Neurocognitive and Psychological Functioning of Children with an Intracranial Germ Cell Tumor

Neurocognitive Dysfunction After Treatment for Pediatric Brain Tumors: Subtype-Specific Findings and Proposal for Brain Network-Informed Evaluations

The increasing number of long-term survivors of pediatric brain tumors requires us to incorporate the most recent knowledge derived from cognitive neuroscience into their oncological treatment. As the lesion itself, as well as each treatment, can cause specific neural damage, the long-term neurocognitive outcomes are highly complex and challenging to assess. The number of neurocognitive studies in this population grows exponentially worldwide, motivating modern neuroscience to provide guidance in follow-up before, during and after treatment. In this review, we provide an overview of structural and functional brain connectomes and their role in the neuropsychological outcomes of specific brain tumor types. Based on this information, we propose a theoretical neuroscientific framework to apply appropriate neuropsychological and imaging follow-up for future clinical care and rehabilitation trials.

Brain and Spinal Tumors Originating from the Germ Line Cells

Primary central nervous system germ cell tumors (CNS GCTs) are part of the GCTs in children and adults. This tumor entity presents with geographic variation, age, and sex predilection. There are two age peaks of incidence distribution at the first few months of life and in adolescence. CNS GCTs are heterogeneous in histopathological subtypes, locations, and tumor marker (AFP, β-hCG) secretions. In the WHO CNS tumor classification, GCTS are classified as germinoma and nongerminomatous GCT (NGGCT) with different subtypes (including teratoma). Excluding mature teratoma, the remaining NGGCTs are malignant (NGMGCT). In teratoma, growing teratoma syndrome and teratoma with somatic-type malignancy should be highlighted. The common intracranial locations are pineal region, neurohypophysis (NH), bifocal pineal-NH, basal ganglia, and cerebral ventricle. Above 50% of intracranial GCTs (IGCTs) present obstructive hydrocephalus. Spinal tumors are rare. Age, locations, hydrocephalus, and serum/CSF titer of β-hCG correlate with clinical manifestations. Delayed diagnosis is common in tumors arising in neurohypophysis, bifocal, and basal ganglia resulting in the increasing of physical dysfunction and hormonal deficits. Staging work-up includes CSF cytology for tumor cells and contrast-enhanced MRI of brain and spine for macroscopic metastasis before treatment commences. The therapeutic approach of CNS GCTs integrates locations, histopathology, staging, tumor marker level, and therapeutic classification. Treatment strategies include surgical biopsy/excision, chemotherapy, radiotherapy (single or combination). Secreting tumors with consistent imaging may not require histopathological diagnosis. Primary germinomas are highly radiosensitive and the therapeutic aim is to maintain high survival rate using optimal radiotherapy regimen with/without chemotherapy combination. Primary NGNGCTs are less radiosensitive. The therapeutic aim is to increase survival utilizing more intensive chemotherapy and radiotherapy. The negative prognostic factors are residue disease at the end of treatment and serum or CSF AFP level >1000 ng/mL at diagnosis. In refractory or recurrent NMGGCTs, besides high-dose chemotherapy, new therapy is necessary. Molecular profiling and analysis help for translational research. Survivors of pediatric brain tumors frequently experience cancer-related cognitive dysfunction, physical disability, pituitary hormone deficiency, and other CNS complications after cranial radiotherapy. Continuous surveillance and assessment may lead to improvements in treatment protocols, transdisciplinary interventions, after-treatment rehabilitation, and quality of life.

Proton therapy for pediatric diencephalic tumors

Diencephalic tumors tend to be low grade tumors located near several critical structures, including the optic nerves, optic chiasm, pituitary, hypothalamus, Circle of Willis, and hippocampi. In children, damage to these structures can impact physical and cognitive development over time. Thus, the goal of radiotherapy is to maximize long term survival while minimizing late effects, including endocrine disruption leading to precocious puberty, height loss, hypogonadotropic hypogonadism, and primary amenorrhea; visual disruption including blindness; and vascular damage resulting in cerebral vasculopathy. Compared to photon therapy, proton therapy offers the potential to decrease unnecessary dose to these critical structures while maintaining adequate dose to the tumor. In this article, we review the acute and chronic toxicities associated with radiation for pediatric diencephalic tumors, focusing on the use of proton therapy to minimize treatment-related morbidity. Emerging strategies to further reduce radiation dose to critical structures will also be considered.

