A Retrospective Genomic Landscape of 661 Young Adult Glioblastomas Diagnosed Using 2016 WHO Guidelines for Central Nervous System Tumors.

The authors present a cohort of 661 young adult glioblastomas diagnosed using 2016 WHO World Health Organization Classification of Tumors of the Central Nervous System, utilizing comprehensive genomic profiling (CGP) to explore their genomic landscape and assess their relationship to currently defined disease entities. This analysis explored variants with evidence of pathogenic function, common copy number variants (CNVs), and several novel fusion events not described in literature. Tumor mutational burden (TMB) mutational signatures, anatomic location, and tumor recurrence are further explored. Using data collected from CGP, unsupervised machine-learning techniques were leveraged to identify 10 genomic classes in previously assigned young adult glioblastomas. The authors relate these molecular classes to current World Health Organization guidelines and reference current literature to give therapeutic and prognostic descriptions where possible.

COVID-19-Related Reduction in Emergency Health Care Utilization Among Febrile Pediatric Oncology Patients.

The severe acute respiratory syndrome coronavirus (SARS-CoV-2) pandemic has disrupted normal health care utilization patterns worldwide, including decreasing emergency department (ED) visits for various medical emergencies. We examined whether this pattern was present in febrile pediatric oncology patients. In this single-center cohort study, we conducted a retrospective chart review of ED visits of febrile pediatric oncology patients during the first 4 months of the global SARS-CoV-2 pandemic and compared those data to the same time periods in the previous 2 years. During the first 5 months of the pandemic, 25 pediatric oncology patients with fever visited our ED; 65 children visited during the same time period in 2018; and 60 visited in 2019. Compared with 2018 and 2019, encounters for 2020 were decreased by 62% and 58%, respectively. A significantly higher percentage of febrile pediatric oncology patients (84%) were admitted to our hospital during the pandemic compared the previous years (58%). Of concern is the possibility that fear of exposure to coronavirus disease-19 (COVID-19) at our health care facility prompted caregivers of pediatric oncology patients to avoid seeking care for their child with fever. Consistent communication with families about the life-threatening nature of fever should be prioritized among pediatric oncology providers.

Targetable BRAF and RAF1 Alterations in Advanced Pediatric Cancers.

RAF family protein kinases signal through the MAPK pathway to orchestrate cellular proliferation, survival, and transformation. Identifying BRAF alterations in pediatric cancers is critically important as therapeutic agents targeting BRAF or MEK may be incorporated into the clinical management of these patients. In this study, we performed comprehensive genomic profiling on 3,633 pediatric cancer samples and identified a cohort of 221 (6.1%) cases with known or novel alterations in BRAF or RAF1 detected in extracranial solid tumors, brain tumors, or hematological malignancies. Eighty percent (176/221) of these tumors had a known-activating short variant (98, 55.7%), fusion (72, 40.9%), or insertion/deletion (6, 3.4%). Among BRAF altered cancers, the most common tumor types were brain tumors (74.4%), solid tumors (10.8%), hematological malignancies (9.1%), sarcomas (3.4%), and extracranial embryonal tumors (2.3%). RAF1 fusions containing intact RAF1 kinase domain (encoded by exons 10-17) were identified in seven tumors, including two novel fusions TMF1-RAF1 and SOX6-RAF1. Additionally, we highlight a subset of patients with brain tumor with positive clinical response to BRAF inhibitors, demonstrating the rationale for incorporating precision medicine into pediatric oncology. IMPLICATIONS FOR PRACTICE: Precision medicine has not yet gained a strong foothold in pediatric cancers. This study describes the landscape of BRAF and RAF1 genomic alterations across a diverse spectrum of pediatric cancers, primarily brain tumors, but also encompassing melanoma, sarcoma, several types of hematologic malignancy, and others. Given the availability of multiple U.S. Food and Drug Administration-approved BRAF inhibitors, identification of these alterations may assist with treatment decision making, as described here in three cases of pediatric cancer.

A comprehensive weight of evidence assessment of published acetaminophen genotoxicity data: Implications for its carcinogenic hazard potential.

