Continuous or repeated prolonged cisplatin infusions in children: a prospective study on ototoxicity, platinum concentrations, and standard serum parameters

The Incidence and Risk Factors of Cisplatin and Carboplatin Ototoxicity in Pediatric Oncology Patients at Tertiary Oncology Center

Pediatric cancers are relatively rare diseases when considering all types of cancer. Platinum-based chemotherapeutic agents are potent agents against a variety of pediatric malignancies. An important adverse effect of platinum-based agents is the occurrence of hearing loss. This hearing loss can pose a challenge to detect especially if the child is in his early of life. It will also significantly affect the child development of social, pedagogical, and personal dimensions. It is integral to identify incidence of platinum-based ototoxicity and risk factors that increase the likelihood of developing hearing loss in cancer children. We performed a retrospective chart review of 123 pediatric patients who had completed cisplatin and carboplatin therapy for a variety of malignancies. Patients were diagnosed at Princess Nourah Oncology Centre between January 2011 and December 2016, were less than 14 years old at diagnosis. Audiograms were scored using the International Society of Pediatric Oncology (SIOP) Boston Scale (0-4), a validated grading system for cisplatin-related hearing loss. Ototoxicity was reported in 16 patients out of 123 with a rate of 13%. The incidence of ototoxicity was highest in CNS tumors such as medulloblastoma (37.5%) and optic glioma (25%). Males were at greater risk for developing hearing loss than females. Cumulative cisplatin dose and addition radiation therapy were also identified as risk factors for development of ototoxicity (P = 0.008). Nature and location of cancer, gender, cumulative dose, and addition of radiation therapy are important clinical biomarkers of cisplatin ototoxicity.

Diversity of dose-individualization and therapeutic drug monitoring practices of platinum compounds: a review

Introduction: Platinum-derived drugs are commonly used for the treatment of solid tumors. The differences in chemical structures of these molecules lead to different pharmacological properties, in terms of indication, efficacy, and toxicity. Their pharmacokinetics (PK) differ according to their respective renal elimination and have led to many studies investigating their dose optimization. Area covered: This review attempts to summarize and compare PK and pharmacodynamics of cisplatin, carboplatin, and oxaliplatin, with an emphasis on differences of dose calculations and opportunities for therapeutic drug monitoring (TDM) in various patient populations. Expert opinion: Although cisplatin and carboplatin can be considered as analogs since they share the same DNA interacting properties, the slower hydrolysis of the latter results in a better safety profile. Carboplatin is the only drug in oncology to be administrated according to a target area under the curve of concentration versus time, considering that its PK variability is almost fully explained by renal function, not by body size. This enables individual dosing based on predicted carboplatin clearance (along with patients renal characteristics) or on actual clearance with TDM, especially in a high-dose protocol.

The identification of dual protective agents against cisplatin-induced oto- and nephrotoxicity using the zebrafish model

Dose-limiting toxicities for cisplatin administration, including ototoxicity and nephrotoxicity, impact the clinical utility of this effective chemotherapy agent and lead to lifelong complications, particularly in pediatric cancer survivors. Using a two-pronged drug screen employing the zebrafish lateral line as an in vivo readout for ototoxicity and kidney cell-based nephrotoxicity assay, we screened 1280 compounds and identified 22 that were both oto- and nephroprotective. Of these, dopamine and L-mimosine, a plant-based amino acid active in the dopamine pathway, were further investigated. Dopamine and L-mimosine protected the hair cells in the zebrafish otic vesicle from cisplatin-induced damage and preserved zebrafish larval glomerular filtration. Importantly, these compounds did not abrogate the cytotoxic effects of cisplatin on human cancer cells. This study provides insights into the mechanisms underlying cisplatin-induced oto- and nephrotoxicity and compelling preclinical evidence for the potential utility of dopamine and L-mimosine in the safer administration of cisplatin.

Different infusion durations for preventing platinum-induced hearing loss in children with cancer

BACKGROUND

Platinum-based therapy, including cisplatin, carboplatin or oxaliplatin, or a combination of these, is used to treat a variety of paediatric malignancies. Unfortunately, one of the most important adverse effects is the occurrence of hearing loss or ototoxicity. In an effort to prevent this ototoxicity, different platinum infusion durations have been studied. This review is the third update of a previously published Cochrane Review.

OBJECTIVES

To assess the effects of different durations of platinum infusion to prevent hearing loss or tinnitus, or both, in children with cancer. Secondary objectives were to assess possible effects of these infusion durations on: a) anti-tumour efficacy of platinum-based therapy, b) adverse effects other than hearing loss or tinnitus, and c) quality of life.

SEARCH METHODS

We searched the electronic databases Cochrane Central Register of Controlled Trials (CENTRAL; the Cochrane Library 14 November 2019), MEDLINE (PubMed) (1945 to 14 November 2019) and Embase (Ovid) (1980 to 14 November 2019). In addition, we handsearched reference lists of relevant articles and we assessed the conference proceedings of the International Society for Paediatric Oncology (2009 up to and including 2019) and the American Society of Pediatric Hematology/Oncology (2014 up to and including 2019). We scanned ClinicalTrials.gov and the World Health Organization International Clinical Trials Registry Platform (WHO ICTRP; apps.who.int/trialsearch) for ongoing trials (both searched on 4 November 2019).

SELECTION CRITERIA

Randomised controlled trials (RCTs) or controlled clinical trials (CCTs) comparing different platinum infusion durations in children with cancer. Only the platinum infusion duration could differ between the treatment groups.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed the study selection, 'Risk of bias' assessment and GRADE assessment of included studies, and data extraction including adverse effects. Analyses were performed according to the guidelines of the Cochrane Handbook for Systematic Reviews of Interventions.

MAIN RESULTS

We identified one RCT and no CCTs; in this update no additional eligible studies were identified. The RCT (total number of children = 91) evaluated the use of a continuous cisplatin infusion (N = 43) versus a one-hour bolus cisplatin infusion (N = 48) in children with neuroblastoma. For the continuous infusion, cisplatin was administered on days one to five of the cycle, but it is unclear if the infusion duration was a total of five days. Risk of bias was present. Only results from shortly after induction therapy were provided. No clear evidence of a difference in hearing loss (defined as asymptomatic and symptomatic disease combined) between the different infusion durations was identified as results were imprecise (risk ratio (RR) 1.39, 95% confidence interval (CI) 0.47 to 4.13, low-quality evidence). Although the numbers of children were not provided, it was stated that tumour response was equivalent in both treatment arms. With regard to adverse effects other than ototoxicity, we were only able to assess toxic deaths. Again, the confidence interval of the estimated effect was too wide to exclude differences between the treatment groups (RR 1.12, 95% CI 0.07 to 17.31, low-quality evidence). No data were available for the other outcomes of interest (i.e. tinnitus, overall survival, event-free survival and quality of life) or for other (combinations of) infusion durations or other platinum analogues.