Socio-behavioral dysfunction in disorders of hypothalamic-pituitary involvement: The potential role of disease-induced oxytocin and vasopressin signaling deficits

Disorders involving hypothalamic and pituitary (HPIT) structures-including craniopharyngioma, Langerhans cell histiocytosis, and intracranial germ cell tumors-can disrupt brain and endocrine function. An area of emerging clinical concern in patients with these disorders is the co-occurring socio-behavioral dysfunction that persists after standard hormone replacement therapy. Although the two neuropeptides most implicated in mammalian social functioning (oxytocin and arginine vasopressin) are of hypothalamic origin, little is known about how disease-induced damage to HPIT structures may disrupt neuropeptide signaling and, in turn, impact patients' socio-behavioral functioning. Here we provide a clinical primer on disorders of HPIT involvement and a review of neuropeptide signaling and socio-behavioral functioning in relevant animal models and patient populations. This collective evidence suggests that neuropeptide signaling disruptions contribute to socio-behavioral deficits experienced by patients with disorders of HPIT involvement. A better understanding of the biological underpinnings of patients' socio-behavioral symptoms is now needed to enable the development of the first targeted pharmacological strategies by which to manage patients' socio-behavioral dysfunction.

Neurobehavioral Impairment in Pediatric Brain Tumor Survivors: A Meta-Analysis

Purpose: The neurocognitive outcomes of pediatric brain tumor survivors have been extensively studied but the risk and predictors for neurobehavioral impairment are less clearly defined. We systematically analyzed the rates of emotional, psychosocial, and attention problems in pediatric brain tumor survivors. Methods: PubMed, Web of Science, Embase, Scopus, and Cochrane were searched for articles published between January 2012 to April 2022. Eligible studies reported neurobehavioral outcomes for PBTS aged 2 to <23 years with a brain tumor diagnosis before 18 years of age. A random-effect meta-analysis was performed in R. Results: The search yielded 1187 unique publications, of which 50 were included in the quantitative analysis. The estimated risk of having emotional, psychosocial, and attention problems were 15% (95%CI 10−20%), 12% (95%CI 9−16%), and 12% (95%CI 9−16%), respectively. PBTS were more likely to have emotional difficulties (Hedge’s g = 0.43 [95%CI 0.34−0.52]), psychosocial problems (Hedge’s g = 0.46 [95%CI 0.33−0.58]), and attention problems (Hedge’s g = 0.48 [95%CI 0.34−0.63]) compared to normal/healthy control subjects. There was no significant difference in the rates of neurobehavioral impairment between children with and without history of cranial radiotherapy. Conclusions: PBTS are at elevated risk of neurobehavioral impairment. Neurobehavioral monitoring should be considered as the standard of care for PBTS.

Hyperbaric Oxygen Therapy as a Complementary Treatment in Glioblastoma-A Scoping Review

Glioblastoma (GBM) is the most common and aggressive malignant brain tumor in adults. The mainstay of management for GBM is surgical resection, radiation (RT), and chemotherapy (CT). Even with optimized multimodal treatment, GBM has a high recurrence and poor survival rates ranging from 12 to 24 months in most patients. Recently, relevant advances in understanding GBM pathophysiology have opened new avenues for therapies for recurrent and newly diagnosed diseases. GBM's hypoxic microenvironment has been shown to be highly associated with aggressive biology and resistance to RT and CT. Hyperbaric oxygen therapy (HBOT) may increase anticancer therapy sensitivity by increasing oxygen tension within the hypoxic regions of the neoplastic tissue. Previous data have investigated HBOT in combination with cytostatic compounds, with an improvement of neoplastic tissue oxygenation, inhibition of HIF-1α activity, and a significant reduction in the proliferation of GBM cells. The biological effect of ionizing radiation has been reported to be higher when it is delivered under well-oxygenated rather than anoxic conditions. Several hypoxia-targeting strategies reported that HBOT showed the most significant effect that could potentially improve RT outcomes, with higher response rates and survival and no serious adverse events. However, further prospective and randomized studies are necessary to validate HBOT's effectiveness in the 'real world' GBM clinical practice.

Neurocognitive and psychological functioning of pediatric brain tumor patients undergoing proton beam therapy for three different tumor types

BACKGROUND

A high proportion of pediatric patients with brain tumors (BTs) are known to experience a decline in neurocognitive function after treatment. We prospectively examined neuropsychological functioning of patients with BTs of varying tumor types at different time points before, during, and after proton beam therapy.

MATERIALS AND METHODS

A total of 98 patients with posterior fossa tumors (PFTs; n = 33), germ cell tumors (GCTs; n = 52), and other supratentorial tumors (STTs; n = 13) underwent baseline neuropsychological assessments and 57 patients underwent follow-up assessments.

