Effect of Sensorineural Hearing Loss on Neurocognitive Functioning in Pediatric Brain Tumor Survivors

How Cancer Harms the Developing Brain: Long-Term Outcomes in Pediatric Cancer Survivors

Survival rates for pediatric cancer are improving, resulting in a rising need to understand and address long-term sequelae. In this narrative review, we summarize the effects of cancer and its treatment on the developing brain, with a focus on neurocognitive function in leukemia and pediatric brain tumor survivors. We then discuss possible mechanisms of brain injury and management considerations.

Neurocognitive Effects and Necrosis in Childhood Cancer Survivors Treated With Radiation Therapy: A PENTEC Comprehensive Review

PURPOSE

A PENTEC review of childhood cancer survivors who received brain radiation therapy (RT) was performed to develop models that aid in developing dose constraints for RT-associated central nervous system (CNS) morbidities.

METHODS AND MATERIALS

A comprehensive literature search, through the PENTEC initiative, was performed to identify published data pertaining to 6 specific CNS toxicities in children treated with brain RT. Treatment and outcome data on survivors were extracted and used to generate normal tissue complication probability (NTCP) models.

RESULTS

The search identified investigations pertaining to 2 of the 6 predefined CNS outcomes: neurocognition and brain necrosis. For neurocognition, models for 2 post-RT outcomes were developed to (1) calculate the risk for a below-average intelligence quotient (IQ) (IQ <85) and (2) estimate the expected IQ value. The models suggest that there is a 5% risk of a subsequent IQ <85 when 10%, 20%, 50%, or 100% of the brain is irradiated to 35.7, 29.1, 22.2, or 18.1 Gy, respectively (all at 2 Gy/fraction and without methotrexate). Methotrexate (MTX) increased the risk for an IQ <85 similar to a generalized uniform brain dose of 5.9 Gy. The model for predicting expected IQ also includes the effect of dose, age, and MTX. Each of these factors has an independent, but probably cumulative effect on IQ. The necrosis model estimates a 5% risk of necrosis for children after 59.8 Gy or 63.6 Gy (2 Gy/fraction) to any part of the brain if delivered as primary RT or reirradiation, respectively.

CONCLUSIONS

This PENTEC comprehensive review establishes objective relationships between patient age, RT dose, RT volume, and MTX to subsequent risks of neurocognitive injury and necrosis. A lack of consistent RT data and outcome reporting in the published literature hindered investigation of the other predefined CNS morbidity endpoints.

Dosimetric analysis of hearing loss after cranial radiation therapy in children: A single-institution study from the french national registry pediart

PURPOSE

To identify dosimetric predictive factors of sensorineural hearing loss (SNHL) in children after cranial radiation therapy (RT) in a single institution using dosimetric data from the French National Registry PediaRT.

METHODS AND MATERIALS

Complete audiological follow-up data were available for 44 children treated with cranial RT between 2014 and 2021 at our institution. The median age at the time of RT initiation was 9 years (range: 2-17 years). No children presented with hearing loss prior to treatment. SNHL was defined as a Chang ototoxicity grade ≥ 1a or higher.

RESULTS

Median audiometric follow-up duration was 51 months. Seven children (16 %) developed SNHL with a median time to occurrence of 33 months (range, 18-46 months). The estimated SNHL cumulative rate at 2 years post-RT was 4,5% ± 3,1% and at 5 years was 21 % ± 7.2 %. Multiple Cox regression models showed that the association of the age at radiotherapy and the dosimetric values to the inner ear canal and cochlea were the most significant predictive factors of SNHL occurrence. No child who received less than 35 Gy on average to both cochleae (n = 26) suffered from SNHL, whereas the 5-year SNHL cumulative incidence for the children who received greater than or equal to 35 Gy on average to either cochlea (n = 18) was 51.8 % ± 15.1 %.

CONCLUSION

Doses received by the inner ear canal and cochlea, associated with the age at RT initiation, are the main predictive factors for radiation-induced SNHL. A median dose to either cochlea over 35 Gy significantly increases the risk of SNHL and justify close audiometric monitoring to detect and equip hearing loss at an early stage.

Oseltamivir (Tamiflu), a Commonly Prescribed Antiviral Drug, Mitigates Hearing Loss in Mice

Hearing loss affects up to 10% of all people worldwide, but currently there is only one FDA-approved drug for its prevention in a subgroup of cisplatin-treated pediatric patients. Here, we performed an unbiased screen of 1,300 FDA-approved drugs for protection against cisplatin-induced cell death in an inner ear cell line, and identified oseltamivir phosphate (brand name Tamiflu), a common influenza antiviral drug, as a top candidate. Oseltamivir phosphate was found to be otoprotective by oral delivery in multiple established cisplatin and noise exposure mouse models. The drug conferred permanent hearing protection of 15-25 dB SPL for both female and male mice. Oseltamivir treatment reduced in mice outer hair cells death after cisplatin treatment and mitigated cochlear synaptopathy after noise exposure. A potential binding protein, ERK1/2, associated with inflammation, was shown to be activated with cisplatin treatment and reduced by oseltamivir cotreatment in cochlear explants. Importantly, the number of infiltrating immune cells to the cochleae in mice post noise exposure, were significantly reduced with oseltamivir treatment, suggesting an anti-inflammatory mechanism of action. Our results support oseltamivir, a widespread drug for influenza with low side effects, as a promising otoprotective therapeutic candidate in both cisplatin chemotherapy and traumatic noise exposure.

Intelligence quotient testing in children with hearing loss: A systematic review

OBJECTIVE

The objective of the current study is to perform a systematic review of the research literature to evaluate the impact of hearing loss on intelligence quotient (IQ) scores in pediatric patients.

DATA SOURCES

Ovid MEDLINE, EMBASE, CINAHL, and Cochrane Central Register of Controlled Trials (CENTRAL) databases were searched from their inception up to December 21st, 2021.

REVIEW METHODS

Studies evaluating neurocognitive testing and hearing loss in children aged 21 years old or younger who had not undergone auditory rehabilitation were included in the study. Two independent reviewers evaluated titles, abstracts, and full texts for all included studies.

RESULTS

The literature search yielded 3199 studies of which 431 studies underwent full-text screening. 21 studies were ultimately selected for inclusion and contained a total of 1716 pediatric patients assessed through 13 different validated tests of intelligence. Six studies included both hearing impaired (HI) and normal hearing (NH) patients, and IQ testing results.

CONCLUSION

The results of this large systematic review demonstrate that hearing impaired children may perform lower than their age-matched normal hearing peers on IQ testing across a battery of IQ testing modalities.

Children with non-central nervous system tumors treated with platinum-based chemotherapy are at risk for hearing loss and cognitive impairments

Background

Childhood cancer survivors (CCS) with chemotherapy induced sensorineural hearing loss (SNHL) are at risk for neurocognitive impairments. The purpose of this study was to determine the relationship between SNHL and cognitive function among CCS.

