Dexrazoxane-associated risk for secondary malignancies in pediatric Hodgkin's disease: a claim without compelling evidence

Cardiotoxicity in pediatric lymphoma survivors

INTRODUCTION

Over the past five decades, the diagnosis and management of children with various malignancies have improved tremendously. As a result, an increasing number of children are long-term cancer survivors. With improved survival, however, has come an increased risk of treatment-related cardiovascular complications that can appear decades later.

AREAS COVERED

This review discusses the pathophysiology, epidemiology and effects of treatment-related cardiovascular complications from anthracyclines and radiotherapy in pediatric lymphoma survivors. There is a paucity of evidence-based recommendations for screening for and treatment of cancer therapy-induced cardiovascular complications. We discuss current preventive measures and strategies for their treatment.

EXPERT OPINION

Significant cardiac adverse effects occur due to radiation and chemotherapy received by patients treated for lymphoma. Higher lifetime cumulative doses, female sex, longer follow-up, younger age, and preexisting cardiovascular disease are associated with a higher incidence of cardiotoxicity. With deeper understanding of the mechanisms of these adverse cardiac effects and identification of driver mutations causing these effects, personalized cancer therapy to limit cardiotoxic effects while ensuring an adequate anti-neoplastic effect would be ideal. In the meantime, expanding the use of cardioprotective agents with the best evidence such as dexrazoxane should be encouraged and further studied.

The safety of current pharmacotherapeutic strategies for osteosarcoma

Introduction: Peri-operative chemotherapy is the backbone of treatment for patients with osteosarcoma. Methotrexate, cisplatinum, doxorubicin and ifosfamide are the main drugs used in chemotherapy regimens used for osteosarcoma.Areas covered: We have reviewed here the relevant literature related to the incidence and management of acute and late toxicities of systemic treatment used for the management of patients with osteosarcoma.Expert opinion: Early diagnosis and appropriate management of acute and late toxicities of chemotherapy is crucial for an efficient care of osteosarcoma patients. Although the incidence and management of chemotherapy-related acute toxicities are well known by most oncologists, the use of high doses of methotrexate have the potential to cause fatal toxicities and, therefore, needs careful monitoring. Moreover, the diagnosis of late toxicities is more challenging and requires long-term follow-up for an appropriate management.

Cardiotoxicity: A Major Setback in Childhood Leukemia Treatment

Ongoing research in the field of pediatric oncology has led to an increased number of childhood cancer survivors reaching adulthood. Therefore, ensuring a good quality of life for these patients has become a rising priority. Considering this, the following review focuses on summarizing the most recent research in anthracycline-induced cardiac toxicity in children treated for leukemia. For pediatric cancers, anthracyclines are one of the most used anticancer drugs, with over half of the childhood cancer survivors believed to have been exposed to them. Anthracyclines cause irreversible cardiomyocyte loss, leading to chronic, progressive heart failure. The risk of developing cardiotoxicity has been known to increase with the treatment-free interval and total cumulative dose. However, because of individual variations in anthracycline metabolism, it has recently been shown that there is no risk-free dose. Moreover, studies have shown that diagnosing anthracycline-induced cardiomyopathy in the symptomatic phase is associated with poor treatment response and prognosis. Thus, early and systematic evaluation of these patients is crucial to allow optimal therapeutic intervention. Although currently echocardiographic assessment of left ventricle ejection fraction and cardiac biomarker evaluation are being used for cardiac function monitoring in oncologic patients, there is no established follow-up and treatment protocol for these patients, and these methods are neither specific nor sensitive for identifying early cardiac dysfunction. All things considered, the need for ongoing research in the field of pediatric cardiooncology is crucial to offer these patients a chance at a good quality of life as adults.

