Cardiovascular effects in childhood cancer survivors treated with anthracyclines

Acute and early-onset cardiotoxicity in children and adolescents with cancer: a systematic review

BACKGROUND

Cardiotoxicity is among the most important adverse effects of childhood cancer treatment. Anthracyclines, mitoxantrone and radiotherapy involving the heart are its main causes. Subclinical cardiac dysfunction may over time progress to clinical heart failure. The majority of previous studies have focused on late-onset cardiotoxicity. In this systematic review, we discuss the prevalence and risk factors for acute and early-onset cardiotoxicity in children and adolescents with cancer treated with anthracyclines, mitoxantrone or radiotherapy involving the heart.

METHODS

A literature search was performed within PubMed and reference lists of relevant studies. Studies were eligible if they reported on cardiotoxicity measured by clinical, echocardiographic and biochemical parameters routinely used in clinical practice during or within one year after the start of cancer treatment in ≥ 25 children and adolescents with cancer. Information about study population, treatment, outcomes of diagnostic tests used for cardiotoxicity assessment and risk factors was extracted and risk of bias was assessed.

RESULTS

Our PubMed search yielded 3649 unique publications, 44 of which fulfilled the inclusion criteria. One additional study was identified by scanning the reference lists of relevant studies. In these 45 studies, acute and early-onset cardiotoxicity was studied in 7797 children and adolescents. Definitions of acute and early-onset cardiotoxicity prove to be highly heterogeneous. Prevalence rates varied for different cardiotoxicity definitions: systolic dysfunction (0.0-56.4%), diastolic dysfunction (30.0-100%), combinations of echocardiography and/or clinical parameters (0.0-38.1%), clinical symptoms (0.0-25.5%) and biomarker levels (0.0-37.5%). Shortening fraction and ejection fraction significantly decreased during treatment. Cumulative anthracycline dose proves to be an important risk factor.

CONCLUSIONS

Various definitions have been used to describe acute and early-onset cardiotoxicity due to childhood cancer treatment, complicating the establishment of its exact prevalence. Our findings underscore the importance of uniform international guidelines for the monitoring of cardiac function during and shortly after childhood cancer treatment.

The role of ginseng derivatives against chemotherapy-induced cardiotoxicity: A systematic review of non-clinical studies

Aims

Although chemotherapy agents are used to treating cancers, they have serious side effects, like their harmful effects on the cardiovascular system, limiting the clinical use of these chemotherapy agents. This study aimed to systematically investigate the potential role of ginseng derivatives in the prevention of chemotherapy-induced cardiac toxicity.

Methods

This systematic review was performed according to PRISMA guidelines strategy in databases till August 2022. First, identify studies related to using search terms in titles and abstracts. After studying and screening 209 articles, 16 articles were selected in this study according to our inclusion and exclusion criteria.

Results

According to the findings of this study, ginseng derivatives showed significant changes in biochemical, histological, and heart weight loss, as well as a reduction in mortality, which occurred in the groups treated with chemotherapy agents compared to the control groups. Co-administration of ginseng derivatives with chemotherapy agents inhibited or reversed these changes to near-moderate levels. The protective effects of ginseng derivatives can be due to their anti-inflammatory, anti-oxidant, and anti-apoptotic action.

Conclusion

This systematic review shows evidence that concomitant administration of ginseng derivatives improves chemotherapy-induced cardiac toxicity. However, for better conclusions about the practical mechanisms of ginseng derivatives in reducing the cardiac toxic effects of chemotherapy agents and evaluating the efficacy and safety of the compound simultaneously, it is necessary to design comprehensive studies.

Correlating decline in left ventricular ejection fraction and longitudinal strain in pediatric cancer patients

PURPOSE

Left ventricular ejection fraction (LVEF) is routinely used to monitor cardiac function in cancer patients. Global longitudinal strain (GLS) detects subclinical myocardial dysfunction. There is no consensus on what constitutes a significant change in GLS in pediatric cancer patients. We aim to determine the change in GLS associated with a simultaneous decline in LVEF in pediatric cancer patients.