Procedure

Inclusion: non-CNS solid tumor diagnosis; history of platinum chemotherapy (cisplatin and/or carboplatin); 8-17 years of age; off anti-cancer treatment for ≥6 months; and English speaking. Exclusion: history of intrathecal chemotherapy, cranial radiation, or baseline neurocognitive disorder. Participants completed the NIH Toolbox Cognition Battery at enrollment. T-tests were used to compare participants with normal hearing to those with hearing loss and the total sample with established Toolbox normative data (mean: 50; SD: 10).

Results

Fifty-seven individuals enrolled; 52 completed full cognitive testing. Participants were on average 12.2 years of age and 7.0 years since treatment completion. Twenty-one participants (40%) received cisplatin, 27 (52%) carboplatin, and 4 (8%) received both. Fifteen participants (29%) demonstrated SNHL based on the better ear. CCS, regardless of the presence or absence of SNHL, demonstrated significantly lower mean cognitive skills compared to the normative sample in attention, executive function, language- vocabulary and oral reading, processing speed, and fluid, crystallized and total composite scores (all p < 0.01). Participants with SNHL had significantly lower crystallized composite (vocabulary, oral reading) than those with normal hearing (41.9 vs. 47.2, p < 0.05, Cohen's d = 0.62).

Conclusions

CCS at risk for platinum induced hearing loss but without cranial radiation or intrathecal chemotherapy exposure demonstrate impaired cognitive skills and those with SNHL demonstrate lower crystallized composite scores.

Communication, academic and social outcomes of childhood cancer survivors with hearing loss: A systematic review

Many children treated for cancer are at risk of hearing loss. However, little is known about how hearing loss impacts their communication, academic and social outcomes. To examine the impact, this systematic review aimed to synthesise and appraise quantitative and qualitative studies reporting on (i) participants with hearing loss treated with platinum-based chemotherapy or cranial radiotherapy during childhood; and (ii) speech, language, academic performance, or social participation findings. Systematic database searches yielded 23 relevant articles that were analysed using narrative synthesis. Difficulties were reported for some but not all communication, academic and social aspects; however, a quality assessment using Grading of Recommendations Assessment, Development and Evaluation (GRADE) revealed low to very low certainty in the findings. Future research should aim to increase the quality of the research evidence and explore how multidisciplinary services can provide evidence-based support for childhood cancer survivors with competing hearing, communication, and social difficulties.

Auditory complications among childhood cancer survivors and health-related quality of life: a PanCareLIFE study

PURPOSE

Auditory complications are potential side effects from childhood cancer treatment. Yet, limited evidence exists about the impact of auditory complications-particularly tinnitus-on health-related quality of life (HRQoL) among childhood cancer survivors (CCS). We determined the prevalence of hearing loss and tinnitus in the European PanCareLIFE cohort of CCS and examined its effect on HRQoL.

METHODS

We included CCS from four European countries who were diagnosed at age ≤ 18 years; survived ≥ 5 years; and aged 25-44 years at study. We assessed HRQoL (Short Form 36), hearing loss, and tinnitus using questionnaires. We used multivariable linear regression to examine associations between these two auditory complications and HRQoL adjusting for socio-demographic and clinical factors.

RESULTS

Our study population consisted of 6,318 CCS (53% female; median age at cancer diagnosis 9 years interquartile range [IQR] 5-13 years) with median age at survey of 31 years (IQR 28-35 years). Prevalence was 7.5% (476/6,318; confidence interval [CI]: 6.9-8.2) for hearing loss and 7.6% (127/1,668; CI: 6.4-9.0) for tinnitus. CCS with hearing loss had impaired physical (coefficient [coef.] -4.3, CI: -7.0 to -1.6) and mental (coef. -3.2, CI: -5.5 to -0.8) HRQoL when compared with CCS with normal hearing. Tinnitus was associated with impaired physical (coef. -8.2, CI: -11.8 to -4.7) and mental (coef. -5.9, CI: -8.8 to -3.1) HRQoL.

CONCLUSION

We observed reduced HRQoL among CCS with hearing loss and tinnitus. Our findings indicate timely treatment of hearing loss and tinnitus may contribute to quality of life of survivors.

IMPLICATIONS FOR CANCER SURVIVORS

CCS who experience auditory complications should be counseled about possible therapeutic and supportive measures during follow-up care.

Children's Oncology Group's 2023 blueprint for research: Cancer control and supportive care

The objective of the Cancer Control and Supportive Care (CCL) Committee in the Children's Oncology Group (COG) is to reduce the overall morbidity and mortality of therapy-related toxicities in children, adolescents, and young adults with cancer. We have targeted five major domains that cause clinically important toxicity: (i) infections and inflammation; (ii) malnutrition and metabolic dysfunction; (iii) chemotherapy-induced nausea and vomiting; (iv) neuro- and oto-toxicty; and (v) patient-reported outcomes and health-related quality of life. Subcommittees for each domain prioritize randomized controlled trials and biology aims to determine which strategies best mitigate the toxicities. The findings of these trials are impactful, informing clinical practice guidelines (CPGs) and directly leading to changes in the standard of care for oncology practice. With the development of new therapies, there will be new toxicities, and the COG CCL Committee is dedicated to developing interventions to minimize acute and delayed toxicities, lessen morbidity and mortality, and improve quality of life in pediatric and young adult patients with cancer.

Reevaluation of sodium thiosulfate otoprotection using the consensus International Society of Paediatric Oncology Ototoxicity Scale: A report from the Children's Oncology Group study ACCL0431

In two randomized trials (Children's Oncology Group ACCL0431 and International Childhood Liver Tumour Strategy Group SIOPEL-6), sodium thiosulfate (STS) demonstrated efficacy in preventing cisplatin-induced hearing loss (CIHL). However, the measures used in those trials have been superseded by the consensus International Society of Paediatric Oncology (SIOP) Ototoxicity Scale. To provide benchmark data for STS efficacy when using this contemporary scale, we reanalyzed ACCL0431 hearing outcomes with the SIOP scale and using multiple timepoints. Compared to the control arm, STS significantly reduced CIHL when assessed by the SIOP scale across these different approaches. These results provide critical data to inform treatment discussions and support future potential trial designs comparing otoprotectants.

Intravenous N-Acetylcysteine to Prevent Cisplatin-Induced Hearing Loss in Children: A Nonrandomized Controlled Phase I Trial

PURPOSE

Cisplatin-induced hearing loss (CIHL) is common and permanent. As compared with earlier otoprotectants, we hypothesized N-acetylcysteine (NAC) offers potential for stronger otoprotection through stimulation of glutathione (GSH) production. This study tested the optimal dose, safety, and efficacy of NAC to prevent CIHL.

PATIENTS AND METHODS

In this nonrandomized, controlled phase Ia/Ib trial, children and adolescents newly diagnosed with nonmetastatic, cisplatin-treated tumors received NAC intravenously 4 hours post-cisplatin. The trial performed dose-escalation across three dose levels to establish a safe dose that exceeded the targeted peak serum NAC concentration of 1.5 mmol/L (as identified from preclinical models). Patients with metastatic disease or who were otherwise ineligible were enrolled in an observation-only/control arm. To evaluate efficacy, serial age-appropriate audiology assessments were performed. Integrated biology examined genes involved in GSH metabolism and post-NAC GSH concentrations.