Age-Related Considerations in Cardio-Oncology

Cardio-Oncology has blossomed as a new field in cardiovascular medicine, in large part due to new therapies, which may have cardiovascular sequelae. Despite this, anthracyclines still serve as cornerstone therapy for most pediatric cancers, several solid tumors and hematological malignancies. Cardiotoxicity is the main limiting concern with anthracyclines, and this is particularly an issue in patients in extremes of age (both young and old patients). Pediatric hearts are susceptible for cardiotoxicity, while in older patients, concomitant risk factors may contribute to lower threshold for cardiotoxic effects. With increasing patient survival, a significant increase in elderly cancer patients and long-term cardiotoxicity effects of anthracyclines, a better mechanistic understanding of age-dependent processes-that define cardiotoxicity-is needed. This review sheds light on how age affects underlying molecular pathways of anthracycline-associated cardiotoxicity and aims to provide preventive strategies that can be used in clinical practice.

Echocardiographic long-term follow-up of adult survivors of pediatric cancer treated with Dexrazoxane-Anthracyclines association

AIMS

Cardiovascular disease is a well-recognized cause of increased late morbidity and mortality among survivors of childhood cancer treated with anthracyclines. Co-administration of Dexrazoxane has been shown to significantly reduce short-term and mid-term cardiotoxicity. Aim of this study was to assess cardiac function in long-term (>10 years) survivors of childhood tumors treated with dexrazoxane/anthracycline association.

METHODS AND RESULTS

Twenty cancer survivors previously treated with co-administration of anthracyclines-dexrazoxane for childhood renal tumors or sarcoma and a control group of 20 healthy subjects were enrolled in the study. Echocardiographic measurements included 3D left ventricular (LV) ejection fraction (LVEF) and LV and right ventricular (RV) global longitudinal strain (GLS). Among cancer survivors group the median age at diagnosis was 5 years (1-17) and they were evaluated at median follow-up time of 21.5 years (10-26). No evidence of cardiac toxicity, as defined by current guidelines, was reported in all survivors. No significant differences in standard and deformation imaging parameters were observed between survivors and controls (3D LVEF 58 ± 3% vs 60 ± 5% p = NS; LV GLS -21 ± 1% vs -21 ± 2% p = NS; RV GLS -23 ± 2% vs -23 ± 5% p = NS). No second tumor was registered in dexrazoxane-treated survivors.

CONCLUSIONS

Our findings may support the role of dexrazoxane as a useful strategy for cardio-protection in children undergoing anthracycline based treatment. However, large randomized trials are needed to confirm the cardio-protective role of dexrazoxane in pediatric setting at long-term follow-up.

Cardiovascular disease in survivors of childhood cancer

PURPOSE OF REVIEW

We review the cardiotoxic chemotherapeutic agents, the clinical and subclinical presentations and progression of their cardiotoxicity, and the management of the subsequent cardiovascular disease in survivors of childhood cancer. We discuss various preventive measures, especially the cardioprotectant, dexrazoxane, whose use with anthracycline chemotherapy, including doxorubicin, is based on strong evidence. Most treatment recommendations for this unique population are based on expert opinion, not on empirical evidence.

RECENT FINDINGS

As patients with childhood cancers live longer, morbidity from the cardiac side effects of chemotherapy is increasing. Treatment-related cardiac damage is irreversible and often progressive. It is imperative that such damage be prevented with strategies such as limiting the cumulative anthracycline dose, the use of anthracycline structural analogues and the use of cardioprotective agents.

SUMMARY

A deeper understanding of the mechanisms of their cardiotoxicity reveals that there is no 'safe' dose of anthracyclines. However, certain risk factors, such as higher lifetime anthracycline cumulative doses, higher anthracycline dose rates, female sex, longer follow-up, younger age at anthracycline treatment and cardiac irradiation, are associated with more severe cardiotoxicity. We advocate the use of dexrazoxane to limit the cardiotoxic effects of anthracycline chemotherapy.

