Anthracyclines are anticancer drugs used in the treatment of different types of childhood cancer. An important adverse effect of anthracyclines is damage to the heart, which can lead to asymptomatic (without complaints) or symptomatic (with complaints) cardiac problems during and after cancer treatment. While there are several drugs available to treat other types of cardiac problems in adults, it is not known if these drugs are beneficial in treating cardiac problems caused by anthracyclines in childhood cancer patients and survivors. A physician confronted with a childhood cancer patient or survivor with anthracycline-induced cardiac problems should be able to make an informed decision on how to treat this patient based on high-quality evidence about the beneficial and adverse effects of the treatment options. We searched for and summarised studies that evaluated drugs for treating anthracycline-induced cardiac problems in childhood cancer patients and survivors.
We identified two randomised studies evaluating two different drugs in two different types of patients. One of these drugs, an angiotensin-converting enzyme (ACE) inhibitor (enalapril), had a short-term beneficial effect on heart function in survivors of childhood cancer with asymptomatic cardiac problems caused by anthracyclines compared with placebo. However, the drug had no significant beneficial effect on other important outcomes and was associated with side effects such as dizziness and fatigue. This study was of reasonable/good quality. The other study was of low quality and found no effect of a short treatment with phosphocreatine in childhood leukaemia patients with symptomatic or asymptomatic cardiac problems compared with a control treatment with vitamin C, adenosine triphosphate, vitamin E, and oral coenzyme Q10.
We could make no definitive conclusions about treatment options for anthracycline-induced cardiac problems in childhood cancer patients and survivors. High-quality studies are needed to determine if there are drugs that improve heart function in these patients.
Only one trial evaluated the effect of enalapril in childhood cancer survivors with asymptomatic cardiac dysfunction. Although there is some evidence that enalapril temporarily improves one parameter of cardiac function (LVESWS), it is unclear whether it improves clinical outcomes. Enalapril was associated with a higher risk of dizziness or hypotension and fatigue. Clinicians should weigh the possible benefits with the known side effects of enalapril in childhood cancer survivors with asymptomatic anthracycline-induced cardiotoxicity.
Only one trial evaluated the effect of phosphocreatine in childhood cancer patients with anthracycline-induced cardiotoxicity. Limited data with a high risk of bias showed no significant difference between phosphocreatine and control treatments on echocardiographic function and clinical outcomes.
We did not identify any RCTs or CCTs studying other medical interventions for symptomatic or asymptomatic cardiotoxicity in childhood cancer patients or survivors.
High-quality studies should be performed.
Anthracyclines are frequently used chemotherapeutic agents for childhood cancer that can cause cardiotoxicity during and after treatment. Although several medical interventions in adults with symptomatic or asymptomatic cardiac dysfunction due to other causes are beneficial, it is not known if the same treatments are effective for childhood cancer patients and survivors with anthracycline-induced cardiotoxicity. This review is an update of a previously published Cochrane review.
To compare the effect of medical interventions on anthracycline-induced cardiotoxicity in childhood cancer patients or survivors with the effect of placebo, other medical interventions, or no treatment.
We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library, 2015, Issue 8), MEDLINE/PubMed (1949 to September 2015), and EMBASE/Ovid (1980 to September 2015) for potentially relevant articles. In addition, we searched reference lists of relevant articles, conference proceedings of the International Society for Paediatric Oncology (SIOP), the American Society of Clinical Oncology (ASCO), the American Society of Hematology (ASH), the International Conference on Long-Term Complications of Treatment of Children & Adolescents for Cancer, and the European Symposium on Late Complications from Childhood Cancer (from 2005 to 2015), and ongoing trial databases (the ISRCTN Register, the National Institutes of Health (NIH) Register, and the trials register of the World Health Organization (WHO); all searched in September 2015).
Randomised controlled trials (RCTs) or controlled clinical trials (CCTs) comparing the effectiveness of medical interventions to treat anthracycline-induced cardiotoxicity with either placebo, other medical interventions, or no treatment.
Two review authors independently performed the study selection. One review author performed the data extraction and 'Risk of bias' assessments, which another review author checked. We performed analyses according to the guidelines in the Cochrane Handbook for Systematic Reviews of Interventions.
In the original version of the review we identified two RCTs; in this update we identified no additional studies. One trial (135 participants) compared enalapril with placebo in childhood cancer survivors with asymptomatic anthracycline-induced cardiac dysfunction. The other trial (68 participants) compared a two-week treatment of phosphocreatine with a control treatment (vitamin C, adenosine triphosphate, vitamin E, oral coenzyme Q10) in leukaemia patients with anthracycline-induced cardiotoxicity. Both studies had methodological limitations.
The RCT on enalapril showed no statistically significant differences in overall survival, mortality due to heart failure, development of clinical heart failure, and quality of life between treatment and control groups. A post-hoc analysis showed a decrease (that is improvement) in one measure of cardiac function (left ventricular end-systolic wall stress (LVESWS): -8.62% change) compared with placebo (+1.66% change) in the first year of treatment (P = 0.036), but not afterwards. Participants treated with enalapril had a higher risk of dizziness or hypotension (risk ratio 7.17, 95% confidence interval 1.71 to 30.17) and fatigue (Fisher's exact test, P = 0.013).
The RCT on phosphocreatine found no differences in overall survival, mortality due to heart failure, echocardiographic cardiac function, and adverse events between treatment and control groups.