Long term hearing degeneration after platinum-based chemotherapy in childhood

Hearing Evaluations in Children With Retinoblastoma Treated With Intra-arterial Carboplatin Chemotherapy: A Single Institution Review

PURPOSE

To determine whether the administration of intra-arterial carboplatin affected the hearing of children with retinoblastoma.

METHODS

Children with retinoblastoma who were treated with intra-arterial carboplatin chemotherapy were included. Hearing tests before chemotherapy including tympanometry, distortion product otoacoustic emissions, and audiogram (if achievable) were performed and repeated 3 to 9 months after concluding intra-arterial therapy. The study was approved by the institutional review board. Patients were identified from the retinoblastoma clinic when the treatment plan included intra-arterial carboplatin chemotherapy. Children were excluded if they had previous intra-arterial carboplatin or preexisting hearing loss but were included if they had systemic carboplatin and dosing was available. Tympanometry was performed to rule out inner ear fluid. All examinations were performed by a certified audiologist with the same equipment, calibrated regularly by a certified technician.

RESULTS

Twenty-two children (32 eyes) were evaluable. Because most children are diagnosed at a young age and are unable to participate in an audiogram, distortion product otoacoustic emission measurement was the primary measurement. No child displayed hearing loss.

CONCLUSIONS

Intra-arterial chemotherapy with carboplatin did not cause ototoxicity in any child by distortion product otoacoustic emission measurement in contrast to systemic chemotherapy where ototoxicity is common. Distortion product otoacoustic emission levels were essentially unchanged from before to after intra-arterial chemotherapy in children with retinoblastoma. These findings suggest that intra-arterial carboplatin does not affect outer hair cell function, and distortion product otoacoustic emission tests can provide useful information when monitoring children at risk of developing carboplatin ototoxicity. [J Pediatr Ophthalmol Strabismus. 20XX;X(X):XXX-XXX.].

Re-telling the story of aminoglycoside ototoxicity: tales from sub-Saharan Africa

Background

Aminoglycosides, such as Streptomycin, are cheap, potent antibiotics widely used Sub-Saharan Africa. However, aminoglycosides are the commonest cause of ototoxicity. The limited prospective epidemiological studies on aminoglycoside ototoxicity from Sub-Saharan Africa motivated this study to provide epidemiological information on Streptomycin-induced ototoxicity, identify risk factors and predictors of ototoxicity.

Method

A longitudinal study of 153 adults receiving Streptomycin-based anti-tuberculous drugs was done. All participants underwent extended frequency audiometry and had normal hearing thresholds at baseline. Hearing thresholds were assessed weekly for 2 months, then monthly for the subsequent 6 months. Ototoxicity was determined using the ASHA criteria. Descriptive statistics were used to analyze socio-demographic variables. Ototoxicity incidence rate was calculated, and Kaplan-Meier estimate used to determine cumulative probability of ototoxicity. Chi-square test was done to determine parameters associated with ototoxicity and Cox regression models were used to choose the predictors of ototoxicity.

Results

Age of participants was 41.43 ± 12.66 years, with a male-to-female ratio of 1:0.6. Ototoxicity was found in 34.6% of the participants, giving an incidence of 17.26 per 1,000-person-week. The mean onset time to ototoxicity was 28.0 ± 0.47 weeks. By 28th week, risk of developing ototoxicity for respondents below 40 years of age was 0.29, and for those above 40 years was 0.77. At the end of the follow-up period, the overall probability of developing ototoxicity in the study population was 0.74. A significant difference in onset of ototoxicity was found between the age groups: the longest onset was seen in <40 years, followed by 40-49 years, and shortest onset in ≥50 years. Hazard of ototoxicity was significantly higher in participants aged ≥50 years compared to participants aged ≤40 years (HR = 3.76, 95% CI = 1.84-7.65). The probability of ototoxicity at 40 g, 60 g and 80 g cumulative dose of Streptomycin was 0.08, 0.43 and 2.34, respectively. Age and cumulative dose were significant predictors of ototoxicity.

Conclusion

The mean onset time to Streptomycin-induced ototoxicity was 28 weeks after commencement of therapy. Age and cumulative dose can reliably predict the onset of Streptomycin-induced ototoxicity. Medium to long term monitoring of hearing is advised for patients on aminoglycoside therapy.

The long-term impacts of hearing loss, tinnitus and poor balance on the quality of life of people living with and beyond cancer after platinum-based chemotherapy: a literature review

PURPOSE

To elucidate the long-term impacts of hearing loss, tinnitus and balance in people living with and beyond cancer (LWBC) treated with platinum-based chemotherapy (PBCT).

METHODS

A literature search was conducted between March and June 2022 using PubMed, Web of Science and Google Scholar. Full-text papers in English were included. Articles explored the impacts of hearing loss, tinnitus and balance and discussed them in the context of treatment. If PBCT was used in conjunction with other treatments, the article was included. There were no constraints on age, cancer type, publication date, location, study design or data type. Sixteen studies and two reviews were included.