RESULTS

Of 52 patients enrolled, 24 received NAC and 28 were in the control arm. The maximum tolerated dose was not reached; analysis of peak NAC concentration identified 450 mg/kg as the recommended phase II dose (RP2D). Infusion-related reactions were common. No severe adverse events occurred. Compared with the control arm, NAC decreased likelihood of CIHL at the end of cisplatin therapy [OR, 0.13; 95% confidence interval (CI), 0.021-0.847; P = 0.033] and recommendations for hearing intervention at end of study (OR, 0.082; 95% CI, 0.011-0.60; P = 0.014). NAC increased GSH; GSTP1 influenced risk for CIHL and NAC otoprotection.

CONCLUSIONS

NAC was safe at the RP2D, with strong evidence for efficacy to prevent CIHL, warranting further development as a next-generation otoprotectant.

The Burden of Surviving Childhood Medulloblastoma: A Population-Based, Matched Cohort Study in Ontario, Canada

PURPOSE

Survivors of childhood medulloblastoma suffer from substantial late effects. We characterized these sequelae using real-world health services data in a population-based cohort of medulloblastoma survivors.

METHODS

All 5-year medulloblastoma survivors diagnosed age < 18 years between 1987 and 2015 in Ontario, Canada, were identified and matched 1:5 with population controls. Index date was 5 years from latest pediatric cancer event. Linkage to provincial administrative health data allowed for comparison of cumulative incidences of several adverse outcomes.

RESULTS

Two hundred thirty survivors, 81.3% of whom had received craniospinal irradiation, were matched with 1,150 controls. The 10-year postindex cumulative incidence of all-cause mortality was 7.9% (95% CI, 3.9 to 11.8) in survivors versus 0.6% (95% CI, 0.1 to 1.1) in controls (hazard ratio [HR], 21.5; 95% CI, 9.8 to 54.0). The cumulative incidence of stroke was higher in survivors (4.8%; 95% CI, 2.2 to 9.0) compared with controls (0.1; 95% CI, 0.01 to 0.7; HR, 45.6; 95% CI, 12.8 to 289.8). Hearing loss requiring an amplification device was present in 24.9% (95% CI, 18.8 to 31.4) of survivors versus 0.3% (95% CI, 0.1 to 1.0) of controls (HR, 96.3; 95% CI, 39.7 to 317.3). Disability support prescription claims were submitted by 44.5% (95% CI, 37.1 to 51.6) of survivors versus 5.5% (95% CI, 4.2 to 7.1) of controls (HR, 10.0; 95% CI, 7.3 to 13.6). Female survivors were significantly less likely to deliver a liveborn child compared with controls (HR, 0.2; 95% CI, 0.1 to 0.7).

CONCLUSION

Survivors of medulloblastoma have significant long-term medical sequelae, increased all-cause mortality, and are frequently dependent on disability supports. Efforts to reduce the toxicity of current therapy, specifically incorporating molecularly informed risk stratification to spare low- and intermediate-risk survivors the toxicity of treatment, are urgently needed. These findings should prompt a re-evaluation of our current treatment approaches where research focused on late-effect interventions should be prioritized.

Impact of Time to Diagnosis on Morbidity and Survival in Children With Malignant Central Nervous System Tumors

OBJECTIVE

The aim was to determine the impact of time to diagnosis (TTD) on morbidity and mortality and to identify factors associated with overall survival (OS) in pediatric patients with malignant central nervous system (CNS) tumors.

METHODS

This is a retrospective review of all malignant CNS tumors presenting to 2 tertiary care pediatric hospitals from 2000 to 2019. Cox proportional hazard model analysis outcomes included TTD and OS as well as morbidity; stratified by tumor category, age, relapse, and presence of metastatic disease.

RESULTS

There were 197 children with malignant CNS tumors (mean age 8.7 y, 61% male). Tumors included medulloblastoma (N=58, 29.4%), ependymoma (N=27, 13.7%), high-grade glioma (N=42, 21.3%), germ cell tumors (N=47, 23.9%), and other embryonal tumors (N=23, 11.7%). Median TTD from symptom onset was 62 (interquartile range: 26.5 to 237.5 d) and 28% had metastatic disease. Three-year progression free survival was 55% and 3-year OS was 73.1%. Increased OS was associated with increased TTD (parameter estimate 0.12; confidence interval [CI]: 0.019-7.06; P =0.019), high-grade glioma (hazard ratio [HR]: 2.46; CI [1.03-5.86]; P =0.042), other embryonal tumor (HR: 2.84; CI [1.06-7.56]; P =0.037), relapse (HR: 10.14; CI: 4.52-22.70; P <0.001) and metastatic disease (HR: 3.25; CI: 1.51-6.96; P =0.002). Vision change (HR: 0.58; CI: 0.313-1.06; P =0.078), hearing loss (HR: 0.71; CI: 0.35-1.42; P =0.355), and cognitive impairment (HR: 0.73; CI: 0.45-1.19; P =0.205) were not associated with TTD in this model.

CONCLUSIONS

Increased median TTD is associated with higher OS in pediatric patients treated for malignant CNS tumors. Tumor biology and treatment modality are more important factors than TTD for predicting morbidity and long-term outcomes in pediatric patients with CNS tumors.

Special considerations in the design and implementation of pediatric otoprotection trials

PURPOSE

Cisplatin-induced hearing loss (CIHL) is a common late effect after childhood cancer treatment having profound, lifelong consequences that lower quality of life. The recent identification of intravenous sodium thiosulfate (STS) as an effective agent for preventing pediatric CIHL represents a paradigm shift that has created new opportunities for expanding STS usage and developing additional otoprotectants. The purpose of this paper is to discuss key considerations and recommendations for the design and implementation of future pediatric otoprotection trials.

METHODS

An approach synthesizing published data and collective experience was used.

RESULTS

Key issues were identified in the categories of translational research, trial designs for systemic and intratympanic agents, measurement of ototoxicity, and biostatistical challenges.

CONCLUSIONS

Future pediatric otoprotection trials should emphasize (1) deep integration of preclinical and early-phase studies; (2) an embedded or free-standing design for systemic agents based on mechanistic considerations; (3) use of suitable audiologic testing batteries for children, SIOP grading criteria, and submission of raw audiologic data for central review; and (4) novel endpoints and innovative study designs that maximize trial efficiency for limited sample sizes. Additional recommendations include routine collection of DNA specimens for assessing modifying effects of genetic susceptibility and meaningful inclusion of patient/family advocates for informing trial development.

IMPLICATIONS FOR CANCER SURVIVORS

Changing the historical paradigm from acceptance to prevention of pediatric CIHL through expanded research with existing and emerging otoprotectants will dramatically improve quality of life for future childhood cancer survivors exposed to cisplatin.

