Supratentorial ependymoma: disease control, complications, and functional outcomes after irradiation

The medical and functional burden of surviving childhood ependymoma: A population-based study in Ontario, Canada

BACKGROUND

Few studies have characterized the burden of late effects among childhood ependymoma survivors. To address this gap, we examined these sequelae using real-world health services data in a population-based ependymoma survivor cohort.

METHODS

All individuals younger than 18 years diagnosed with an ependymoma in Ontario, Canada between 1987 and 2015 who had survived at least 5 years from their latest pediatric cancer event (index date) were matched 1:5 with population controls. Following linkage with provincial health services data, the cumulative incidences of multiple medical and functional outcomes between survivors and controls were compared.

RESULTS

Among 96 survivors, 77.1% had been irradiated and 9.4% had received cisplatin. At 10 years post-index, survivors were at significantly higher risk of all-cause mortality (7.1%, 95% confidence interval [CI]: 1.0-13.3 vs. 0.3%, 95% CI: 0.0-1.0; p = .0002), non-obstetric hospitalization (45.1%, 95% CI: 32.6-56.7 vs. 10.6%, 95% CI: 7.6-14.1; p < .0001), stroke (6.5%, 95% CI: 2.3-13.7 vs. 0%; p < .0001), severe hearing loss requiring an amplification device (7.5%, 95% CI: 2.7-15.7 vs. 0%; p < .0001), receiving homecare service (27.6%, 95% CI: 18.5-37.5 vs. 7.7%, 95% CI: 5.3-10.7; p < .0001), and submitting a disability support prescription claim (24.0%, 95% CI: 14.8-34.3 vs. 5.4%, 95% CI: 3.5-7.8; p < .0001) compared to controls.

CONCLUSIONS

Pediatric ependymoma survivors are highly vulnerable to severe late sequelae, including death, stroke, severe hearing loss, and disability. Urgent efforts are needed to improve risk-stratification approaches that mitigate exposure to toxic therapies for children with lower risk disease. Interventions to prevent or decrease the risk of developing late sequelae are critical to optimizing survivor long-term health.

Approaches to Minimise the Neurodevelopmental Impact of Choroid Plexus Carcinoma and Its Treatment

Choroid plexus carcinomas (CPC) are rare aggressive tumours that primarily affect very young children. Treatment for CPC typically involves a combination of surgery, chemotherapy, and radiation therapy. Whilst considered necessary for a cure, these therapies have significant neurocognitive consequences for patients, negatively impacting cognitive function including memory, attention, executive functioning, and full-scale intelligence quotients (FSIQ). These challenges significantly impact the quality of life and ultimately socioeconomic parameters such as the level of educational attainment, marital status, and socioeconomic status. This review looks at the tumour- and treatment-related causes of neurocognitive damage in CPC patients and the progress made in finding strategies to reduce these. Opportunities to mitigate the neurodevelopmental consequences of surgery, chemotherapy, and radiation therapy are explored in the context of CPC treatment. Evaluation of the pathological and biological mechanisms of injury has identified innovative approaches to neurocognitive protection and neurorehabilitation, which aim to limit the neurocognitive damage. This review aims to highlight multiple approaches physicians can use when treating young children with CPC, to focus on neurocognitive outcomes as a measure of success.

The Current State of Radiotherapy for Pediatric Brain Tumors: An Overview of Post-Radiotherapy Neurocognitive Decline and Outcomes

Tumors of the central nervous system are the most common solid malignancies diagnosed in children. While common, they are also found to have some of the lowest survival rates of all malignancies. Treatment of childhood brain tumors often consists of operative gross total resection with adjuvant chemotherapy or radiotherapy. The current body of literature is largely inconclusive regarding the overall benefit of adjuvant chemo- or radiotherapy. However, it is known that both are associated with conditions that lower the quality of life in children who undergo those treatments. Chemotherapy is often associated with nausea, emesis, significant fatigue, immunosuppression, and alopecia. While radiotherapy can be effective for achieving local control, it is associated with late effects such as endocrine dysfunction, secondary malignancy, and neurocognitive decline. Advancements in radiotherapy grant both an increase in lifetime survival and an increased lifetime for survivors to contend with these late effects. In this review, the authors examined all the published literature, analyzing the results of clinical trials, case series, and technical notes on patients undergoing radiotherapy for the treatment of tumors of the central nervous system with a focus on neurocognitive decline and survival outcomes.

