Drugs to prevent hearing loss in children receiving platinum chemotherapy for cancer

Review question

We reviewed the evidence of the effectiveness of any medical intervention to prevent hearing loss in children with cancer treated with platinum-based therapy (that is, including the anti-cancer drugs cisplatin, carboplatin, oxaliplatin, or a combination of these). We also looked at anti-cancer effectiveness, side effects other than hearing loss and quality of life.

Background

Platinum-based chemotherapy, including cisplatin, carboplatin, oxaliplatin, or a combination of these, is used in the treatment of different types of childhood cancer. Unfortunately, one of the most important side effects of platinum chemotherapy is hearing loss. This can occur not only during treatment but also years after the end of treatment. Although it is not life-threatening the loss of hearing, especially during the first three years of life, may lead to difficulties with school performance and psychosocial functioning. Prevention of platinum-induced hearing loss is thus very important and might improve the quality of life of children undergoing cancer treatment and those who have survived treatment with platinum-based chemotherapy.

Study characteristics

The evidence is current to July 2016.

We found two randomized studies (clinical studies where people are randomly put into one of two or more treatment groups) and one controlled study (clinical studies where people are put into one of two or more treatment groups but this is not done in a random way) (149 participants), all comparing amifostine with no additional treatment. Two studies included children with osteosarcoma (a type of bone cancer), the other study included children with hepatoblastoma (a type of liver cancer). Combining the results of the included studies was not possible.

Key results

At the moment there is no evidence from individual studies showing that the use of amifostine prevents hearing loss. Only one study reported results on cancer response and side effects, so we could make no definitive conclusions. None of the studies assessed survival and quality of life. We identified no adequate studies for other possible drugs to prevent hearing loss and for other types of cancer. Before definitive conclusions can be made about the usefulness of possible drugs to prevent hearing loss (either amifostine or another drug) in children treated with platinum chemotherapy more high quality research is needed.

Quality of the evidence

The quality of the evidence was low.

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.

Read the full abstract...
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 strategy: 

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.

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