Risk-benefit of dexrazoxane for preventing anthracycline-related cardiotoxicity: re-evaluating the European labeling

Dexrazoxane can prevent anthracycline-associated cardiotoxicity. However, in 2011, its use in children was contraindicated by the EMA over concerns of increased risk of infection, myelosuppression and second primary malignancies, and because its efficacy in children had not then been established. We review here the evidence published since 2011, which confirms that dexrazoxane is an effective cardioprotectant in children and adolescents, is not associated with an increased risk of second primary malignancies or excess early or late mortality and does not impair chemotherapy efficacy. Based on this evidence, the contraindication for children and adolescents requiring high doses of anthracyclines and at risk for cardiotoxicity was removed from the European labeling for dexrazoxane.

Anthracycline-induced cardiotoxicity in patients with paediatric bone sarcoma and soft tissue sarcoma

OBJECTIVES

Anthracycline cardiotoxicity is an important side-effect in long-term childhood cancer survivors. We evaluated the incidence of and factors associated with anthracycline cardiotoxicity in a population of patients diagnosed with bone or soft tissue sarcoma. Materials and methods We retrospectively enrolled patients diagnosed with bone or soft tissue sarcoma, from 1995 to 2011, treated with anthracycline chemotherapy at our Centre and with a follow-up echocardiography carried out ⩾3 years from cardiotoxic therapy completion. Cardiac toxicity was graded using Common Terminology Criteria for Adverse Events version 4.0.

RESULTS

A total of 82 patients were eligible. The median age at treatment was 11.9 years (1.44-18). We evaluated the median cumulative anthracycline dose, age at treatment, sex, thoracic radiotherapy, hematopoietic stem cell transplantation, and high-dose cyclophosphamide treatment as possible risk factors for cardiotoxicity. The median cumulative anthracycline dose was 390.75 mg/m2 (80-580). Of the 82 patients, 12 (14.6%) developed cardiotoxicity with grade ⩾2 ejection fraction decline: four patients were asymptomatic and did not receive any treatment; six patients were treated with pharmacological heart failure therapy; one patient with severe cardiomyopathy underwent heart transplantation and did not need any further treatment; and one patient died while waiting for heart transplantation. The median time at cardiac toxicity, from the end of anthracycline frontline chemotherapy, was 4.2 years (0.05-9.6). Cumulative anthracycline dose ⩾300 mg/m2 (p 0.04) was the only risk factor for cardiotoxicity on statistical analyses.

CONCLUSIONS

In our population, the cumulative incidence of cardiotoxicity is comparable to rates in the literature. This underlines the need for primary prevention and lifelong cardiac toxicity surveillance programmes in long-term childhood cancer survivors.

Dexrazoxane for cardioprotection in older adults with acute myeloid leukemia

Anthracyclines constitute the backbone of intensive adult acute myeloid leukemia (AML) therapy. Cardiotoxicity is one of its most serious adverse effects, and its incidence increases with cumulative dose. Dexrazoxane is a cardioprotective agent used in conjunction with anthracycline therapy. There is limited data of its usage in adult AML patients. We report the outcomes of six older adults at high risk of anthracycline-induced cardiotoxicity who received dexrazoxane during induction/re-induction therapy. Five had preserved left-ventricular function while two proceeded onto stem-cell transplantation. Additional investigation of dexrazoxane in adult leukemia therapy is warranted, particularly in older patients at highest risk for cardiovascular mortality.

Prevention of cardiotoxicity among survivors of childhood cancer

LINKED ARTICLES

This article is part of a joint Themed section with the British Journal of Pharmacology on Cardiotoxicity. The rest of the Themed section will appear in a future issue of BJP and will be available at http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1476-5381 The number of survivors of childhood cancers has increased exponentially over the past few decades. However, these survivors are also at substantially increased long-term risk of morbidity and mortality, especially from treatment-related cardiotoxicity. Preventing these risks is now a priority when treating children and adolescents with cancer. Dexrazoxane reduces the risk of anthracycline-induced cardiotoxicity among adults and children with cancer without reducing its antineoplastic effects or event-free survival. Thus, it should be strongly considered as a part of therapy for children and adolescents treated with anthracyclines.

