

From 1997 to 2019, 949 children<15 years were diagnosed with a CNS tumor. Age-standardized incidence was 42.1 (95% CI, 39.4-44.6) per million person-years and stable during this period. Age-specific incidence for children aged 0-4 years was 47.7 per million. More than one-third (n = 374, 39.4%) were treated with surgery alone. Overall survival rates 5 and 10 years after diagnosis were 77.6% (95% CI, 74.7-80.2) and 74.7% (95% CI, 71.7-77.5). Five-year overall survival improved from 73.0% (95% CI, 68.9-76.7) in 1997-2008 to 83.2% (95% CI, 79.2-86.4) in 2009-2019 (p-value < 0.0001) in children aged 0-4 years (p = 0.0006).

CONCLUSION

Incidence rates are stable but remain among the highest in the world. Despite improved survival rates in recent years in younger children, some subtypes still have a poor prognosis.

Disability-Adjusted Life Years and Mortality Rate Attributed to Brain and Central Nervous System Cancer in the Middle East and North Africa Countries

BACKGROUND

Primary brain tumors are among the main causes of death. This study aimed to determine the epidemiological features of the brain and central nervous system cancer in the Middle East and North Africa (MENA) region.

METHODS

In this study, data of the Global Burden of Disease (GBD) study were used to estimate the incidence, prevalence, deaths, disability-adjusted life years (DALYs), and mortality in 21 countries in the MENA region from 1990 to 2019 based on age and sex. The percentage of the changes of epidemiologic indicators was calculated between 1990 and 2019.

RESULTS

Palestine and Turkey had the highest rate of brain and central nervous system cancer in 2019. Saudi Arabia, Oman, Iraq, and Lebanon had the highest percentage of incidence rate changes from 1990 to 2019. The prevalence of brain and central nervous system cancer in the MENA region was increased from 7.51 (95% CI: 4.95-11.01) in 1990 to 16.45 (95% CI: 10.83-19.54) in 2019 (percentage of changes = 54.35%). The standardized age mortality rate in the MENA region was increased by 2.7% in 2019 compared to that in 1990. The rate of standardized age of DALY per 100,000 individuals in the MENA region decreased from 135.09 (95% CI: 92.57-199.92) in 1990 to 128.34 (95% CI: 87.81-151.3) in 2019.

CONCLUSION

The incidence rate, prevalence, and standardized age mortality (per 100,000) had increased significantly in the MENA region in 2019 compared to those in 1990. Focusing on the diversity of the estimates of such indices in different countries of MENA can lead to the identification of important risk factors for brain cancer in future studies.

Circular RNAs in Hedgehog Signaling Activation and Hedgehog-Mediated Medulloblastoma Tumors

Simple Summary

Here the expression profile of circular RNAs in Hedgehog signaling-dependent cell lines and medulloblastoma cells was interrogated. Using stringent criteria, a reduced expression of seven circular RNAs in Hedgehog-dependent medulloblastoma versus cerebellum was clearly established. Depletion and/or overexpression of these deregulated RNA circles in two medulloblastoma cell lines revealed minimal effects in cellular proliferation based on two independent assays. These findings highlight the complexity of gene expression outcomes and the possibility that gene products may not necessarily have an obvious phenotypic impact on the cellular context where they are present. It is not inconceivable that a substantial number of differentially expressed circular RNAs may represent “passenger molecules” with little impact on a cell, reflecting the stochasticity of the gene expression and splicing processes.

Abstract

Within the past decade, circular RNAs have largely emerged as novel regulators of human biology, including brain function and cancer development. On the other hand, the Hedgehog pathway has established roles in regulating biological processes, including tumorigenesis. Here, the circular RNA transcriptome, in the context of Hedgehog signaling activation of medulloblastoma Daoy and human embryonic palatal mesenchyme HEPM cells, was determined. In total, 29 out of the 30 selected circular RNAs were validated by Sanger sequencing, with some regulated to a limited extent by Hedgehog signaling. Interestingly, back-spliced junctions, the marker of exonic RNA circles, were also identified at a low frequency within poly (A) mRNAs, reflecting exon repetition events. Thirteen circular RNAs had reduced expression in human medulloblastoma tumors in comparison to normal cerebellum. For seven out of these thirteen RNA circles, the linear mRNAs originating from the same genes did not exhibit a reduced expression. Depletion and/or overexpression of these seven circular RNAs minimally affected medulloblastoma cell proliferation. These findings highlight that differential expression of a gene product may not necessarily elicit an obvious phenotypic impact. Consequently, further analysis is required to determine the possible subtle contributions to the development of this cerebellar tumor.