RESULTS

Hearing loss and tinnitus can cause communication difficulties and subsequent social withdrawal. There were deficits in cognition, child development and educational performance. Employment and the ease of everyday life were disrupted by hearing loss and tinnitus, whereas poor balance interfered with walking and increased the risk of falls. Depression and anxiety were related to ototoxicity. Most notable were the differing mindsets experienced by adults LWBC with ototoxicity. There was evidence of inadequate monitoring of ototoxicity by clinicians and a lack of communication between clinicians and patients about ototoxicity as a side effect.

CONCLUSIONS

Ototoxicity has a negative long-term impact on multiple areas of life for adults and children LWBC. This can compromise their quality of life.

IMPLICATIONS FOR CANCER SURVIVORS

Increased awareness, monitoring and education surrounding these issues may lead to earlier intervention and better management of ototoxicity, enhancing the quality of life of people LWBC.

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.

Supporting Cells and Their Potential Roles in Cisplatin-Induced Ototoxicity

Cisplatin is a known ototoxic chemotherapy drug, causing irreversible hearing loss. Evidence has shown that cisplatin causes inner ear damage as a result of adduct formation, a proinflammatory environment and the generation of reactive oxygen species within the inner ear. The main cochlear targets for cisplatin are commonly known to be the outer hair cells, the stria vascularis and the spiral ganglion neurons. Further evidence has shown that certain transporters can mediate cisplatin influx into the inner ear cells including organic cation transporter 2 (OCT2) and the copper transporter Ctr1. However, the expression profiles for these transporters within inner ear cells are not consistent in the literature, and expression of OCT2 and Ctr1 has also been observed in supporting cells. Organ of Corti supporting cells are essential for hair cell activity and survival. Special interest has been devoted to gap junction expression by these cells as certain mutations have been linked to hearing loss. Interestingly, cisplatin appears to affect connexin expression in the inner ear. While investigations regarding cisplatin-induced hearing loss have been focused mainly on the known targets previously mentioned, the role of supporting cells for cisplatin-induced ototoxicity has been overlooked. In this mini review, we discuss the implications of supporting cells expressing OCT2 and Ctr1 as well as the potential role of gap junctions in cisplatin-induced cytotoxicity.

Long-term auditory follow-up in the management of pediatric platinum-induced ototoxicity

PURPOSE

Irreversible bilateral sensorineural hearing loss is a common side effect of platinum compounds. Because of the extended overall survival, a prolonged hearing surveillance and management of hearing impairments are emerging concerns for pediatric oncology.

METHODS

In this retrospective observational study, we enrolled 38 children out of 116 treated at our institution by chemotherapy (cisplatin and/or carboplatin) with or without irradiation between 2007 and 2014, submitted to hearing monitoring before every cycle of chemotherapy, and who completed a 5-year long-term audiological follow-up. Chemotherapy regimens, demographic findings, cumulative doses, and cranial irradiation were compared.

RESULTS

At the end of 5-year follow-up, ototoxicity was significantly increased compared to that observed at the end of chemotherapy (52.5% vs 39.5%, p < 0.001). A late onset of hearing loss was experienced in 13.1% of children, while in 26.3% progressive hearing loss was measured. Deafness at the end of chemotherapy and irradiation were significant prognostic factors for late ototoxicity outcomes (Odds Ratio 7.2-CI 1.67-31.1-p < 0.01 and 5.25-CI 1.26-21.86-p < 0.01 respectively). No significant differences were found between cisplatin and combined treatment (i.e., cisplatin shifted to carboplatin during monitoring for the onset of ototoxicity) and ototoxicity was not associated with platinum compounds cumulative dose (p > 0.05). 13.1% of children needed hearing aids at the end of follow-up.

CONCLUSION

Long-term monitoring of at least 5 years prevents the harmful effects of hearing deprivation identifying late onset/progressive hearing loss after platinum compound chemotherapy in children thanks to early hearing rehabilitation, especially in those who underwent multimodal therapy or subjected to irradiation.

Ototoxic effects of antineoplastic drugs: a systematic review

INTRODUCTION

Platinum-based chemotherapeutics play an important role in the treatment of cancer at different levels and are the most cited ototoxic agents when scientific evidence is analyzed.

OBJECTIVE

To present scientific evidence based on a systematic literature review, PRISMA, in order to systematize information on the ototoxic effects of using antineoplastic drugs.

METHODS

For the selection of studies, the combination based on the Medical Subject Heading Terms (MeSH) was used. The Medline (Pubmed), LILACS, SciELO, SCOPUS, WEB OF SCIENCE and BIREME databases were used, without restriction of language, period, and location. Evaluation of the quality of the articles was carried out, which included articles with a minimum score of 6 in the modified scale of the literature. The designs of the selected studies were descriptive, cohort, and cross-sectional, which were related to the research objective.

RESULTS

Three articles were included in this systematic review. The ototoxicity caused by cisplatin alone varied from 45% to 83.3%, while that caused by the use associated with carboplatin varied from 16.6% to 75%. There was a significant variation in the cumulative doses of these antineoplastic agents, both in isolated and in combination. Auditory changes, especially at high frequencies, were evident after completion of treatment.

