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

Long-term outcomes among survivors of childhood osteosarcoma: A report from the Childhood Cancer Survivor Study (CCSS)

PURPOSE

Treatment strategies for osteosarcoma evolving between 1970 and 1999 improved 5-year survival and continue as standard of care today. This report evaluates the impact of these evolving therapies on long-term health outcomes.

METHODS

Five-year survivors of childhood osteosarcoma in CCSS treated from 1970 to 1999 were evaluated for late (>5 years from diagnosis) mortality, chronic health conditions (CHCs), and health status using piecewise-exponential and logistical models. Comparisons were made between survivors and siblings without cancer, and among survivors examining historical and current standard chemotherapies (e.g., methotrexate/doxorubicin/cisplatin [MAP] vs. others), specific chemotherapy agents and surgical approaches (amputation vs. limb salvage [LS]). Models were evaluated adjusting for attained age, sex, race, ethnicity, and age at diagnosis.

RESULTS

A total of 1257 survivors of osteosarcoma were followed on average for 24.4 years. Twenty-year all-cause late mortality was 13.3% (95% confidence interval [CI]: 11.7%-14.9%) overall and 11.7% (95% CI: 6.9%-16.5%) for the subset treated with MAP plus LS. Survivors were at higher risk of CHCs (rate ratio [RR] 3.7, 95% CI: 3.2-4.3) than the sibling cohort, most notably having more serious cardiac, musculoskeletal, and hearing CHCs. Within the survivor cohort, the risk of severe CHCs was twice as high with MAP versus no chemotherapy (RR 2.1, 95% CI: 1.3-3.4). Compared with primary amputation, serious musculoskeletal CHCs were higher after LS (RR 6.6, 95% CI: 3.6-13.4), without discernable differences in health status.

CONCLUSION

Contemporary osteosarcoma therapy with MAP plus LS, while improving 5-year disease-free survival, continues to be associated with a high burden of late mortality, CHCs, and health status limitations.

Use of Sodium Thiosulfate as an Otoprotectant in Patients With Cancer Treated With Platinum Compounds: A Review of the Literature

PURPOSE

Hearing loss occurs in 50%-70% of children treated with cisplatin. Scientific efforts have led to the recent approval of a pediatric formula of intravenous sodium thiosulfate (STS) for otoprotection by the US Food and Drug Administration, the European Medicines Agency, and the Medicines and Health Regulatory Authority in the United Kingdom. To inform stakeholders regarding the clinical utility of STS, the current review summarizes available literature on the efficacy, pharmacokinetics (PK), and safety of systemic STS to minimize cisplatin-induced hearing loss (CIHL).

DESIGN

A comprehensive narrative review is presented.

RESULTS

Thirty-one articles were summarized. Overall, systemic STS effectively reduces CIHL in the preclinical and controlled clinical study settings, in both adults and children with cancer. The extent of CIHL reduction depends on the timing and dosing of STS in relation to cisplatin. Both preclinical and clinical data suggest that systemic STS may affect plasma platinum levels, but studies are inconclusive. Delayed systemic administration of STS, at 6 hours after the cisplatin infusion, does not affect cisplatin-induced inhibition of tumor growth or cellular cytotoxicity in the preclinical setting, nor affect cisplatin efficacy and survival in children with localized disease in the clinical setting.

CONCLUSION

Systemic administration of STS effectively reduces the development and degree of CIHL in both the preclinical and clinical settings. More studies are needed on the PK of STS and cisplatin drug combinations, the efficacy and safety of STS in patients with disseminated disease, and the ability of STS to prevent further deterioration of pre-established hearing loss.