The impact of socioeconomic status (SES) on cognitive outcomes following radiotherapy for pediatric brain tumors: a prospective, longitudinal trial

BACKGROUND

Socioeconomic status (SES) is a determinant of cognitive and academic functioning among healthy and ill children; however, few pediatric oncology studies examine SES and long-term cognitive functioning. The current study systematically investigated SES as a predictor of cognitive outcomes among children treated for localized brain tumors (BT) with photon radiation therapy (RT).

METHODS

248 children treated on a prospective, longitudinal, phase II trial of conformal RT (54-59.4 Gy) for ependymoma, low-grade glioma, or craniopharyngioma were monitored serially with cognitive assessments (intelligence quotient [IQ], reading, math, attention, adaptive function) for 10 years (2209 observations, median age at RT = 6.6 years, 48% male, 80% Caucasian). SES was derived from the Barratt Simplified Measure of Social Status, which incorporates parental occupation, education, and marital status.

RESULTS

Overall, SES scores fell in the low range (Barratt median = 37). At pre-RT baseline, linear mixed models revealed significant associations between SES and IQ, reading, math, attention, and adaptive function, with higher SES associated with better performance (P < .005). SES predicted change over time in IQ, reading, and math; higher SES was associated with less decline (P < .001). Accounting for sex and age at RT, SES remained predictive of IQ, reading, and math. Analysis of variance revealed a greater relative contribution of SES than sex or age at RT to reading and math.

CONCLUSIONS

SES represents a novel predictor of cognitive performance before and after RT for pediatric BT. These findings have broad implications as high SES represents a protective factor. Developing interventions to mitigate the effects of low SES is warranted.

An Insight into Pathophysiological Features and Therapeutic Advances on Ependymoma

Simple Summary

Although biological information and the molecular classification of ependymoma have been studied, the treatment systems for ependymoma are still insufficient. In addition, because the disease occurs infrequently, it is difficult to obtain sufficient data to conduct large-scale or randomized clinical trials. Therefore, this study is intended to emphasize the importance of understanding its pathological characteristics and prognosis as well as developing treatments for ependymoma through multilateral studies.

Abstract

Glial cells comprise the non-sensory parts of the central nervous system as well as the peripheral nervous system. Glial cells, also known as neuroglia, constitute a significant portion of the mammalian nervous system and can be viewed simply as a matrix of neural cells. Despite being the “Nervenkitt” or “glue of the nerves”, they aptly serve multiple roles, including neuron repair, myelin sheath formation, and cerebrospinal fluid circulation. Ependymal cells are one of four kinds of glial cells that exert distinct functions. Tumorigenesis of a glial cell is termed a glioma, and in the case of an ependymal cell, it is called an ependymoma. Among the various gliomas, an ependymoma in children is one of the more challenging brain tumors to cure. Children are afflicted more severely by ependymal tumors than adults. It has appeared from several surveys that ependymoma comprises approximately six to ten percent of all tumors in children. Presently, the surgical removal of the tumor is considered a standard treatment for ependymomas. It has been conspicuously evident that a combination of irradiation therapy and surgery is much more efficacious in treating ependymomas. The main purpose of this review is to present the importance of both a deep understanding and ongoing research into histopathological features and prognoses of ependymomas to ensure that effective diagnostic methods and treatments can be developed.

Canadian Pediatric Neuro-Oncology Standards of Practice

Primary CNS tumors are the leading cause of cancer-related death in pediatrics. It is essential to understand treatment trends to interpret national survival data. In Canada, children with CNS tumors are treated at one of 16 tertiary care centers. We surveyed pediatric neuro-oncologists to create a national standard of practice to be used in the absence of a clinical trial for seven of the most prevalent brain tumors in children. This allowed description of practice across the country, along with a consensus. This had a multitude of benefits, including understanding practice patterns, allowing for a basis to compare in future research and informing Health Canada of the current management of patients. This also allows all children in Canada to receive equivalent care, regardless of location.