CONCLUSION

Auditory changes after the use of platinum-based antineoplastic drugs were found, however, there was an important heterogeneity regarding the frequency of ototoxicity and the cumulative dose of the drugs used.

Ototoxicity in cancer survivors: Experience and proposal of a surveillance protocol

INTRODUCTION

Ototoxicity occurs in different percentages in patients after treatment with platinum-based chemotherapy or cranial radiation therapy. The aim of this study was to present our experience in ototoxicity monitoring.

MATERIAL AND METHODS

A review was made of the registry of paediatric cancer patients referred to the Children's Hearing Loss Unit from 1999 to 2019.

RESULTS

Of the 46 patients referred to this unit, 41 had received platinum as part of their treatment, 17 patients underwent neurosurgery, and 18 patients received cranial radiation therapy. An anamnesis and otoscopy were performed on all of them, and the monitoring was carried out with tone-verbal audiometry and/or distortion products. Hearing loss was observed in eight patients (21.05% of patients referred for audiological follow-up) as a consequence of the treatment. It was impossible to determine the audiological situation in eight patients at the end of treatment. Hearing aid adaption was necessary in two patients. In coordination with Paediatric Oncology, a change from cisplatin to carboplatin due to bilateral grade two ototoxicity was considered appropriate during treatment in one patient.

CONCLUSION

Adequate coordination with Paediatric Oncology is essential to carry out active surveillance for ototoxicity and to modify, if possible, the dosage or type of chemotherapy in case hearing is affected. In our experience, and following current recommendations, a pre-treatment assessment is usually performed, as well as monitoring during treatment, at the end of treatment, and annually thereafter due to the risk of a later development of hearing loss.

Factors influencing participation rates in clinical late-effect studies of childhood cancer survivors

To ensure external validation of a study population in clinical late-effect studies of childhood cancer, the participation rate must be high. This study investigated demographic data in Nordic late-effect studies and potential factors impacting participation rates such as cancer type, time since diagnosis, and duration of clinical examinations. We found 80 published studies originating from 16 cohorts, with median follow-up of 6.0 years (range 3-14). The overall participation rates ranged from 27% to 100%. The highest participation rates were seen in studies of survivors with solid tumors (92%) and the lowest in hematologic malignancies (67%) and central nervous system tumors (73%). The clinical examination in 10 studies (62.5%) lasted for more than 3 hours. Neither duration of the clinical examination nor time since diagnosis seemed to affect the participation rate. We encourage future studies to describe the recruitment process more thoroughly to improve understanding of the factors influencing participation rates.

Changing the time intervals between cisplatin cycles alter its ototoxic side effect

Various methods have been tested and deployed clinically to identify and minimize cisplatin ototoxicity. Upon early identification of hearing loss, one of the possible approaches to reducing future ototoxicity is to increase the gaps or breaks between cycles or doses of cisplatin. However, recent findings about the retention of cisplatin in the cochlea and the potential for its long-term ototoxic effects call into question whether such an approach is effective in reducing hearing loss. The current study was undertaken to determine whether increasing the rest intervals between cycles of cisplatin altered the resulting ototoxicity. CBA/CaJ mice were exposed to a cumulative dose of 48 mg/kg cisplatin delivered in three cycles of 16 mg/kg (4 mg/kg per day for 4 consecutive days). The cycles were separated by either 10, 17, or 87 days to determine if the inter-cycle rest intervals affected resulting ototoxicity. Ototoxicity was measured using auditory brainstem response threshold shifts and hair cell losses. Results indicated that longer intervals between cycles of cisplatin led to lower threshold shifts and outer hair cell lesions. The results support the principle that 'slowing down' cisplatin dosing by increasing rest intervals between doses can reduce the ototoxic side effect. Further testing is needed to optimize the timing and to determine the impact of longer inter-cycle intervals on cisplatin's anti-tumor efficacy.

Early Physiological and Cellular Indicators of Cisplatin-Induced Ototoxicity

Cisplatin chemotherapy often causes permanent hearing loss, which leads to a multifaceted decrease in quality of life. Identification of early cisplatin-induced cochlear damage would greatly improve clinical diagnosis and provide potential drug targets to prevent cisplatin's ototoxicity. With improved functional and immunocytochemical assays, a recent seminal discovery revealed that synaptic loss between inner hair cells and spiral ganglion neurons is a major form of early cochlear damage induced by noise exposure or aging. This breakthrough discovery prompted the current study to determine early functional, cellular, and molecular changes for cisplatin-induced hearing loss, in part to determine if synapse injury is caused by cisplatin exposure. Cisplatin was delivered in one to three treatment cycles to both male and female mice. After the cisplatin treatment of three cycles, threshold shift was observed across frequencies tested like previous studies. After the treatment of two cycles, beside loss of outer hair cells and an increase in high-frequency hearing thresholds, a significant latency delay of auditory brainstem response wave 1 was observed, including at a frequency region where there were no changes in hearing thresholds. The wave 1 latency delay was detected as early cisplatin-induced ototoxicity after only one cycle of treatment, in which no significant threshold shift was found. In the same mice, mitochondrial loss in the base of the cochlea and declining mitochondrial morphometric health were observed. Thus, we have identified early spiral ganglion-associated functional and cellular changes after cisplatin treatment that precede significant threshold shift.

