Outcomes of pediatric glioblastoma treated with adjuvant chemoradiation with temozolomide and correlation with prognostic factors

Paediatric cerebellar glioblastoma - long-term survival following surgery and adjuvant chemoradiotherapy: A case report and literature review

Introduction

Paediatric cerebellar glioblastoma is an exceptionally rare clinical entity, with very few cases described in the literature. In the majority of reported cases, prognosis is extremely poor, despite surgical and oncological management. The paucity of data results in lack of consensus as to the optimal management of these patients, with the objective of prolonging survival.

Research question

Do patient or tumour characteristics suggest more favourable rates of progression-free survival in paediatric cerebellar glioblastoma?

Material and methods

Tumour histopathology plus retrospective molecular analysis of archived samples, as well treatment strategy and patient characteristics of a six-year-old child with cerebellar glioblastoma and prolonged progression-free survival were assessed. Characteristics in the published literature that inferred prolonged survival were identified and compared.

Results

Paediatric cerebellar glioblastoma is extremely rare, with only a handful of cases reported over several decades, during which time diagnostic and therapeutic techniques have evolved markedly. Consequently, the scarcity of data with sufficient granularity means that limited conclusions can be drawn. Specific clinical and histopathological factors (i.e. female sex, young age, EGFR negativity and surgical resection plus adjuvant chemoradiotherapy) may indicate a more favourable progression-free survival.

Discussion and conclusion

Rates of progression-free survival in this rare condition are generally poor, however, several patient and tumour characteristics may infer more favourable prognosis. As increasingly refined means of diagnosis and characterisation are developed, particularly as a result of advances in molecular analyses, more adjuvant treatment options are likely to come on stream in future.

Therapeutically targeting the unique disease landscape of pediatric high-grade gliomas

Pediatric high-grade gliomas (pHGG) are a rare yet devastating malignancy of the central nervous system's glial support cells, affecting children, adolescents, and young adults. Tumors of the central nervous system account for the leading cause of pediatric mortality of which high-grade gliomas present a significantly grim prognosis. While the past few decades have seen many pediatric cancers experiencing significant improvements in overall survival, the prospect of survival for patients diagnosed with pHGGs has conversely remained unchanged. This can be attributed in part to tumor heterogeneity and the existence of the blood-brain barrier. Advances in discovery research have substantiated the existence of unique subgroups of pHGGs displaying alternate responses to different therapeutics and varying degrees of overall survival. This highlights a necessity to approach discovery research and clinical management of the disease in an alternative subtype-dependent manner. This review covers traditional approaches to the therapeutic management of pHGGs, limitations of such methods and emerging alternatives. Novel mutations which predominate the pHGG landscape are highlighted and the therapeutic potential of targeting them in a subtype specific manner discussed. Collectively, this provides an insight into issues in need of transformative progress which arise during the management of pHGGs.

Updates on management of gliomas in the molecular age

Gliomas are primary brain tumors derived from glial cells of the central nervous system, afflicting both adults and children with distinct characteristics and therapeutic challenges. Recent developments have ushered in novel clinical and molecular prognostic factors, reshaping treatment paradigms based on classification and grading, determined by histological attributes and cellular lineage. This review article delves into the diverse treatment modalities tailored to the specific grades and molecular classifications of gliomas that are currently being discussed and used clinically in the year 2023. For adults, the therapeutic triad typically consists of surgical resection, chemotherapy, and radiotherapy. In contrast, pediatric gliomas, due to their diversity, require a more tailored approach. Although complete tumor excision can be curative based on the location and grade of the glioma, certain non-resectable cases demand a chemotherapy approach usually involving, vincristine and carboplatin. Additionally, if surgery or chemotherapy strategies are unsuccessful, Vinblastine can be used. Despite recent advancements in treatment methodologies, there remains a need of exploration in the literature, particularly concerning the efficacy of treatment regimens for isocitrate dehydrogenase type mutant astrocytomas and fine-tuned therapeutic approaches tailored for pediatric cohorts. This review article explores into the therapeutic modalities employed for both adult and pediatric gliomas in the context of their molecular classification.