Role of aryl hydrocarbon receptor in central nervous system tumors: Biological and therapeutic implications

Aryl hydrocarbon receptor (AHR) is a ligand-activated transcription factor, whose canonical pathway mainly regulates the genes involved in xenobiotic metabolism. However, it can also regulate several responses in a non-canonical manner, such as proliferation, differentiation, cell death and cell adhesion. AhR plays an important role in central nervous system tumors, as it can regulate several cellular responses via different pathways. The polymorphisms of the AHR gene have been associated with the development of gliomas. In addition, the metabolism of tumor cells promotes tumor growth, particularly in tryptophan synthesis, where some metabolites, such as kynurenine, can activate the AhR pathway, triggering cell proliferation in astrocytomas, medulloblastomas and glioblastomas. Furthermore, as part of the changes in neuroblastomas, AHR is able to downregulate the expression of proto-oncogene c-Myc, induce differentiation in tumor cells, and cause cell cycle arrest and apoptosis. Collectively, these data suggested that the modulation of the AhR pathway may downregulate tumor growth, providing a novel strategy for applications for the treatment of certain tumors through the control of the AhR pathway.

Global Trends in Survival From Astrocytic Tumors in Adolescents and Young Adults: A Systematic Review

Background

Brain tumors represent an important cause of cancer-related death in adolescents and young adults. Most are diagnosed in low-income and middle-income countries. We aimed to conduct the first, to our knowledge, systematic review of time trends and geographical variation in survival in this age group.

Methods

We included observational studies describing population-based survival from astrocytic tumors in patients aged 15-39 years. We queried 6 electronic databases from database inception to December 31, 2019. This review is registered with PROSPERO, number CRD42018111981.

Results

Among 5640 retrieved records, 20 studies fulfilled the inclusion criteria. All but 1 study focused on high-income countries. Five-year survival from astrocytoma (broad morphology group) mostly varied between 48.0% and 71.0% (1973-2004) without clear trends or geographic differences. Adolescents with astrocytoma had better outcomes than young adults, but survival values were similar when nonmalignant tumors were excluded. During 2002-2007, 5-year survival for World Health Organization grade I-II tumors was in the range of 72.6%-89.1% in England, Germany, and the United States but lower in Southeastern Europe (59.0%). Five-year survival for anaplastic astrocytoma varied between 39.6% and 55.4% (2002-2007). Five-year survival from glioblastoma was in the range of 14.2%-23.1% (1991-2009).

Conclusions

Survival from astrocytic tumors remained somewhat steady over time, with little change between 1973 and 2009. Survival disparities were difficult to examine, because nearly all the studies were conducted in affluent countries. Studies often adopted the International Classification of Childhood Cancer, which, however, did not allow to accurately describe variation in survival. Larger studies are warranted, including underrepresented populations and providing more recent survival estimates.

Leveraging an Open Science Drug Discovery Model to Develop CNS-Penetrant ALK2 Inhibitors for the Treatment of Diffuse Intrinsic Pontine Glioma

There are currently no effective chemotherapeutic drugs approved for the treatment of diffuse intrinsic pontine glioma (DIPG), an aggressive pediatric cancer resident in the pons region of the brainstem. Radiation therapy is beneficial but not curative, with the condition being uniformly fatal. Analysis of the genomic landscape surrounding DIPG has revealed that activin receptor-like kinase-2 (ALK2) constitutes a potential target for therapeutic intervention given its dysregulation in the disease. We adopted an open science approach to develop a series of potent, selective, orally bioavailable, and brain-penetrant ALK2 inhibitors based on the lead compound LDN-214117. Modest structural changes to the C-3, C-4, and C-5 position substituents of the core pyridine ring afforded compounds M4K2009, M4K2117, and M4K2163, each with a superior potency, selectivity, and/or blood-brain barrier (BBB) penetration profile. Robust in vivo pharmacokinetic (PK) properties and tolerability mark these inhibitors as advanced preclinical compounds suitable for further development and evaluation in orthotopic models of DIPG.

Myalgia and Hematuria in Association with Clonidine and Arginine Administration for Growth Hormone Stimulation Tests

Growth hormone deficiency (GHD) in children has significant impacts on growth and metabolism. Two-agent GH stimulation tests are commonly used to diagnose GHD, and these tests are generally considered safe. We report the case of a 5-year 5-month-old boy with a history of anaplastic ependymoma who underwent GH stimulation testing for growth deceleration using clonidine and arginine. He developed bilateral calf myalgia and gross hematuria within 24 hours of the tests. Myalgia and hematuria resolved spontaneously. Importantly, the literature review and database searches for hematuria identified 6 cases with clonidine and 20 cases with arginine. This case highlights an unusual combination of adverse reactions to clonidine and arginine in children undergoing GH stimulation testing to assess for GHD. Pediatric endocrinologists need to be aware of the potential for these side effects to allow appropriate management, and further studies are needed to clarify the mechanisms and frequency of these side effects. We recommend that patients and families need to be counselled about hematuria as an association of GH testing with these medications.