METHODS

This is a retrospective longitudinal study of pediatric cancer patients treated with anthracyclines between October 2017 and November 2019. GLS was measured by 2-dimensional speckle tracking. The study outcome was a decline in LVEF, defined as a decrease in LVEF of ≥ 10% points from baseline or LVEF < 55%. We evaluated two echocardiograms per patient, one baseline, and one follow-up. The follow-up echocardiogram was either (1) the first study that met the outcome or (2) the last echocardiogram available in patients without the outcome. Statistical analyses included receiver operator characteristic curves and univariable and multivariable Cox proportional hazards regression.

RESULTS

Out of 161 patients, 33 (20.5%) had a decline in LVEF within one year of follow-up. GLS reduction by ≥ 15% from baseline and follow-up GLS >-18% had sensitivities of 85% and 78%, respectively, and specificities of 86% and 83%, respectively, to detect LVEF decline. GLS reduction by ≥ 15% from baseline and follow-up GLS >-18% were independently associated with simultaneous LVEF decline [hazard ratio (95% confidence intervals): 16.71 (5.47-51.06), and 12.83 (4.62-35.63), respectively].

CONCLUSION

Monitoring GLS validates the decline in LVEF in pediatric cancer patients.

Advanced Imaging and New Cardiac Biomarkers in Long-term Follow-up After Childhood Cancer

OBJECTIVES

Pathologic ejection fraction (EF), shortening fraction (FS), and standard heart failure biomarkers (high sensitive troponin T and N-terminal brain natriuretic peptide) during follow-up after childhood cancer have been associated with irreversible cardiac damage. We aimed to evaluate strain imaging values by echocardiography and new biomarkers for heart failure with preserved ejection fraction (HFpEF) as potential more sensitive parameters for cardiac deterioration in childhood cancer survivors (CCS).

MATERIALS AND METHODS

Prospective study with 50 CCS (median 16.2 y) at a median follow-up of 13 years. In addition to standard echo and laboratory parameters for heart failure, strain measurements and new biomarkers, including myocardial inflammation (interleukin 6), extracellular matrix (ECM) remodeling (C-telopeptide for type I collagen, intact N-terminal propeptide of type III procollagen), and other heart failure biomarkers (galectin 3, solutable ST2, growth differentiation factor 15), were obtained and compared with 50 healthy controls.

RESULTS

No significant differences in EF, FS, high sensitive troponin T, N-terminal brain natriuretic peptide, interleukin 6, solutable ST2, and galectin 3 were found between study and control groups. In contrast, strain imaging showed significant differences between both groups (global longitudinal strainGLS -16.1% vs. -20.4%, P<0.0001; global circumferential strain -14.3 vs. -21.4%, P<0.0001), detecting 66% (global longitudinal strain) and 76% (global circumferential strain) of patients with pathologic values in contrast to 6% (EF) and 16% (FS) for standard parameters. Markers for disturbances of ECM remodeling (C-telopeptide for type I collagen, intact N-terminal propeptide of type III procollagen, each P<0.0001) and growth differentiation factor 15 (P<0.0001) were significantly different between the groups.

CONCLUSION

Strain imaging and new cardiac biomarkers used in HFpEF focusing on ECM remodeling appear to be more sensitive in detecting early remodeling processes in CCS than standard echo and laboratory parameters.

Anthracycline Induced Cardiac Disorders in Childhood Acute Lymphoblastic Leukemia: A Single-Centre, Retrospective, Observational Study