AUTHORS' CONCLUSIONS

Since only one eligible RCT evaluating the use of a continuous cisplatin infusion versus a one-hour bolus cisplatin infusion was found, and that had methodological limitations, no definitive conclusions can be made. It should be noted that 'no evidence of effect', as identified in this review, is not the same as 'evidence of no effect'. For other (combinations of) infusion durations and other platinum analogues no eligible studies were identified. More high-quality research is needed.

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.

Cisplatin Toxicity in Children with Malignancy

Platinum’ derivates are antineoplastic agents widely adopted for their efficacy for the treatment of many pediatric cancers. The use of cisplatin has positively influenced the results of the cure of different childhood malignancies. However, cisplatin-based treatments are limited by the risk of severe and progressive toxicities, such as oto- or nephrotoxicity, that can be more serious in very young children expecially when high cumulative doses and/or radiotherapy is administered. A correct knowledge of the cisplatin’ pharmacological features might be of interest for clinicians in order to manage its potential toxicities. Based on the positive trend in the cure of children with cancer, it is crucial that all children receiving cisplatin-based chemotherapy have and appropriate and long-term follow-up to improve their quality of life.

Genetic Determinants of Ototoxicity During and After Childhood Cancer Treatment: Protocol for the PanCareLIFE Study

Background

Survival rates after childhood cancer now reach nearly 80% in developed countries. However, treatments that lead to survival and cure can cause serious adverse effects with lifelong negative impacts on survivor quality of life. Hearing impairment is a common adverse effect in children treated with cisplatin-based chemotherapy or cranial radiotherapy. Ototoxicity can extend from high-tone hearing impairment to involvement of speech frequencies. Hearing impairment can impede speech and language and neurocognitive development. Although treatment-related risk factors for hearing loss following childhood cancer treatment have been identified, the individual variability in toxicity of adverse effects after similar treatment between childhood cancer patients suggests a role for genetic susceptibility. Currently, 12 candidate gene approach studies have been performed to identify polymorphisms predisposing to platinum-induced ototoxicity in children being treated for cancer. However, results were inconsistent and most studies were underpowered and/or lacked replication.

Objective

We describe the design of the PanCareLIFE consortium’s work packages that address the genetic susceptibility of platinum-induced ototoxicity.

Methods

As a part of the PanCareLIFE study within the framework of the PanCare consortium, we addressed genetic susceptibility of treatment-induced ototoxicity during and after childhood cancer treatment in a large European cohort by a candidate gene approach and a genome-wide association screening.

Results

This study included 1124 survivors treated with cisplatin, carboplatin, or cranial radiotherapy for childhood cancer, resulting in the largest clinical European cohort assembled for this late effect to date. Within this large cohort we defined a group of 598 cisplatin-treated childhood cancer patients not confounded by cranial radiotherapy. The PanCareLIFE initiative provided, for the first time, a unique opportunity to confirm already identified determinants for hearing impairment during childhood cancer using a candidate gene approach and set up the first international genome-wide association study of cisplatin-induced direct ototoxicity in childhood cancer patients to identify novel allelic variants. Results will be validated in an independent replication cohort. Patient recruitment started in January 2015 and final inclusion was October 2017. We are currently performing the analyses and the first results are expected by the end of 2019 or the beginning of 2020. 

Conclusions

Genetic factors identified as part of this pan-European project, PanCareLIFE, may contribute to future risk prediction models that can be incorporated in future clinical trials of platinum-based therapies for cancer and may help with the development of prevention strategies.

International Registered Report Identifier (IRRID)

DERR1-10.2196/11868

Association between genetic polymorphisms and platinum-induced ototoxicity in children

Platinum is extensively used in the treatment of several childhood cancers. However, ototoxicity is one of the most notable adverse effects, especially in children. Several studies suggest that genetics may predict its occurrence. Here, polymorphisms associated with platinum-induced ototoxicity were selected from the literature and were investigated in a pediatric population treated with platinum-based agents. In this retrospective study, patients treated with cisplatin and/or carboplatin were screened. The patients with pre- and post-treatment audiogram (Brock criteria) available were included. We selected polymorphisms that have previously been associated with cisplatin ototoxicity with a minor allele frequency ≥30%. Deletion of GSTM1 and GSTT1, rs1799735 (GSTM3), rs1695 (GSTP1), rs4880 (SOD2), rs2228001 (XPC), rs1799793 (XPD) and rs4788863 (SLC16A5) were investigated. Data of one hundred and six children matching the eligible criteria were analyzed. Thirty-three patients (31%) developed ototoxicity (with a Brock grade ≥2). The probability of hearing loss increased significantly in patients carrying the null genotype for GSTT1 (P = 0.03), A/A genotype at rs1695 (P = 0.01), and C/C genotype at rs1799793 (P = 0.008). We also showed an association of the cumulative doses of carboplatin with cisplatin ototoxicity (P <0.05). To conclude, deletion of GSTT1, rs1695 and rs1799793 may constitute potential predictors of platinum-induced ototoxicity.

Different infusion durations for preventing platinum-induced hearing loss in children with cancer

BACKGROUND

Platinum-based therapy, including cisplatin, carboplatin or oxaliplatin, or a combination of these, is used to treat a variety of paediatric malignancies. Unfortunately, one of the most important adverse effects is the occurrence of hearing loss or ototoxicity. In an effort to prevent this ototoxicity, different platinum infusion durations have been studied. This review is the second update of a previously published Cochrane review.

OBJECTIVES

To assess the effects of different durations of platinum infusion to prevent hearing loss or tinnitus, or both, in children with cancer. Secondary objectives were to assess possible effects of these infusion durations on: a) anti-tumour efficacy of platinum-based therapy, b) adverse effects other than hearing loss or tinnitus, and c) quality of life.

SEARCH METHODS

We searched the electronic databases Cochrane Central Register of Controlled Trials (CENTRAL; the Cochrane Library 15 March 2018), MEDLINE (PubMed) (1945 to 15 March 2018) and Embase (Ovid) (1980 to 15 March 2018). In addition, we handsearched reference lists of relevant articles and we assessed the conference proceedings of the International Society for Paediatric Oncology (2009 up to and including 2017) and the American Society of Pediatric Hematology/Oncology (2014 up to and including 2017). We scanned ClinicalTrials.gov and the World Health Organization International Clinical Trials Registry Platform (WHO ICTRP; apps.who.int/trialsearch) for ongoing trials (searched on 12 March 2018 and 13 March 2018 respectively).

SELECTION CRITERIA

Randomised controlled trials (RCTs) or controlled clinical trials (CCTs) comparing different platinum infusion durations in children with cancer. Only the platinum infusion duration could differ between the treatment groups.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed the study selection, 'Risk of bias' assessment and GRADE assessment of included studies, and data extraction including adverse effects. Analyses were performed according to the guidelines of the Cochrane Handbook for Systematic Reviews of Interventions.