Protective mechanism of ferulic acid against neomycin-induced ototoxicity in zebrafish

Ototoxicity refers to damage of sensory hair cells and functional hearing impairment following aminoglycosides exposure. Previously, we have determined that ferulic acid (FA) protected hair cells against serial concentrations of neomycin-induced ototoxic damage. The aim of the present study is to assess the mechanism and effects of FA on neomycin-induced hair cells loss and impact on mechanosensory-mediated behaviors alteration using transgenic zebrafish (pvalb3b: TagGFP). We first identified the optimal protective condition as pre/co-treatment method in early fish development. Pretreatment of the larvae with FA significantly protected against neomycin-induced hair cells loss through preventing neomycin passed through the cytoplasm of hair cells, and subsequently decreased reactive oxygen species production and TUNEL signals in 4 day post-fertilization (dpf) transgenic zebrafish larvae. Moreover, preservation of functional hair cells correlated directly with rescue of the altered swimming behavior, indicates FA pretreatment protects against neomycin ototoxic damage in 7-dpf transgenic zebrafish larvae. Together, our findings unravel the otoprotective role of FA as an effective agent against neomycin-induced ototoxic effects and offering the theoretical foundation for discovering novel candidates for hearing protection.

Establishment, Maintenance, and Performance of the Cooperative Osteosarcoma Study Group (COSS)

INTRODUCTION

Osteosarcoma treatment has benefitted greatly from collaborative research. This paper describes the history and accomplishments of the Cooperative Osteosarcoma Study Group (COSS), mainly dedicated to clinical questions, as well as remaining challenges.

MATERIALS AND METHODS

Narrative review of over four decades of uninterrupted collaboration within the multi-national German-Austrian-Swiss COSS group.

RESULTS

Since its very first prospective osteosarcoma trial starting in 1977, COSS has continuously been able to provide high-level evidence on various tumor- and treatment-related questions. This includes both the cohort of patients enrolled into prospective trials as well as those patients excluded from them for various reasons, followed in a prospective registry. Well over one hundred disease-related publications attest to the group's impact on the field. Despite these accomplishments, challenging problems remain.

DISCUSSION

Collaborative research within a multi-national study group resulted in better definitions of important aspects of the most common bone tumor, osteosarcoma, and its treatments. Important challenges continue to persist.

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.

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.

The cumulative incidence of cisplatin-induced hearing loss in young children is higher and develops at an early stage during therapy compared with older children based on 2052 audiological assessments

BACKGROUND

Ototoxicity is a common adverse event of cisplatin treatment. The authors investigated the development of cisplatin-induced hearing loss (CIHL) over time in children with cancer by age and examined the influence of other clinical characteristics on the course of CIHL.

METHODS

Data from Canadian patients with childhood cancer were retrospectively reviewed. Hearing loss was graded according to International Society of Pediatric Oncology criteria. The Kaplan-Meier method was applied to estimate the cumulative incidence of CIHL for the total cohort and according to age. Cox regression models were used to explore the effects of independent variables on CIHL development up to 3 years after the start of therapy.

RESULTS

In total, 368 patients with 2052 audiological assessments were included. Three years after initiating therapy, the cumulative incidence of CIHL was highest in patients aged ≤5 years (75%; 95% confidence interval [CI], 66%-84%), with a rapid increase observed to 27% (95% CI, 21%-35%) at 3 months and to 61% (95% CI, 53%-69%) at 1 year, compared with patients aged >5 years (48%; 95% CI, 37%-62%; P < .001). The total cumulative dose of cisplatin at 3 months (per 100 mg/m² increase: hazard ratio [HR], 1.20; 95% CI, 1.01-1.41) vincristine (HR, 2.87; 95% CI, 1.89-4.36) and the total duration of concomitantly administered antibiotics (>30 days: HR, 1.85; 95% CI, 1.17-2.95) further influenced CIHL development over time.

CONCLUSIONS

In young children, the cumulative incidence of CIHL is higher compared with that in older children and develops early during therapy. The course of CIHL is further influenced by the total cumulative dose of cisplatin and other ototoxic (co-)medication. These results highlight the need for audiological monitoring at each cisplatin cycle.

Recommendations for Age-Appropriate Testing, Timing, and Frequency of Audiologic Monitoring During Childhood Cancer Treatment: An International Society of Paediatric Oncology Supportive Care Consensus Report

Importance

Ototoxicity is an irreversible direct and late effect of certain childhood cancer treatments. Audiologic surveillance during therapy as part of the supportive care pathway enables early detection of hearing loss, decision-making about ongoing cancer treatment, and, when applicable, the timely use of audiologic interventions. Pediatric oncologic clinical practice and treatment trials have tended to be driven by tumor type and tumor-specific working groups. Internationally accepted standardized recommendations for monitoring hearing during treatment have not previously been agreed on.