Anthracycline-associated cardiotoxicity is frequently seen in cancer survivors years after treatment, but it is rare in patients on chemotherapy. This study aimed to investigate the clinical characteristics of cardiac disorders in children with acute lymphoblastic leukemia (ALL) during chemotherapy. A retrospective case study was conducted in children with ALL, for whom electrocardiogram (ECG) and echocardiography (Echo) were regularly assessed before each course of chemotherapy. The cardiac disorders were diagnosed according to the Common Terminology Criteria for Adverse Events (CTCAE) Version 5.0. Binary logistic regression analysis was used to identify risk factors associated with cardiac disorders. There were 171 children eligible for the study, and 78 patients (45.61%) were confirmed as having cardiac disorders. The incidence of cardiac disorders was dependent upon the cumulative dose of daunorubicin (DNR) (p = 0.030, OR = 1.553, 95% CI: 1.005–3.108). Four patients (2.34%) presented with palpitation, chest pain, and persistent tachycardia, and they were cured or improved after medical intervention. A total of 74 patients (43.27%) had subclinical cardiac disorders confirmed by ECG or Echo. ECG abnormalities were commonly seen in the induction and continuation treatments, including arrhythmias (26, 15.20%), ST changes (24, 14.04%) and conduction disorders (4, 2.34%). Pericardial effusion (14, 8.19%), left ventricular hypertrophy (11, 6.43%), a widened pulmonary artery (5, 2.92%) and valvular insufficiency (5, 2.92%) suggested by Echo occurred after induction chemotherapy. Therefore, cardiac disorders with clinical manifestations are rare and need early intervention. Subclinical cardiac disorders are common but very hidden in children during ALL chemotherapy. Regular ECG and Echo could help paediatricians to identify and monitor patients with asymptomatic cardiac disorders earlier.

The role of taurine on chemotherapy-induced cardiotoxicity: A systematic review of non-clinical study

AIMS

Although chemotherapeutic agents have highly beneficial effects against cancer, they disturb the body's normal homeostasis. One of the critical side effects of chemotherapeutic agents is their deleterious effect on the cardiac system, which causes limitations of their clinical usage. Taurine constitutes more than 50% of the amino acids in the heart. The use of taurine might prevent chemotherapy-induced cardiotoxicity. This systematic study aims to evaluate the protective role of taurine against cardiotoxicity induced by chemotherapy.

METHODS

A systematic search was performed in databases up to November 2020, and the review is designed on PRISMA guidelines. The search keywords were selected based on our study target and were searched in the title and abstract. After the consecutive screening, out of a whole of 94 articles, 8 articles were included according to our inclusion and exclusion criteria.

KEY FINDINGS

According to the study results, chemotherapy decreases body and heart weight and increases mortality. Also, it induces some biochemical and histological changes compared to the control group. By co-administration of taurine with chemotherapy, alterations returned near to the average level. These protective effects of taurine are mediated through anti-oxidant, anti-inflammatory, and anti-apoptotic properties.

SIGNIFICANCE

Based on evaluated non-clinical studies, taurine ameliorates chemotherapy-induced cardiotoxicity, but its possible interaction with the efficacy of anti-cancer medicines that mostly act through induction of oxidants remains to be elucidated in the future. This needs conducting well-designed studies to assess the effectiveness and safety of this combination simultaneously.

Exploring Social Ecological Determinants of Physical Activity Among Adult Survivors of Childhood Cancer

Purpose: Adult survivors of childhood cancer (ASCCs) are at high risk for cardiovascular disease from chemotherapy- and radiation therapy-related cardiotoxicity. Physical activity (PA) can reduce this risk, but the majority of ASCCs do not engage in sufficient PA. The purpose of this study was to identify barriers, facilitators, and resources for PA among ASCCs using the ecological model of physical activity (EMPA) as a theoretical framework. Methods: A concept elicitation survey was distributed independently to ASCCs (diagnosed with cancer before the age of 18, and currently 18-39 years old) and parents/legal guardians of an ASCC. The survey consisted of open-ended questions asking about barriers, facilitators, and resources for PA. Content analysis of open-ended questions categorized responses into levels of the EMPA and identified key themes. Results: Seventeen ASCCs and eight parents of ASCCs completed the survey. The majority of barriers, facilitators, and resources reported were at the individual and microsystem level of the EMPA. Six themes emerged, suggesting that ASCC's PA was related to proximity/access, social support, equipment, time/schedule, finances, and health-related barriers. Conclusion: This is the first study to examine barriers, facilitators, and resources of PA among ASCCs using the EMPA. Findings from this study provide a multilevel perspective on the influences of PA among ASCCs, and can be used for future, in-depth qualitative studies and quantitative survey development, and as a foundational step toward supportive efforts in increasing PA among ASCCs.