Severity of hearing loss after platinum chemotherapy in childhood cancer survivors

BACKGROUND

Hearing loss is a potential side effect from childhood cancer treatment. We described the severity of hearing loss assessed by audiometry in a representative national cohort of childhood cancer survivors (CCS) and identified clinical risk factors.

PROCEDURE

We included all CCS from the Swiss Childhood Cancer Registry who were diagnosed ≤18 age and treated with platinum-based chemotherapy between 1990 and 2014. We extracted audiograms, treatment-related information, and demographic data from medical records. Two reviewers independently assessed the severity of hearing loss at latest follow-up using the Münster Ototoxicity Scale. We used ordered logistic regression to identify clinical risk factors for severity of hearing loss.

RESULTS

We analyzed data from 270 CCS. Median time from cancer diagnosis to last audiogram was 5 years (interquartile range 2.5-8.1 years). We found 53 (20%) CCS with mild, 78 (29%) with moderate, and 75 (28%) with severe hearing loss. Higher severity grades were associated with (a) younger age at cancer diagnosis (odds ratio [OR] 5.4, 95% confidence interval [CI]: 2.5-12.0 for <5 years); (b) treatment in earlier years (OR 4.8, 95% CI: 2.1-11.0 for 1990-1995); (c) higher cumulative cisplatin doses (OR 13.5, 95% CI: 4.7-38.8 for >450 mg/m² ); (d) concomitant cranial radiation therapy (CRT) (OR 4.4, 95% CI: 2.5-7.8); and (e) hematopoietic stem cell transplantation (HSCT) (OR 2.7, 95% CI: 1.0-7.2).

CONCLUSION

Three of four CCS treated with platinum-based chemotherapy experienced some degree of hearing loss. We recommend closely monitoring patient's hearing function if treated at a young age with high cumulative cisplatin doses, and concomitant CRT as part of long-term care.

Global burden of ototoxic hearing loss associated with platinum-based cancer treatment: A systematic review and meta-analysis

Platinum-based chemotherapeutic agents cisplatin and carboplatin are widely used in cancer treatment worldwide and may result in ototoxic hearing loss. The high incidence of cancer and salient ototoxic effects of platinum-based compounds pose a global public health threat. The purpose of this study was twofold. First, to estimate the prevalence of ototoxic hearing loss associated with treatment with cisplatin and/or carboplatin via a systematic review and meta-analysis. Second, to estimate the annual global burden of ototoxic hearing loss associated with exposure to cisplatin and/or carboplatin. For the systematic review, three databases were searched (Ovid Medline, Ovid Embase, and Web of Science Core Collection) and studies that reported prevalence of objectively measured ototoxic hearing loss in cancer patients were included. A random effects meta-analysis determined pooled prevalence (95% confidence intervals [CI]) of ototoxic hearing loss overall, and estimates were stratified by treatment and patient attributes. Estimates of ototoxic hearing loss burden were created with published global estimates of incident cancers often treated with platinum-based compounds and cancer-specific treatment rates. Eighty-seven records (n = 5077 individuals) were included in the meta-analysis. Pooled prevalence of ototoxic hearing loss associated with cisplatin and/or carboplatin exposure was 43.17% [CI 37.93–48.56%]. Prevalence estimates were higher for regimens involving cisplatin (cisplatin only: 49.21% [CI 42.62–55.82%]; cisplatin & carboplatin: 56.05% [CI 45.12–66.43%]) versus carboplatin only (13.47% [CI 8.68–20.32%]). Our crude estimates of burden indicated approximately one million individuals worldwide are likely exposed to cisplatin and/or carboplatin, which would result in almost half a million cases of hearing loss per year, globally. There is an urgent need to reduce impacts of ototoxicity in cancer patients. This can be partially achieved by implementing existing strategies focused on primary, secondary, and tertiary hearing loss prevention. Primary ototoxicity prevention via otoprotectants should be a research and policy priority.

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An estimated one million people are exposed to chemotherapeutic drugs per year.

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An estimated half a million cases of hearing loss per year are from chemotherapy.

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Hearing loss prevalence after exposure to cisplatin and/or carboplatin is 43%.

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Primary, secondary and tertiary prevention of hearing loss should be prioritized.

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Ototoxic hearing loss prevention is a global public health priority.

Hearing loss and intellectual outcome in children treated for embryonal brain tumors: Implications for young children treated with radiation sparing approaches

Purpose

We investigate the impact of severe sensorineural hearing loss (SNHL) and for the first time evaluate the effect of unilateral versus bilateral SNHL on intellectual outcome in a cohort of children with embryonal brain tumors treated with and without radiation.

Methods

Data were from 94 childhood survivors of posterior fossa (PF) embryonal brain tumors who were treated with either: (1) chemotherapy alone (n = 16, 7.11 [3.41] years, 11M/5F), (2) standard‐dose craniospinal irradiation (CSI) and/or large boost volumes (n = 44, 13.05 [3.26] years, 29M/15F), or (3) reduced‐dose CSI with a boost restricted to the tumor bed (n = 34, 11.07 [3.80] years, 19M/15F). We compared intellectual outcome between children who: (1) did and did not develop SNHL and (2) developed unilateral versus bilateral SNHL. A Chang grade of ≥2b that required the use of a hearing aid was considered severe SNHL. Comparisons were made overall and within each treatment group separately.

Results

Patients who developed SNHL had lower full scale IQ (p = 0.007), verbal comprehension (p = 0.003), and working memory (p = 0.02) than patients without SNHL. No differences were observed between patients who had unilateral versus bilateral SNHL (all p > 0.05). Patients treated with chemotherapy alone who developed SNHL had lower mean working memory (p = 0.03) than patients who did not develop SNHL. Among patients treated with CSI, no IQ indices differed between those with and without SNHL (all p > 0.05).

Conclusions

Children treated for embryonal brain tumors who develop severe SNHL have lower intellectual outcome than patients with preserved hearing: this association is especially profound in young children treated with radiation sparing approaches. We also demonstrate that intellectual outcome is similarly impaired in patients who develop unilateral versus bilateral SNHL. These findings suggest that early intervention to preserve hearing is critical.

Late effects of radiation therapy in pediatric patients and survivorship

Advances in multimodality therapy have led to childhood cancer cure rates over 80%. However, surgery, chemotherapy, and radiotherapy may lead to debilitating or even fatal long-term effects among childhood survivors beyond those inflicted by the primary disease process. It is critical to understand, mitigate, and prevent these late effects of cancer therapy to improve the quality of life of childhood cancer survivors. This review summarizes the various late effects of radiotherapy and acknowledges the Pediatric Normal Tissue Effects in the Clinic (PENTEC), an international collaboration that is systematically analyzing the association between radiation treatment dose/volume and consequential organ toxicities, in developing children as a basis to formulate recommendations for clinical practice of pediatric radiation oncology. We also summarize initiatives for survivorship and surveillance of late normal tissue effects related to radiation therapy among long-term survivors of childhood cancer treated in the past.