In 2019, the California Office of Environmental Health Hazard Assessment initiated a review of the carcinogenic hazard potential of acetaminophen, including an assessment of its genotoxicity. The objective of this analysis was to inform this review process with a weight-of-evidence assessment of more than 65 acetaminophen genetic toxicology studies that are of widely varying quality and conformance to accepted standards and relevance to humans. In these studies, acetaminophen showed no evidence of induction of point or gene mutations in bacterial and mammalian cell systems or in in vivo studies. In reliable, well-controlled test systems, clastogenic effects were only observed in unstable, p53-deficient cell systems or at toxic and/or excessively high concentrations that adversely affect cellular processes (e.g., mitochondrial respiration) and cause cytotoxicity. Across the studies, there was no clear evidence that acetaminophen causes DNA damage in the absence of toxicity. In well-controlled clinical studies, there was no meaningful evidence of chromosomal damage. Based on this weight-of-evidence assessment, acetaminophen overwhelmingly produces negative results (i.e., is not a genotoxic hazard) in reliable, robust high-weight studies. Its mode of action produces cytotoxic effects before it can induce the stable, genetic damage that would be indicative of a genotoxic or carcinogenic hazard.

Assessment of the biochemical pathways for acetaminophen toxicity: Implications for its carcinogenic hazard potential.

In 2019 California's Office of Environmental Health Hazard Assessment (OEHHA) initiated a review of the carcinogenic hazard potential of acetaminophen. In parallel with this review, herein we evaluated the mechanistic data related to the steps and timing of cellular events following therapeutic recommended (≤4 g/day) and higher doses of acetaminophen that may cause hepatotoxicity to evaluate whether these changes indicate that acetaminophen is a carcinogenic hazard. At therapeutic recommended doses, acetaminophen forms limited amounts of N-acetyl-p-benzoquinone-imine (NAPQI) without adverse cellular effects. Following overdoses of acetaminophen, there is potential for more extensive formation of NAPQI and depletion of glutathione, which may result in mitochondrial dysfunction and DNA damage, but only at doses that result in cell death - thus making it implausible for acetaminophen to induce the kind of stable, genetic damage in the nucleus indicative of a genotoxic or carcinogenic hazard in humans. The collective data demonstrate a lack of a plausible mechanism related to carcinogenicity and are consistent with rodent cancer bioassays, epidemiological results reviewed in companion manuscripts in this issue, as well as conclusions of multiple international health authorities.

Treatment of Pediatric Glioblastoma with Combination Olaparib and Temozolomide Demonstrates 2-Year Durable Response.

For pediatric patients with high-grade gliomas, standard-of-care treatment includes surgery, chemotherapy, and radiation therapy; however, most patients ultimately succumb to their disease. With advances in genomic characterization of pediatric high-grade gliomas, the use of targeted therapies in combination with current treatment modalities offer the potential to improve survival in this patient population. In this report, we present the case of a 3-year-old girl with glioblastoma who continues to experience an exceptional and durable response (>2 years) to the poly (ADP-ribose) polymerase (PARP) inhibitor olaparib. Our patient presented with persistent and progressive seizure activity that upon workup was the result of a large heterogeneously enhancing, mixed cystic and solid mass in the left frontal-parietal-temporal region. Histopathologic analysis of resected tumor tissue confirmed the diagnosis of glioblastoma, and comprehensive genomic profiling demonstrated absence of any BRAF or H3F3A mutations. Genomic profiling, however, did reveal a probable germline heterozygous BRCA2 Lys3326Ter (K3226*) nonsense variant. After debulking surgery, the patient received standard-of-care treatment with radiation and temozolomide. Nine months later the PARP inhibitor olaparib was administered in combination with temozolomide for 16 cycles. This regimen was well tolerated by the patient and serial imaging showed reduction in tumor size. Since completion of the regimen, the patient remains neurologically intact with no evidence of tumor recurrence. To our knowledge, this represents the first case of a pediatric glioblastoma that maintains a durable response to a therapeutic strategy that included the PARP inhibitor olaparib and more generally highlights the potential clinical utility of incorporating these agents into the treatment of pediatric high-grade gliomas. KEY POINTS: Germline mutations detected in pediatric gliomas may represent a cancer predisposition syndrome. Integrating molecular testing into routine clinical care for pediatric patients with glioma is critical to identify therapeutic targets and patients with a cancer predisposition syndrome. Patients with glioma with defects in DNA repair pathway components (e.g., BRCA1/2) may show increased responsiveness to poly (ADP-ribose) polymerase (PARP) inhibitors. Combining PARP inhibitors with temozolomide (standard-of-care treatment) revealed no adverse events or toxicities over the course of 18 months.

Application of the DILIsym® Quantitative Systems Toxicology drug-induced liver injury model to evaluate the carcinogenic hazard potential of acetaminophen.