MAIN RESULTS

We identified one RCT and no CCTs; in this update no additional studies were identified. The RCT (total number of children = 91) evaluated the use of a continuous cisplatin infusion (N = 43) versus a one-hour bolus cisplatin infusion (N = 48) in children with neuroblastoma. For the continuous infusion, cisplatin was administered on days one to five of the cycle, but it is unclear if the infusion duration was a total of five days. Risk of bias was present. Only results from shortly after induction therapy were provided. No clear evidence of a difference in hearing loss (defined as asymptomatic and symptomatic disease combined) between the different infusion durations was identified as results were imprecise (risk ratio (RR) 1.39, 95% confidence interval (CI) 0.47 to 4.13, low-quality evidence). Although the numbers of children were not provided, it was stated that tumour response was equivalent in both treatment arms. With regard to adverse effects other than ototoxicity, we were only able to assess toxic deaths. Again, the confidence interval of the estimated effect was too wide to exclude differences between the treatment groups (RR 1.12, 95% CI 0.07 to 17.31, low-quality evidence). No data were available for the other outcomes of interest (i.e. tinnitus, overall survival, event-free survival and quality of life) or for other (combinations of) infusion durations or other platinum analogues.

AUTHORS' CONCLUSIONS

Since only one eligible RCT evaluating the use of a continuous cisplatin infusion versus a one-hour bolus cisplatin infusion was found, and that had methodological limitations, no definitive conclusions can be made. It should be noted that 'no evidence of effect', as identified in this review, is not the same as 'evidence of no effect'. For other (combinations of) infusion durations and other platinum analogues no eligible studies were identified. More high-quality research is needed.

Quantitative Bioimaging of Platinum via Online Isotope Dilution-Laser Ablation-Inductively Coupled Plasma Mass Spectrometry

A new calibration strategy for elemental bioimaging based on online isotope dilution analysis (IDA) and laser ablation-inductively coupled plasma mass spectrometry (LA-ICPMS) was developed and applied for the quantification of platinum in rat kidney tissues. A dry ¹⁹⁴Pt spike aerosol was added in a post-cell setup, and the natural ¹⁹⁴Pt/¹⁹⁵Pt isotope ratio of the sample aerosol from laser ablation was changed accordingly. Spike mass flow determination was carried out based on reversed IDA using a reference standard. Quantitative data obtained by the new approach correlated well with those obtained by external calibration when analyzing parallel tissue slices of rat kidney from cisplatin perfusion studies. The novel quantification approach is traceable to SI units, as IDA is an definitive method. Signal drifts are compensated as the second isotope acts as an internal standard.

Front-line window therapy with cisplatin in patients with primary disseminated Ewing sarcoma: A study by the Associazione Italiana di Ematologia ed Oncologia Pediatrica and Italian Sarcoma Group

The aim was to assess the activity of cisplatin (CDDP) in Ewing sarcoma (ES). The study consisted of front-line window therapy with CDDP 120 mg/sqm every 3 weeks for two courses in children and young adults with primary disseminated ES. Response was assessed using the Response Evaluation Criteria in Solid Tumours criteria, and Simon's two-stage design was applied. Twelve consecutive patients were enrolled in stage 1. Only one objective response was observed. Since the target response rate was not achieved, accrual was stopped and CDDP as a single agent in ES was judged unworthy of further assessment.

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.

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.

Different infusion durations for preventing platinum-induced hearing loss in children with cancer

BACKGROUND

Platinum-based therapy, including cisplatin, carboplatin or oxaliplatin, or a combination of these, is used to treat a variety of paediatric malignancies. Unfortunately, one of the most important adverse effects is the occurrence of hearing loss or ototoxicity. In an effort to prevent this ototoxicity, different platinum infusion durations have been studied. This review is an update of a previously published Cochrane review.

OBJECTIVES

To assess the effects of different durations of platinum infusion to prevent hearing loss or tinnitus, or both, in children with cancer. Secondary objectives were to assess possible effects of these infusion durations on: a) anti-tumour efficacy of platinum-based therapy, b) adverse effects other than hearing loss or tinnitus, and c) quality of life.

SEARCH METHODS

We searched the electronic databases Cochrane Central Register of Controlled Trials (CENTRAL; The Cochrane Library 2016, Issue 4), MEDLINE (PubMed) (1945 to 18 May 2016) and EMBASE (Ovid) (1980 to 18 May 2016). In addition, we handsearched reference lists of relevant articles and we assessed the conference proceedings of the International Society for Paediatric Oncology (2009 up to and including 2015) and the American Society of Pediatric Hematology/Oncology (2014 and 2015). We scanned ClinicalTrials.gov and the World Health Organization International Clinical Trials Registry Platform (WHO ICTRP; apps.who.int/trialsearch) for ongoing trials (searched on 20 May 2016 and 24 May 2016 respectively).

SELECTION CRITERIA

Randomised controlled trials (RCTs) or controlled clinical trials (CCTs) comparing different platinum infusion durations in children with cancer. Only the platinum infusion duration could differ between the treatment groups.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed the study selection, risk of bias assessment and GRADE assessment of included studies, and data extraction including adverse effects. Analyses were performed according to the guidelines of the Cochrane Handbook for Systematic Reviews of Interventions.

MAIN RESULTS

We identified one RCT and no CCTs; in this update no additional studies were identified. The RCT (total number of children = 91) evaluated the use of a continuous cisplatin infusion (N = 43) versus a one-hour bolus cisplatin infusion (N = 48) in children with neuroblastoma. For the continuous infusion, cisplatin was administered on days 1 to 5 of the cycle but it is unclear if the infusion duration was a total of 5 days. Methodological limitations were present. Only results from shortly after induction therapy were provided. No clear evidence of a difference in hearing loss (defined as asymptomatic and symptomatic disease combined) between the different infusion durations was identified as results were imprecise (risk ratio (RR) 1.39, 95% confidence interval (CI) 0.47 to 4.13, low quality evidence). Although the numbers of children were not provided, it was stated that tumour response was equivalent in both treatment arms. With regard to adverse effects other than ototoxicity we were only able to assess toxic deaths. Again, the confidence interval of the estimated effect was too wide to exclude differences between the treatment groups (RR 1.12, 95% CI 0.07 to 17.31, low quality evidence). No data were available for the other outcomes of interest (i.e. tinnitus, overall survival, event-free survival and quality of life) or for other (combinations of) infusion durations or other platinum analogues.

AUTHORS' CONCLUSIONS

Since only one eligible RCT evaluating the use of a continuous cisplatin infusion versus a one-hour bolus cisplatin infusion was found, and that had methodological limitations, no definitive conclusions can be made. It should be noted that 'no evidence of effect', as identified in this review, is not the same as 'evidence of no effect'. For other (combinations of) infusion durations and other platinum analogues no eligible studies were identified. More high quality research is needed.

Human OCT2 variant c.808G>T confers protection effect against cisplatin-induced ototoxicity

AIM

Assuming that genetic variants of the SLC22A2 and SLC31A1 transporter affect patients' susceptibility to cisplatin-induced ototoxicity, we compared the distribution of 11 SLC22A2 variants and the SLC31A1 variant rs10981694 between patients with and without cisplatin-induced ototoxicity.

