Advances in the Treatment of Pediatric Brain Tumors

Short-term sensorimotor training incorporating cognitive tasks for pediatric survivors of posterior fossa tumors: a pilot study

PURPOSE

Posterior fossa tumors account for half of all childhood brain tumors, prompting the search for effective and affordable interventions to combat the neurocognitive and motor sequelae of the tumor and its treatment. The main aim of this pilot study was to evaluate the feasibility and effects of sensorimotor training incorporating cognitive tasks for a group of pediatric survivors of posterior fossa tumors.

MATERIALS AND METHODS

A total of 48 participants (Mage= 12.3 ± 3.25 years, 41.7% female; 56% with malignant tumors) in remission after completing treatment for posterior fossa tumors were enrolled. Participants received 3 weeks of sensorimotor training targeting visual-motor and cognitive abilities on a FitLight Trainer™. The protocol consisted of 2-3 15-minute training sessions per week, with each session including tasks designed to promote: (1) eye-hand and eye-foot coordination and motor control (simple sensorimotor reaction task); (2) inhibitory control (inhibition task); (3) inhibitory control and working memory (color task).

RESULTS

Participants completed an average of six sessions, indicating a moderate adherence rate. Results showed a significant reduction in visuomotor reaction time across age and tumor subgroups in nearly all tasks, which might indicate improvement in the targeted functions, with performance characteristics varying across subgroups.

CONCLUSION

The results suggest that training might be a feasible intervention to promote visual-motor performance in pediatric survivors of posterior fossa tumors across age and tumor type groups, however, further research should address the assessment issues and other limitations of the present study, to provide a more substantial justification for the use of this training.

Molecular characterization of gliomas and glioneuronal tumors amid Noonan syndrome: cancer predisposition examined

Introduction

In the setting of pediatric and adolescent young adult cancer, increased access to genomic profiling has enhanced the detection of genetic variation associated with cancer predisposition, including germline syndromic conditions. Noonan syndrome (NS) is associated with the germline RAS pathway activating alterations and increased risk of cancer. Herein, we describe our comprehensive molecular profiling approach, the association of NS with glioma and glioneuronal tumors, and the clinical and histopathologic characteristics associated with the disease.

Methods

Within an institutional pediatric cancer cohort (n = 314), molecular profiling comprised of paired somatic disease-germline comparator exome analysis, RNA sequencing, and tumor classification by DNA methylation analysis was performed.

Results

Through the implementation of paired analysis, this study identified 4 of 314 (1.3%) individuals who harbored a germline PTPN11 variant associated with NS, of which 3 individuals were diagnosed with a glioma or glioneuronal tumor. Furthermore, we extend this study through collaboration with a peer institution to identify two additional individuals with NS and a glioma or glioneuronal tumor. Notably, in three of five (60%) individuals, paired genomic profiling led to a previously unrecognized diagnosis of Noonan syndrome despite an average age of cancer diagnosis of 16.8 years. The study of the disease-involved tissue identified signaling pathway dysregulation through somatic alteration of genes involved in cellular proliferation, survival, and differentiation.

Discussion

Comparative pathologic findings are presented to enable an in-depth examination of disease characteristics. This comprehensive analysis highlights the association of gliomas and glioneuronal tumors with RASopathies and the potential therapeutic challenges and importantly demonstrates the utility of genomic profiling for the identification of germline cancer predisposition.

The telovelar approach for fourth ventricular tumors in children: is removal of the posterior arch of C1 necessary?

PURPOSE

Various surgical nuances of the telovelar approach have been suggested. The necessity of removing the posterior arch of C1 to accomplish optimal tumor exposure is still debated. Therefore, we report on our experience and technical details of the fourth ventricular tumor resection in a modified prone position without systematic removal of the posterior arch of C1.

METHODS

A retrospective analysis of all pediatric patients, who underwent a fourth ventricular tumor resection in the modified prone position between 2012 and 2021, was performed.

RESULTS

We identified 40 patients with a median age of 6 years and a M:F ratio of 25:15. A telovelar approach was performed in all cases. In 39/40 patients, the posterior arch of C1 was not removed. In the remaining patient, the reason for removing C1 was tumor extension below the level of C2 with ventral extension. Gross or near total resection could be achieved in 34/39 patients, and subtotal resection in 5/39 patients. In none of the patients, a limited exposure, sight of view, or range of motion caused by the posterior arch of C1 was encountered, necessitating an unplanned removal of the posterior arch of C1. Importantly, in none of the cases, the surgeon had the impression of a limited sight of view to the most rostral parts of the fourth ventricle, which necessitated a vermian incision.