In 2019, the California Office of Environmental Health Hazard Assessment (OEHHA) initiated a review of the carcinogenic hazard potential of acetaminophen. The objective of the analysis herein was to inform this review by assessing whether variability in patient baseline characteristics (e.g. baseline glutathione (GSH) levels, pharmacokinetics, and capacity of hepatic antioxidants) leads to potential differences in carcinogenic hazard potential at different dosing schemes: maximum labeled doses of 4 g/day, repeated doses above the maximum labeled dose (>4-12 g/day), and acute overdoses of acetaminophen (>15 g). This was achieved by performing simulations of acetaminophen exposure in thousands of diverse virtual patients scenarios using the DILIsym® Quantitative Systems Toxicology (QST) model. Simulations included assessments of the dose and exposure response for toxicity and mode of cell death based on evaluations of the kinetics of changes of: GSH, N-acetyl-p-benzoquinone-imine (NAPQI), protein adducts, mitochondrial dysfunction, and hepatic cell death. Results support that, at therapeutic doses, cellular GSH binds to NAPQI providing sufficient buffering capacity to limit protein adduct formation and subsequent oxidative stress. Simulations evaluating repeated high-level supratherapeutic exposures or acute overdoses indicate that cell death precedes DNA damage that could result in carcinogenicity and thus acetaminophen does not present a carcinogenicity hazard to humans at any dose.

A critical review of the acetaminophen preclinical carcinogenicity and tumor promotion data and their implications for its carcinogenic hazard potential.

In 2019 the California Office of Environmental Health Hazard Assessment (OEHHA) initiated a review of the carcinogenic hazard potential of acetaminophen, including an assessment of the long-term rodent carcinogenicity and tumor initiation/promotion studies. The objective of the analysis herein was to inform this review process with a weight-of-evidence assessment of these studies and an assessment of the relevance of these models to humans. In most of the 14 studies, there were no increases in the incidences of tumors in any organ system. In the few studies in which an increase in tumor incidence was observed, there were factors such as absence of a dose response and a rodent-specific tumor supporting that these findings are not relevant to human hazard identification. In addition, we performed qualitative analysis and quantitative simulations of the exposures to acetaminophen and its metabolites and its toxicity profile; the data support that the rodent models are toxicologically relevant to humans. The preclinical carcinogenicity results are consistent with the broader weight of evidence assessment and evaluations of multiple international health authorities supporting that acetaminophen is not a carcinogenic hazard.

Precision Neuro-oncology: the Role of Genomic Testing in the Management of Adult and Pediatric Gliomas.

OPINION STATEMENT: In recent years, large-scale genomic studies have expanded our knowledge regarding genomic drivers in tumors of the central nervous system. While histopathologic analysis of brain tumors remains the primary method for tumor classification, the clinical utility of molecular and genomic testing to support and/or complement tumor classification continues to expand. This approach enhances diagnostic accuracy and provides clinicians with objective data to facilitate discussions regarding prognosis and treatment decisions, including selection of clinical trials. Ensuring accurate diagnoses is fundamental to the management of brain tumor patients. However, given the morphologic overlap among primary brain tumors, genomic data can be used to help distinguish tumor lineage. In its clearest form, we have embraced the concept of an integrated diagnosis, which combines traditional histopathology findings with molecular and genomic data. Patient prognosis varies significantly based on a tumor's genomic profile. For neuro-oncology patients, outcome studies linking diagnoses with genomic profiles show significant differences based on tumor biomarkers such as IDH1/2, H3F3A, BRAF, and CDKN2A and TERT status. Therefore, easy access to reliable genomic data is important in understanding a patient's disease and developing a clinical strategy wherein targeted molecular or immune therapies can be incorporated into the discussion.

Scientific and Regulatory Policy Committee (SRPC) Review: Interpretation and Use of Cell Proliferation Data in Cancer Risk Assessment.

Increased cell proliferation is a central key event in the mode of action for many non-genotoxic carcinogens, and quantitative cell proliferation data play an important role in the cancer risk assessment of many pharmaceutical and environmental compounds. Currently, there is limited unified information on assay standards, reference values, targeted applications, study design issues, and quality control considerations for proliferation data. Here, we review issues in measuring cell proliferation indices, considerations for targeted studies, and applications within current risk assessment frameworks. As the regulatory environment moves toward more prospective evaluations based on quantitative pathway-based models, standardization of proliferation assays will become an increasingly important part of cancer risk assessment. To help address this development, we also discuss the potential role for proliferation data as a component of alternative carcinogenicity testing models. This information should improve consistency of cell proliferation methods and increase efficiency of targeted testing strategies.

Recommendations from a global cross-company data sharing initiative on the incorporation of recovery phase animals in safety assessment studies to support first-in-human clinical trials.