[Ototoxicity in cancer survivors: experience and proposal of a surveillance protocol]

INTRODUCTION

Ototoxicity occurs in different percentages in patients after treatment with platinum-based chemotherapy or cranial radiation therapy. The aim of this study was to present experience in ototoxicity monitoring.

MATERIAL AND METHODS

A review was made of the registry of paediatric cancer patients referred to the Children's Hearing Loss Unit from 1999 to 2019.

RESULTS

Of the 46 patients referred to this unit, 41 had received platinum as part of their treatment, 17 patients underwent neurosurgery, and 18 patients received cranial radiation therapy. An anamnesis and otoscopy were performed on all of them, and the monitoring was carried out with tone-verbal audiometry and/or distortion products. Hearing loss was observed in eight patients (21.05% of patients referred for audiological follow-up) as a consequence of the treatment. It was impossible to determine the audiological situation in eight patients at the end of treatment. Hearing aid adaption was necessary in two patients. In coordination with Paediatric Oncology, a change from cisplatin to carboplatin due to bilateral grade two ototoxicity was considered appropriate during treatment in one patient.

CONCLUSION

Adequate coordination with Paediatric Oncology is essential to carry out active surveillance for ototoxicity and to modify, if possible, the dosage or type of chemotherapy in case hearing is affected. In our experience, and following current recommendations, a pre-treatment assessment is usually performed, as well as monitoring during treatment, at the end of treatment, and annually thereafter due to the risk of a later development of hearing loss.

Ototoxicity after platinum-based chemotherapy in the treatment of melanotic neuroectodermal tumour of infancy

Melanotic neuroectodermal tumor of infancy (MNTI) is a rare infantile tumor that originates from mesenchymal-neuroectodermal cells, the treatment of which uses platinum derivatives that can affect hearing loss. The present study evaluated the long-term effects of ototoxicity following chemotherapy with cisplatin, vincristine, cyclophosphamide, teniposide and adriamycin in a 10-year-old patient after surgical removal of a MNTI tumor at the age of 8 months. Audiometric tests (high-frequency tonal audiometry, speech audiometry, speech acoustics, tympanometry and absorbance measurements) were performed during a 10-year follow-up after receiving chemotherapy. Hearing disorders in the high-frequency range (6,000 to 16,000 Hz range) were demonstrated for both ears, indicating that these may be the long-term effects of chemotherapy with use of platinum compounds during the treatment of infants.

Effects of chemotherapy on the auditory system of children with cancer: a systematic literature review

ABSTRACT Purpose: to identify and analyze the effects of chemotherapy on the auditory system of children and/or adolescents with cancer treated with cisplatin and carboplatin, assessed through standardized audiological procedures. Methods: studies in Brazilian Portuguese and in English were searched for, as available in the databases Science Direct, PubMed, LILACS, BIREME, Embase, SciELO, Web of Science and Cochrane. The descriptors were: Hearing Loss, Audiology, Child Cancer, Chemotherapy, and Child. Articles with levels 1 and 2 of scientific evidence, published in the last 20 years (1997 to 2017), were considered, of which the audiological results were analyzed, as well as the prevalence of hearing loss in children with cancer undergoing chemotherapy. Results: 3,625 articles were found, of which only 23 were selected for analysis in the present review. Studies have shown a high incidence of sensorineural hearing loss and decrease or even loss of otoacoustic emissions in children and adolescents with cancer, even after the first dose of chemotherapy drugs, with high frequencies being the most affected. Conclusion: there is evidence that both carboplatin and especially cisplatin from the first doses may impair the hearing of children and adolescents, mainly affecting the cochlear function, thus, the importance of long-term audiological monitoring.

Looking beyond the audiogram in ototoxicity associated with platinum-based chemotherapy

Introduction

Ototoxicity associated with platinum-based chemotherapy is highly prevalent and can cause detrimental consequences among cancer survivors.

Discussion

In this article, we highlight important aspects of the evaluation of ototoxicity with the aim to increase awareness of Oncologists in this regard. Standard pure tone audiometry alone is inadequate for this context. Comprehensive and consistent hearing tests should be implemented in a monitoring and surveillance program. High-frequency audiometry (10–16 kHz) is a sensitive tool in the detection of ototoxic hearing loss at onset. In addition to threshold audiometry, measures of speech comprehension (both in quiet and in noise) can add useful information in the evaluation of hearing in real-life situations. Not only hearing loss, but also tinnitus and imbalance are common in patients who receive platinum-based chemotherapy, and can cause debilitating effects upon quality of life in this population. Moreover, self-report measures associated with cochlear and vestibular handicaps can provide valuable information regarding the impact of ototoxicity.