Objective

To provide standard recommendations on hearing loss monitoring during childhood cancer therapy for clinical practice.

Methods

An Ototoxicity Task Force was formed under the umbrella of the International Society of Paediatric Oncology, consisting of international audiologists, otolaryngologists, and leaders in the field of relevant pediatric oncology tumor groups. Consensus meetings conducted by experts were organized, aimed at providing standardized recommendations on age-directed testing, timing, and frequency of monitoring during cancer treatment based on literature and consensus. Consensus statements were prepared by the core group, adapted following several videoconferences, and finally agreed on by the expert panel.

Findings

The consensus reached was that children who receive ototoxic cancer treatment (platinum agents, cranial irradiation, and/or brain surgery) require a baseline case history, monitoring of their middle ear and inner ear function, and assessment of tinnitus at each audiologic follow-up. As a minimum, age-appropriate testing should be performed before and at the end of treatment. Ideally, audiometry with counseling before each cisplatin cycle should be considered in the context of the individual patient, specific disease, feasibility, and available resources.

Conclusions and Relevance

This is an international multidisciplinary consensus report providing standardized supportive care recommendations on hearing monitoring in children undergoing potentially ototoxic cancer treatment. The recommendations are intended to improve the care of children with cancer and facilitate comparative research on the timing and development of hearing loss caused by different cancer treatment regimens.

Feasibility and first results of a prospective cohort study to investigate cisplatin-associated ototoxicity amongst cancer patients in South Africa

Background

Cervical cancer, one of the most common cancers affecting females in South Africa, commonly requires a cisplatin-based-treatment regimen, which has been associated with ototoxic side effects. However, cisplatin-associated ototoxicity is largely under-reported in South Africa, despite its impact of hearing loss having serious overt ramifications on the quality of life of these patients. Hence, a prospective cohort study was undertaken to assess the audiological changes in female cervical cancer patients receiving cisplatin therapy.

Objective

To present details of the feasibility study and initial results on hearing patterns in cervical cancer patients receiving cisplatin chemotherapy. .

Methods

Fifty cervical cancer patients commencing with cisplatin chemotherapy underwent audiological assessments at a hospital in South Africa at various time intervals. Assessments included case history, otoscopic examination, immittance audiometry, pure tone audiometry (including high-frequency audiometry), speech audiometry, and distortion product otoacoustic emission testing. Data analysis involved the use of descriptive statistics and the Cochran-Armitage trend test for a linear trend in proportions.

Results

Fifty participants, aged between 32 and 79 years (Mean: 53 years; SD = 11.00), were recruited. Clinical findings revealed an incidence of 100% ototoxic hearing loss at the one-month post-treatment, i.e., 98%  after three cycles of cisplatin and 2%  at one-month post-chemotherapy. Sensorineural hearing loss and high-frequency tinnitus were most common. Deterioration in hearing thresholds was more evident in the extended high-frequency range, with the number of “no-responses,” from 11,200 Hz to 20,000 Hz, increasing with each successive audiological evaluation. This study further indicated that recruitment and follow-up of study participants within a limited resource setting are possible. However, cognizance must be given to a multidisciplinary approach and constant engagement with participants through regular contact either telephonically or via a short-message-system.

Conclusion

Exposure to cisplatin treatment contributed to hearing loss in females with cervical cancer, highlighting the need for ototoxicity monitoring during chemotherapy treatments. Furthermore, the results indicate that it is possible to conduct prospective cohort studies, using a multidisciplinary approach in limited-resource environments with appropriate planning and training strategies, as this study was able to achieve its aim successfully.

Combination Therapy of Cisplatin and other Agents for Osteosarcoma: A Review

Background:

Osteosarcoma is the most common type of primary bone tumor in children and adolescents, which is associated with rapid progression and poor prognosis. Multimodal therapy is the most common approach utilized for osteosarcoma management, such as the application of chemotherapy in combination with surgery or radiation therapy. Cisplatin is one of the predominantly used chemotherapeutic agents for osteosarcoma. Optimally, it is employed in combination with other chemotherapeutic drugs along with surgery or radiation therapy. Despite the availability of numerous treatment approaches, the patient survival rate has not definitively improved over the past three decades.