An international expert group which includes 30 organisations (pharmaceutical companies, contract research organisations, academic institutions and regulatory bodies) has shared data on the use of recovery animals in the assessment of pharmaceutical safety for early development. These data have been used as an evidence-base to make recommendations on the inclusion of recovery animals in toxicology studies to achieve scientific objectives, while reducing animal use. Recovery animals are used in pharmaceutical development to provide information on the potential for a toxic effect to translate into long-term human risk. They are included on toxicology studies to assess whether effects observed during dosing persist or reverse once treatment ends. The group devised a questionnaire to collect information on the use of recovery animals in general regulatory toxicology studies to support first-in-human studies. Questions focused on study design, the rationale behind inclusion or exclusion and the impact this had on internal and regulatory decisions. Data on 137 compounds (including 53 biologicals and 78 small molecules) from 259 studies showed wide variation in where, when and why recovery animals were included. An analysis of individual study and programme design shows that there are opportunities to reduce the use of recovery animals without impacting drug development.

A living ex vivo platform for functional, personalized brain cancer diagnosis.

Functional precision medicine platforms are emerging as promising strategies to improve pre-clinical drug testing and guide clinical decisions. We have developed an organotypic brain slice culture (OBSC)-based platform and multi-parametric algorithm that enable rapid engraftment, treatment, and analysis of uncultured patient brain tumor tissue and patient-derived cell lines. The platform has supported engraftment of every patient tumor tested to this point: high- and low-grade adult and pediatric tumor tissue rapidly establishes on OBSCs among endogenous astrocytes and microglia while maintaining the tumor's original DNA profile. Our algorithm calculates dose-response relationships of both tumor kill and OBSC toxicity, generating summarized drug sensitivity scores on the basis of therapeutic window and allowing us to normalize response profiles across a panel of U.S. Food and Drug Administration (FDA)-approved and exploratory agents. Summarized patient tumor scores after OBSC treatment show positive associations to clinical outcomes, suggesting that the OBSC platform can provide rapid, accurate, functional testing to ultimately guide patient care.

Pilot study to determine effect of an altruism intervention focusing on herd immunity to enhance influenza vaccination rates.

OBJECTIVE: A prospective, single-arm clinical trial was conducted to evaluate an altruism-tailored educational intervention to improve parental attitudes and vaccine uptake in vaccine-hesitant parents. METHODS: Vaccine-hesitant parents at two primary care sites, spanning two influenza seasons from 2020 to 2021 were provided an intervention (spoken and written communication) which highlighted altruistic benefits of accepting the seasonal influenza vaccine to optimize herd immunity to help protect pediatric cancer patients. Eligible parents included those with children eligible for the seasonal influenza vaccine, those who were proficient in English, and those with scores on the adjusted Vaccine Hesitancy Scale (aVHS) suggesting vaccine hesitancy (score ≥ 3). Enrollees completed a demographic questionnaire, underwent the educational intervention, and repeated the aVHS. Vaccination status at that visit was assessed. The primary outcome was change in aVHS scores obtained pre- and post-intervention. Influenza vaccine acceptance, along with demographic information, were also analyzed. RESULTS: We enrolled 510 parents of influenza vaccine eligible children and identified 73 vaccine-hesitant parents. There was an overall trend toward lower aVHS score, with a mean change in hesitancy score of -0.4 (P < 0.01). 43/73 (58.9 %) of the cohort experienced a positive effect toward a lower aVHS score, and 27/73 (37.0 %) of vaccine hesitant subjects became non-hesitant on the aVHS. Several demographic characteristics were associated with vaccine hesitancy in the screening population: educational level lower than bachelor's degree (p = 0.03), household income < 400 % of federal poverty level (p < 0.01), unmarried (p = 0.02), and identifying with a political affiliation other than Democrat (p < 0.01). However, no demographic characteristics were significantly associated with an individual becoming non-hesitant. Our altruism-tailored communication approach carried the largest positive impact on the altruism-specific question on the aVHS, decreasing the post-intervention response value by nearly 25 % (P < 0.01). CONCLUSIONS: Our altruism-tailored communication approach significantly improved attitudes regarding childhood influenza vaccine among vaccine-hesitant parents. CLINICALTRIALS: gov Identifier: NCT04568590.

Bilateral conjunctival extranodal marginal zone B-cell lymphoma.

Extranodal marginal zone B-cell lymphomas (EMZLs), while relatively common in adults, are rare entities in the pediatric population. A subclass of the typically aggressive non-Hodgkin lymphomas, the few reported pediatric cases indicate that, as in adults, these tumors tend to be indolent. We present a case of EMZL arising in the conjunctivae in a 9-year-old male with bilateral disease. The patient was treated with surgical excision alone and has remained disease-free 6 years after the operation.

