Hepatoblastoma, cisplatin, and ototoxicity: good news on deaf ears

Medical interventions for the prevention of platinum-induced hearing loss in children with cancer

BACKGROUND

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

OBJECTIVES

To assess the efficacy of medical interventions to prevent hearing loss and to determine possible effects of these interventions on antitumour efficacy, toxicities other than hearing loss and quality of life in children with cancer treated with platinum-based therapy as compared to placebo, no additional treatment or another protective medical intervention.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials, MEDLINE (PubMed) and Embase (Ovid) to 8 January 2019. We handsearched reference lists of relevant articles and assessed the conference proceedings of the International Society for Paediatric Oncology (2006 up to and including 2018), the American Society of Pediatric Hematology/Oncology (2007 up to and including 2018) and the International Conference on Long-Term Complications of Treatment of Children and Adolescents for Cancer (2010 up to and including 2015). We scanned ClinicalTrials.gov and the World Health Organization International Clinical Trials Registry Platform (WHO ICTRP; apps.who.int/trialsearch) for ongoing trials (on 2 January 2019).

SELECTION CRITERIA

Randomized controlled trials (RCTs) or controlled clinical trials (CCTs) evaluating platinum-based therapy with an otoprotective medical intervention versus platinum-based therapy with placebo, no additional treatment or another protective medical intervention in children with cancer.

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

We identified two RCTs and one CCT (total number of participants 149) evaluating the use of amifostine versus no additional treatment in the original version of the review; the updates identified no additional studies. Two studies included children with osteosarcoma, and the other study included children with hepatoblastoma. Children received cisplatin only or a combination of cisplatin and carboplatin, either intra-arterially or intravenously. Pooling of results of the included studies was not possible. From individual studies the effect of amifostine on symptomatic ototoxicity only (i.e. National Cancer Institute Common Toxicity Criteria version 2 (NCICTCv2) or modified Brock grade 2 or higher) and combined asymptomatic and symptomatic ototoxicity (i.e. NCICTCv2 or modified Brock grade 1 or higher) were uncertain (low-certainty evidence). Only one study including children with osteosarcoma treated with intra-arterial cisplatin provided information on tumour response, defined as the number of participants with a good or partial remission. The available-data analysis (data were missing for one participant), best-case scenario analysis and worst-case scenario analysis showed a difference in favour of amifostine, although the certainty of evidence for this effect was low. There was no information on survival for any of the included studies. Only one study, including children with osteosarcoma treated with intra-arterial cisplatin, provided data on the number of participants with adverse effects other than ototoxicity grade 3 or higher (on NCICTCv2 scale). There was low-certainty evidence that grade 3 or 4 vomiting was higher with amifostine (risk ratio (RR) 9.04, 95% confidence interval (CI) 1.99 to 41.12). The effects on cardiotoxicity and renal toxicity grade 3 or 4 were uncertain (low-certainty evidence). None of the studies evaluated quality of life.In the recent update, we also identified one RCT including 109 children with localized hepatoblastoma evaluating the use of sodium thiosulfate versus no additional treatment. Children received intravenous cisplatin only (one child also received carboplatin). There was moderate-certainty evidence that both symptomatic ototoxicity only (i.e. Brock criteria grade 2 or higher) and combined asymptomatic and symptomatic ototoxicity (i.e. Brock criteria grade 1 or higher) was lower with sodium thiosulfate (combined asymptomatic and symptomatic ototoxicity: RR 0.52, 95% CI 0.33 to 0.81; symptomatic ototoxicity only: RR 0.39, 95% CI 0.19 to 0.83). The effect of sodium thiosulfate on tumour response (defined as number of participants with a complete or partial response at the end of treatment), overall survival (calculated from time of randomization to death or last follow-up), event-free survival (calculated from time of randomization until disease progression, disease relapse, second primary cancer, death, or last follow-up, whichever came first) and adverse effects other than hearing loss and tinnitus grade 3 or higher (according to National Cancer Institute Common Toxicity Criteria Adverse Effects version 3 (NCICTCAEv3) criteria) was uncertain (low-certainty evidence for all these outcomes). Quality of life was not assessed.We found no eligible studies for possible otoprotective medical interventions other than amifostine and sodium thiosulfate and for other types of malignancies.