Conclusions

It is vital to build awareness about the variety and impact of the symptoms of ototoxicity. Comprehensive evaluation of hearing status along with self-reported impact of the cochlear and vestibular handicap should be implemented in a monitoring and surveillance program for appropriate investigation and management.

An optimized, clinically relevant mouse model of cisplatin-induced ototoxicity

Cisplatin-induced ototoxicity results in significant, permanent hearing loss in pediatric and adult cancer survivors. Elucidating the mechanisms underlying cisplatin-induced hearing loss as well as the development of therapies to reduce and/or reverse cisplatin ototoxicity have been impeded by suboptimal animal models. Clinically, cisplatin is most commonly administered in multi-dose, multi-cycle protocols. However, many animal studies are conducted using single injections of high-dose cisplatin, which is not reflective of clinical cisplatin administration protocols. Significant limitations of both high-dose, single-injection protocols and previous multi-dose protocols in rodent models include high mortality rates and relatively small changes in hearing sensitivity. These limitations restrict assessment of both long-term changes in hearing sensitivity and effects of potential protective therapies. Here, we present a detailed method for an optimized mouse model of cisplatin ototoxicity that utilizes a multi-cycle administration protocol that better approximates the type and degree of hearing loss observed clinically. This protocol results in significant hearing loss with very low mortality. This mouse model of cisplatin ototoxicity provides a platform for examining mechanisms of cisplatin-induced hearing loss as well as developing therapies to protect the hearing of cancer patients receiving cisplatin therapy.

Cisplatin-induced Ototoxicity in Children With Solid Tumor

Cisplatin is the principal chemotherapeutic agent and also tremendously increases the survival for pediatric patients with neuroblastoma or hepatoblastoma. With the extended overall survival period, clinical medical workers and parents gradually attach more attention to the late effect of chemotherapy of these children. The purpose of this study is to analyze the incidence and risk factors of cisplatin-based hearing loss. We retrospectively collected the archives of cisplatin-based chemotherapy and audiometric evaluation from 2005 through 2017 at Xinhua Hospital. From 384 patients treated with cisplatin, full data of 59 patients were available, and 14 cases (23.7%) were identified as significant hearing loss. The median time from usage of platinum compounds to the most recent audio test was 406 days. Cumulative and single maximum cisplatin dose was 622.6±283.2 and 137.6±51.6 mg/m/cycle, respectively. Accumulated cisplatin dose (95% confidence interval, 1.001-1.006; P=0.012) and single maximum cisplatin dose (95% confidence interval, 1.000-1.029; P=0.049) were independently important predictors for moderate to severe hearing loss in children treated with cisplatin. Cisplatin can cause ototoxicity which profoundly handicap language development and social communication for children. Regular audiological management and long-term follow-up are strongly recommended for this vulnerable group.

Recommendations for ototoxicity surveillance for childhood, adolescent, and young adult cancer survivors: a report from the International Late Effects of Childhood Cancer Guideline Harmonization Group in collaboration with the PanCare Consortium

Childhood, adolescent, and young adult (CAYA) cancer survivors treated with platinum-based drugs, head or brain radiotherapy, or both have an increased risk of ototoxicity (hearing loss, tinnitus, or both). To ensure optimal care and reduce consequent problems-such as speech and language, social-emotional development, and learning difficulties-for these CAYA cancer survivors, clinical practice guidelines for monitoring ototoxicity are essential. The implementation of surveillance across clinical settings is hindered by differences in definitions of hearing loss, recommendations for surveillance modalities, and remediation. To address these deficiencies, the International Guideline Harmonization Group organised an international multidisciplinary panel, including 32 experts from ten countries, to evaluate the quality of evidence for ototoxicity following platinum-based chemotherapy and head or brain radiotherapy, and formulate and harmonise ototoxicity surveillance recommendations for CAYA cancer survivors.

Long term platinum-induced ototoxicity in pediatric patients

OBJECTIVES

Platinum-based chemotherapy treatments are effective against a variety of pediatric malignancies. However, its use can lead to permanent hearing loss. The aim of this study was to evaluate the long-term effect of platinum chemotherapy on hearing and evaluate its progression.

METHODS

Prospective cohort study. All records of pediatric patients receiving platinum-based chemotherapy between 2001 and 2006 were reviewed. Demographics and audiograms performed before, during, and following chemotherapy were analyzed. An updated audiogram and a video head impulse test were performed. A hearing ability questionnaire was also completed.

RESULTS

Thirty-nine patients met the inclusion criteria. Of these, 12 patients were included in the study; 14 were deceased, 8 had incomplete data and 5 were excluded for other reasons. Median age at chemotherapy was 4.3 years (range 10 months-14.2 years). Seven patients had received cisplatin, two received carboplatin and three received both agents. Five had also received cranial irradiation. With a median follow-up time of 11.9 years, 58.3% had developed hearing loss and two patients wore bilateral hearing aids; 67% of the patients with hearing loss had worsening of their hearing in the long-term. All patients referred difficulties in various subscales measured by the questionnaire. Three patients had decreased vestibulo-ocular reflex gains.