Neurocognitive Outcomes and Interventions in Long-Term Survivors of Childhood Cancer

Recent research has demonstrated that survivors of childhood cancer are at risk for a myriad of late effects that affect physical and mental quality of life. We discuss the patterns and prevalence of neurocognitive problems commonly experienced by survivors of CNS tumors and acute lymphoblastic leukemia, the two most commonly researched cancer diagnoses. Research documenting the direct effects of tumor location and treatment type and intensity is presented, and patient characteristics that moderate outcomes (eg, age at diagnosis and sex) are discussed. Potential biologic mechanisms of neurotoxic treatment exposures, such as cranial irradiation and intrathecal and high-dose antimetabolite chemotherapy, are reviewed. Genetic, brain imaging, and neurochemical biomarkers of neurocognitive impairment are discussed. Long-term survivors of childhood cancer are also at risk for physical morbidity (eg, cardiac, pulmonary, endocrine) and problems with health behaviors (eg, sleep); research is reviewed that demonstrates these health problems contribute to neurocognitive impairment in survivors with or without exposure to neurotoxic therapies. We conclude this review with a discussion of literature supporting specific interventions that may be beneficial in the treatment of survivors who already experience neurocognitive impairment, as well as in the prevention of impairment manifestation.

Progression-free survival of children with localized ependymoma treated with intensity-modulated radiation therapy or proton-beam radiation therapy

BACKGROUND

The treatment for childhood intracranial ependymoma includes maximal surgical resection followed by involved-field radiotherapy, commonly in the form of intensity-modulated radiation therapy (IMRT). Proton-beam radiation therapy (PRT) is used at some centers in an effort to decrease long-term toxicity. Although protons have the theoretical advantage of a minimal exit dose to the surrounding uninvolved brain tissue, it is unknown whether they have the same efficacy as photons in preventing local recurrence.

METHODS

A retrospective review of medical records from September 2000 to April 2013 was performed. Seventy-nine children with newly diagnosed localized intracranial ependymomas treated with either IMRT (n = 38) or PRT (n = 41) were identified, and progression-free survival (PFS) was analyzed with Kaplan-Meier and Cox multivariate analyses.

RESULTS

The median age at diagnosis was 3.7 years for all patients (range, 0.4-18.7 years). There were 54 patients with infratentorial tumors (68% of the total population). Patients treated with PRT were younger (median age, 2.5 vs 5.7 years; P = .001) and had a shorter median follow-up (2.6 vs 4.9 years; P < .0001). Gross total resection (GTR) was achieved in 67 patients (85%) and was more frequent in the PRT group versus the IMRT group (93% vs 76%; P = .043). The 3-year PFS rates were 60% and 82% with IMRT and PRT, respectively (P = .031).

CONCLUSIONS

Children with localized ependymomas treated with PRT have a 3-year PFS rate comparable to that of children treated with IMRT. This analysis suggests that local control is not compromised by the use of PRT. The data also support GTR as the only prognostic factor for PFS. Cancer 2017;123:2570-78. © 2017 American Cancer Society.

Final results of the second prospective AIEOP protocol for pediatric intracranial ependymoma

BACKGROUND

This prospective study stratified patients by surgical resection (complete = NED vs incomplete = ED) and centrally reviewed histology (World Health Organization [WHO] grade II vs III).

METHODS

WHO grade II/NED patients received focal radiotherapy (RT) up to 59.4 Gy with 1.8 Gy/day. Grade III/NED received 4 courses of VEC (vincristine, etoposide, cyclophosphamide) after RT. ED patients received 1-4 VEC courses, second-look surgery, and 59.4 Gy followed by an 8-Gy boost in 2 fractions on still measurable residue. NED children aged 1-3 years with grade II tumors could receive 6 VEC courses alone.

RESULTS

From January 2002 to December 2014, one hundred sixty consecutive children entered the protocol (median age, 4.9 y; males, 100). Follow-up was a median of 67 months. An infratentorial origin was identified in 110 cases. After surgery, 110 patients were NED, and 84 had grade III disease. Multiple resections were performed in 46/160 children (28.8%). A boost was given to 24/40 ED patients achieving progression-free survival (PFS) and overall survival (OS) rates of 58.1% and 68.7%, respectively, in this poor prognosis subgroup. For the whole series, 5-year PFS and OS rates were 65.4% and 81.1%, with no toxic deaths. On multivariable analysis, NED status and grade II were favorable for OS, and for PFS grade II remained favorable.

CONCLUSIONS

In a multicenter collaboration, this trial accrued the highest number of patients published so far, and results are comparable to the best single-institution series. The RT boost, when feasible, seemed effective in improving prognosis. Even after multiple procedures, complete resection confirmed its prognostic strength, along with tumor grade. Biological parameters emerging in this series will be the object of future correlatives and reports.

Proton beam therapy for pediatric ependymoma

BACKGROUND

The aim of this study was to evaluate the efficacy of proton beam therapy for pediatric patients with ependymoma.