Intellectual changes after radiation for children with brain tumors: which brain structures are most important?

BACKGROUND

The objective of this study was to evaluate the contribution of radiation dose to different intracranial structures on changes in intellectual function for children with brain tumors.

METHODS

We evaluated children with brain tumors treated in 2005-2017 who had longitudinal neuropsychological assessments and available photon dosimetric data (if radiation therapy [RT] given). Full Scale Intelligence Quotient (FSIQ) and index scores were evaluated (perceptual reasoning index [PRI], processing speed index [PSI], verbal comprehension index [VCI], and working memory index [WMI]). Multivariable linear mixed effects models were used to model endpoints, with age at RT and dose to different brain regions as fixed effects and patient-specific random intercepts. P-values (P*) were adjusted for multiple comparisons.

RESULTS

Sixty-nine patients were included, 56 of whom received RT. Median neuropsychological follow-up was 3.2 years. Right temporal lobe mean dose was strongly associated with decline in FSIQ (P* = 0.005); with each gray increase in mean dose, there was a decrease of 0.052 FSIQ points per year. Dose to 50% (D50) of the supratentorial brain was associated with decline in PSI (P* = 0.006) and WMI (P* = 0.001). Right and left hippocampus D50 were individually strongly associated with declines in VCI (P* = 0.009 for each). Presence of a ventriculoperitoneal shunt decreased FSIQ by 10 points.

CONCLUSIONS

We reported associations between dosimetry to specific brain regions and intellectual outcomes, with suggested avoidance structures during RT planning. These models can help clinicians anticipate changes in neurocognition post-RT and guide selection of an optimal RT plan.

Prevalence and risk factors for cisplatin-induced hearing loss in children, adolescents, and young adults: a multi-institutional North American cohort study

BACKGROUND

Cisplatin is used to treat a wide range of childhood cancers and cisplatin-induced hearing loss (CIHL) is a common and debilitating toxicity. We aimed to address persistent knowledge gaps in CIHL by establishing benchmarks for the prevalence of and risk factors for CIHL.

METHODS

In this multi-institutional cohort study, children (age 0-14 years), adolescents, and young adults (age 15-39 years) diagnosed with a cisplatin-treated tumour from paediatric cancer centres, who had available cisplatin dosing information, and primary audiology data for central review from consortia located in Canada and the USA were eligible for inclusion. Audiology was centrally reviewed and CIHL graded using the consensus International Society of Pediatric Oncology (SIOP) Boston Ototoxicity Scale. We assessed the prevalence of moderate or severe CIHL (SIOP grade ≥2) at latest follow-up and end of therapy, in each demographic, diagnosis, and treatment group and their relative contributions to risk for CIHL. Secondary endpoints explored associations of cisplatin dose reductions and CIHL with survival. We also examined whether cisplatin dose reductions and CIHL were associated with survival outcomes.

FINDINGS

We included 1481 patients who received cisplatin. Of the 1414 (95·5%) participants who had audiometry at latest follow-up (mean 3·9 years [SD 4·2] since diagnosis), 620 (43·8%) patients developed moderate or severe CIHL. The highest prevalence of CIHL was seen in the youngest patients (aged <5 years; 360 [59·4%] of 606 patients) and those with a CNS tumour (221 [50·9%] of 434 patients), hepatoblastoma (110 [65·9%] of 167 patients), or neuroblastoma (154 [62·1%] of 248 patients). After accounting for cumulative cisplatin dose, higher fractionated doses were associated with risk for CIHL (for each 10mg/m2 increase per day, adjusted odds ratio [aOR] 1·15 [95% CI 1·07-1·25]; for each 50 mg/m2 increase per cycle aOR 2·16 [1·37-3·51]). Vincristine exposure was newly identified as a risk factor for CIHL (aOR 3·55 [2·19-5·84]). Dose reductions and moderate or severe CIHL were not significantly associated with survival differences.

INTERPRETATION

Using this large, multicentre cohort, benchmarks were established for the prevalence of CIHL in patients treated with cisplatin. Variations in cisplatin dosing confer additive risk for developing CIHL and warrant investigation as a potential approach to decrease the burden of therapy.

FUNDING

US National Institutes of Health and National Institute on Deafness and Other Communication Disorders, US National Institutes of Health and National Cancer institute, St Baldrick's Foundation, Genome Canada, Genome British Columbia, Canadian Institutes of Health Research, the Canada Foundation for Innovation, University of British Columbia, British Columbia Children's Hospital Research Institute, British Columbia Provincial Health Services Authority, Health Canada, and C17 Research Network.

Longitudinal associations between exposure to anesthesia and neurocognitive functioning in pediatric medulloblastoma

AIM

To examine whether anesthesia exposure is associated with neurocognitive decline in pediatric medulloblastoma.

METHODS

Patients were treated at St. Jude Children's Research Hospital and completed ≥2 protocol-directed neurocognitive assessments (n = 107) as part of a multisite clinical trial for pediatric medulloblastoma (NCT00085202). Patients received risk-adapted craniospinal photon irradiation, followed by four cycles of high-dose chemotherapy and stem cell rescue. Neurocognitive testing was completed at study baseline (after surgery and <2 weeks of starting radiation therapy) and annually for 5 years. Data on anesthesia exposure during treatment was abstracted from medical records.

RESULTS

Patients were 10.2 years at diagnosis on average (SD = 4.5; 37% female, 73% average-risk). Mean cumulative anesthesia duration was 20.4 h (SD = 15.2; range 0.7-55.6 h). In the overall group, longer anesthesia duration was associated with greater declines in IQ (Estimate = -0.08, P < 0.001), attention (Estimate = -0.10, P < .001) and processing speed (Estimate = -0.13, P < 0.001). Similar results were shown in subgroups of patients who were <7 years at diagnosis (IQ = -0.14, P = 0.027; Attention = -0.25: P = 0.011), ≥7 years at diagnosis (Attention = -0.07, P = 0.039; Processing Speed = -0.08, P = 0.022), treated for high-risk disease (IQ = -0.09, P = 0.024; Attention = -0.11, P = 0.034; Processing Speed = -0.13, P = 0.001), or treated for average-risk disease (IQ = -0.05, P = .022; Attention = -0.08, P = 0.011; Processing Speed = -0.10, P < 0.001).

CONCLUSION

Greater anesthesia exposure is a risk factor for clinically significant neurocognitive decline, in addition to factors of age at diagnosis and treatment risk arm. This result is notable as there are evidence-based strategies that can limit the need for anesthesia. Limiting anesthesia exposure, as feasible, may mitigate neurocognitive late effects, and thus, improve quality of life for survivors.