Subclinical Cardiac Dysfunction in Childhood Cancer Survivors on 10-Years Follow-Up Correlates With Cumulative Anthracycline Dose and Is Best Detected by Cardiopulmonary Exercise Testing, Circulating Serum Biomarker, Speckle Tracking Echocardiography, and Tissue Doppler Imaging

Background: Survivors of childhood cancer are at risk for anthracycline- and/or radiotherapy-induced cardiotoxicity. Aims: The aim of this study was to assess clinical, laboratory, and imaging parameters of subclinical cardiovascular disease in childhood cancer survivors. Methods: Patients underwent cardiopulmonary exercise test (CPET), laboratory testing, transthoracic echocardiography (TTE) with tissue doppler imaging (TDI) and speckle tracking. A subset of patients also underwent cardiovascular magnetic resonance imaging (CMR). Findings were correlated to cumulative anthracycline and exposure to mediastinal irradiation during cancer treatment. In a subgroup analysis, TTE and CMR findings were compared to data from 40 gender- and age-matched patients with childhood onset hypertrophic cardiomyopathy (HCM). Results: Cardiac evaluation was performed in 79 patients (43 males) at 11.2 ± 4.5 years after cancer treatment. Oncologic diagnosis at a median age of 12.0 years was Hodgkin lymphoma in 20, sarcoma in 17, acute leukemia in 24, relapse leukemia in 10, and others in 8 patients. Cumulative anthracycline dose exceeded 300 mg/m² in 28 patients. Twenty six patients also received mediastinal irradiation. Decreased peak respiratory oxygen uptake in % predicted on CPET, increased levels of N-terminal pro-brain natriuretic peptide (NTproBNP), increased global longitudinal strain on TTE speckle tracking, and diastolic dysfunction on TDI were the most prominent findings on detailed cardiology follow-up. In contrast to HCM patients, childhood cancer survivors did not show left ventricular hypertrophy (LVPWd z-score median 0.9 vs. 2.8, p < 0.001), hyperdynamic systolic function on TTE (Ejection fraction 62 ± 7 vs. 72 ± 12%, p = 0.001), or fibrotic myocardial changes on CMR (Late gadolinium positive 0/13 vs. 13/36, p = 0.001; extracellular volume fraction 22 ± 2 vs. 28 ± 3, p < 0.001) at time of follow-up. There was no correlation between chest radiation exposure and abnormal cardiac findings. Cumulative anthracycline dose was the only significant independent predictor on multivariate analysis for any cardiovascular abnormality on follow-up (p = 0.036). Conclusion: Increasing cumulative anthracycline dose during cancer treatment correlates with subclinical cardiac dysfunction in childhood cancer survivors best detected by elevated cardiac serum biomarkers, decreased exercise capacity on CPET, and abnormalities on echocardiographic speckle tracking and TDI.

Doxorubicin-Induced Cardiotoxicity in Collaborative Cross (CC) Mice Recapitulates Individual Cardiotoxicity in Humans