PATIENTS & METHODS

Genotyping was performed in 64 pediatric patients and significant findings were re-evaluated in 66 adults.

RESULTS

The SLC22A2 polymorphism rs316019 (c.808G>T; Ser270Ala) was significantly associated with protection from cisplatin-induced ototoxicity in the pediatric (p = 0.022) and the adult cohort (p = 0.048; both: Fisher's exact test). This result was confirmed by multiple logistic regression analysis accounting for age which was identified as a relevant factor for ototoxicity as well (rs316019: OR [G/T vs G/G] = 0.12, p = 0.009; age: OR [per year]: 0.84, p = 0.02).

CONCLUSION

These results identified rs316019 as potential pharmacogenomic marker for cisplatin-induced ototoxicity and point to a critical role of SLC22A2 for cisplatin transport in humans and its contribution to the organ specific side effects of this drug. Original submitted 17 September 2014; Revision submitted 19 December 2014.

N-acetylcysteine chemoprotection without decreased cisplatin antitumor efficacy in pediatric tumor models

Decreasing oxidative damage with the antioxidant agent N-acetylcysteine (NAC) can block the side effects of chemotherapy, but may diminish anti-tumor efficacy. We tested the potential for interactions of high dose NAC against a minimally effective cisplatin chemotherapy regimen in rat models of human pediatric cancers. Athymic rats received subcutaneous implantation of human SK-N-AS neuroblastoma cells or intra-cerebellar implantation of human D283-MED medulloblastoma cells. Rats were untreated or treated with cisplatin (3 or 4 mg/kg IV) with or without NAC (1,000 mg/kg IV) 30 min before or 4 h after cisplatin treatment. Blood urea nitrogen (BUN) and tumor volumes were measured. Cisplatin decreased the growth of SK-N-AS neuroblastoma subcutaneous tumors from 17.7 ± 4.9 to 6.4 ± 2.5 fold over baseline 2 weeks after treatment (P < 0.001). Pretreatment with NAC decreased cisplatin efficacy, while 4 h delayed NAC did not significantly affect cisplatin anti-tumor effects (relative tumor volume 6.8 ± 2.0 fold baseline, P < 0.001). In D283-MED medulloblastoma brain tumors, cisplatin decreased final tumor volume to 3.9 ± 2.3 mm(3) compared to untreated tumor volume of 45.9 ± 38.7 (P = 0.008). Delayed NAC did not significantly alter cisplatin efficacy (tumor volume 6.8 ± 8.1 mm(3), P = 0.014 versus control). Cisplatin was minimally nephrotoxic in these models. NAC decreased cisplatin-induced elevations in BUN (P < 0.02). NAC chemoprotection did not alter cisplatin therapy, if delayed until 4 h after chemotherapy. These data support a Phase I/II clinical trial of delayed NAC to reduce ototoxicity in children with localized pediatric cancers.

Comparison of the effectiveness of monitoring Cisplatin-induced ototoxicity with extended high-frequency pure-tone audiometry or distortion-product otoacoustic emission

Background and Objectives

To compare the effectiveness of monitoring cisplatin-induced ototoxicity in adult patients using extended high-frequency pure-tone audiometry (EHF-PTA) or distortion-product otoacoustic emission (DP-OAE) and to evaluate the concurrence of ototoxicity and nephrotoxicity in cisplatin-treated patients.

Subjects and Methods

EHF-PTA was measured at frequencies of 0.25, 0.5, 1, 2, 3, 4, 6, 8, 9, 11.2, 12.5, 14, 16, 18, and 20 kHz and DP-OAE at frequencies of 0.5, 0.75, 1, 1.5, 2, 3, 4, 6, and 8 kHz in cisplatin-treated patients (n=10). Baseline evaluations were made immediately before chemotherapy and additional tests were performed before each of six cycles of cisplatin treatment. Laboratory tests to monitor nephrotoxicity were included before every cycle of chemotherapy.

Results

Four of 10 patients showed threshold changes on EHF-PTA. Five of 10 patients showed reductions in DP-OAE, but one was a false-positive result. The results of EHF-PTA and DP-OAE were consistent in two patients. Only one patient displayed nephrotoxicity on laboratory tests after the third cycle.

Conclusions

In our study, the incidence rate of cisplatin-induced ototoxicity was 40% with EHF-PTA or DP-OAE. Although both EHF-PTA and DP-OAE showed the same sensitivity in detecting ototoxicity, they did not produce the same results in all patients. These two hearing tests could be used to complement one another. Clinicians should use both tests simultaneously in every cycle of chemotherapy to ensure the detection of ototoxicity.

Different infusion durations for preventing platinum-induced hearing loss in children with cancer

BACKGROUND

Platinum-based therapy, including cisplatin, carboplatin or oxaliplatin, or a combination of these, is used to treat a variety of paediatric malignancies. Unfortunately, one of the most important adverse effects is the occurrence of hearing loss or ototoxicity. In an effort to prevent this ototoxicity, different platinum infusion durations have been studied.

OBJECTIVES

To assess the effects of different durations of platinum infusion to prevent hearing loss or tinnitus, or both, in children with cancer. Secondary objectives were to assess possible effects of these infusion durations on: a) anti-tumour efficacy of platinum-based therapy, b) adverse effects other than hearing loss or tinnitus, and c) quality of life.

SEARCH METHODS

We searched the electronic databases Cochrane Central Register of Controlled Trials (CENTRAL 2013, Issue 12), MEDLINE (PubMed) (1945 to 4 December 2013) and EMBASE (Ovid) (1980 to 4 December 2013). In addition, we handsearched reference lists of relevant articles and the conference proceedings of the International Society for Paediatric Oncology (2009 to 2013). We scanned ClinicalTrials.gov (www.clinicaltrials.gov) and the World Health Organization International Clinical Trials Registry Platform (WHO ICTRP) (http://www.who.int/ictrp/en/) for ongoing trials (both searched on 13 December 2013).

SELECTION CRITERIA

Randomised controlled trials (RCTs) or controlled clinical trials (CCTs) comparing different platinum infusion durations in children with cancer. Only the platinum infusion duration could differ between the treatment groups.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed the study selection, risk of bias assessment and GRADE assessment of included studies, and data extraction including adverse effects. Analyses were performed according to the guidelines of the Cochrane Handbook for Systematic Reviews of Interventions.

MAIN RESULTS

We identified one RCT and no CCTs. The RCT (total number of children = 91) evaluated the use of a continuous cisplatin infusion (N = 43) versus a one hour bolus cisplatin infusion (N = 48) in children with neuroblastoma. For the continuous infusion, cisplatin was administered on days 1 to 5 of the cycle but it is unclear if the infusion duration was a total of 5 days. Methodological limitations were present. Only results from shortly after induction therapy were provided. No clear evidence of a difference in hearing loss (defined as asymptomatic and symptomatic disease combined) between the different infusion durations was identified as results were imprecise (RR 1.39; 95% CI 0.47 to 4.13, low quality evidence). Although the numbers of children were not provided, it was stated that tumour response was equivalent in both treatment arms. With regard to adverse effects other than ototoxicity we were only able to assess toxic deaths. Again, the confidence interval of the estimated effect was too wide to exclude differences between the treatment groups (RR 1.12; 95% CI 0.07 to 17.31, low quality evidence). No data were available for the other outcomes of interest (i.e. tinnitus, overall survival, event-free survival and quality of life) or for other (combinations of) infusion durations or other platinum analogues.