Methods:

We have summarized all findings regarding the combination of cisplatin with other chemotherapeutic agents as well as with phytochemical compounds.

Results:

A combination of cisplatin with a phytochemical compound synergistically enhances the killing effect of cisplatin on osteosarcoma cells with fewer side effects compared to combination with other chemotherapeutic agents.

Conclusion:

Conclusively, a combination of cisplatin with selected chemotherapeutic drugs has been shown to be effective. However, the unchanged survival rate has posed an urge to search for a new combination regimen. As a collaborative effort to substantiate the therapeutic efficacy, the combination with phytochemical compounds shows a promising response both in vitro as well as in the preclinical study.

Canadian Pediatric Neuro-Oncology Standards of Practice

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

Hearing and Other Neurologic Problems

Ototoxicity and other neurologic toxicities are potential consequences of exposure to common therapeutic agents used during treatment of childhood cancer, including platinum and vinca alkaloid chemotherapy, cranial radiation, surgery involving structures critical to cochlear and neurologic function, and supportive care medications such as aminoglycoside antibiotics and loop diuretics. This article provides an overview of ototoxicity and other neurologic toxicities related to childhood cancer treatment, discusses the challenges that these toxicities may pose for survivors, and presents an overview of current recommendations for surveillance and clinical management of these potentially life-altering toxicities in survivors of childhood cancers.

Ototoxicity and Platinum Uptake Following Cyclic Administration of Platinum-Based Chemotherapeutic Agents

Cisplatin is a widely used anti-cancer drug used to treat a variety of cancer types. One of the side effects of this life-saving drug is irreversible ototoxicity, resulting in permanent hearing loss in many patients. In order to understand why cisplatin is particularly toxic to the inner ear, we compared the hearing loss and cochlear uptake of cisplatin to that of two related drugs, carboplatin and oxaliplatin. These three drugs are similar in that each contains a core platinum atom; however, carboplatin and oxaliplatin are considered less ototoxic than cisplatin. We delivered these three drugs to mice using a 6-week cyclic drug administration protocol. We performed the experiment twice, once using equimolar concentrations of the drugs and once using concentrations of the drugs more proportional to those used in the clinic. For both concentrations, we detected a significant hearing loss caused by cisplatin and no hearing loss caused by carboplatin or oxaliplatin. Cochlear uptake of each drug was measured using inductively coupled plasma mass spectrometry (ICP-MS) to detect platinum. Cochlear platinum levels were highest in mice treated with cisplatin followed by oxaliplatin, while carboplatin was largely excluded from the cochlea. Even when the drug doses were increased, cochlear platinum remained low in mice treated with oxaliplatin or carboplatin. We also examined drug clearance from the inner ear by measuring platinum levels at 1 h and 24 h after drug administration. Our findings suggest that the reduced cochlear platinum we observed with oxaliplatin and carboplatin were not due to increased clearance of these drugs relative to cisplatin. Taken together, our data indicate that the differential ototoxicity among cisplatin, carboplatin, and oxaliplatin is attributable to differences in cochlear uptake of these three drugs.

A Review of Cisplatin-Associated Ototoxicity

Cisplatin, an effective antineoplastic drug used in the treatment of many cancers, has ototoxic potential, thus placing cancer patients, receiving this treatment, at risk of hearing loss. It is therefore important for health care professionals managing these patients to be aware of cisplatin's ototoxic properties and its clinical signs to identify patients at risk of developing a hearing impairment. Eighty-five English peer-reviewed articles and two books, from January 1975 to July 2015, were identified from PubMed, ScienceDirect, and EBSCOhost. An overview of cisplatin-associated ototoxicity, namely its clinical features, incidence rates, molecular and cellular mechanisms, and risk factors, is presented in this article. This review further highlights the importance of a team-based approach to complement an audiological monitoring program in reducing any further loss in the quality of life of affected patients, as there is currently no otoprotective agent routinely recommended for the prevention of cisplatin-associated ototoxicity.

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.

Long-term neurologic health and psychosocial function of adult survivors of childhood medulloblastoma/PNET: a report from the Childhood Cancer Survivor Study

Background

Medulloblastoma is the most common malignant childhood brain tumor, although long-term risks for chronic neurologic health and psychosocial functioning in aging adult survivors are incompletely characterized.