ATM inhibition enhances the efficacy of radiation across distinct molecular subgroups of pediatric high-grade glioma

BACKGROUND

Pediatric high-grade glioma (pHGG) is largely incurable and accounts for most brain tumor-related deaths in children. Radiation is a standard therapy, yet the benefit from this treatment modality is transient, and most children succumb to disease within 2 years. Recent large-scale genomic studies suggest that pHGG has alterations in DNA damage response (DDR) pathways that induce resistance to DNA damaging agents. The aim of this study was to evaluate the therapeutic potential and molecular consequences of combining radiation with selective DDR inhibition in pHGG.

METHODS

We conducted an unbiased screen in pHGG cells that combined radiation with clinical candidates targeting the DDR and identified the ATM inhibitor AZD1390. Subsequently, we profiled AZD1390 + radiation in an extensive panel of early passage pHGG cell lines, mechanistically characterized response to the combination in vitro in sensitive and resistant cells and evaluated the combination in vivo using TP53 wild-type and TP53 mutant orthotopic xenografts.

RESULTS

AZD1390 significantly potentiated radiation across molecular subgroups of pHGG by increasing mutagenic nonhomologous end joining and augmenting genomic instability. In contrast to previous reports, ATM inhibition significantly improved the efficacy of radiation in both TP53 wild-type and TP53 mutant isogenic cell lines and distinct orthotopic xenograft models. Furthermore, we identified a novel mechanism of resistance to AZD1390 + radiation that was marked by an attenuated ATM pathway response which dampened sensitivity to ATM inhibition and induced synthetic lethality with ATR inhibition.

CONCLUSIONS

Our study supports the clinical evaluation of AZD1390 in combination with radiation in pediatric patients with HGG.

High-Grade Gliomas in Children-A Multi-Institutional Polish Study

Simple Summary

High-grade gliomas constitute less than 5% of pediatric brain tumors. Due to the rarity of such a diagnosis, the lack of consensus about the best therapeutic approach, and the difficulty in conducting prospective trials; a retrospective multi-institutional analysis, such as the one presented in this article, is needed. We carried out the survival analysis of children diagnosed and treated with high-grade gliomas in seven major polish institutions. The assessment of the outcome of 82 consecutive patients with grade III and grade IV tumors was performed and showed a 5-year overall survival of only 30%. The extent of resection, immediate temozolomide-based chemotherapy, and radical radiotherapy were found as factors positively influencing survival.

Abstract

Due to the rarity of high-grade gliomas (HGG) in children, data on this topic are scarce. The study aimed to investigate the long-term results of treatment of children with HGG and to identify factors related to better survival. We performed a retrospective analysis of patients treated for HGG who had the main tumor located outside the brainstem. The evaluation of factors that correlated with better survival was performed with the Cox proportional-hazard model. Survival was estimated with the Kaplan–Meier method. The study group consisted of 82 consecutive patients. All of them underwent surgery as primary treatment. Chemotherapy was applied in 93% of children with one third treated with temozolomide. After or during the systemic treatment, 79% of them received radiotherapy with a median dose of 54 Gy. Median follow-up was 122 months, and during that time, 59 patients died. One-, 2-, 5-, and 10-year overall survival was 78%, 48%, 30% and 17%, respectively. Patients with radical (R0) resection and temozolomide-based chemotherapy had better overall survival. Progression-free survival was better in patients after R0 resection and radical radiotherapy. The best outcome in HGG patients was observed in patients after R0 resection with immediate postoperative temozolomide-based chemotherapy and radical radiotherapy.

Clinical behaviour and outcome in pediatric glioblastoma: current scenario

Pediatric glioblastoma (pGBM) is a rare entity accounting for only approximately 3% of all childhood brain tumors. Treatment guidelines for pGBM have been extrapolated from those in adult glioblastoma. Rarity of pGBM and underrepresentation of pediatric population in major studies precludes from defining the ideal treatment protocol for these patients. Maximum safe resection is performed in most of the cases followed by postoperative radiotherapy in children over 3 years of age. Benefit of temozolomide is unclear in these patients. Here, we present the clinicopathological details and outcome of six pGBM patients treated at our institute in 2018–2019.