RESULTS

All groups displayed significantly lower performance intelligence quotient (PIQ) and processing speed (PS) scores than the normative means at baseline. The PFT group exhibited significantly lower scores for full-scale IQ, PIQ, PS, attention, and executive function. The GCT group displayed full-scale IQ scores within the normal range, but a significantly high proportion had memory deficits. In the STT group, all functions except for the PIQ and PS were intact. Longitudinal evaluations demonstrated stable global IQ scores over time in all groups. In the PFT group, verbal comprehension, attention, and PS improved over time. However, in the GCT group, verbal IQ scores declined significantly and psychological problems worsened over time, which were correlated with poorer neurocognitive function at 3-5 years after treatment. In the STT group, no significant changes were observed.

CONCLUSION

Because patients with BTs exhibit various types of neurocognitive deficit before radiotherapy, early cognitive treatment tailored to the tumor type maybe beneficial. Interventions for psychological problems and memory function may be necessary, especially for patients with GCT.

The Japan Society for Neuro-Oncology Guideline on the Diagnosis and Treatment of Central Nervous System Germ Cell Tumors

Primary CNS germ cell tumors (GCTs) are rare neoplasms predominantly observed in the pediatric and young adult populations. In line with the hypothesis that the primordial germ cell is the cell-of-origin, histopathological examinations for this pathology involve a diverse range of components mirroring the embryogenic developmental dimensions. Chemotherapy and radiotherapy are the mainstays of treatment, with surgery having a limited role for diagnosis and debulking of residual tissue after treatment. While better management has been achieved over recent decades by modifying radiation coverage and selecting appropriate chemotherapy, standardization of treatment remains challenging, partly due to the low volume of cases encountered in each institution. As the incidence is higher in East Asia, including Japan, the Japan Society for Neuro-Oncology established a multidisciplinary task force to create an evidence-based guideline for CNS GCTs. This guideline provides recommendations for multiple dimensions of clinical management for CNS GCTs, with particular focus on diagnostic measures including serum markers, treatment algorithms including surgery, radiotherapy and chemotherapy, and under-investigated but important areas such as treatment for recurrent cases, long-term follow-up protocols and long-term sequelae. This guideline serves the purpose of helping healthcare professionals keep up to date with current knowledge and standards of management for patients with this rare disease in daily clinical practice, as well as driving future translational and clinical research by recognizing unmet needs concerning this tumor.

Behavior Disorder and Social Function Impairment in Children with Basal Ganglia Germ Cell Tumors

PURPOSE

Basal ganglia intracranial germ cell tumors (iGCTs) can specifically destroy the basal ganglia network, leading to several cognitive, learning, behavioral, and social impairments. This study aimed to investigate the behavior and social disorders of patients with basal ganglia iGCTs.

PATIENTS AND METHODS

We recruited 30 newly diagnosed iGCTs patients (and their parents) for the current study. The Child Behavior Checklist/6-18 was used to evaluate emotional and behavioral problems. The Conner's Parent Rating Scales was used to assess symptoms of hyperactivity/impulsivity and conduct problems. The health-related quality of life (HRQoL) was assessed using the Pediatric Quality of Life Inventory 4.0 Generic Core Scale. Performance status was assessed using the Lansky play-performance scale and Karnofsky performance scale. The effects of basal ganglia lesions on these scores were examined.

RESULTS

Patients with basal ganglia iGCTs (n = 10) had more behavioral problems (attention problems, aggressive behavior, learning problems, hyperactivity index), social function impairment, anxiety/depression, and poorer HRQoL compared to patients with non-basal ganglia iGCTs (n = 20). There was no significant difference in the Lansky play-performance/Karnofsky performance scale scores.

CONCLUSION

This study demonstrates the effects of basal ganglia lesions on behavioral and emotional outcomes, social functions, and HRQoL of patients with iGCTs. The results may help to understand the function of basal ganglia and provide evidence for the benefit of early psychological intervention to improve the treatment for this rare disease.

Neurocognitive impairment following proton therapy for paediatric brain tumour: a systematic review of post-therapy assessments

BACKGROUND

Proton therapy (PT), frequently utilised to treat paediatric brain tumour (PBT) patients, eliminates exit dose and minimises dose to healthy tissues that theoretically can mitigate treatment-related effects including cognitive deficits. As clinical outcome data are emerging, we aimed to systematically review current evidence of cognitive changes following PT of PBT.