Methods

The Childhood Cancer Survivor Study (CCSS) includes 380 five-year survivors of medulloblastoma/primitive neuroectodermal tumor (PNET; median age at follow-up: 30 y, interquartile range 24-36) and sibling comparison (n = 4031). Cumulative incidence of neurologic health conditions was reported. Cox regression models provided hazard ratios (HRs) and 95% CIs. Cross-sectional outcomes were assessed using generalized linear models.

Results

Compared with siblings, survivors were at increased risk of late-onset hearing loss (HR: 36.0, 95% CI: 23.6-54.9), stroke (HR: 33.9, 95% CI: 17.8-64.7), seizure (HR: 12.8, 95% CI: 9.0-18.1), poor balance (HR: 10.4, 95% CI: 6.7-15.9), tinnitus (HR: 4.8, 95% CI: 3.5-6.8), and cataracts (HR: 31.8, 95% CI: 16.7-60.5). Temporal/frontal lobe radiotherapy of 50 Gy or more increased risk for hearing loss (HR: 1.9, 95% CI: 1.1-1.3), seizure (HR: 2.1, 95% CI: 1.1-3.9), stroke (HR: 3.5, 95% CI: 1.3-9.1), and tinnitus (HR: 2.0, 95% CI: 1.0-3.9). Survivors were less likely than siblings to earn a college degree (relative risk [RR]: 0.49, 95% CI: 0.39-0.60), marry (RR: 0.35, 95% CI: 0.29-0.42), and live independently (RR: 0.58, 95% CI: 0.52-0.66).

Conclusions

Adult survivors of childhood medulloblastoma/PNET demonstrate pronounced risk for hearing impairment, stroke, lower educational attainment, and social independence. Interventions to support survivors should be a high priority.

Protein Synthesis Inhibition and Activation of the c-Jun N-Terminal Kinase Are Potential Contributors to Cisplatin Ototoxicity

Cisplatin has been regarded as an effective and versatile chemotherapeutic agent for nearly 40 years. Though the associated dose-dependent ototoxicity is known, the cellular mechanisms by which cochleovestibular hair cell death occur are not well understood. We have previously shown that aminoglycoside ototoxicity is mediated in part by cytosolic protein synthesis inhibition. Despite a lack of molecular similarity, aminoglycosides were shown to elicit similar stress pathways to cisplatin. We therefore reasoned that there may be some role of protein synthesis inhibition in cisplatin ototoxicity. Employing a modification of the bioorthogonal noncanonical amino acid tagging (BONCAT) method, we evaluated the effects of cisplatin on cellular protein synthesis. We show that cisplatin inhibits cellular protein synthesis in organ of Corti explant cultures. Similar to what was found after gentamicin exposure, cisplatin activates both the c-Jun N-terminal kinase (JNK) and mammalian target of rapamycin (mTOR) pathways. In contrast to aminoglycosides, cisplatin also inhibits protein synthesis in all cochlear cell types. We further demonstrate that the multikinase inhibitor sorafenib completely prevents JNK activation, while providing only moderate hair cell protection. Simultaneous stimulation of cellular protein synthesis by insulin, however, significantly improved hair cell survival in culture. The presented data provides evidence for a potential role of protein synthesis inhibition in cisplatin-mediated ototoxicity.

Hearing loss after platinum treatment is irreversible in noncranial irradiated childhood cancer survivors

Cisplatin and carboplatin are effective antineoplastic agents. They are also considered to be potentially highly ototoxic. To date, no long-term follow-up data from well-documented cohorts with substantial numbers of childhood cancer survivors (CCS) with platinum-related hearing loss are available. Therefore, in this study, we studied the reversibility of ototoxicity from discontinuation of treatment onwards in a national cohort of platinum-treated survivors with hearing loss at the end of cancer treatment. Of the 168 CCS with follow-up audiograms, we longitudinally evaluated the course of hearing function in 61 CCS who showed hearing impairment at discontinuation of treatment according to the Münster criteria (>20 dB at ≥4-8 kHz). Survivors were treated with platinum (median total cumulative dose cisplatin: 480 mg/m² and median total cumulative dose carboplatin: 2520 mg/m²). Median follow-up time was 5.5 years (range: 1.0-28.8 years). The results showed that none of these survivors revealed improvement of hearing function even till 28.8 years after discontinuation of treatment (grade <2b during long-term follow-up). An increase in hearing loss with two or three Münster degrees was observed in five of 61 survivors after 1.6-19.6 years. Overall, this indicates that ototoxicity after platinum treatment may be irreversible and that longitudinal clinical audiological monitoring and care is required in long-term survivors of childhood cancer on a large scale.