Effect of Remote Ischaemic Conditioning in Oncology Patients Undergoing Chemotherapy: Rationale and Design of the ERIC-ONC Study--A Single-Center, Blinded, Randomized Controlled Trial

Cancer survival continues to improve, and thus cardiovascular consequences of chemotherapy are increasingly important determinants of long‐term morbidity and mortality. Conventional strategies to protect the heart from chemotherapy have important hemodynamic or myelosuppressive side effects. Remote ischemic conditioning (RIC) using intermittent limb ischemia‐reperfusion reduces myocardial injury in the setting of percutaneous coronary intervention. Anthracycline cardiotoxicity and ischemia‐reperfusion injury share common biochemical pathways in cardiomyocytes. The potential for RIC as a novel treatment to reduce subclinical myocyte injury in chemotherapy has never been explored and will be investigated in the Effect of Remote Ischaemic Conditioning in Oncology (ERIC‐ONC) trial (clinicaltrials.gov NCT 02471885). The ERIC‐ONC trial is a single‐center, blinded, randomized, sham‐controlled study. We aim to recruit 128 adult oncology patients undergoing anthracycline‐based chemotherapy treatment, randomized in a 1:1 ratio into 2 groups: (1) sham procedure or (2) RIC, comprising 4, 5‐minute cycles of upper arm blood pressure cuff inflations and deflations, immediately before each cycle of chemotherapy. The primary outcome measure, defining cardiac injury, will be high‐sensitivity troponin‐T over 6 cycles of chemotherapy and 12 months follow‐up. Secondary outcome measures will include clinical, electrical, structural, and biochemical endpoints comprising major adverse cardiovascular clinical events, incidence of cardiac arrhythmia over 14 days at cycle 5/6, echocardiographic ventricular function, N‐terminal pro‐brain natriuretic peptide levels at 3 months follow‐up, and changes in mitochondrial DNA, micro‐RNA, and proteomics after chemotherapy. The ERIC‐ONC trial will determine the efficacy of RIC as a novel, noninvasive, nonpharmacological, low‐cost cardioprotectant in cancer patients undergoing anthracycline‐based chemotherapy.

Cardiovascular disease in adult survivors of childhood cancer

Treatment advances have increased survival in children with cancer, but subclinical, progressive, irreversible, and sometimes fatal treatment-related cardiovascular effects may appear years later. Cardio-oncologists have identified promising preventive and treatment strategies. Dexrazoxane provides long-term cardioprotection from doxorubicin-associated cardiotoxicity without compromising the efficacy of anticancer treatment. Continuous infusion of doxorubicin is as effective as bolus administration in leukemia treatment, but no evidence has indicated that it provides long-term cardioprotection; continuous infusions should be eliminated from pediatric cancer treatment. Angiotensin-converting enzyme inhibitors can delay the progression of subclinical and clinical cardiotoxicity. All survivors, regardless of whether they were treated with anthracyclines or radiation, should be monitored for systemic inflammation and the risk of premature cardiovascular disease. Echocardiographic screening must be supplemented with screening for biomarkers of cardiotoxicity and perhaps by identification of genetic susceptibilities to cardiovascular diseases; optimal strategies need to be identified. The health burden related to cancer treatment will increase as this population expands and ages.

Dexrazoxane

Anthracyclines are a fundamental part of many childhood cancer therapy regimens; however, the discovery of anthracycline-induced cardiotoxicity has raised concern and led to dose limitation. The cardiotoxicity of anthracyclines has resulted in an increased demand for cardioprotectants. Dexrazoxane is the only cardioprotectant that has proven efficacy in reducing cardiotoxic effects when given prior to the administration of anthracyclines. Currently, it is still considered an “off-label” use due to a paucity of data in the literature on dexrazoxane administration in children. Nevertheless, through evaluation of the available data, dexrazoxane is observed to be safe, tolerable, and efficacious in mitigating the cardiotoxic effects of anthracycline in children, without jeopardizing its antineoplastic activity or increasing the risk of developing secondary malignant neoplasms.