METHODS

Proton beam therapy was conducted for six patients (three boys and three girls; age, 2-6 years; median, 5 years) with ependymoma. The tumors were WHO grades 2 and 3 in two and four patients, respectively. All patients underwent surgery (subtotal and gross total resection in three patients each) and proton beam therapy at doses of 50.4-61.2 GyE (median, 56.7 GyE). The mean doses to normal brain tissue in proton beam therapy and photon radiotherapy were simulated using the same treatment planning computed tomography images.

RESULTS

All patients completed the planned irradiation. The follow-up period was 13-44 months (median, 24.5 months) from completion of proton beam therapy and all patients were alive at the end of this period. Local recurrence in the treatment field occurred in one patient at 4 months after proton beam therapy at 50.4 GyE. Alopecia and mild dermatitis occurred in all patients, but there was no severe toxicity. One patient had a once-off seizure after proton beam therapy and alopecia persisted in another patient for 31 months, but no patients had difficulty with daily life. The simulation showed that proton beam therapy reduces the dose to normal brain tissue by approximately half compared with photon radiotherapy.

CONCLUSIONS

Proton beam therapy for pediatric ependymoma is safe, does not have specific toxicities, and can reduce irradiation of normal brain tissue.

Brainstem-sparing craniospinal irradiation delivered with pencil beam scanning proton therapy

Delivery of craniospinal irradiation (CSI) is a curative approach to recurrent ependymoma, but is associated with risks from re-irradiation, particularly of the brainstem. Pencil beam scanning proton therapy allows delivery of CSI with sparing of normal tissues. Here, we describe a case of brainstem-sparing CSI that resulted in excellent coverage of the craniospinal axis with minimal radiation to brainstem. This is a novel concept that compares favorably to previously described methods using x-rays that may result in underdosing of surrounding tissues in effort to spare brainstem.

EphB2 activation is required for ependymoma development as well as inhibits differentiation and promotes proliferation of the transformed cell

Our intracranial implantation mouse model of ependymoma clearly demonstrates overexpression of the ephrin receptor EphB2 in Ink4a/Arf^(−/−) supratentorial embryonic neural stem cells (STeNSCs) to be essential for transformation and disease development; however the requirement for and consequence of receptor activation on transformation and neural stem cell function were not examined. We definitively illustrate the necessity for receptor activation in cellular transformation and the importance of implantation site and microenvironment in directing ependymoma development. In vitro assays of EphB2 overexpressing Ink4a/Arf^(−/−) STeNSCs showed no changes in their neural stem cell characteristics (stem cell marker expression and self-renewal) upon receptor activation, but EphB2 driven tumor cells were inhibited significantly in differentiation and exhibited increased tumorsphere formation and cellular proliferation in response to ephrin-B ligand mediated receptor activation. Additionally, we observed substantial differences in the phosphorylation state of several key proteins involved in Ras and p38 MAPK signaling when comparing EphB2 overexpressing Ink4a/Arf^(−/−) STeNSCs and tumor cells with relatively little change in total protein levels. We propose that EphB2 mediated ependymoma development is a multifactorial process requiring microenvironment directed receptor activation, resulting in changes in the phosphorylation status of key regulatory proteins, maintenance of a stem-like state and cellular proliferation.

Emotional and behavioral functioning after conformal radiation therapy for pediatric ependymoma

PURPOSE

The standard of care for pediatric patients with ependymoma involves postoperative radiation therapy. Prior research suggests that conformal radiation therapy (CRT) is associated with relative sparing of cognitive and academic functioning, but little is known about the effect of CRT on emotional and behavioral functioning.

METHODS AND MATERIALS

A total of 113 patients with pediatric ependymoma underwent CRT using photons as part of their enrollment on an institutional trial. Patients completed annual evaluations of neurocognitive functioning during the first 5 years after CRT. Emotional and behavioral functioning was assessed via the Child Behavior Checklist.

RESULTS

Before CRT, emotional and behavioral functioning were commensurate with those of the normative population and within normal limits. After 5 years, means remained within normal limits but were significantly below the normative mean. Linear mixed models revealed a significant increase in attention problems over time. These problems were associated with age at diagnosis/CRT, tumor location, and extent of resection. A higher-than-expected incidence of school problems was present at all assessment points after baseline.

CONCLUSIONS

The use of photon CRT for ependymoma is associated with relatively stable emotional and behavioral functioning during the first 5 years after treatment. The exception is an increase in attention problems. Results suggest that intervening earlier in the survivorship period-during the first year posttreatment-may be beneficial.