Older age is a protective factor for academic achievements irrespective of treatment modalities for posterior fossa brain tumours in children

The treatment of children with posterior fossa brain tumours (PFBT) impacts their long term functional and imaging outcomes. This study aimed to evaluate academic achievement correlated with long-term sequelae after different PFBT treatment modalities. The study cohort consisted of 110 survivors (median age at diagnosis 10.1 years and median time of follow up 13.2 years) who completed hearing questionnaires, neurological assessment and MRI of the brain ≥5 years after the end of treatment. There were three treatment groups. A cisplatin group which underwent cisplatin chemotherapy, radiotherapy and surgery (medulloblastoma N = 40), a radiotherapy group which underwent radiotherapy and surgery (astrocytoma/ependymoma N = 30), and a surgery group (astrocytoma N = 40). Academic achievement was correlated to the age at diagnosis, ototoxicity, Karnofsky score (KS), and MRI findings (Fazekas Score (FS)- treatment related parenchymal changes). For a modelled age at diagnosis of five years, the cisplatin group had lower academic achievements compared to the radiotherapy (p = 0.028) and surgery (p = 0.014) groups. Academic achievements evaluated at a modelled age of 10 years at diagnosis did not significantly differ among the treatment groups. The cisplatin group exhibited a higher occurrence of ototoxicity than the radiotherapy (p<0.019) and surgery groups (p<0.001); however, there was no correlation between ototoxicity and academic achievements (p = 0.722) in older age at diagnosis. The radiotherapy group exhibited lower KS than the surgery group (p<0.001). KS significantly influenced academic achievements in all groups (p<0.000). The cisplatin group exhibited higher FS than the surgery group (p<0.001) while FS did not correlate with academic achievement (p = 0.399). Older age is a protective factor for academic achievements irrespective of a treatment modality.

Assessment of provider perspectives on otoprotection research for children and adolescents: A Children's Oncology Group Cancer Control and Supportive Care Committee survey

BACKGROUND

Cisplatin-induced hearing loss (CIHL) is a common and debilitating toxicity for childhood cancer survivors. Understanding provider perspectives is crucial to developing otoprotection studies that are both informative and feasible. Two international trials (ACCL0431 and SIOPEL6) investigated the drug sodium thiosulfate (STS) as an otoprotectant, but definitive interpretation of the findings of these trials has been challenging. Adoption of STS has therefore been uneven, and provider perspectives on its role are unknown.

PROCEDURE

The Children's Oncology Group (COG) Cancer Control and Supportive Care Neurotoxicity Subcommittee therefore conducted a survey of providers at COG institutions to determine perspectives on pediatric otoprotection practices and research surrounding three major themes: (1) prevalence of routine use of STS with cisplatin-based regimens, (2) application of audiometry to cisplatin therapy, and (3) preferred modalities for otoprotection research.

RESULTS

Survey respondents (45%, 44/98 surveyed institutions) were of diverse institutional sizes, practice settings, and geographical locations primarily in the United States and Canada. Overall, respondents considered CIHL an important toxicity and indicated strong enthusiasm for future studies (98%, 40/41). Results indicated that while STS was the current or planned standard of care in a minority of responding institutions (36%, 16/44), most sites were receptive to its inclusion in appropriate study designs. Application of audiometry for ototoxicity monitoring varied widely across sites. For otoprotection research, systemic agents were preferred (68%, 28/41) as compared with intratympanic approaches.

CONCLUSION

These results suggest that pediatric otoprotection trials remain of interest to providers; the emphasis of these trials should remain on systemic and not intratympanic therapy.

The role of cerebellum in the child neuropsychological functioning

This chapter proposes a review of neuropsychologic and behavior findings in pediatric pathologies of the cerebellum, including cerebellar malformations, pediatric ataxias, cerebellar tumors, and other acquired cerebellar injuries during childhood. The chapter also contains reviews of the cerebellar mutism/posterior fossa syndrome, reported cognitive associations with the development of the cerebellum in typically developing children and subjects born preterm, and the role of the cerebellum in neurodevelopmental disorders such as autism spectrum disorders and developmental dyslexia. Cognitive findings in pediatric cerebellar disorders are considered in the context of known cerebellocerebral connections, internal cellular organization of the cerebellum, the idea of a universal cerebellar transform and computational internal models, and the role of the cerebellum in specific cognitive and motor functions, such as working memory, language, timing, or control of eye movements. The chapter closes with a discussion of the strengths and weaknesses of the cognitive affective syndrome as it has been described in children and some conclusions and perspectives.

Association of Hearing Impairment With Neurocognition in Survivors of Childhood Cancer

Importance

Despite advancements in cancer therapy and supportive care, childhood cancer survivors remain at risk for chronic morbidities associated with disease and treatment, such as hearing impairment (HI) and neurocognitive deficits. This study, to our knowledge, is the first to objectively measure hearing and neurocognitive function in a large cohort of long-term survivors of childhood cancer stratified by treatment exposures.

Objective

To assess the association of HI with neurocognitive function and the factors in HI that mediate neurocognitive outcomes in survivors of childhood cancer.

Design, Setting, and Participants

Data analyzed in this cross-sectional study were collected for the period April 25, 2007, to June 30, 2017, from participants in the St. Jude Lifetime Cohort Study (SJLIFE), an ongoing study that quantifies the long-term health outcomes of survivors of childhood cancer. Participants included those treated at St. Jude Children's Research Hospital (Memphis, Tennessee) for childhood cancer who survived 5 or more years after their original diagnosis and who were eligible for audiologic and neurocognitive testing. Hearing outcomes were coded using the Chang Ototoxicity Grading Scale. Data analysis was performed from March 22, 2019, to March 5, 2020.

Main Outcomes and Measures

Hearing and neurocognitive function. Survivors were grouped by hearing sensitivity (normal hearing [Chang grade 0], mild HI [Chang grades 1a, 1b, and 2a], or severe HI [Chang grade ≥2b]) and stratified by treatment exposure (platinum-only exposure group [treated with cisplatin and/or carboplatin chemotherapy], cochlear radiotherapy [RT] exposure group [treated with cochlear RT with or without platinum-based chemotherapy], or no exposure group [no platinum-based chemotherapy or cochlear RT]). Multivariable log-binomial models were adjusted for age at diagnosis, time since diagnosis, sex, and relevant treatment exposures.

Results

A total of 1520 survivors of childhood cancer were analyzed, among whom 814 were male survivors (53.6%), the median (interquartile range [IQR]) age was 29.4 (7.4-64.7) years, and the median (IQR) time since diagnosis was 20.4 (6.1-53.8) years. Prevalence and risk of severe HI among survivors were higher in survivors in the platinum-only (n = 107 [34.9%]; relative risk [RR], 1.68 [95% CI, 1.20-2.37]) or cochlear RT (n = 181 [38.3%]; RR, 2.69 [95% CI, 2.02-3.57) exposure group compared with those in the no exposure group (n = 65 [8.8%]). Severe HI was associated with deficits in verbal reasoning skills (no exposure group RR, 1.11 [95% CI, 0.50-2.43]; platinum-only exposure group RR, 1.93 [95% CI, 1.21-3.08]; cochlear RT exposure group RR, 2.00 [95% CI, 1.46-2.75]), verbal fluency (no exposure group RR, 1.86 [95% CI, 1.19-2.91]; platinum-only exposure group RR, 1.83 [95% CI, 1.24-2.71]; cochlear RT exposure group RR, 1.45 [95% CI, 1.09-1.94]), visuomotor speed (no exposure group RR, 1.87 [95% CI, 1.07-3.25]; platinum-only exposure group RR, 3.10 [95% CI, 1.92-4.99]; cochlear RT exposure group RR, 1.40 [95% CI, 1.11-1.78]), and mathematics skills (no exposure group RR, 1.90 [95% CI, 1.18-3.04]; platinum-only exposure group RR, 1.63 [95% CI, 1.05-2.53]; cochlear RT exposure group RR, 1.58 [95% CI, 1.15-2.18]), compared with survivors with normal hearing or with mild HI.

