Pre-irradiation intensive induction and marrow-ablative consolidation chemotherapy in young children with newly diagnosed high-grade brainstem gliomas: report of the "head-start" I and II clinical trials

An Update on H3K27M-altered Diffuse Midline Glioma: Diagnostic and Therapeutic Challenges in Clinical Practice

H3K27-altered diffuse midline glioma (DMG H3K27-altered) is a relatively newly-designated WHO entity which primarily affects the midline structures of the central nervous system (CNS), including the brainstem (predominantly pontine region), thalamus, midbrain, or spinal cord, and primarily affects children and young adults. Despite the proximity of these tumors to eloquent areas in the CNS, novel stereotactic approaches have facilitated the ability to obtain tissue diagnoses without significant morbidity, providing molecular diagnostic information in more than half of patients. Conventionally fractionated radiation therapy to a total dose of 54-60 Gy in 27-30 fractions and 24 Gy in 12 fractions play a crucial role in the definitive treatment of these tumors in the primary and salvage settings, respectively. Hypofractionated regimens may allow for accelerated treatment courses in selected patients without jeopardizing disease control or survival. The decision to add concurrent or adjuvant systemic therapy mainly relies on the physicians' experience without solid evidence in the literature in favor of any particular regimen. Recently, novel agents, such as ONC201 have demonstrated promising oncologic outcomes in progressive/recurrent tumors and are currently under investigation in ongoing randomized trials. Given the scarcity of data and well-established guidelines due to the rare nature of the disease, we provide a contemporary overview on the molecular underpinnings of this disease entity, describe the role of radiotherapy and systemic therapy, and present practice management principles based on the published literature.

A multimodal imaging-based classification for pediatric diffuse intrinsic pontine gliomas

OBJECT

Pediatric diffuse intrinsic pontine glioma (DIPG) is a radiologically heterogeneous disease entity, here we aim to establish a multimodal imaging-based radiological classification and evaluate the outcome of different treatment strategies under this classification frame.

METHODS

This retrospective study included 103 children diagnosed with DIPGs between January 2015 and August 2018 in Beijing Tiantan Hospital (Beijing, China). Multimodal radiological characteristics, including conventional magnetic resonance imaging (MRI), diffuse tensor imaging/diffuse tensor tractography (DTI/DTT), and positron emission tomography (PET) were reviewed to construct the classification. The outcome of different treatment strategies was compared in each DIPG subgroup using Kaplan-Meier method (log-rank test) to determine the optimal treatment for specific DIPGs.

RESULTS

Four radiological DIPG types were identified: Type A ("homocentric", n=13), Type B ("ventral", n=41), Type C ("eccentric", n=37), and Type D ("dorsal", n=12). Their treatment modalities were grouped as observation (43.7%), cytoreductive surgery (CRS) plus radiotherapy (RT) (24.3%), RT alone (11.7%), and CRS alone (20.4%). CRS+RT mainly fell into type C (29.7%), followed by type B1 (21.9%) and type D (50%). Overall, CRS+RT exhibited a potential survival advantage compared to RT alone, which was more pronounced in specific type, but this did not reach statistical significance, due to limited sample size and unbalanced distribution.

CONCLUSION

We proposed a multimodality imaging-based radiological classification for pediatric DIPG, which was useful for selecting optimal treatment strategies, especially for identifying candidates who may benefit from CRS plus RT. This classification opened a window into image-guided integrated treatment for pediatric DIPG.

Myeloablative Carboplatin and Thiotepa With Autologous Stem Cell Rescue for Nonmedulloblastoma High-risk CNS Tumors in Young Children

Malignant central nervous system (CNS) tumors in young children have a poor prognosis and pose a therapeutic challenge. We describe 11 patients with high-risk CNS tumors (6 atypical teratoid/rhabdoid tumor, 4 nonmedulloblastoma CNS embryonal tumors, and 1 glioblastoma multiforme) who received 32 consolidation cycles of myeloablative carboplatin/thiotepa followed by autologous peripheral blood stem cell rescue. All patients underwent successful stem cell harvest without significant complications. Mean time to absolute neutrophil count ≥0.5×103/µL was 10.2±1.3 days and the mean length of hospital stay was 15.7±3.0 days. There were no regimen-related deaths. Five-year event-free survival and overall survival were 45.5±15.0% and 58.4±16.3%, respectively. Tandem carboplatin/thiotepa consolidation with autologous stem cell rescue is well-tolerated in young children with nonmedulloblastoma CNS tumors.