MATERIALS AND METHODS

We searched PubMed and Scopus electronic databases to identify eligible reports on cognitive changes following PT of PBT according to PRISMA guidelines. Reports were extracted for information on demographics and cognitive outcomes. Then, they were systematically reviewed based on three themes: (1) comparison with photon therapy, (2) comparison with baseline cognitive measures, to population normative mean or radiotherapy-naïve PBT patients and (3) effects of dose distribution to cognition.

RESULTS

Thirteen reports (median size (range): 70 (12-144)) were included. Four reports compared the cognitive outcome between PBT patients treated with proton to photon therapy and nine compared with baseline/normative mean/radiotherapy naïve from which two reported the effects of dose distribution. Reports found significantly poorer cognitive outcome among patients treated with photon therapy compared with proton therapy especially in general cognition and working memory. Craniospinal irradiation (CSI) was consistently associated with poorer cognitive outcome while focal therapy was associated with minor cognitive change/difference. In limited reports available, higher doses to the hippocampus and temporal lobes were implicated to larger cognitive change.

CONCLUSION

Available evidence suggests that PT causes less cognitive deficits compared with photon therapy. Children who underwent focal therapy with proton were consistently shown to have low risk of cognitive deficit suggesting the need for future studies to separate them from CSI. Evidence on the effect of dose distribution to cognition in PT is yet to mature.

Long term toxicity of intracranial germ cell tumor treatment in adolescents and young adults

PURPOSE

The purpose of this study is to describe the long-term toxicities of intracranial germ cell tumor (IGCT) in the adolescent and young adult (AYA) population.

METHODS

We report late toxicities of a multi-center cohort of AYA patients treated for IGCT between 1975 and 2015. Charts were retrospectively reviewed for hormone deficiency, ototoxicity, seizure disorder, visual deterioration, cerebrovascular events, second neoplasm, psychiatric illness, and neurocognitive impairment. Statistical analysis was performed for late toxicities to evaluate the influence of select factors.

RESULTS

Our patient cohort included 112 patients with IGCTs; 84% of patients had a germinoma as opposed to a non-germinomatous germ cell tumor (NGGCT), median age at radiotherapy (RT) was 19 years, and median follow-up was 8.3 years. Of the 94 patients with germinoma, 32 (34%) received both chemotherapy and RT as part of their upfront treatment, while 62 (66%) received RT alone. All 18 patients with NGGCT received chemotherapy and RT. The most common late toxicity following IGCT treatments was physician-reported neurocognitive impairment, with a 10-year cumulative incidence (CI) of 38.5%. Ten-year CI of treatment-induced ototoxicity was 39.2% for patients who received cisplatin, compared to 3.6% for those who received carboplatin but no cisplatin (p < 0.005). Suprasellar/hypothalamic tumor location was associated with 10-year CI of treatment-induced hormone deficiency (36.1 vs 6.2%, p < 0.005).

CONCLUSIONS

A significant proportion of AYAs treated for IGCTs experience late effects from treatment, including neurocognitive impairment, ototoxicity, and hormone deficiency. Suprasellar/hypothalamic tumor location and cisplatin were associated with a higher risk of treatment-induced hormone deficiency and ototoxicity, respectively.

Comparison on epidemiology, tumor location, histology, and prognosis of intracranial germ cell tumors between Mayo Clinic and Japanese consortium cohorts

OBJECTIVE

Central nervous system (CNS) germ cell tumors (GCTs) are rare malignant neoplasms that arise predominantly in adolescents and young adults. CNS GCTs demonstrate characteristic trends in national associations, with implications for both tumor incidence and genetics. Although the incidence of CNS GCTs is markedly higher in East Asia than Western countries, direct comparative analyses between these CNS GCT populations are limited.

METHODS

In Japan, to facilitate the genomic analyses of CNS GCTs, the Intracranial Germ Cell Tumor Genome Analysis Consortium was established in 2011, and more than 200 cases of GCTs are available for both tumor tissue and clinical data, which is organized by the National Cancer Center (NCC) Japan. At the Mayo Clinic, there have been 98 cases of intracranial GCTs treated by the Department of Neurologic Surgery since 1988. In this paper, the authors compared the epidemiology, clinical presentation including location and histology, and prognosis between cases treated in the US and Japan.