Challenges in the treatment of breast cancer brain metastases: evidence, unresolved questions, and a practical algorithm

Breast cancer is the leading cause of brain metastases in women. Large randomized clinical trials that have evaluated local therapies in patients with brain metastases include patients with brain metastases from a variety of cancer types. The incidence of brain metastases in the breast cancer population continues to grow, which is, aside from the rising breast cancer incidence, mainly attributable to improvements in systemic therapies leading to more durable control of extracranial metastatic disease and prolonged survival. The management of breast cancer brain metastases remains challenging, even more so with the continued advancement of local and highly effective systemic therapies. For most patients, a metastases-directed initial approach (i.e., radiation, surgery) represents the most appropriate initial therapy. Treatment should be based on multidisciplinary team discussions and a shared decision with the patients taking into account the risks and benefits of each therapeutic modality with the goal of prolonging survival while maintaining quality of life. In this narrative review, a multidisciplinary group of experts will address challenging questions in the context of current scientific literature and propose a therapeutic algorithm for breast cancer patients with brain metastases.

Acid ceramidase is a novel drug target for pediatric brain tumors

Pediatric brain tumors are the most common solid tumors in children and are also a leading culprit of cancer-related fatalities in children. Pediatric brain tumors remain hard to treat. In this study, we demonstrated that medulloblastoma, pediatric glioblastoma, and atypical teratoid rhabdoid tumors express significant levels of acid ceramidase, where levels are highest in the radioresistant tumors, suggesting that acid ceramidase may confer radioresistance. More importantly, we also showed that acid ceramidase inhibitors are highly effective at targeting these pediatric brain tumors with low IC₅₀ values (4.6–50 μM). This data suggests acid ceramidase as a novel drug target for adjuvant pediatric brain tumor therapies. Of these acid ceramidase inhibitors, carmofur has seen clinical use in Japan since 1981 for colorectal cancers and is a promising drug to undergo further animal studies and subsequently a clinical trial as a treatment for pediatric patients with brain tumors.

Extent of surgical resection and adjuvant temozolomide improves survival in pediatric GBM: a single center experience

BACKGROUND

Pediatric glioblastoma (pGBM) is an uncommon entity. The importance of concurrent and adjuvant temozolomide is not known in this subset of patients.

METHODS

We retrospectively analyzed our database between 2000 and 2015. All patients were treated with maximally safe surgical resection. This was followed by a uniform treatment schedule of post-operative radiation with concurrent daily temozolomide at 75 mg/m². Radiation dose was 60 Gy in 30 fractions planned by 3-dimensional conformal radiotherapy. Concurrent and adjuvant temozolomide was used in all patients treated after 2007. Four weeks later, adjuvant temozolomide was started at 150 mg/m², day 1 to 5 every 28 days and escalated to 200 mg/m² from the second cycle onwards if well tolerated. Log-rank test was used to compare survival distribution. The data was analyzed using SPSS (version 16).

RESULTS

Fifty-one patients were analyzed. Median age was 14 years (range: 5 to 21 years). Thirty-five males and 16 females were noted. Median symptom duration was 4 months. Twenty-eight patients underwent a gross total resection (GTR) while 17 underwent a subtotal resection; six patients underwent decompression. Thirty-three patients received concurrent chemotherapy while 27 received adjuvant chemotherapy. Median progression-free survival (PFS) was 15.1 months. One- and 3-year PFS was 54.4% and 3-year PFS was 24.6.7%. The median overall survival was 17.4 months. In univariate analysis survival was better for gross total resection (17.4 months vs. 11.5 months; p = 0.037), and significance maintained after multivariate analysis p = 0.026, HR 3.069, 95% CI 1.14-8.23. In univariate analysis, survival was better for patients receiving temozolomide but did not achieve significance. However, in multivariate analysis, use of temozolomide was associated with significantly improved survival p = 0.036, HR 3.315, 95% CI 1.07-10.19.

CONCLUSIONS

GTR improves survival significantly in pGBM. Adjuvant temozolomide may improve survival in pGBM.

Management of glioblastoma after recurrence: A changing paradigm

Glioblastoma remains the most common primary brain tumor after the age of 40years. Maximal safe surgery followed by adjuvant chemoradiotherapy has remained the standard treatment for glioblastoma (GBM). But recurrence is an inevitable event in the natural history of GBM with most patients experiencing it after 6-9months of primary treatment. Recurrent GBM poses great challenge to manage with no well-defined management protocols. The challenge starts from differentiating radiation necrosis from true local progression. A fine balance needs to be maintained on improving survival and assuring a better quality of life. Treatment options are limited and ranges from re-excision, re-irradiation, systemic chemotherapy or a combination of these. Re-excision and re-irradiation must be attempted in selected patients and has been shown to improve survival outcomes. To facilitate the management of GBM recurrences, a treatment algorithm is proposed.