Treatment-related cardiotoxicity in survivors of childhood cancer

Treatment advances and higher participation rates in clinical trials have rapidly increased the number of survivors of childhood cancer. However, chemotherapy and radiation treatments are cardiotoxic and can cause cardiomyopathy, conduction defects, myocardial infarction, hypertension, stroke, pulmonary oedema, dyspnoea and exercise intolerance later in life. These cardiotoxic effects are often progressive and irreversible, emphasizing a need for effective prevention and treatment to reduce or avoid cardiotoxicity. Medical interventions, such as angiotensin-converting enzyme inhibitors, β-blockers, and growth hormone therapy, might be used to treat cardiotoxicity in childhood cancer survivors. Preventative strategies should include the use of dexrazoxane, which provides cardioprotection without reducing the oncological efficacy of doxorubicin chemotherapy; less-toxic anthracycline derivatives and the use of antioxidant nutritional supplements might also be beneficial. Continuous-infusion doxorubicin provides no benefit over bolus infusion in children. Identifying patient-related (for example, obesity and hypertension) and drug-related (for example, cumulative dose) risk factors for cardiotoxicity could help tailor treatments to individual patients. However, all survivors of childhood cancer are at increased risk of cardiotoxicity, suggesting that survivor screening recommendations for assessment of global risk of premature cardiovascular disease should apply to all survivors. Optimal, evidence-based monitoring strategies and multiagent preventative treatments still need to be identified.

Early and delayed cardioprotective intervention with dexrazoxane each show different potential for prevention of chronic anthracycline cardiotoxicity in rabbits

Despite incomplete understanding to its mechanism of action, dexrazoxane (DEX) is still the only clearly effective cardioprotectant against chronic anthracycline (ANT) cardiotoxicity. However, its clinical use is currently restricted to patients exceeding significant ANT cumulative dose (300mg/m(2)), although each ANT cycle may induce certain potentially irreversible myocardial damage. Therefore, the aim of this study was to compare early and delayed DEX intervention against chronic ANT cardiotoxicity and study the molecular events involved. The cardiotoxicity was induced in rabbits with daunorubicin (DAU; 3mg/kg/week for 10 weeks); DEX (60mg/kg) was administered either before the 1st or 7th DAU dose (i.e. after ≈300mg/m(2) cumulative dose). While both DEX administration schedules prevented DAU-induced premature deaths and severe congestive heart failure, only the early intervention completely prevented the left ventricular dysfunction, myocardial morphological changes and mitochondrial damage. Further molecular analyses did not support the assumption that DEX cardioprotection is based and directly proportional to protection from DAU-induced oxidative damage and/or deletions in mtDNA. Nevertheless, DAU induced significant up-regulation of heme oxygenase 1 pathway while heme synthesis was inversely regulated and both changes were schedule-of-administration preventable by DEX. Early and delayed DEX interventions also differed in ability to prevent DAU-induced down-regulation of expression of mitochondrial proteins encoded by both nuclear and mitochondrial genome. Hence, the present functional, morphological as well as the molecular data highlights the enormous cardioprotective effects of DEX and provides novel insights into the molecular events involved. Furthermore, the data suggests that currently recommended delayed intervention may not be able to take advantage of the full cardioprotective potential of the drug.

An expert opinion on pharmacologic approaches to reducing the cardiotoxicity of childhood acute lymphoblastic leukemia therapies

INTRODUCTION

Acute lymphoblastic leukemia (ALL) is the most common hematologic malignancy in children. Treatment-related cardiac damage is progressive and often difficult to reverse. Strategies to minimize cardiotoxicity during treatment are crucial to prevent severe lasting effects on health and quality of life.