CONCLUSION

A telovelar approach without the removal of the posterior arch of C1 allows for an optimal exposure of the fourth ventricle provided that critical nuances in patient positioning are considered.

OV Modulators of the Paediatric Brain TIME: Current Status, Combination Strategies, Limitations and Future Directions

Oncolytic viruses (OVs) are characterised by their preference for infecting and replicating in tumour cells either naturally or after genetic modification, resulting in oncolysis. Furthermore, OVs can elicit both local and systemic anticancer immune responses while specifically infecting and lysing tumour cells. These characteristics render them a promising therapeutic approach for paediatric brain tumours (PBTs). PBTs are frequently marked by a cold tumour immune microenvironment (TIME), which suppresses immunotherapies. Recent preclinical and clinical studies have demonstrated the capability of OVs to induce a proinflammatory immune response, thereby modifying the TIME. In-depth insights into the effect of OVs on different cell types in the TIME may therefore provide a compelling basis for using OVs in combination with other immunotherapy modalities. However, certain limitations persist in our understanding of oncolytic viruses' ability to regulate the TIME to enhance anti-tumour activity. These limitations primarily stem from the translational limitations of model systems, the difficulties associated with tracking reliable markers of efficacy throughout the course of treatment and the role of pre-existing viral immunity. In this review, we describe the different alterations observed in the TIME in PBTs due to OV treatment, combination therapies of OVs with different immunotherapies and the hurdles limiting the development of effective OV therapies while suggesting future directions based on existing evidence.

Effects of cognitive-motor intervention for pediatric posterior fossa tumor survivors: results of a pilot study

The purpose of this prospective pilot study was to evaluate the feasibility and effects of cognitive-motor intervention on the cognitive and motor abilities of pediatric survivors of posterior fossa tumors. The study involved patients aged 7 to 18 years with cognitive deficits who had completed primary treatment for posterior fossa tumors. 25 participants (Mage=11.3 ± 2.93, 64% male; 17 medulloblastoma, 1 ependymoma, 1 desmoplastic medulloblastoma, 6 piloid astrocytoma; 22 in remission (Mmonths =45), 3 in stabilization (Mmonths=49)) were recruited from the Research Institute for Brain Development and Peak Performance. The intervention consisted of two phases with a 3-month break for home training, and a total duration of 6 months. Each phase lasted 7 weeks and included two assessment procedures (pre- and post-intervention) and 10 training sessions over a period of 5 weeks (two 3-hour sessions per week). At baseline and pre- and post-intervention, all participants underwent a battery of cognitive and motor tests. Each training session included gross motor training (GMT), graphomotor training (GT), and cognitive-motor training (CMT). Statistical analysis was performed using the Friedman test for repeated measures and post-hoc Durbin-Conover test. The results indicated significant improvements in visuospatial working memory, visual attention, eye-hand coordination, semantic verbal fluency, auditory-motor synchronization, reaction time, and a decrease in the rate of ataxia. These improvements remained stable even in the absence of direct intervention. The findings demonstrate positive effects and feasibility of the intervention and suggest the need for further research in this area including randomized controlled feasibility studies with a larger sample.

Brazilian pediatric patients with gliomas: treatment characteristics and survival outcomes

Background

The current study aimed to determine the overall survival (OS) rates of patients diagnosed with pediatric gliomas in Brazil, accounting for the influence of age, treatment modalities, and tumor site, using a population-based national database.

Materials and methods

Patients diagnosed with pediatric gliomas of central nervous system (CNS) from 1999-2020 were identified from The Fundação Oncocentro de São Paulo public database. The Kaplan-Meier and the log-rank test were used for survival analysis.

Results

A total of 1296 patients were included. The most common histologic tumor types were glioblastomas (38.27%; n = 496), pilocytic astrocytoma (32.87%; n = 426), and astrocytoma grade II (20.76%; n = 269). A total of 379 (29.24%) had brainstem tumors. The mean follow-up was 135 months [95% confidence interval (CI) 128-142\. The 1-year, 3-year 5-year OS for pilocytic astrocytoma were 93.72%, 89.98%, and 88.97%; for grade II gliomas, 80.36%, 71.89%, and 68.60%; for grade III gliomas, 53.72%; 31.87%, and 28.33%; and for glioblastoma, 52.90%, 28.76%, 25.20%, respectively. Brainstem tumors had the worse OS compared to no brainstem tumors (p = 0.001). For high-grade glioma (grade III/IV), excluding brainstem tumors (n = 570), young patients had greater median OS (0 to 3 years:22 months; 4 to 18 years:13 months; p = 0.005). Regarding the treatment modalities, combined treatments were associated with higher median survival compared to less intensive therapy (surgery: 11 months; surgery and chemotherapy: 16 months; surgery, radiotherapy, and chemotherapy: 20 months; p = 0.005).