AUTHORS' CONCLUSIONS

Since only one eligible RCT evaluating the use of a continuous cisplatin infusion versus a one hour bolus cisplatin infusion was found, and that had methodological limitations, no definitive conclusions can be made. It should be noted that 'no evidence of effect', as identified in this review, is not the same as 'evidence of no effect'. For other (combinations of) infusion durations and other platinum analogues no eligible studies were identified. More high quality research is needed.

Atypical teratoid rhabdoid tumor: improved long-term survival with an intensive multimodal therapy and delayed radiotherapy. The Medical University of Vienna Experience 1992-2012

Atypical teratoid rhabdoid tumors (ATRTs) are recently defined highly aggressive embryonal central nervous system tumors with a poor prognosis and no definitive guidelines for treatment. We report on the importance of an initial correct diagnosis and disease-specific therapy on outcome in 22 consecutive patients and propose a new treatment strategy. From 1992 to 2012, nine patients initially diagnosed correctly as ATRT (cohort A, median age 24 months) were treated according to an intensive multimodal regimen (MUV-ATRT) consisting of three 9-week courses of a dose-dense regimen including doxorubicin, cyclophosphamide, vincristine, ifosfamide, cisplatin, etoposide, and methotrexate augmented with intrathecal therapy, followed by high-dose chemotherapy (HDCT) and completed with local radiotherapy. Thirteen patients were treated differently (cohort B, median age 30 months) most of whom according to protocols in use for their respective diagnoses. As of July 2013, 5-year overall survival (OS) and event-free survival (EFS) for all 22 consecutive patients was 56.3 ± 11.3% and 52.9 ± 11.0%, respectively. For MUV-ATRT regimen-treated patients (cohort A) 5-year OS was 100% and EFS was 88.9 ± 10.5%. For patients treated differently (cohort B) 5-year OS and EFS were 28.8 ± 13.1%. All nine MUV-ATRT regimen-treated patients are alive for a median of 76 months (range: 16–197), eight in first complete remission. Our results compare favorably to previously published data. The drug combination and sequence used in the proposed MUV-ATRT regimen appear to be efficacious in preventing early relapses also in young children with M1–M3 stage disease allowing postponement of radiotherapy until after HDCT.

Cisplatin-induced ototoxicity in pediatric solid tumors: the role of glutathione S-transferases and megalin genetic polymorphisms

Cisplatin-induced ototoxicity, an important dose-limiting side effect, has proven high interindividual variability. Glutathione S-transferases (GSTs) are isoenzymes involved in cellular detoxification processes. Megalin has been demonstrated to bind aminoglycosides, known to be similar to cisplatin for their ototoxicity. The GSTs and megalin expression is genetically polymorphic, which might be responsible for the variability in cisplatin-induced ototoxicity. The genotyping of GSTM1, GSTT1 polymorphisms, and 2 nonsynonymous single nucleotide polymorphisms (SNPs) at megalin genes, rs2075252 and rs2228171, were performed in 68 children diagnosed with solid tumors who received cisplatin-based chemotherapy. After the end of treatment, audiometry demonstrated hearing loss in 79.4% of patients according to Brock classification. The cumulative cisplatin dose >400 mg/m is associated with increased risk of cisplatin-induced ototoxicity [odds ratio (OR), 17.5; 95% confidence interval (CI), 3.09-98.62]. GSTT1 wild genotype and C-allele of rs2228171 SNPs of megalin gene occurred with higher frequency in patients with ototoxicity (P=0.023; OR, 10; 95% CI, 1.80-56.00 and P=0.034; OR, 2.67; 95% CI, 1.22-5.82, respectively). In conclusion, our results suggested that GSTT1 wild genotype and C-allele of rs2228171 SNPs might be risk factors for ototoxicity. The cumulative cisplatin dose <400 mg/m should be beneficial in order to ameliorate ototoxicity.

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.

Survival trends and long-term toxicity in pediatric patients with osteosarcoma

Background. This study was conducted to investigate the clinical characteristics and treatment results of osteosarcoma in pediatric patients during the past 30 years. Trends in survival rates and long-term toxicity were analyzed. Procedure. 130 pediatric patients under the age of 20 years with primary localized or metastatic high-grade osteosarcoma were analyzed regarding demographic, treatment-related variables, long-term toxicity, and survival data. Results. Comparison of the different time periods of treatment showed that the 5-year OS improved from 58.6% for children diagnosed during 1979–1983 to 78.6% for those diagnosed during 2003–2008 (P = 0.13). Interestingly, the basic treatment agents including cisplatin, doxorubicin, and methotrexate remained the same. Treatment reduction due to acute toxicity was less frequent in patients treated in the last era (7.1% versus 24.1% in patients treated in 1979–1983; P = 0.04). Furthermore, late cardiac effects and secondary malignancies can become evident many years after treatment. Conclusion. We elucidate the prevalence of toxicity to therapy of patients with osteosarcoma over the past 30 years. The overall improvement in survival may in part be attributed to improved supportive care allowing regimens to be administered to best advantage with higher tolerance of chemotherapy and therefore less chemotherapy-related toxicity.

Anti-tumor activity of the HSP90 inhibitor SNX-2112 in pediatric cancer cell lines

BACKGROUND

HSP90 plays a central role in stabilizing client proteins involved in malignant processes. SNX-2112 is an orally administered potent HSP90 inhibitor that has demonstrated pre-clinical anti-tumor activity in adult malignancies. As many childhood tumors depend upon HSP90 client proteins, we sought to test the pre-clinical efficacy of SNX-2112 in a panel of pediatric cancer cell lines both as a single-agent and in combination with cisplatin (CP).

PROCEDURE

Eight cell lines (from osteosarcoma, neuroblastoma, hepatoblastoma, and lymphoma) were studied. Short- and long-term effects of SNX-2112 were assessed by MTT and clonogenic assays. Cell cycling was measured using flow cytometry. Status of HSC70, HSP72, AKT1, C-Raf, and PARP was assessed by immunoblotting. Efficacy of SNX-2112 in combination with CP was assessed using median-effect analysis.

RESULTS

Cell lines studied demonstrated sensitivity to SNX-2112 with IC(50) values ranging from 10-100 nM. Low dose treatments (12 nM) resulted in a cytostatic response with a minimal increase in sub-G1 content. A higher dose (70 nM) exhibited a more prolonged inhibition and larger sub-G1 accumulation. Observed levels of AKT1 and C-Raf were markedly reduced over time along with an increase in PARP cleavage. In concurrently administered combination treatments, SNX-2112 and CP synergistically inhibited cell growth.