Cisplatin-Associated Ototoxicity: A Review for the Health Professional

Cisplatin is an effective drug used in the treatment of many cancers, yet its ototoxic potential places cancer patients, exposed to this drug, at risk of hearing loss, thus negatively impacting further on a patient's quality of life. It is paramount for health care practitioners managing such patients to be aware of cisplatin's ototoxic properties and the clinical signs to identify patients at risk of developing hearing loss. English peer-reviewed articles from January 1975 to July 2015 were assessed from PubMed, Science Direct, and Ebscohost. Seventy-nine articles and two books were identified for this review, using MeSH terms and keywords such as "ototoxicity", "cisplatin", "hearing loss", and "ototoxicity monitoring". This review provides an up-to-date overview of cisplatin-associated ototoxicity, namely, its clinical features, incidence rates, and molecular and cellular mechanisms and risk factors, to health care practitioners managing the patient with cancer, and highlights the need for a team-based approach to complement an audiological monitoring programme to mitigate any further loss in the quality of life of affected patients, as there is currently no otoprotective agent recommended routinely for the prevention of cisplatin-associated ototoxicity. It also sets the platform for effective dialogue towards policy formulation and strengthening of health systems in developing countries.

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.

Audiological Monitoring in Children Treated with Platinum Chemotherapy

Platinum compounds constitute the standard treatment for solid tumors in pediatric oncology. The purpose of this study is to assess the impact of platinum compounds in the development of ototoxicity in children following chemotherapy. This study included 160 patients treated with cisplatin and carboplatin for malignant solid diseases from 2007 to 2014. Their audiograms were classified according to the Boston SIOP ototoxicity scale. Twenty-five percent of the children treated with platinum compounds developed ototoxicity. The incidence of ototoxicity was correlated with the type of platinum derivative (i.e. cisplatin vs. carboplatin), coadministration of both drugs and concomitant cranial radiotherapy, but not with sex and age. Cumulative dose was correlated only with the cisplatin administration. Nine patients (8.6%) showed further progression of hearing impairment after the end of chemotherapy. The low rate of ototoxicity suggests the pivotal role of auditory monitoring in children treated with platinum compounds in order to be able to identify hearing loss at an early stage and to provide, jointly with pediatric oncologists, strategies to reduce further progression of cochlear toxicity.

Noncarboplatin-induced Sensorineural Hearing Loss in a Patient With an Intracranial Nongerminomatous Germ Cell Tumor

Treatment for intracranial germ cell tumors includes platinum-based chemotherapy and external beam radiation therapy, which are risk factors for hearing loss. In patients who experience significant sensorineural ototoxicity due to cochlear hair cell injury, dose reduction of chemotherapy may be necessary. This report describes an adolescent male, with excellent treatment response for an intracranial nongerminomatous germ cell tumor, who developed sensorineural hearing loss, which was central rather than cochlear in origin and unrelated to carboplatin. This patient highlights the need to carefully differentiate the type and etiology of sensorineural hearing loss in patients with brain tumors receiving ototoxic chemotherapy.

Protective effects of the seaweed phlorotannin polyphenolic compound dieckol on gentamicin-induced damage in auditory hair cells

OBJECTIVES

Drug-induced ototoxicity from compounds such as aminoglycosides and platinum can damage the inner ear resulting in hearing loss, tinnitus or balance problems and may be caused by the formation of reactive oxygen species (ROS). Dieckol is a phlorotannin polyphenolic compound with strong antioxidant effects found in edible brown algae. This study investigated the protective effects of dieckol on drug-induced ototoxicity in cochlear cultures obtained from neonatal mice.