RESULTS

There was no significant difference in age and sex distributions between the databases. However, there was a significant difference in the tumor locations; specifically, the frequency of basal ganglia was higher in the NCC database compared with the Mayo Clinic (8.4% vs 0%, p = 0.008), and bifocal location (neurohypophysis and pineal gland) was higher at the Mayo Clinic than at the NCC (18.8% vs 5.8%, p = 0.002). There was no difference in histological subdivisions between the databases. There was no difference in progression-free survival (PFS) and overall survival (OS) of germinoma cases and OS of nongerminomatous GCT (NGGCT) cases treated with chemotherapy and radiation therapy covering whole ventricles. However, PFS of NGGCTs differed significantly, and was better in the NCC cohorts (p = 0.04).

CONCLUSIONS

There appears to be a differential distribution of GCTs by neuroanatomical location between major geographic and national groups. Further study is warranted to better characterize any underlying genomic, epigenetic, or environmental factors that may be driving the phenotypic differences.

The impact of neuroimaging advancement on neurocognitive evaluation in pediatric brain tumor survivors: A review

Pediatric brain tumors are a type of tumors that are commonly present in children and young adults. With the improvement of treatment, the quality of life, especially the cognitive functioning, is gaining increasingly more attention. Apart from cognitive evaluations, neuroimaging studies begin to play an important part in neurocognitive functioning investigation. In this way, the brain tissue changes caused by tumor variables (including tumor location and tumor size) and treatment variables (including surgery, chemotherapy and radiotherapy) can be detected by neuroimaging. Recent advancement of neuroimaging techniques, such as functional-MRI (fMRI) and diffusion tensor imaging (DTI), made great contributions to understanding cognitive dysfunction and quantifying the effects of tumor variables and treatment variables. In recent years, laminar-fMRI provided a potentially valuable tool for examining the exact origins of neural activity and cognitive function. On the other hand, molecular fMRI might guide diagnosis and treatment of brain disease in the future by using new biomarkers, and DTI can detect white matter changes and obtain some anatomically specific information.

Cognitive Profile of Children With Intracranial Germ Cell Tumor According to Tumor Location

PURPOSE

The purpose of this study was to evaluate the long-term cognitive sequelae and to describe the neuropsychological profile of patients with intracranial germ cell tumors according to tumor location (pineal or suprasellar site).

PATIENTS AND METHODS

Forty-five children treated at Gustave Roussy between 1991 and 2010 were assessed with neuropsychological tests to measure IQ, memory, visuospatial, motor, and executive skills at a mean delay of 4.2 years after diagnosis. All patients have received chemotherapy associated with surgery in 17 cases. Thirty-nine patients received, radiotherapy (focal 27, focal plus ventricles 8, craniospinal 4). Twenty-three patients had 2 IQ assessments with a mean delay of 4.1 years between the first and second.

RESULTS

Full scale IQ was preserved, with higher verbal IQ than other IQ indexes. Visuospatial, fine-motor, and executive difficulties were present in a significant proportion of patients. Visuospatial and fine-motor deficits were significantly associated with oculomotor difficulties, more present in the pineal than in the suprasellar group. No cognitive decline was observed between the first and the second IQ assessment.

CONCLUSIONS

Overall cognitive abilities were preserved in children treated for central nervous system germ cell tumor.

Practice patterns and survival outcomes of intracranial germinoma: an analysis of the National Cancer Database

The goal of the study is to examine the practice pattern and survival outcome of adult and pediatric patients with intracranial germinoma. Patients from the National Cancer Database (NCDB) brain tumor registry between the years 2004-2014 with intracranial germinoma were extracted for analysis. Patients who had distant metastasis, received no treatments, or only surgery/chemotherapy alone were excluded. An age cutoff of > 21 years old was used to define the pediatric population. Patients were stratified by the treatments radiation therapy alone (RT) and chemotherapy followed by radiation therapy (C + RT). 445 patients with intracranial germinoma meeting our inclusion criteria were identified. Of the adult patients, 65.7% received RT and 34.3% received C + RT, compared to the pediatric patients, where 31.8% received RT and 68.2% received C + RT. Those patients who received C + RT had a lower radiation dose compared to the RT group (p < 0.001). The 5 and 10 year overall survival (OS) for the entire cohort was 92.6 and 87.9%, respectively. Univariate analysis demonstrated improved OS with younger age, private insurance, C + RT treatment, and pediatric patients. Only age and insurance type remained significant on multivariate analysis. The 5 year OS was 92.6% (RT) versus 97.2% (C + RT) (p = 0.307) and 83.4% (RT) versus 95.4% (C + RT) (p = 0.122) in the pediatric and adult patients, respectively. There is a higher use of C + RT with an accompanied reduction in RT dose in the treatment of intracranial germinoma. There is no difference in survival between the treatment approaches of RT or C + RT in the NCDB patient cohort.