CONCLUSIONS

SNX-2112 showed marked single-agent activity in pediatric cancer cell lines with downstream effects on HSP90 client proteins. The combination of SNX-2112 and CP showed synergistic activity in two cell lines tested. Further studies of HSP90 inhibitors such as SNX-2112 as a single agent or in combination with chemotherapy are warranted in pediatric cancer.

The plasma and cerebrospinal fluid pharmacokinetics of the platinum analog satraplatin after intravenous administration in non-human primates

BACKGROUND

Satraplatin is an orally bioavailable platinum analog with preclinical activity in cisplatin resistant models and clinical activity in adults with refractory cancers. The cerebrospinal fluid (CSF) penetration of cisplatin and carboplatin in non-human primates (NHP) is limited (3.7 and 2.6%, respectively). We evaluated the plasma and CSF pharmacokinetics (PK) of satraplatin after an intravenous (IV) dose in NHP.

METHODS

Satraplatin (120 mg/m(2)) was administered as 1 h IV infusion in DMSO (5%) and normal saline to 5 NHP. Serial blood and CSF samples were obtained over 48 h. Plasma ultrafiltrate (UF) was immediately prepared by centrifugation. Platinum was quantified in plasma UF and CSF using a validated atomic absorption spectroscopy assay with lower limit of quantification (LLQ) of 0.025 μM in UF and 0.006 μM after concentration in CSF. Pharmacokinetic parameters were estimated using non-compartmental analyses. CSF penetration was calculated from the CSF AUC(0-48h) : plasma UF AUC(0-48h).

RESULTS

Satraplatin was well tolerated. Median (range) PK parameters in plasma UF were: maximum concentration (C (max)) 8.3 μM (5.7-10.6), area under the curve (AUC(0-48h)) 29.2 μM h (22.6-33.2), clearance 0.36 l/h/kg (0.31-0.37), and t (1/2) 18.8 h (13.4-25). Satraplatin was detected in the CSF of all NHP. Median (range) PK parameters in CSF were: C (max) 0.07 μM (0.02-0.12), AUC(0-48h) 1.2 μM h (0.49-2.43). The median (range) CSF penetration of satraplatin was 4.3% (2.2-7.4).

CONCLUSIONS

Satraplatin penetration into CSF is similar to that of carboplatin and cisplatin, despite its greater lipophilicity. The development of a phase I trial of satraplatin for refractory childhood solid tumors including brain tumors is in progress.

Survival and long-term outcomes in children with hepatoblastoma treated with continuous infusion of cisplatin and doxorubicin

Despite high survival rates, many survivors of hepatoblastoma develop late effects including ototoxicity and cardiomyopathy. With the goal of minimizing long-term toxicities, our institution treated hepatoblastoma with continuous infusion of doxorubicin and cisplatinum (PLADO), rather than short infusion or bolus dosing as used in other treatment protocols. This retrospective cohort study includes consecutive patients diagnosed between 1985 and 2007. Patients were scheduled for treatment with 6 cycles of continuous infusion of PLADO with resection after the third or fourth cycle. Audiograms and echocardiograms were obtained at baseline, after every 2 chemotherapy cycles and yearly after the completion of therapy. Fifty-five patients were treated (34 localized; 21 metastatic). Fifty-one patients received at least 1 cycle of PLADO. Median follow-up was 7.0 years (range, 0.11 to 17.8 y). Event-free and overall survival for these 51 patients were 72.2% (standard error 6.3%) and 75.6% (standard error 6.2%) respectively. Of the 38 survivors treated with cisplatin who had an audiogram during follow-up, 4 (11%) demonstrated severe (Brock grade 3/4) and 13 (34%) mild (Brock grade 1/2) hearing loss. At a median of 10.0 years (range, 5.0 to 13.0 y) after therapy, 2 of 41 (5%) patients who were still alive had evidence of cardiac dysfunction. Overall, continuous infusion of PLADO therapy resulted in survival rates consistent with those observed in intergroup studies, but rates of chronic cardiac and ototoxicity did not differ sufficiently from those observed after shorter infusion of PLADO therapy to warrant the use of continuous infusions.

Micellization of cisplatin (NC-6004) reduces its ototoxicity in guinea pigs

Nanocarriers potentially reduce or prevent chemotherapy-induced side effects, facilitating the translation of nanocarrier formulation into the clinic. To date, organ-specific toxicity by nanocarriers remains to be clarified. Here, we studied the potential of polymeric micelle nanocarriers to prevent the ototoxicity, which is a common side effect of high-dose cisplatin (CDDP) therapy. In this study, we evaluated the ototoxicity of CDDP-incorporating polymeric micelles (NC-6004) in guinea pigs in comparison with that of cisplatin. Their auditory brainstem responses (ABRs) to 2, 6, 12, 20, and 30kHz sound stimulation were measured before and 5 days after the drug administration. Groups treated with NC-6004 showed no apparent ABR threshold shifts, whereas groups treated with CDDP showed dose-dependent threshold shifts particularly at the higher frequencies. Consistent with the ABR results, groups treated with NC-6004 showed excellent hair-cell preservation, whereas groups treated with CDDP exhibited significant hair-cell loss (P<0.05). Synchrotron radiation-induced X-ray fluorescence spectrometry imaging demonstrated that the platinum distribution and concentration in the organ of Corti were significantly reduced (P<0.01) in guinea pigs treated with NC-6004 compared with guinea pigs treated with CDDP. These findings indicate that micellization of CDDP reduces its ototoxicity by circumventing the vulnerable cells in the inner ear.

Do pharmacokinetic polymorphisms explain treatment failure in high-risk patients with neuroblastoma?

PURPOSE

Neuroblastoma is the most common extracranial solid tumour in childhood. It accounts for 15% of all paediatric oncology deaths. In the last few decades, improvement in treatment outcome for high-risk patients has not occurred, with an overall survival rate <30-40%. Many reasons may account for such a low survival rate. The aim of this review is to evaluate whether pharmacogenetic factors can explain treatment failure in neuroblastoma.

METHODS

A literature search based on PubMed's database Medical Subject Headings (MeSH) was performed to retrieve all pertinent publications on current treatment options and new classes of drugs under investigation. One hundred and fifty-eight articles wer reviewed, and relevant data were extracted and summarised.

RESULTS AND CONCLUSIONS

Few of the large number of polymorphisms identified thus far showed an effect on pharmacokinetics that could be considered clinically relevant. Despite their clinical relevance, none of the single nucleotide polymorphisms (SNPs) investigated can explain treatment failure. These findings seem to reflect the clinical context in which anti-tumour drugs are used, i.e. in combination with multimodal therapy. In addition, many pharmacogenetic studies did not assess (differences in) drug exposure, which could contribute to explaining pharmacogenetic associations. Furthermore, it remains unclear whether the significant activity of new drugs on different neuroblastoma cell lines translates into clinical efficacy, irrespective of resistance or myelocytomatosis viral related oncogene, neuroblastoma derived (MYCN) amplification. Elucidation of the clinical role of pharmacogenetic factors in the treatment of neuroblastoma demands an integrated pharmacokinetic-pharmacodynamic approach to the analysis of treatment response data.