Conclusions and Relevance

Results of this study suggest that severe HI in childhood cancer survivors is associated with neurocognitive deficits independent of the neurotoxic treatment received. Early screening and intervention for HI may facilitate the development and maintenance of neurocognitive function and identify individuals at risk for impairment.

Cisplatin-induced ototoxicity in organotypic cochlear cultures occurs independent of gap junctional intercellular communication

Cisplatin is a very effective chemotherapeutic, but severe and permanent hearing loss remains a prevalent side effect. The processes underpinning cisplatin-induced ototoxicity are not well understood. Gap junction channels composed of connexin (Cx) subunits allow for the passage of small molecules and ions between contacting neighboring cells. These specialized channels have been postulated to enhance cisplatin-induced cell death by spreading “death signals” throughout the supporting cells of the organ of Corti. This study sought to investigate the role of Cx43 in cisplatin-induced ototoxicity using organotypic cochlear cultures from control and two Cx43-mutant mouse strains harboring either a moderate (Cx43^I130T/+) or severe (Cx43^G60S/+) reduction of Cx43 function. Cochlear cultures from Cx43-mutant mice with a severe reduction in Cx43-based gap junctional intercellular communication (GJIC) had an enhanced number of hair cells that were positive for cleaved caspase 3, a marker of active apoptosis, after cisplatin treatment. In cisplatin-treated organotypic cochlear cultures, there was a decrease in the co-localization of Cx26 and Cx30 compared with untreated cultures, suggesting that cisplatin causes reorganization of connexin composition in supporting cells. Both Cx26 and Cx30 protein expression as well as GJIC were decreased in organotypic cochlear cultures treated with the gap-junction blocker carbenoxolone. When cisplatin and carbenoxolone were co-administered, there were no differences in hair cell loss compared with cisplatin treatment alone. Using cisplatin-treated control and Cx43-ablated organ of Corti derived HEI-OC1 mouse cells, we found that greatly reducing GJIC led to preferential induction of an ER stress pathway. Taken together, this study strongly suggests that inhibition of GJIC in organ of Corti cells does not lead to differential susceptibility to cisplatin-induced ototoxicity. Although cisplatin causes the same degree of cell death in gap junction competent and incompetent cochlear cells, the engagement of the mitochondrial dysregulation and ER stress differs.

Effect of sensorineural hearing loss on neurocognitive and adaptive functioning in survivors of pediatric embryonal brain tumor

PURPOSE

Survivors of pediatric embryonal brain tumors (BT) are at high risk for sensorineural hearing loss (SNHL) associated with neurocognitive decline. However, previous studies have not assessed the relationship between SNHL and adaptive functioning. We examined neurocognitive and adaptive functioning in patients with and without SNHL.

METHODS

Participants included 36 patients treated for an embryonal BT with craniospinal irradiation (CSI) and cisplatin chemotherapy who were assessed 6.7 years post-treatment on average. The impact of SNHL on neurocognitive performance and parent-rated adaptive functioning was assessed in univariate and multivariate analyses.

RESULTS

There were 17 cases with SNHL (mean age at evaluation = 14.4) and 19 cases with NH (mean age at evaluation = 13.8). After accounting for age at diagnosis and additional covariates in multivariable analyses, SNHL was associated with worse overall intellectual functioning (p = 0.027) and perceptual reasoning (p = 0.016) performance. There was no effect of SNHL on adaptive functioning in multivariable models. Age at diagnosis and sex were associated with performance on neurocognitive measures.

CONCLUSIONS

SNHL in pediatric embryonal BT is associated with increased risk for neurocognitive deficits in conjunction with other demographic and treatment-related factors.

Carboplatin-based regimen in pediatric intracranial germ-cell tumors (IC-GCTs): effectiveness and ototoxicity

Background

Induction chemotherapy with carboplatin followed by radiotherapy has been used for many years for treating intracranial germ-cell tumors (IC-GCTs) in Thailand. The objective of this study was to assess treatment outcomes, focusing on survival and ototoxicity.

Methods

The outcomes of all patients with IC-GCT treated at Ramathibodi Hospital and the Prasat Neurological Institute between 2000 and 2017 were reviewed and analyzed, including all patient characteristics and treatment modalities. Five-year overall survival (OS) and event-free survival (EFS) were analyzed using the Kaplan-Meier method, and factors affecting survival were compared using the log-rank test.

Results

Fifty-three patients age 1-14 years (median, 11 years) were included in this study. The median follow-up time was 63 months. The 5-year EFS and OS rates were 94.3% and 96.2% for all patients, respectively. No statistical difference in OS or EFS was observed between the data of recipients in the carboplatin-based and historical cisplatin-based therapies in our institutes. Concerning radiotherapy, omission of radiotherapy or focal irradiation results in worse long-term survival outcomes, but reduction in dose of radiotherapy to less than 40 Gy did not cause any negative impact on survival rates. Furthermore, carboplatin was associated with lower rates of hearing loss than cisplatin (5.7% vs 87.5%).

Conclusions

Induction chemotherapy with carboplatin-based regimens was associated with excellent survival rates and low ototoxicity in patients with IC-GCT. Radiotherapy should be given to all patients with a minimal volume equivalent to whole-ventricular radiotherapy, during which doses of lower than 40 Gy can be effectively used.

Prevalence of Ototoxicity Following Hematopoietic Stem Cell Transplantation in Pediatric Patients

The use of hematopoietic stem cell transplantation (HSCT) is increasing for a variety of diseases. Ototoxicity from this procedure has not been extensively studied. A retrospective chart review examined 275 patients from this institution who underwent HSCT between January 1, 2007, and April 30, 2017. Data extracted included therapy before HSCT and the subsequent course of transplantation. Evaluable patients had complete medical records and interpretable audiograms available. Ototoxicity constituted significant threshold changes from baseline or changes in International Society of Pediatric Oncology/Boston Ototoxicity Grading Scale (SIOP) grade comparing audiogram results just before HSCT with those following the transplantation procedure. A total of 147 patients were evaluable. Ototoxicity was observed in 10.2% of the patients. Higher SIOP grade before HSCT was significantly associated with a higher risk of post-transplantation ototoxicity (P < .01). Previous cisplatin treatment (P < .0001), but not carboplatin or radiation treatment, was also associated with ototoxicity. Patients with a solid tumor or brain tumor (P < .0001) and those who received an autologous transplant (P = .0002) were also at increased risk. No post-transplantation event was significantly associated with ototoxicity. Ototoxicity affects a significant percentage of patients undergoing HSCT, and careful monitoring is needed to identify patients impacted by this procedure.