AREAS COVERED

This comprehensive review covers the pathophysiology and various presentations, both clinical and subclinical, of treatment-induced cardiotoxicity and characteristics associated with increased risk of cardiac dysfunction in childhood ALL survivors. Additionally, contemporary prevention strategies such as limiting cumulative anthracycline dose, altering drug administration schedule, the use of anthracycline structural analogs, liposomal encapsulated anthracyclines, cardioprotective agents and nutritional supplements are critically analyzed. Finally, this review covers the management options of chemotherapy-induced damage and other treatment-related cardiotoxicity.

EXPERT OPINION

Higher lifetime cumulative doses of anthracyclines, younger age at diagnosis, longer follow-up, female sex, higher dose rates and cranial irradiation are associated with more severe cardiotoxic effects. Long-term adverse effects of both anthracycline and non-anthracycline chemotherapeutic agents are becoming an increasing focus during treatment of childhood malignancies. There must be a careful balance between achieving remission of childhood ALL while avoiding the development of another often-fatal illness, heart failure.

Cardiovascular effects in childhood cancer survivors treated with anthracyclines

Anthracyclines are commonly used to treat childhood leukemias and lymphomas, as well as other malignancies, leading to a growing population of long-term childhood cancer survivors. However, their use is limited by cardiotoxicity, increasing survivors' vulnerability to treatment-related complications that can markedly affect their quality of life. Survivors are more likely to suffer from heart failure, coronary artery disease, and cerebrovascular accidents compared to the general population. The specific mechanisms of anthracycline cardiotoxicity are complex and remain unclear. Hence, determining the factors that may increase susceptibility to cardiotoxicity is of great importance, as is monitoring patients during and after treatment. Additionally, treatment and prevention options, such as limiting cumulative dosage, liposomal anthracyclines, and dexrazoxane, continue to be explored. Here, we review the cardiovascular complications associated with the use of anthracyclines in treating malignancies in children and discuss methods for preventing, screening, and treating such complications in childhood cancer survivors.

Assessment of dexrazoxane as a cardioprotectant in doxorubicin-treated children with high-risk acute lymphoblastic leukaemia: long-term follow-up of a prospective, randomised, multicentre trial

BACKGROUND

Doxorubicin chemotherapy is associated with cardiomyopathy. Dexrazoxane reduces cardiac damage during treatment with doxorubicin in children with acute lymphoblastic leukaemia (ALL). We aimed to establish the long-term effect of dexrazoxane on the subclinical state of cardiac health in survivors of childhood high-risk ALL 5 years after completion of doxorubicin treatment.

METHODS

Between January, 1996, and September, 2000, children with high-risk ALL were enrolled from nine centres in the USA, Canada, and Puerto Rico. Patients were assigned by block randomisation to receive ten doses of 30 mg/m² doxorubicin alone or the same dose of doxorubicin preceded by 300 mg/m² dexrazoxane. Treatment assignment was obtained through a telephone call to a centralised registrar to conceal allocation. Investigators were masked to treatment assignment but treating physicians and patients were not; however, investigators, physicians, and patients were masked to study serum cardiac troponin-T concentrations and echocardiographic measurements. The primary endpoints were late left ventricular structure and function abnormalities as assessed by echocardiography; analyses were done including all patients with data available after treatment completion. This trial has been completed and is registered with ClinicalTrials.gov, number NCT00165087.