Epidemiology and Survival of Patients With Brainstem Gliomas: A Population-Based Study Using the SEER Database

Background

Brainstem glioma is a primary glial tumor that arises from the midbrain, pons, and medulla. The objective of this study was to determine the population-based epidemiology, incidence, and outcomes of brainstem gliomas.

Methods

The data pertaining to patients with brainstem gliomas diagnosed between 2004 and 2016 were extracted from the SEER database. Descriptive analyses were conducted to evaluate the distribution and tumor-related characteristics of patients with brainstem gliomas. The possible prognostic indicators were analyzed by Kaplan-Meier curves and a Cox proportional hazards model.

Results

The age-adjusted incidence rate was 0.311 cases per 100,000 person-years between 2004 and 2016. A total of 3387 cases of brainstem gliomas were included in our study. Most of the patients were white and diagnosed at 5-9 years of age. The most common diagnosis confirmed by histological review was ependymoma/anaplastic ependymoma. The median survival time was 24 months. Patients with tumors less than 3 cm in size had a better prognosis. Surgery was effective at improving overall survival. There was no evidence that radiotherapy and chemotherapy improved overall survival.

Conclusion

Brainstem gliomas can be diagnosed at any age. Ependymoma/anaplastic ependymoma is the most common pathological diagnosis. The prognosis is poor, and timely diagnosis and surgery are effective at improving the prognosis. We suggest that more attention should be given to the treatment of patients with brainstem gliomas.

Infantile/Congenital High-Grade Gliomas: Molecular Features and Therapeutic Perspectives

Brain tumors in infants account for less than 10% of all pediatric nervous system tumors. They include tumors diagnosed in fetal age, neonatal age and in the first years of life. Among these, high-grade gliomas (HGGs) are a specific entity with a paradoxical clinical course that sets them apart from their pediatric and adult counterparts. Currently, surgery represents the main therapeutic strategy in the management of these tumors. Chemotherapy does not have a well-defined role whilst radiotherapy is rarely performed, considering its late effects. Information about molecular characterization is still limited, but it could represent a new fundamental tool in the therapeutic perspective of these tumors. Chimeric proteins derived from the fusion of several genes with neurotrophic tyrosine receptor kinase mutations have been described in high-grade gliomas in infants as well as in neonatal age and the recent discovery of targeted drugs may change the long-term prognosis of these tumors, along with other target-driven therapies. The aim of this mini review is to highlight the recent advances in the diagnosis and treatment of high-grade gliomas in infants with a particular focus on the molecular landscape of these neoplasms and future clinical applications.

Improving long-term survival in diffuse intrinsic pontine glioma

INTRODUCTION

Diffuse intrinsic pontine glioma (DIPG) is an almost universally fatal pediatric brain cancer. There has been no improvement in event-free survival (EFS) or overall survival (OS) despite immense effort through a multitude of clinical trials to find a cure. Recently, there has been a surge in the knowledge of DIPG biology, including the discovery of a recurrent H3F3A mutation in over 80% of these tumors.

AREAS COVERED

The authors review the most recent approaches to diagnosis and treatment of DIPG including chemotherapy, biologics, surgical approaches, and immunotherapy.

EXPERT OPINION

The authors propose four main opportunities to improve long-term survival. First, patients should be enrolled in scientifically sound clinical trials that include molecularly profiling either via stereotactic biopsy or liquid biopsy. Second, clinical trials should include more innovative endpoints other than traditional EFS and OS such as MRI/PET imaging findings combined with surrogates of activity (e.g. serial liquid biopsies) to better ascertain biologically active treatments. Third, innovative clinical trial approaches are needed to help allow for the rapid development of combination therapies to be tested. Finally, effort should be concentrated on reversing the effects of the histone mutation, as this malfunctioning development program seems to be key to DIPG relentlessness.