METHODS

Cochlear explants were pretreated with dieckol and exposed to gentamicin for 48h. The explants were then fixed and stained with fluorescein isothiocyanate-phalloidin and the intact hair cells counted. The free radical scavenging activity of dieckol was assessed using a 1,1-diphenyl-2-picrylhydrazyl assay. E. coli (Escherichia coli) cultures were used to evaluate the effect of dieckol on the antibiotic activity of gentamicin.

RESULTS

Gentamicin treatment resulted in dose-dependent hair cell loss that was partially protected by dieckol. Moreover, at concentrations >67μM dieckol had significant radical scavenging activity. Dieckol did not compromise the antibiotic effect of gentamicin.

CONCLUSIONS

These findings suggest that dieckol can be used as a therapeutic agent that reduces the damage caused by drug-induced ototoxicity.

Ototoxicity and cancer therapy

Ototoxicity is a well-established toxicity associated with a subgroup of antineoplastic therapies that includes platinum chemotherapy, radiation or surgery involving the ear and auditory nerve, and supportive care agents such as aminoglycoside antibiotics and loop diuretics. The reported prevalence of ototoxicity in patients who have received potentially ototoxic therapy ranges from 4% to 90% depending on factors such as age of the patient population, agent(s) used, cumulative dose, and administration techniques. The impact of ototoxicity on subsequent health-related and psychosocial outcomes in these patients can be substantial, and the burden of morbidity related to ototoxic agents is particularly high in very young children. Considerable interindividual variability in the prevalence and severity of ototoxicity has been observed among patients receiving similar treatment, suggesting genetic susceptibility as a risk factor. The development and testing of otoprotective agents is ongoing; however, to the author's knowledge, no US Food and Drug Administration-approved otoprotectants are currently available. Prospective monitoring for ototoxicity allows for comparison of auditory outcomes across clinical trials, as well as for early detection, potential alterations in therapy, and auditory intervention and rehabilitation to ameliorate the adverse consequences of hearing loss. Cancer 2016;122:1647-58. © 2016 American Cancer Society.

[Hearing disorders in the children presenting with various chronic diseases]

The objective of the present study was to improve the effectiveness of early diagnostics and prophylaxis of hearing disturbances in the children presenting with various chronic diseases. As is known, there are several dozens of neurologic disorders associated with hearing disorders. By way of example, there is a group of nephropathologies responsible for the loss of hearing in the children. Specifically, hearing impairment can be one of the symptoms of diabetes mellitus. The patients presenting with mucopolysaccharidosis make up a group at risk of hearing impairment. Sensorineural loss of hearing is widespread among the children presenting with coeliac disease. The protocols for the treatment of certain pathologies envisage the application of certain medications possessed of the cytotoxic activity, such as preparations for chemo- and radiotherapy or cytostatic agents that suppress cell proliferation when applied for the management of some autoimmune diseases. It is concluded that cooperation between health providers representing different medical disciplines may be instrumental in the organization of efficacious screening for the detection of children with severe chronic pathology.

Incus necrosis after irradiation

OBJECTIVES

Osteoradionecrosis (ORN) of the temporal bone is a rare, late complication of radiotherapy to the temporal bone region for head and neck or skull base tumours. ORN can occur as a localized or a diffuse type, according to the extension of the affected temporal bone. It can lead to otitis externa, otitis media, aseptic labyrinthitis and may lead to serious intracranial complications. Hearing loss may be conductive, sensorineural, or mixed. A few case studies report of previously irradiated patients presenting with conductive hearing loss presumably caused by ORN of the ossicular chain. In only one case report of diffuse ORN, ORN of the ossicles was histologically proven, leading to the conclusion that ossicular chain involvement as the sole entity of ORN would not exist. However, the presented case report disputes this.

PATIENTS

A 13-year-old boy presenting with a unilateral mixed hearing loss as the sole otological complaint, 10 years after radiotherapy for an anaplastic ependymoma.

RESULTS

Middle ear inspection revealed ORN of the incus which was confirmed by histological investigation.

CONCLUSION

ORN of the ossicular chain as a late complication can occur as an isolated entity and may present as conductive hearing loss predominantly in the low frequencies. Middle ear inspection and ossicular chain reconstruction should be attempted, bearing in mind the risk of iatrogenic lacerations of a thin tympanic membrane and possibly a delayed wound healing.