CONCLUSION

Platinum-induced hearing loss in pediatric patients can be progressive and debilitating. A long term audiometric follow-up of at least 10 years is suggested for these patients.

Elevated visual dependency in young adults after chemotherapy in childhood

Chemotherapy in childhood can result in long-term neurophysiological side-effects, which could extend to visual processing, specifically the degree to which a person relies on vision to determine vertical and horizontal (visual dependency). We investigated whether adults treated with chemotherapy in childhood experience elevated visual dependency compared to controls and whether any difference is associated with the age at which subjects were treated. Visual dependency was measured in 23 subjects (mean age 25.3 years) treated in childhood with chemotherapy (CTS) for malignant, solid, non-CNS tumors. We also stratified CTS into two groups: those treated before 12 years of age and those treated from 12 years of age and older. Results were compared to 25 healthy, age-matched controls. The subjective visual horizontal (SVH) and vertical (SVV) orientations was recorded by having subjects position an illuminated rod to their perceived horizontal and vertical with and without a surrounding frame tilted clockwise and counter-clockwise 20° from vertical. There was no significant difference in rod accuracy between any CTS groups and controls without a frame. However, when assessing visual dependency using a frame, CTS in general (p = 0.006) and especially CTS treated before 12 years of age (p = 0.001) tilted the rod significantly further in the direction of the frame compared to controls. Our findings suggest that chemotherapy treatment before 12 years of age is associated with elevated visual dependency compared to controls, implying a visual bias during spatial activities. Clinicians should be aware of symptoms such as visual vertigo in adults treated with chemotherapy in childhood.

Decreased postural control in adult survivors of childhood cancer treated with chemotherapy

The objective of cancer treatment is to secure survival. However, as chemotherapeutic agents can affect the central and peripheral nervous systems, patients must undergo a process of central compensation. We explored the effectiveness of this compensation process by measuring postural behaviour in adult survivors of childhood cancer treated with chemotherapy (CTS). We recruited sixteen adults treated with chemotherapy in childhood for malignant solid (non-CNS) tumours and 25 healthy age-matched controls. Subjects performed posturography with eyes open and closed during quiet and perturbed standing. Repeated balance perturbations through calf vibrations were used to study postural adaptation. Subjects were stratified into two groups (treatment before or from 12 years of age) to determine age at treatment effects. Both quiet (p = 0.040) and perturbed standing (p ≤ 0.009) were significantly poorer in CTS compared to controls, particularly with eyes open and among those treated younger. Moreover, CTS had reduced levels of adaptation compared to controls, both with eyes closed and open. Hence, adults treated with chemotherapy for childhood cancer may suffer late effects of poorer postural control manifested as reduced contribution of vision and as reduced adaptation skills. These findings advocate development of chemotherapeutic agents that cause fewer long-term side effects when used for treating children.

Determinants of ototoxicity in 451 platinum-treated Dutch survivors of childhood cancer: A DCOG late-effects study

Platinum-containing chemotherapeutics are efficacious for a variety of pediatric malignancies, nevertheless these drugs can induce ototoxicity. However, ototoxicity data on large cohorts of childhood cancer survivors (CCSs) who received platinum agents, but not cranial irradiation are scarce. Therefore, we have studied the frequency and determinants of ototoxicity in a cross-sectional multicenter CCS cohort, including the role of co-medication since it has been suggested that these play a role in ototoxicity. We have collected treatment data and audiograms from the medical records of CCS treated in the seven pediatric oncology centres in The Netherlands. Ototoxicity was defined as Münster grade ≥2b (>20 dB at ≥4-8 kHz). Four-hundred-fifty-one CCS who received platinum agents, but not cranial irradiation (median age at diagnosis: 4.9 years, range: 0.01-19 years) were included. The overall frequency of ototoxicity was 42%. Ototoxicity was observed in 45% of the cisplatin-treated CCS, in 17% of the carboplatin-treated CCS and in 75% of the CCS that had received both agents. Multivariate analysis showed that younger age at diagnosis (odds ratio [OR]: 0.6, 95% confidence interval [CI]: 0.5-0.6 per 5 years increase); higher total cumulative dose cisplatin (OR: 1.2, 95% CI: 1.2-1.5 per 100 mg/m² increase); and co-treatment with furosemide (OR: 2.3, 95% CI: 1.4-3.9) were associated with ototoxicity. We conclude that treatment with (higher total cumulative dose of) cisplatin, young age and furosemide co-medication independently are associated with an increased risk of ototoxicity in CCS. Future prospective studies are necessary to confirm the additive risk of co-medication on the development of ototoxicity.

Ototoxicity (cochleotoxicity) classifications: A review

OBJECTIVE

Drug-mediated ototoxicity, specifically cochleotoxicity, is a concern for patients receiving medications for the treatment of serious illness. A number of classification schemes exist, most of which are based on pure-tone audiometry, in order to assist non-audiological/non-otological specialists in the identification and monitoring of iatrogenic hearing loss. This review identifies the primary classification systems used in cochleototoxicity monitoring. By bringing together classifications published in discipline-specific literature, the paper aims to increase awareness of their relative strengths and limitations in the assessment and monitoring of ototoxic hearing loss and to indicate how future classification systems may improve upon the status-quo.