Transtympanic Ringer's lactate application in the prevention of cisplatinum-induced ototoxicity in a chinchilla animal model

Objective: Ototoxicity is currently the most frequent dose-limiting side effect of cisplatinum chemotherapy. To date, there is no protocol to prevent dose-related ototoxicity, despite its prevalence and predictability. Previous animal studies have found lactate to be effective in the prevention of cisplatinum-induced ototoxicity. The objective of this study was to test the protective benefits of transtympanic Ringer's lactate in the prevention of cisplatinum-induced ototoxicity.

Study Design: A randomized prospective controlled trial was conducted in an animal model.

Setting: Animal care research facilities of The Montreal Children's Hospital Research Institute.

Subjects and Methods: A total of 44 chinchillas were exposed to systemic cisplatinum injected intraperitoneally in divided cycles to reach the targeted cumulative dosage of 16 mg/kg. Ototopical application of Ringer's lactate solution 0.2 mL twice per day during the chemotherapy cycles was performed. Each animal had one experimental (Ringer's) and one control ear. Distortion product otoacoustic emissions (DPOAEs) were collected for a wide range of frequencies (between 1 and 16 kHz), and scanning electron microscopy was performed to evaluate the protective effects of Ringer's lactate.

Results: Ototopical application of Ringer's lactate solution in our established chinchilla animal model did not provide an otoprotective effect as measured by the DPOAE response and electron microscopy.

Conclusion: In our study, the intratympanic application of Ringer's lactate solution through a tympanostomy ventilation tube did not provide an otoprotective effect. Further studies are needed to better assess the otoprotective or ototoxic effects of Ringer's lactate and other antioxidants on animal and human hearing.

Phase I Study of Weekly Oxaliplatin in Relapsed or Refractory Pediatric Solid Malignancies

Purpose

To explore feasibility, maximum-tolerated dose (MTD), and recommended dose (RD) for phase II studies of weekly oxaliplatin for the treatment of relapsed or refractory pediatric solid malignancies.

Patients and Methods

Eligible patients were 6 months to 21 years old, had a diagnosis of a solid malignancy, and had experienced treatment failure with at least two or more previous lines of therapy. The phase I study was multicentric, open-label, and nonrandomized. It foresaw two phases: a dose-escalation phase (comprising six levels) to find the RD and an extension at the RD to evaluate the cumulative toxicity. Oxaliplatin was administered intravenously over 2 hours on days 1, 8, and 15 of a 28-day cycle.

Results

Forty-five patients were enrolled: 29 patients in the dose-escalation phase and 16 patients in the extension at the RD. Median age was 9.5 years (range, 2.8 to 20.0 years) and 7.8 years (range, 1.8 to 19.2 years), respectively. The dose-limiting toxicities during the first treatment cycle were grade 3 (G3) sepsis at 50 mg/m2, G3 dysesthesia at 90 mg/m2, and G3 dysesthesia and G3 paresthesia at 110 mg/m2, thus the MTD and RD was 90 mg/m2. No case of ototoxicity was reported. Stable disease was reported in seven patients (16.3%), and confirmed partial response was observed in two patients (4.7%), one with neuroblastoma and one with osteosarcoma.

Conclusion

Oxaliplatin administered in a weekly schedule has an acceptable safety profile, different from cisplatin and carboplatin, and shows activity in children with relapsed or refractory solid tumors, suggesting further investigation in pediatric malignancies.

Identification of genetic and chemical modulators of zebrafish mechanosensory hair cell death

Inner ear sensory hair cell death is observed in the majority of hearing and balance disorders, affecting the health of more than 600 million people worldwide. While normal aging is the single greatest contributor, exposure to environmental toxins and therapeutic drugs such as aminoglycoside antibiotics and antineoplastic agents are significant contributors. Genetic variation contributes markedly to differences in normal disease progression during aging and in susceptibility to ototoxic agents. Using the lateral line system of larval zebrafish, we developed an in vivo drug toxicity interaction screen to uncover genetic modulators of antibiotic-induced hair cell death and to identify compounds that confer protection. We have identified 5 mutations that modulate aminoglycoside susceptibility. Further characterization and identification of one protective mutant, sentinel (snl), revealed a novel conserved vertebrate gene. A similar screen identified a new class of drug-like small molecules, benzothiophene carboxamides, that prevent aminoglycoside-induced hair cell death in zebrafish and in mammals. Testing for interaction with the sentinel mutation suggests that the gene and compounds may operate in different pathways. The combination of chemical screening with traditional genetic approaches is a new strategy for identifying drugs and drug targets to attenuate hearing and balance disorders.

Loss of sensory hair cells in the inner ear is observed in the majority of hearing and balance disorders, affecting the health of more than 600 million people worldwide. Exposure to environmental toxins and certain pharmaceutical drugs such as aminoglycoside antibiotics and some cancer chemotherapy agents account for many of these hearing and balance problems. Variation in the genetic makeup between individuals plays a major role in establishing differences in susceptibility to environmental agents that damage the inner ear. Using zebrafish larvae, we developed a screen to uncover genes leading to differences in antibiotic-induced death of hair cells and to identify compounds that protect hair cells from damage. The combination of chemical screening with traditional genetic approaches offers a new strategy for identifying drugs and drug targets to attenuate hearing and balance disorders.

Hearing loss, quality of life, and academic problems in long-term neuroblastoma survivors: a report from the Children's Oncology Group

OBJECTIVES

Among a cohort of long-term neuroblastoma survivors, our aims were to (1) assess the association between treatment intensity and parent-reported hearing loss in the child, (2) evaluate the strength of the association between hearing loss and parent-reported academic and psychosocial difficulties in the child, and (3) examine the association between parent-reported academic and psychosocial difficulties in the child and the child's self-reported quality of life.

PATIENTS AND METHODS

Through a mailed survey that included the Pediatric Quality of Life Inventory 4.0 and an outcomes questionnaire for parents, we evaluated 137 children (aged 8-17 years) who were previously enrolled in 1 of 2 Children's Cancer Group neuroblastoma clinical studies.

RESULTS

Childhood survivors of neuroblastoma who had prevalent hearing loss, as reported by their parents, had at least twice the risk of an identified problem with reading skills, math skills, and/or attention and a similarly higher risk of a general learning disability and/or special educational needs than did neuroblastoma survivors without hearing loss. Consistent with this finding, hearing loss was associated with a 10-point-lower mean score in the school-functioning scale of the Pediatric Quality of Life Inventory 4.0. We also observed a clear pattern of poorer self-reported quality-of-life scores among children with parent-reported academic and psychosocial problems compared with those without such problems, particularly with school functioning, even after controlling for reported hearing loss.