Cancer risk assessment approaches at the FDA/CDER: Is the era of the 2-year bioassay drawing to a close?

Determining the carcinogenic potential of materials to which humans have significant exposures is an important, complex, and imperfect exercise. Not only are the methods for such determinations protracted and expensive and use large numbers of animals, extrapolation of data from such studies to human risk is imprecise. With improved understanding of oncogene activation and tumor suppressor gene inactivation, a number of animal models have been developed to dramatically reduce latency for chemically induced cancers and has led to the development and use of shorter carcinogenicity assays. Recent studies by a number of investigators suggest that specific gene signature patterns seen after short-term exposure of rats to test chemicals can predict long-term outcomes in cancer bioassays with relatively high accuracy. In addition, a recent survey performed by PhRMA member companies examined two hundred drug years to determine whether histological biomarkers seen at the end of a six- or twelve-month toxicology study in rats can predict the outcome of a two-year carcinogenicity study. With only a handful of exceptions, chronic studies appear capable of predicting effects at the end of two years with good accuracy. It is hoped that the combination of results from transgenic mouse assays and six-month rat studies will soon supplant the need for most two-year bioassays.

Multi-Cell Type Glioblastoma Tumor Spheroids for Evaluating Sub-Population-Specific Drug Response.

Glioblastoma (GBM) is a lethal, incurable form of cancer in the brain. Even with maximally aggressive surgery and chemoradiotherapy, median patient survival is 14.5 months. These tumors infiltrate normal brain tissue, are surgically incurable, and universally recur. GBMs are characterized by genetic, epigenetic, and microenvironmental heterogeneity, and they evolve spontaneously over time and as a result of treatment. However, tracking such heterogeneity in real time in response to drug treatments has been impossible. Here we describe the development of an in vitro GBM tumor organoid model that is comprised of five distinct cellular subpopulations (4 GBM cell lines that represent GBM subpopulations and 1 astrocyte line), each fluorescently labeled with a different color. These multi-cell type GBM organoids are then embedded in a brain-like hyaluronic acid hydrogel for subsequent studies involving drug treatments and tracking of changes in relative numbers of each fluorescently unique subpopulation. This approach allows for the visual assessment of drug influence on individual subpopulations within GBM, and in future work can be expanded to supporting studies using patient tumor biospecimen-derived cells for personalized diagnostics.

Infant High-Grade Gliomas Comprise Multiple Subgroups Characterized by Novel Targetable Gene Fusions and Favorable Outcomes.

Infant high-grade gliomas appear clinically distinct from their counterparts in older children, indicating that histopathologic grading may not accurately reflect the biology of these tumors. We have collected 241 cases under 4 years of age, and carried out histologic review, methylation profiling, and custom panel, genome, or exome sequencing. After excluding tumors representing other established entities or subgroups, we identified 130 cases to be part of an "intrinsic" spectrum of disease specific to the infant population. These included those with targetable MAPK alterations, and a large proportion of remaining cases harboring gene fusions targeting ALK (n = 31), NTRK1/2/3 (n = 21), ROS1 (n = 9), and MET (n = 4) as their driving alterations, with evidence of efficacy of targeted agents in the clinic. These data strongly support the concept that infant gliomas require a change in diagnostic practice and management. SIGNIFICANCE: Infant high-grade gliomas in the cerebral hemispheres comprise novel subgroups, with a prevalence of ALK, NTRK1/2/3, ROS1, or MET gene fusions. Kinase fusion-positive tumors have better outcome and respond to targeted therapy clinically. Other subgroups have poor outcome, with fusion-negative cases possibly representing an epigenetically driven pluripotent stem cell phenotype.See related commentary by Szulzewsky and Cimino, p. 904.This article is highlighted in the In This Issue feature, p. 890.

Leveraging exploratory investigational new drug studies to accelerate drug development.

In 2006, the U.S. Food and Drug Administration published its guide on exploratory investigational new drug (IND) studies with the goal of making the approach to early-stage, pilot clinical trials more flexible within the context of current regulations. The exploratory IND allows sponsors to initiate clinical trials of limited scale with reduced preclinical requirements. These studies may be important vehicles for the conduct of proof-of-principle pharmacodynamic investigations of highly potent molecules, for bioavailability studies that require only a single drug dose to be administered, and for imaging trials that permit critical dosimetry and biodistribution investigations of new molecules. These trials were done with no therapeutic intent and must be followed by traditional dose-escalation investigations that are supported by standard preclinical toxicologic and pharmacologic studies. To the extent that they allow early evaluations of essential drug characteristics that can only be obtained in humans, exploratory IND trials have the potential to limit the cost and improve the development times of new agents.