DESIGN

Literature review.

STUDY SAMPLE

PubMed identified 4878 articles containing the search term ototox*.

RESULTS

A systematic search identified 13 key classification systems. Cochleotoxicity classification systems can be divided into those which focus on hearing change from a baseline audiogram and those that focus on the functional impact of the hearing loss.

CONCLUSIONS

Common weaknesses of these grading scales included a lack of sensitivity to small adverse changes in hearing thresholds, a lack of high-frequency audiometry (>8 kHz), and lack of indication of which changes are likely to be clinically significant for communication and quality of life.

Incidence of platinum-induced ototoxicity in pediatric patients in Quebec

BACKGROUND

The antineoplastic agents cisplatin and carboplatin are widely-used and highly-effective against a variety of pediatric cancers. Unfortunately, ototoxicity is a frequently encountered side effect of platinum-based chemotherapy. There is currently no treatment or prevention for platinum-induced ototoxicity and development of hearing loss may lead to devastating consequences on the quality of life of pediatric cancer survivors. The objective of this study is to determine the incidence of platinum-induced ototoxicity in a large series of pediatric patients and to evaluate the incidence of progression of ototoxicity after completion of treatment.

PROCEDURES

A retrospective chart review of pediatric patients treated with cisplatin or carboplatin between 2000 and 2012 was conducted. The incidence of ototoxicity was determined based on the American-Speech-Language-Hearing Association (ASHA) criteria and severity was based on the Chang classification.

RESULTS

Four hundred and sixty-six patients received platinum-based chemotherapy. Patients were excluded due to congenital hearing loss (n = 1) and insufficient data for calculating the platinum dose (n = 24) or for assessing ototoxicity (n = 135). Three hundred and six patients were included in the analysis. Post-chemotherapy ototoxicity was detected in 148 (48%) patients, and clinically-significant ototoxicity was present in 91 (30%). In addition, based on the ASHA criteria, 48% of patients (97/204) with long-term follow-up had further deterioration of their hearing after completion of treatment.

CONCLUSIONS

Ototoxicity following chemotherapy with cisplatin or carboplatin is common and can frequently progress after the completion of treatment. Long-term follow-up is strongly recommended.

Evaluation of amifostine for protection against cisplatin-induced serious hearing loss in children treated for average-risk or high-risk medulloblastoma

BACKGROUND

The purpose of this study was to evaluate amifostine for protection from cisplatin-induced serious hearing loss in patients with average-risk medulloblastoma by extending a previous analysis to a much larger sample size. In addition, this study aimed to assess amifostine with serious hearing loss in patients with high-risk medulloblastoma treated with cisplatin.

METHODS

Newly diagnosed medulloblastoma patients (n = 379; ages 3-21 years), enrolled on one of 2 sequential St. Jude clinical protocols that included 4 courses of 75 mg/m(2) cisplatin, were compared for hearing loss by whether or not they received 600 mg/m(2) of amifostine immediately before and 3 hours into each cisplatin infusion. Amifostine administration was not randomized. The last audiological evaluation between 5.5 and 24.5 months following protocol treatment initiation was graded using the Chang Ototoxicity Scale. A grade of ≥ 2b (loss requiring a hearing aid or deafness) was considered a serious event.

RESULTS

Among average-risk patients (n = 263), amifostine was associated with protection from serious hearing loss (adjusted OR, 0.30; 95% CI, 0.14-0.64). For high-risk patients (n = 116), however, there was not sufficient evidence to conclude that amifostine prevented serious hearing loss (OR, 0.89; 95% CI, 0.31-2.54).

CONCLUSIONS

Although patients in this study were not randomly assigned to amifostine treatment, we found evidence in favor of amifostine administration for protection against cisplatin-induced serious hearing loss in average-risk but not in high-risk, medulloblastoma patients.

The use of high-frequency audiometry increases the diagnosis of asymptomatic hearing loss in pediatric patients treated with cisplatin-based chemotherapy

BACKGROUND

Cisplatin may cause permanent cochlear damage by changing cochlear frequency selectivity and can lead to irreversible sensorineural hearing loss. High-frequency audiometry (HFA) is able to assess hearing frequencies above 8,000 Hz; hence, it has been considered a high-quality method to monitor and diagnose early and asymptomatic signs of ototoxicity in patients receiving cisplatin.

PROCEDURE

Forty-two pediatric patients were evaluated for hearing loss induced by cisplatin utilizing HFA, and its diagnostic efficacy was compared to that of standard pure-tone audiometry and distortion-product otoacoustic emissions (DPOAEs). The patient population consisted of those who signed an informed consent form and had received cisplatin chemotherapy between 1991 and 2008 at the Hospital de Clínicas de Porto Alegre Pediatric Unit, Brazil.