Indian data on central nervous tumors: A summary of published work

Tumors of the central nervous system (CNS) constitute approximately 2% of all malignancies. Although relatively rare, the associated morbidity and mortality and the significant proportion of affected young and middle-aged individuals has a major bearing on the death-adjusted life years compared to other malignancies. CNS tumors encompass a very broad spectrum with regards to age, location, histology, and clinical outcomes. Advances in diagnostic imaging, surgical techniques, radiotherapy equipment, and generation of newer chemotherapeutic and targeted agents over the past few years have helped improving treatment outcome. Further insights into the molecular pathways leading to the development of tumors made in the past decade are being incorporated into routine clinical practice. Several focused groups within India have been working on a range of topics related to CNS tumors, and a significant body of work from India, in the recent years, is being increasingly recognized throughout the world. The present article summarizes key published work with particular emphasis on gliomas and medulloblastoma, the two commonly encountered tumors.

Pediatric gliosarcoma treated with adjuvant radiotherapy and temozolomide

PURPOSE

Primary pediatric gliosarcoma (pPGS) is an extremely rare entity with only 25 cases reported in the English literature. The value of concurrent and adjuvant temozolomide is not known in this group of patient.

METHODS

Five patients of pPGS treated from 2006 to 2011 were included in this retrospective analysis. All patients underwent maximal safe surgical resection. Adjuvant therapy included conformal radiation 60 Gy in 30 fractions (2 Gy daily for 5 days in a week) with concurrent temozolomide 75 mg/m(2) daily followed by six cycles of maintenance temozolomide 150-200 mg/m(2) (day 1 to day 5) every 4 weeks. We combined the survival data of 25 patients (already published) and five of our patients and analyzed them in terms of progression free survival (PFS) and overall survival (OS) using Kaplan-Meier method.

RESULTS

Male to female ratio was 1:4 and median age was 12 years (range, 7-19 years). All but one patient underwent gross total resection and four patients completed adjuvant radiotherapy as well as concurrent and adjuvant temozolomide. At a median follow up of 22.6 months (range, 0 to 45.3 months), two patients were dead and two were alive without disease while one was lost to follow up. For the pooled data, estimated median PFS and OS of all 30 patients reported in literature were 12 and 43 months, respectively. Two years PFS and OS rate for all patients was 44.2 and 62.9%, respectively.

CONCLUSION

Adjuvant radiotherapy and temozolomide is well tolerated and show an encouraging survival in pPGS.

Therapeutic approach beyond conventional temozolomide for newly diagnosed glioblastoma: Review of the present evidence and future direction

Glioblastoma multiforme (GBM) is the most aggressive form of primary brain tumor. Maximal safe surgical resection followed by adjuvant partial brain radiation with concurrent and adjuvant temozolomide (TMZ) (oral alkylating agent) is the standard of care. Five years survival in TMZ treated patient reaches 9.8%. We aimed to summarize the changes in the management of GBM beyond conventional temozolomide based adjuvant treatment. We searched the PUBMED with the following key words: Glioblastoma, phase III trial, Phase II trial, adjuvant treatment in GBM. Clinical research has found a wide range of molecular aberrations in GBM and attempts are being made to further improve survival with the addition of different classes of drugs. Angiogenesis inhibitors, oncolytic vaccines, dose dense TMZ, and anti-epidermal growth factor receptor monoclonal antibody in phase III trials have failed to improve survival. Recent studies have also shown that the management strategies might be different and needs to be customized as per the age of patients such as pediatric and elderly patients. In addition, treatments should be personalized depending on the molecular aberrations. We reviewed all published phase III trials for newly diagnosed GBM as well as also looked into possible future directions in this review. Limited progress has happed beyond conventional TMZ in the adjuvant treatment of GBM. Newer insights are emerging about treatment intensification and introduction of newer molecular targeted drugs with more information about molecular aberrations.