AUTHORS' CONCLUSIONS

At the moment there is no evidence from individual studies in children with osteosarcoma or hepatoblastoma treated with different platinum analogues and dosage schedules that underscores the use of amifostine as an otoprotective intervention as compared to no additional treatment. Since pooling of results was not possible and the evidence was of low certainty, no definitive conclusions can be made. Since we found only one RCT evaluating the use of sodium thiosulfate in children with localized hepatoblastoma treated with cisplatin, no definitive conclusions on benefits and harms can be drawn. It should be noted that 'no evidence of effect', as identified in this review, is not the same as 'evidence of no effect'. We identified no eligible studies for other possible otoprotective medical interventions and other types of malignancies, so no conclusions can be made about their efficacy in preventing ototoxicity in children treated with platinum-based therapy. More high-quality research is needed.

Disease-specific Hospitalizations Among 5-Year Survivors of Hepatoblastoma: A Nordic Population-based Cohort Study

INTRODUCTION

The long-term risk of somatic disease in hepatoblastoma survivors has not been thoroughly evaluated in previous studies. In this population-based study of 86 five-year HB survivors, we used inpatient registers to evaluate the risk for a range of somatic diseases.

METHODS

In total, 86 five-year survivors of hepatoblastoma were identified in the Nordic cancer registries from 1964 to 2008 and 152,231 population comparisons were selected. Study subjects were followed in national hospital registries for somatic disease classified into 12 main diagnostic groups. Standardized hospitalization rate ratios (RRs) and absolute excess risks were calculated.

RESULTS

After a median follow-up of 11 years, 35 of the 86 five-year hepatoblastoma survivors had been hospitalized with a total of 69 hospitalizations, resulting in an RR of 2.7 (95% confidence interval [CI], 2.2-3.5) and an overall absolute excess risk of 4.2 per 100 person-years. Highest risk was seen for benign neoplasms (RR=16) with 6 hospitalizations for benign neoplasms in the colon and one in rectum.

CONCLUSIONS

The pattern of hospitalizations found in this first comprehensive follow-up of hepatoblastoma survivors seems reassuring. Less than 50% of the 5-year survivors had been hospitalized and often for diseases that were not severe or life-threatening.

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.

Dose modifications and pharmacokinetics of adjuvant cisplatin monotherapy while on hemodialysis for patients with hepatoblastoma

Hepatoblastoma can be associated with chronic kidney disease and genitourinary anomalies. Cisplatin is a key agent for treating hepatoblastoma but renal clearance and toxicity can limit its use in end-stage renal disease. We present pharmacokinetic data and clinical outcomes using cisplatin on hemodialysis for three patients with hepatoblastoma. All patients were initially treated with surgery and adjuvant cisplatin [1.67 mg/kg (2 patients) or 50 mg/m² (1 patient)]. The patient treated with body surface area-based dosing had higher exposures and ototoxicity. Treating hepatoblastoma with cisplatin on hemodialysis using 1.67 mg/kg achieved clinical efficacy with minimal morbidity.

Medical interventions for the prevention of platinum-induced hearing loss in children with cancer

BACKGROUND

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

OBJECTIVES

To assess the efficacy of medical interventions to prevent hearing loss and to determine possible effects of these interventions on anti-tumour efficacy, toxicities other than hearing loss and quality of life in children with cancer treated with platinum-based therapy.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2016, Issue 6), MEDLINE (PubMed) (1945 to 8 July 2016) and EMBASE (Ovid) (1980 to 8 July 2016). In addition, we handsearched reference lists of relevant articles and we assessed the conference proceedings of the International Society for Paediatric Oncology (2006 up to and including 2015), the American Society of Pediatric Hematology/Oncology (2007 up to and including 2016) and the International Conference on Long-Term Complications of Treatment of Children and Adolescents for Cancer (2010 up to and including 2015). We scanned the International Standard Randomized Controlled Trial Number (ISRCTN) Register (www.isrctn.com) and the National Institute of Health Register (www.clinicaltrials.gov) for ongoing trials (both searched on 12 July 2016).

SELECTION CRITERIA

Randomized controlled trials (RCTs) or controlled clinical trials (CCTs) evaluating platinum-based therapy together with an otoprotective medical intervention versus platinum-based therapy with placebo, no additional treatment or another protective medical intervention in children with cancer.