RESULTS

Forty-two patients were evaluated. The median age at study assessment was 14.5 years (range 4-37 years). Hearing loss was detected in 24 patients (57%) at conventional frequencies. Alterations of DPOAEs were found in 64% of evaluated patients and hearing loss was observed in 36 patients (86%) when high-frequency test was added. The mean cisplatin dose was significantly higher (P = 0.046) for patients with hearing impairment at conventional frequencies.

CONCLUSION

The results suggest that HFA is more effective than pure-tone audiometry and DPOAEs in detecting hearing loss, particularly at higher frequencies. It may be a useful tool for testing new otoprotective agents, beside serving as an early diagnostic method for detecting hearing impairment.

Prospective evaluation of cisplatin- and carboplatin-mediated ototoxicity in paediatric and adult soft tissue and osteosarcoma patients

Platinum-compound chemotherapy is known to have ototoxic side-effects. However, there is a paucity of literature examining hearing function prospectively and longitudinally in cohorts containing paediatric and adult patients treated within the same cisplatin- or carboplatin-containing treatment trial protocols. In Germany, Austria and Switzerland, late effects of treatment for osteosarcoma and soft tissue sarcoma have been prospectively and longitudinally registered by the Late Effects Surveillance System since 1998. The aim of this study was to analyse cisplatin- and carboplatin-induced ototoxity in a group of 129 osteosarcoma and soft tissue sarcoma patients treated within the COSS-96, CWS-96 and CWS-2002P treatment trials. The cohort consisted of 112 children and 17 adults. The median age at diagnosis was 13.56 (IQR, 10.26-16.27) years. Follow-up was 6.97 (IQR, 0.87-15.63) months. Hearing function was examined by audiometry before and after platinum treatment. A total of 108 patients were treated with cisplatin with a median cumulative dose of 360 mg/m(2). Thirteen patients received carboplatin with a median cumulative dose of 1500 mg/m(2) and 8 patients were treated with both platinum compounds (median cisplatin dose, 240 mg/m(2); IQR, 240-360 mg/m(2) and median carboplatin dose: 1200 mg/m(2); IQR, 600-3000 mg/m(2)). Following cessation of therapy, 47.3% of the patients demonstrated a hearing impairment, namely 55 children (49.1%) and 6 adults (42.1%). Out of thirteen children treated with carboplatin with a cumulative dose of 1500 mg/m(2), six revealed a significant hearing impairment. Although ototoxicity caused by platinum compounds is considered irreversible, we identified hearing improvements over time in 11 children (9.8%) and 3 adults (17.6%). None of these patients received irradiation to the head. We conclude that hearing loss is frequent in children treated with protocols containing platinum compounds and recommend prospective testing via audiometry.

Cisplatin and aminoglycoside antibiotics: hearing loss and its prevention

This review introduces the pathology of aminoglycoside antibiotic and the cisplatin chemotherapy classes of drugs, discusses oxidative stress in the inner ear as a primary trigger for cell damage, and delineates the ensuing cell death pathways. Among potentially ototoxic (damaging the inner ear) therapeutics, the platinum-based anticancer drugs and the aminoglycoside antibiotics are of critical clinical importance. Both drugs cause sensorineural hearing loss in patients, a side effect that can be reproduced in experimental animals. Hearing loss is reflected primarily in damage to outer hair cells, beginning in the basal turn of the cochlea. In addition, aminoglycosides might affect the vestibular system while cisplatin seems to have a much lower likelihood to do so. Finally, based on an understanding the mechanisms of ototoxicity pharmaceutical ways of protection of the cochlea are presented.

Hearing impairment after platinum-based chemotherapy in childhood

BACKGROUND

Chemotherapy is used in the treatment of children and adolescents with malignant diseases. Some of the chemotherapeutic agents are highly toxic and may cause a number of side effects. The primary objective of this study was to evaluate the long-term effects on hearing in cancer survivors who had received platinum-based chemotherapy in childhood or adolescence.

PROCEDURE

Medical records of 297 patients, who had received treatment for cancer at the Children's Hospital, Landspitali University Hospital in Iceland between 1981 and 2006, were retrospectively reviewed. Fifteen subjects fulfilled the eligibility criteria for the study and underwent an extended audiometric evaluation.

RESULTS

The results showed that three of the subjects had a high frequency hearing loss. In one subject, we observed a hearing recovery just after the completion of chemotherapy, but the hearing deteriorated again some years later. Nine of the 15 subjects (60%) had tinnitus after the cancer treatment. An evaluation of subjective hearing disability and handicap (The Hearing Measurements Scale) revealed that some subjects had great difficulties with hearing in certain situations. The Hearing Measurement Scale showed that the pure-tone audiogram findings were only partly associated with the apparent hearing difficulties.

CONCLUSION

Regular follow-up hearing examinations, which include both pure-tone audiogram investigations and subjective hearing disability assessments, should be performed during and after chemotherapy to identify subjects who require particular attention. This will ensure that hearing impaired individuals are provided with the most suitable listening devices, to promote good speech and social development.