FINDINGS

100 children were assigned to doxorubicin (66 analysed) and 105 to doxorubicin plus dexrazoxane (68 analysed). 5 years after the completion of doxorubicin chemotherapy, mean left ventricular fractional shortening and end-systolic dimension Z scores were significantly worse than normal for children who received doxorubicin alone (left ventricular fractional shortening: -0·82, 95% CI -1·31 to -0·33; end-systolic dimension: 0·57, 0·21-0·93) but not for those who also received dexrazoxane (-0·41, -0·88 to 0·06; 0·15, -0·20 to 0·51). The protective effect of dexrazoxane, relative to doxorubicin alone, on left ventricular wall thickness (difference between groups: 0·47, 0·46-0·48) and thickness-to-dimension ratio (0·66, 0·64-0·68) were the only statistically significant characteristics at 5 years. Subgroup analysis showed dexrazoxane protection (p=0·04) for left ventricular fractional shortening at 5 years in girls (1·17, 0·24-2·11), but not in boys (-0·10, -0·87 to 0·68). Similarly, subgroup analysis showed dexrazoxane protection (p=0·046) for the left ventricular thickness-to-dimension ratio at 5 years in girls (1·15, 0·44-1·85), but not in boys (0·19, -0·42 to 0·81). With a median follow-up for recurrence and death of 8·7 years (range 1·3-12·1), event-free survival was 77% (95% CI 67-84) for children in the doxorubicin-alone group, and 76% (67-84) for children in the doxorubicin plus dexrazoxane group (p=0·99).

INTERPRETATION

Dexrazoxane provides long-term cardioprotection without compromising oncological efficacy in doxorubicin-treated children with high-risk ALL. Dexrazoxane exerts greater long-term cardioprotective effects in girls than in boys.

FUNDING

US National Institutes of Health, Children's Cardiomyopathy Foundation, University of Miami Women's Cancer Association, Lance Armstrong Foundation, Roche Diagnostics, Pfizer, and Novartis.

Cardioprotective interventions for cancer patients receiving anthracyclines

BACKGROUND

Anthracyclines are among the most effective chemotherapeutic agents in the treatment of numerous malignancies. Unfortunately, their use is limited by a dose-dependent cardiotoxicity. In an effort to prevent this cardiotoxicity, different cardioprotective agents have been studied.

OBJECTIVES

The objective of this review was to assess the efficacy of different cardioprotective agents in preventing heart damage in cancer patients treated with anthracyclines.

SEARCH STRATEGY

We searched the databases of the Cochrane Central Register of Controlled Trials (CENTRAL, Issue 2, 2007), MEDLINE (1966 to April 2007) and EMBASE (1980 to April 2007). In addition, we handsearched reference lists and conference proceedings of the SIOP and ASCO meetings (1998 to 2006).

SELECTION CRITERIA

Randomised controlled trials (RCTs) in which any cardioprotective agent was compared to no additional or placebo therapy in cancer patients (children and adults) receiving anthracyclines.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed the study selection, quality assessment and data-extraction including adverse effects.

MAIN RESULTS

We identified RCTs for seven cardioprotective agents: N-acetylcysteine, phenetylamines, coenzyme Q10, combination of vitamins E and C and N-acetylcysteine, L-carnitine, carvedilol and dexrazoxane (mostly adults with advanced breast cancer). All studies had methodological limitations. For the first six agents, there were too few studies to allow pooling of results. None of the individual studies showed a cardioprotective effect. The nine included studies of dexrazoxane enrolled 1403 patients. The meta-analysis of dexrazoxane showed a statistically significant benefit in favour of dexrazoxane for the occurrence of heart failure (Relative Risk (RR) 0.29, 95% CI 0.20 to 0.41). No evidence was found for a difference in response rate or survival between the dexrazoxane and control group. Only for one adverse effect (abnormal white blood cell count at nadir) a difference in favour of the control group was identified.

AUTHORS' CONCLUSIONS

For cardioprotective agents for which pooling was impossible, no definitive conclusions can be made about their efficacy. Dexrazoxane prevents heart damage and no evidence for a difference in response rate or survival between the dexrazoxane and control group was identified. Only for an abnormal white blood cell count at nadir a clearly significant difference in favour of the control group was identified. We conclude that if the risk of cardiac damage is expected to be high, it might be justified to use dexrazoxane in patients with cancer treated with anthracyclines. However, for each individual patient clinicians should weigh the cardioprotective effect of dexrazoxane against the possible risk of adverse effects.