Cognitive Implications of Ototoxicity in Pediatric Patients With Embryonal Brain Tumors

PURPOSE

Sensorineural hearing loss (SNHL) is associated with intellectual and academic declines in children treated for embryonal brain tumors. This study expands upon existing research by examining core neurocognitive processes that may result in reading difficulties in children with treatment-related ototoxicity.

PATIENTS AND METHODS

Prospectively gathered, serial, neuropsychological and audiology data for 260 children and young adults age 3 to 21 years (mean, 9.15 years) enrolled in a multisite research and treatment protocol, which included surgery, risk-adapted craniospinal irradiation (average risk, n = 186; high risk, n = 74), and chemotherapy, were analyzed using linear mixed models. Participants were assessed at baseline and up to 5 years after diagnosis and grouped according to degree of SNHL. Included were 196 children with intact hearing or mild to moderate SNHL (Chang grade 0, 1a, 1b, or 2a) and 64 children with severe SNHL (Chang grade 2b or greater). Performance on eight neurocognitive variables targeting reading outcomes (eg, phonemics, fluency, comprehension) and contributory cognitive processes (eg, working memory, processing speed) was analyzed.

RESULTS

Participants with severe SNHL performed significantly worse on all variables compared with children with normal or mild to moderate SNHL (P ≤ .05), except for tasks assessing awareness of sounds and working memory. Controlling for age at diagnosis and risk-adapted craniospinal irradiation dose, performance on the following four variables remained significantly lower for children with severe SNHL: phonemic skills, phonetic decoding, reading comprehension, and speed of information processing (P ≤ .05).

CONCLUSION

Children with severe SNHL exhibit greater reading difficulties over time. Specifically, they seem to struggle most with phonological skills and processing speed, which affect higher level skills such as reading comprehension.

Audiological monitoring in Swiss childhood cancer patients

BACKGROUND

Full audiological monitoring is the best strategy to detect hearing loss early and to provide timely intervention in the absence of a clinical method of otoprotection. Full monitoring requires audiological evaluation before, and then during and after ototoxic cancer treatment. In a worldwide context of monitoring protocols that vary substantially, we analyzed the audiological monitoring of childhood cancer patients over the last decade across treatment centers in Switzerland.

PROCEDURE

We retrospectively searched for audiological evaluations in all nine Swiss Pediatric Oncology Centers. We analyzed proportions of patients who had audiological monitoring and described type and timing of monitoring. We determined predictors of audiological monitoring using multivariable logistic regression and described time trends.

RESULTS

We included 185 patients from the Swiss Childhood Cancer Registry diagnosed from 2005 to 2013 who had platinum chemotherapy and/or cranial radiation ≥30 Gray and who were alive at time of study. Less than half of children, 43%, had full audiological monitoring (before, during, and after treatment), while 72% were tested after cancer treatment. Nonstudy patients were less likely to have had monitoring in all phases of cancer treatment. Patients who received treatment with cisplatin or both platinum chemotherapy and cranial radiation were more likely to have had monitoring after treatment. Monitoring during and after treatment increased over the study period, but monitoring before treatment was insufficient in all time periods.

CONCLUSIONS

Our population-based study indicates that audiological monitoring is insufficient in Switzerland, particularly for nonstudy patients. Clinicians must become more aware of the importance of full audiological monitoring.

Long-term auditory complications after childhood cancer: A report from the Swiss Childhood Cancer Survivor Study

BACKGROUND

Auditory complications are an adverse event of childhood cancer treatment, especially common in children treated with platinum chemotherapy or cranial radiation. Variation between diagnostic childhood cancer groups has rarely been studied, and we do not know if the burden of auditory complications has changed over the last decades.

PROCEDURE

Within the Swiss Childhood Cancer Survivor Study, we sent a questionnaire to all survivors who were diagnosed at age 16 years or less between 1976 and 2005. We compared prevalence of self-reported hearing loss and tinnitus between all diagnostic childhood cancer groups and siblings, used multivariable logistic regression to analyze the effect of treatment-related factors on hearing loss, and compared the cumulative incidence of hearing loss between different periods of cancer diagnosis.

RESULTS

Prevalence of self-reported hearing loss was higher in survivors (10%) than in siblings (3%, P < 0.001), and highest in survivors of central nervous system tumors (25%). Significant risk factors were treatment with platinum compounds (carboplatin: odds ratio [OR] 2.4; cisplatin: OR 9.4), cranial radiation (>29 Gy: OR >1.7), or brain surgery (OR 2.2). Children diagnosed in 1986-1995, when platinum compounds came into widespread use, had a significantly higher cumulative incidence of hearing loss than those diagnosed in 1976-1985. In the most recent period, 1996-2005, the risk decreased again, both for patients treated with platinum compounds and with cranial radiation.

CONCLUSIONS

Our data show that the burden of hearing loss has stabilized in recently treated survivors, suggesting that survivors have benefited from new treatment regimens that use less ototoxic radiation and more carefully dosed platinum compounds.

Core deficits and quality of survival after childhood medulloblastoma: a review

Background

Medulloblastoma is the most common malignant central nervous system tumor in children. Treatment most often includes surgical resection, craniospinal irradiation, and adjuvant chemotherapy. Although survival has improved dramatically, the tumor and its treatments have devastating long-term side effects that negatively impact quality of survival (QoS). The objective was to review the literature on QoS following childhood medulloblastoma.

Methods

This narrative review is based on a Medline database search and examination of the reference lists of papers selected.

Results

Frequent problems after medulloblastoma treatment include medical complications, such as long-term neurological and sensory (hearing loss) impairments; endocrine deficits, including growth problems; and secondary tumors. Neurocognitive impairment is repeatedly reported, with decreasing cognitive performances over time. Although all cognitive domains may be affected, low processing speed, attention difficulties, and working memory difficulties are described as the core cognitive deficits resulting from both cerebellar damage and the negative effect of radiation on white matter development. Long-term psychosocial limitations include low academic achievement, unemployment, and poor community integration with social isolation. Important negative prognostic factors include young age at diagnosis, conventional craniospinal radiotherapy, presence of postoperative cerebellar mutism, and perioperative complications. The influence of environmental factors, such as family background and interventions, remains understudied.

Conclusion

Future studies should focus on the respective impact of radiation, cerebellar damage, genomic and molecular subgroup parameters, and environmental factors on cognitive and psychosocial outcomes. Long-term (probably lifelong) follow-up into adulthood is required in order to monitor development and implement timely, suitable, multi-disciplinary rehabilitation interventions and special education or support when necessary.