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

We identified two RCTs and one CCT (total number of participants 149) evaluating the use of amifostine versus no additional treatment in the original version of the review; the updates identified no additional studies. Two studies included children with osteosarcoma, and the other study included children with hepatoblastoma. Children received cisplatin only or a combination of cisplatin and carboplatin, either intra-arterially or intravenously. Pooling of results of the included studies was not possible. However, in the individual studies there was no significant difference in symptomatic ototoxicity only (that is, grade 2 or higher) and combined asymptomatic and symptomatic ototoxicity (that is, grade 1 or higher) between children treated with or without amifostine. Only one study, including children with osteosarcoma treated with intra-arterial cisplatin, provided information on tumour response, defined as the number of participants with a good or partial remission. The available data analysis (data were missing for one participant), best case scenario analysis and worst case scenario analysis all showed a difference in favour of amifostine, but this difference was significant only in the worst case scenario analysis (P = 0.04). There was no information on survival for any of the included studies. Only one study, including children with osteosarcoma treated with intra-arterial cisplatin, provided data on the number of participants with adverse effects other than ototoxicity grade 3 or higher. There was a significant difference in favour of the control group in the occurrence of vomiting grade 3 or 4 (risk ratio (RR) 9.04; 95% confidence interval (CI) 1.99 to 41.12; P = 0.004). There was no significant difference between treatment groups for cardiotoxicity and renal toxicity grade 3 or 4. None of the studies evaluated quality of life. The quality of evidence for the different outcomes was low. We found no eligible studies for possible otoprotective medical interventions other than amifostine and other types of malignancies.

AUTHORS' CONCLUSIONS

At the moment there is no evidence from individual studies in children with osteosarcoma or hepatoblastoma treated with different platinum analogues and dosage schedules that underscores the use of amifostine as an otoprotective intervention as compared to no additional treatment. Since pooling of results was not possible and all studies had serious 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'. Based on the currently available evidence, we are unable to give recommendations for clinical practice. We identified no eligible studies for other possible otoprotective medical interventions and other types of malignancies, so no conclusions can be made about their efficacy in preventing ototoxicity in children treated with platinum-based therapy. More high quality research is needed.

Luminescent pentafluorophenyl-cycloplatinated complexes: synthesis, characterization, photophysics, cytotoxicity and cellular imaging

Pentafluorophenyl cycloplatinated complexes have been synthesized and their photophysical properties studied and investigated by DFT, TD-DFT calculations. The cellular localization and the cytotoxicity of [Pt(C^N)(C₆F₅)(DMSO)] complexes towards two different cell lines has been assessed.

Cyclopalladated primary amines: a preliminary study of antiproliferative activity through apoptosis induction

Twelve cyclometallated palladium(II) complexes containing primary aromatic amines [benzylamine (a), (R)-1-(1-naphthyl)ethylamine (b) and 2-phenylaniline (c)] as anionic bidentate (C,N)(-) ligands have been evaluated against a panel of human adenocarcinoma cell lines (A549 lung, MDA-MB231 and MCF7 breast, and the cisplatin resistant HCT116 colon). The results revealed a remarkable antiproliferative activity of the triphenylphosphane mononuclear compounds 3-4 (series a, b, c) and the best inhibition was provided for 3c and 4c with the 2-phenylaniline ligand and a six membered chelate ring. Interestingly, 3c and 4c were 14 and 19 times more potent than cisplatin for the inhibition of the cisplatin resistant HCT116 human adenocarcinoma cell line, respectively. Cyclopalladated complexes 3c and 4c exercise their antiproliferative activity over A549 cells mainly through the induction of apoptosis (38 and 31-fold increase in early apoptotic cells, respectively).

Medical interventions for the prevention of platinum-induced hearing loss in children with cancer

BACKGROUND

Platinum-based therapy, including cisplatin, carboplatin and/or oxaliplatin, 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 otoprotective medical interventions have been studied. This review is an update of a previously published Cochrane review.

OBJECTIVES

The primary objective was to assess the efficacy of any medical intervention to prevent hearing loss in children with cancer treated with platinum-based therapy (that is including cisplatin, carboplatin and/or oxaliplatin) when compared to placebo, no additional treatment or a different protective medical intervention. Secondary objectives were to determine possible effects of these interventions on anti-tumour efficacy, toxicities other than hearing loss and quality of life.

SEARCH METHODS

We searched the electronic databases Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2014, Issue 1), MEDLINE (PubMed) (1945 to 17 March 2014) and EMBASE (Ovid) (1980 to 17 March 2014). In addition, we handsearched reference lists of relevant articles and the conference proceedings of the International Society for Paediatric Oncology (2006 to 2013), the American Society of Pediatric Hematology/Oncology (2007 to 2013) and the International Conference on Long-Term Complications of Treatment of Children and Adolescents for Cancer (2010 to 2013). We scanned the International Standard Randomized Controlled Trial Number (ISRCTN) Register and the National Institute of Health Register for ongoing trials (www.controlled-trials.com) (searched on 17 March 2014).