Conclusion

In our cohort, low-grade gliomas had favorable prognoses and outcomes. Patients diagnosed with glioblastomas and brainstem gliomas had the worst OS. For high-grade gliomas, undergoing treatment de-intensification in the Brazilian pediatric population is associated with worse survival.

Overcoming the challenge of a thin skull in a 2-year-old patient undergoing laser interstitial thermal therapy using an individualized stereotactic platform: illustrative case

BACKGROUND

Ependymoma is the third most common pediatric brain tumor that can present with headaches, cranial nerve deficits, nausea, vomiting, and ataxia. Current treatment is maximal safe resection followed by radiation therapy. More recently, laser interstitial thermal therapy (LITT) has become an alternative to traditional resection. In this report, the authors describe the utilization of a single-use, patient-specific stereotactic platform for the treatment of supratentorial ependymoma with LITT.

OBSERVATIONS

A 2-year-old female had a complex history of supratentorial ependymoma after multiple craniotomies for repeated tumor progression and ventriculoperitoneal shunt placement. Imaging demonstrated an enlarging, complex, enhancing mass in the right occipital region. LITT was decided on for treatment. Given the thinness of the patient's skull, which precluded traditional means of stereotaxy, the authors elected to use a personalized stereotactic platform. Immediate postoperative imaging captured complete laser ablation of the tumor, with long-term imaging demonstrating a decreased tumor size.

LESSONS

Individualized stereotactic platforms are increasingly used in adult populations, but pediatric use continues to be infrequent. In this report, the authors present the youngest reported case using a personalized stereotactic platform and show the effectiveness of this system for performing LITT in the youngest of populations with very thin skulls.

Incidence and Mortality of Malignant Brain Tumors after 20 Years of Mobile Use

(1) Objective: This population-based study was performed to examine the trends of incidence and deaths due to malignant neoplasm of the brain (MNB) in association with mobile phone usage for a period of 20 years (January 2000-December 2019) in Taiwan. (2) Methods: Pearson correlation, regression analysis, and joinpoint regression analysis were used to examine the trends of incidence of MNB and deaths due to MNB in association with mobile phone usage. (3) Results: The findings indicate a trend of increase in the number of mobile phone users over the study period, accompanied by a slight rise in the incidence and death rates of MNB. The compound annual growth rates further support these observations, highlighting consistent growth in mobile phone users and a corresponding increase in MNB incidences and deaths. (4) Conclusions: The results suggest a weaker association between the growing number of mobile phone users and the rising rates of MNB, and no significant correlation was observed between MNB incidences and deaths and mobile phone usage. Ultimately, it is important to acknowledge that conclusive results cannot be drawn at this stage and further investigation is required by considering various other confounding factors and potential risks to obtain more definitive findings and a clearer picture.

Pediatric Posterior Fossa ATRT: A Case Report, New Treatment Strategies and Perspectives

Posterior fossa atypical teratoid rhabdoid tumor (ATRT) is a rare childhood tumor usually associated with a dismal prognosis. Although upfront surgical gross total resection (GTR) has classically been the first line of treatment, new multimodal treatments, including two-stage surgery, are showing promising results in terms of overall survival (OS) and complication rate. We present a case of a 9-month-old child treated with two-staged surgery and chemotherapy. When deemed risky, multimodal treatments, including staged surgeries, can be a safe alternative to reduce surgical mortality and morbidity. At 23 months old, the patient had normal global development and no major impact on quality of life. We, therefore, discuss the most recent advancements from a treatment perspective, including molecular targeting.

Human papillomavirus in cancer: Infection, disease transmission, and progress in vaccines

Human papillomaviruses (HPVs) infect epithelial cells of human beings, and their replication cycle is associated with epithelial differentiation. More than 200 genotypes of HPVs were identified, and each of these HPVs shows distinct specificity for tissues and infection. HPV infection was involved in the development of lesions on the feet, genital warts and hands. The evidence of HPV infection revealed the role of HPVs in neck and head squamous cell carcinoma, esophageal cancer, cervical cancer, head and neck cancer, brain and lung tumours. The independent traditional risk factors, various clinical outcomes, and increased prevalence among certain populations and geographical regions have led increasing interest in HPV infection. The mode of HPVs transmission remains unclear. Moreover, in recent years, vertical transmission of HPVs was reported. This review concludes present knowledge about HPV infection, virulence strains, clinical significance of HPVs, and mode of transmission, and vaccination strategies.