CONCLUSIONS

We found evidence that long-term neuroblastoma survivors, especially those with hearing loss, are at elevated risk for academic learning problems and psychosocial difficulties. We also found strong concordance between parent-reported learning problems in the child and indications of distress in the child's self-reported quality of life.

Adjuvant and neoadjuvant combination chemotherapy for osteogenic sarcoma

PURPOSE OF REVIEW

The most recent developments regarding chemotherapy treatment of osteogenic sarcoma are reviewed, with special emphasis on prospective clinical trials and evaluations of late effects of chemotherapy.

RECENT FINDINGS

In recent years, clinical research has essentially focused on possible refinements of the classic four-drug (methotrexate, cisplatin, doxorubicin and ifosfamide) therapy rather than investigating new drugs. It has been demonstrated that dose-intensification does not improve prognosis. Many investigators have evaluated late chemotherapy-related side effects, particularly in terms of cardiac, renal and auditive toxicity, risk of infertility and of second tumors. Recent findings recommend further studies to define the role of the immunostimulating agent muramyl tripeptide-phosphatidilethanolamine in osteosarcoma. Preclinical and phase II studies suggest an activity of mammalian target of rapamycin (mTOR) inhibitors in osteosarcoma, which also deserves further clinical studies.

SUMMARY

At present, patients with nonmetastatic osteosarcoma of the extremity aged less than 40 years have an expected 5-year survival rate of 70% with a chemotherapy regimen based on methotrexate, cisplatin, doxorubicin and ifosfamide. Further improvement cannot be achieved by dose intensification of treatment and new strategies are required. Prolonged follow-up is mandatory due to the risk of late effects, second tumors and late relapse from osteosarcoma.

Cisplatininduzierte Hörstörungen bei Kindern in Abhängigkeit von der Pigmentierung der Iris

BACKGROUND

Cisplatin is commonly used as a chemotherapeutic agent in the treatment of solid tumors. Ototoxicity is an important side-effect. Melanin in the inner ear either plays an otoprotective role or has a negative influence on hearing. The concentration of cochlear melanin correlates with its concentration in the iris.

PATIENTS AND METHODS

We retrospectively examined 65 children (37 males, 28 females, average age 7.5 years) treated with cisplatin at the University Clinic of Muenster, Germany. We checked whether their eye color could be inferred from the prevalence and extent of cisplatin-induced hearing loss.

RESULTS

We found a hearing loss of >20 dB in 29 light-eyed and in 21 dark-eyed patients. Seven light-eyed and eight dark-eyed patients did not suffer from hearing impairment. Using the chi(2)-test on these four parameters, we found no significant connection between iris pigmentation and the prevalence or extent of hearing loss, although light-eyed children (80.6%) suffered more from hearing loss than dark-eyed children (72.4%). After the end of therapy with cisplatin, the prevalence of hearing loss was 83.3% in children up to 6 years and 71.4% in children older than 6 years. The average cumulative dose of cisplatin was 372 mg/m(2) of body surface in children with hearing loss, compared to 390 mg/m(2) in children without hearing loss.

CONCLUSION

We found no significant correlation between iris pigmentation (eye color) and hearing loss. Cisplatin-induced hearing loss occurs frequently and requires repeated monitoring.

Megalin genetic polymorphisms and individual sensitivity to the ototoxic effect of cisplatin

Ototoxicity and nephrotoxicity are dose-limiting side effects of cisplatin. Megalin, a member of the low-density lipoprotein receptor family, is highly expressed in renal proximal tubular cells and marginal cells of the stria vascularis of the inner ear - tissues, which accumulate high levels of platinum-DNA adducts. On the assumption that the mechanisms of cisplatin-induced nephro- and ototoxicity involve megalin we analyzed the incidence of the non-synonymous single nucleotide polymorphisms (SNP) rs2075252 and rs4668123 in 25 patients who developed a distinct hearing loss during cisplatin therapy and in 25 patients without hearing impairment after cisplatin therapy. We found no association between cisplatin-induced ototoxicity and any allele of rs4668123 but observed a higher frequency of the A-allele of rs2075252 in the group with hearing impairment than in the group with normal hearing after cisplatin therapy (0.32 versus 0.14) (chi(2)=5.83, P<0.02; odds ratio: 3.45; 95% confidence interval: 1.11-11.2) indicating that SNPs at the megalin gene might impact the individual susceptibility against cisplatin-induced ototoxicity.

Early Changes in Auditory Function As a Result of Platinum Chemotherapy: Use of Extended High-Frequency Audiometry and Evoked Distortion Product Otoacoustic Emissions

Purpose

The objective is to describe progressive changes in hearing and cochlear function in children and adolescents treated with platinum-based chemotherapy and to begin preliminary evaluation of the feasibility of extended high-frequency audiometry and distortion product otoacoustic emissions for ototoxicity monitoring in children.

Patients and Methods

Baseline and serial measurement of conventional pure-tone audiometry (0.5 to 8 kHz) and evoked distortion product otoacoustic emissions (DPOAEs) were conducted for 32 patients age 8 months to 20 years who were treated with cisplatin and/or carboplatin chemotherapy. Seventeen children also had baseline and serial measurement of extended high-frequency (EHF) audiometry (9 to 16 kHz). Audiologic data were analyzed to determine the incidence of ototoxicity using the American Speech-Language-Hearing Association criteria, and the relationships between the different measures of ototoxicity.

Results

Of the 32 children, 20 (62.5%) acquired bilateral ototoxicity in the conventional frequency range during chemotherapy treatment, and 26 (81.3%) had bilateral decreases in DPOAE amplitudes and dynamic range. Of the 17 children with EHF audiometry results, 16 (94.1%) had bilateral ototoxicity in the EHF range. Pilot data suggest that EHF thresholds and DPOAEs show ototoxic changes before hearing loss is detected by conventional audiometry.

Conclusion

EHF audiometry and DPOAEs have the potential to reveal earlier changes in auditory function than conventional frequency audiometry during platinum chemotherapy in children.

Molecular mechanisms of resistance and toxicity associated with platinating agents

Platinating agents, including cisplatin, carboplatin, and oxaliplatin, have been used clinically for nearly 30years as part of the treatment of many types of cancers, including head and neck, testicular, ovarian, cervical, lung, colorectal and relapsed lymphoma. The cytotoxic lesion of platinating agents is thought to be the platinum intrastrand crosslink that forms on DNA, although treatment activates a number of signal transduction pathways. Treatment with these agents is characterized by resistance, both acquired and intrinsic. This resistance can be caused by a number of cellular adaptations, including reduced uptake, inactivation by glutathione and other anti-oxidants, and increased levels of DNA repair or DNA tolerance. Here we investigate the pathways that treatment with platinating agents activate, the mechanisms of resistance, potential candidate genes involved in the development of resistance, and associated clinical toxicities. Although the purpose of this review is to provide an overview of cisplatin, carboplatin, and oxaliplatin, we have focused primarily on preclinical data that has clinical relevance generated over the past five years.