SELECTION CRITERIA

Randomized controlled trials (RCTs) or controlled clinical trials (CCTs) evaluating platinum-based therapy together with an otoprotective medical intervention versus platinum-based therapy with placebo, no additional treatment or another protective medical intervention in children with cancer.

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

We identified two RCTs and one CCT (total number of patients 149) evaluating the use of amifostine versus no additional treatment in the original version of the review; in this update no additional studies were identified. Two studies included children with osteosarcoma, and the other study included children with hepatoblastoma. Patients received cisplatin only or a combination of cisplatin and carboplatin, either administered intra-arterially or intravenously. All studies had methodological limitations. Unfortunately pooling of the results of the included studies was not possible. However, in the individual studies no significant difference was identified in symptomatic ototoxicity only (that is grade 2 or higher) and combined asymptomatic and symptomatic ototoxicity (that is grade 1 or higher) between children treated with or without amifostine. Only one study, including children with osteosarcoma treated with intra-arterial cisplatin, provided information on tumour response, defined as the number of patients with a good or partial remission. The available data analysis (data were missing for one patient), best case scenario analysis and worst case scenario analysis all showed a difference in favour of amifostine, but this difference was significant only in the worst case scenario analysis (P = 0.04). No information on survival was available for any of the included study populations. Only one study, including children with osteosarcoma treated with intra-arterial cisplatin, provided data on the number of patients with adverse effects other than ototoxicity grade 3 or higher. There was a significant difference in favour of the control group in the occurrence of vomiting grade 3 or 4 (risk ratio (RR) 9.04; 95% confidence interval (CI) 1.99 to 41.12; P = 0.004). No significant difference was identified between treatment groups for cardiotoxicity and renal toxicity grade 3 or 4. None of the studies evaluated quality of life. No eligible studies were found for possible otoprotective medical interventions other than amifostine and other types of malignancies.

AUTHORS' CONCLUSIONS

At the moment there is no evidence from individual studies in children with osteosarcoma or hepatoblastoma treated with different platinum analogues and dosage schedules which underscores the use of amifostine as an otoprotective intervention as compared to no additional treatment. Since pooling of results was not possible and all studies had serious 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'. Based on the currently available evidence, we are not able to give recommendations for clinical practice. No eligible studies were identified for other possible otoprotective medical interventions and other types of malignancies, so no conclusions can be made about their efficacy in preventing ototoxicity in children treated with platinum-based therapy. More high quality research is needed.

Medical interventions for the prevention of platinum-induced hearing loss in children with cancer

BACKGROUND

Platinum-based therapy, including cisplatin, carboplatin and/or oxaliplatin, 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 otoprotective medical interventions have been studied.

OBJECTIVES

The primary objective was to assess the efficacy of different otoprotective medical interventions in preventing hearing loss in children with cancer treated with platinum-based therapy. Secondary objectives were to determine possible effects of these interventions on anti-tumour efficacy, toxicities other than hearing loss and quality of life.

SEARCH METHODS

We searched the electronic databases Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2011, Issue 4), MEDLINE (PubMed) (1945 to 22 December 2011) and EMBASE (Ovid) (1980 to 22 December 2011). In addition, we handsearched reference lists of relevant articles and the conference proceedings of the International Society for Paediatric Oncology (2006 to 2011), the American Society of Pediatric Hematology/Oncology (2007 to 2011) and the International Conference on Long-Term Complications of Treatment of Children and Adolescents for Cancer (2010). We scanned the International Standard Randomized Controlled Trial Number (ISRCTN) Register and the National Institute of Health Register for ongoing trials (www.controlled-trials.com) (searched on 20 December 2011).

SELECTION CRITERIA

Randomized controlled trials (RCTs) or controlled clinical trials (CCTs) evaluating platinum-based therapy together with an otoprotective medical intervention versus platinum-based therapy with placebo, no additional treatment or another protective medical intervention in children with cancer.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed the study selection, risk of bias 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 two RCTs and one CCT (total number of patients 149) evaluating the use of amifostine versus no additional treatment. Two studies included children with osteosarcoma, the other study included children with hepatoblastoma. Patients received cisplatin only or a combination of cisplatin and carboplatin, either administered intra-arterially or intravenously. All studies had methodological limitations. Unfortunately, pooling of the results of included studies was not possible. However, in all individual studies no significant difference was identified in symptomatic ototoxicity only (that is grade 2 or higher) and combined asymptomatic and symptomatic ototoxicity (that is grade 1 or higher) between children treated with or without amifostine. Only one study, including children with osteosarcoma treated with intra-arterial cisplatin, provided information on tumour response, defined as the number of patients with a good or partial remission. The 'available data' analysis (data were missing for one patient), 'best case scenario' analysis and 'worst case scenario' analysis all showed a difference in favour of amifostine, but this difference was significant only in the 'worst case scenario' analysis (P = 0.04). No information on survival was available for any of the included study populations. Only one study, including children with osteosarcoma treated with intra-arterial cisplatin, provided data on the number of patients with adverse effects other than ototoxicity grade 3 or higher. There was a significant difference in favour of the control group in the occurrence of vomiting grade 3 or 4 (RR 9.04; 95% CI 1.99 to 41.12; P = 0.004). No significant difference was identified between treatment groups for cardiotoxicity and renal toxicity grade 3 or 4. None of the studies evaluated quality of life. No eligible studies were found for possible otoprotective medical interventions other than amifostine and other types of malignancies.

AUTHORS' CONCLUSIONS

At the moment there is no evidence from individual studies in children with osteosarcoma and hepatoblastoma treated with different platinum analogues and dosage schedules which underscores the use of amifostine as an otoprotective intervention as compared to no additional treatment. Since pooling of results was not possible and all studies had serious 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'. Based on the currently available evidence, we are not able to give recommendations for clinical practice. For other possible otoprotective medical interventions and other types of malignancies no eligible studies were identified, so no conclusions can be made about their efficacy in preventing ototoxicity in children treated with platinum-based therapy. More high quality research is needed.

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.

The design and screening of drugs to prevent acquired sensorineural hearing loss

INTRODUCTION

Sensorineural hearing loss affects a high percentage of the population. Ototoxicity is a serious and pervasive problem in patients treated with cisplatin. Strategies to ameliorate ototoxicity without compromising on antitumor activity of treatments are urgently needed. Similar problems occur with aminoglycoside antibiotic therapy for infections. Noise-induced hearing loss affects a large number of people. The use of ear protection is not always possible or effective. The prevention of hearing loss with drug therapy would have a huge impact in reducing the number of people with hearing loss from these major causes.

AREAS COVERED

This review discusses significant research findings dealing with the use of protective agents against hearing loss caused by cisplatin, aminoglycoside antibiotics and noise trauma. The efficacy in animal studies and the application of these protective agents in clinical trials that are ongoing are presented.

EXPERT OPINION

The reader will gain new insights into current and projected future strategies to prevent sensorineural hearing loss from cisplatin chemotherapy, aminoglycoside antibiotic therapy and noise exposure. The future appears to offer numerous agents to prevent hearing loss caused by cisplatin, aminoglycoside antibiotics and noise. Novel delivery systems will provide ways to guide these protective agents to the desired target areas in the inner ear and circumvent problems with therapeutic interference of antitumor and antibiotics agents as well as minimize undesired side effects.

Anticancer activity of a combination of cisplatin and fisetin in embryonal carcinoma cells and xenograft tumors

Use of chemotherapeutic drug cisplatin is limited because of its toxicity. Therefore, efforts continue for the discovery of novel combination therapies with cisplatin to reduce its effective treatment dose. This study evaluates the potential of fisetin, a flavonoid, to increase cisplatin cytotoxicity in human embryonal carcinoma NT2/D1 cells. Addition of fisetin to cisplatin enhanced cisplatin cytotoxicity in vitro at four times lower dose than that required by cisplatin monotherapy for similar cytotoxic effects. Cisplatin, fisetin monotherapy, and addition of fisetin to cisplatin in a combination increased FasL expression. Cisplatin and fisetin as single agents activated caspases-8 and -3 and caspases-9 and -7, respectively, whereas combination treatment activated all 4 caspases. Increases in p53 and p21 and decreases in cyclin B1 and survivin occurred, all effects being more exaggerated with the combination. Fisetin, with or without cisplatin, increased expression of proapoptotic protein Bak and induced its mitochondrial oligomerization. Bid truncation and mitochondrial translocation of Bid and p53 was induced by fisetin in the presence or absence of cisplatin. Downregulation of p53 by short hairpin RNA during drug treatment decreased p21 levels but caused survivin increase, thus reducing cell death. Upstream to p53, inhibition of p38 phosphorylation reduced p53 phosphorylation and cell death. In a NT2/D1 mouse xenograft model, combination therapy was most effective in reducing tumor size. In summary, findings of this study suggest that addition of fisetin to cisplatin activates both the mitochondrial and the cell death receptor pathway and could be a promising regimen for the elimination of embryonal carcinoma cells.