Anthracyclines cause progressive cardiotoxicity whose ultimate severity is individual to the patient. Genetic determinants contributing to this variation are difficult to study using current mouse models. Our objective was to determine whether a spectrum of anthracycline induced cardiac disease can be elicited across 10 Collaborative Cross mouse strains given the same dose of doxorubicin. Mice from ten distinct strains were given 5 mg/kg of doxorubicin intravenously once weekly for 5 weeks (total 25 mg/kg). Mice were killed at acute or chronic timepoints. Body weight was assessed weekly, followed by terminal complete blood count, pathology and a panel of biomarkers. Linear models were fit to assess effects of treatment, sex, and sex-by-treatment interactions for each timepoint. Impaired growth and cardiac pathology occurred across all strains. Severity of these varied by strain and sex, with greater severity in males. Cardiac troponin I and myosin light chain 3 demonstrated strain- and sex-specific elevations in the acute phase with subsequent decline despite ongoing progression of cardiac disease. Acute phase cardiac troponin I levels predicted the ultimate severity of cardiac pathology poorly, whereas myosin light chain 3 levels predicted the extent of chronic cardiac injury in males. Strain- and sex-dependent renal toxicity was evident. Regenerative anemia manifested during the acute period. We confirm that variable susceptibility to doxorubicin-induced cardiotoxicity observed in humans can be modeled in a panel of CC strains. In addition, we identified a potential predictive biomarker in males. CC strains provide reproducible models to explore mechanisms contributing to individual susceptibility in humans.

Avaliação econômica do uso de dexrazoxano na profilaxia de cardiotoxicidade em crianças em tratamento quimioterápico com antraciclinas

Resumo: O câncer em indivíduos de 0 a 19 anos é considerado raro, quando comparado à incidência em faixas etárias maiores, sendo estimado entre 2% e 3% de todos os tumores malignos registrados no Brasil. O uso de antraciclinas está frequentemente associado ao aparecimento de cardiotoxicidade e faz parte de aproximadamente 60% dos protocolos terapêuticos em oncologia pediátrica. Dentre as estratégias existentes para a prevenção de cardiotoxicidade, o dexrazoxano obteve resultados favoráveis pautados em desfechos intermediários (marcadores bioquímicos e medidas ecocardiográficas). Foi desenvolvida, neste trabalho, uma avaliação de custo-efetividade que compare o uso do dexrazoxano em diferentes populações, além de uma avaliação do impacto orçamentário causado pela possível incorporação da tecnologia. Foi utilizado o horizonte temporal de toda a vida do paciente e a perspectiva de análise do Sistema Único de Saúde. Uma análise de impacto orçamentário para cada tecnologia também foi construída. Após uma busca na literatura, foi desenvolvido um modelo de Markov capaz de comparar o uso do dexrazoxano em seis perfis de pacientes com risco de desenvolver cardiotoxicidade. Usar o medicamento nas crianças menores de cinco anos de idade se mostrou a alternativa mais custo-efetiva (razão de custo-efetividade incremental - RCEI de R$ 6.156,96), seguida de usar em todos os pacientes (RCEI de R$ 58.968,70). Caso o preço diminua a um valor menor que R$ 250,00 por frasco, a alternativa de usar em todas as crianças se torna a mais custo-efetiva. O impacto orçamentário ao final de cinco anos foi de R$ 30.622.404,81 para uso apenas nas crianças menores de cinco anos. Usar a tecnologia em todas as crianças produziria um impacto incremental de R$ 94.352.898,77.

Mesenchymal stem cells confer resistance to doxorubicin-induced cardiac senescence by inhibiting microRNA-34a

Doxorubicin (DOXO) is a chemotherapeutic agent widely used in the treatment of various types of cancer. However, cardiotoxicity is a major side effect of DOXO therapy due to the ability of this compound to induce cardiac cellular senescence. It is well known that microRNA (miR)-34a serves a role in cardiac dysfunction and ageing, and that it is involved in several cellular processes associated with DOXO-induced cardiotoxicity. Furthermore, mesenchymal stem cell (MSC)-based therapies have been reported to modulate cellular senescence. In the present study, the Transwell system was used to co-culture H9c2 cells and MSCs, and cell proliferation and viability were assessed. The expression of senescence-related genes, p53 and p16, and telomere length were analyzed using reverse transcription-quantitative polymerase chain reaction (PCR), and the protein expression levels of situin 1 (SIRT1) were detected by western blotting. Additionally, telomerase activity of H9c2 was examined using the Telo TAGGG Telomerase PCR ELISA PLUS kit. The present study revealed that, in the presence of DOXO, H9c2 cells were in senescence, as characterized by a low proliferation rate, poor viability and a marked increase in the expression of p53 and p16. By contrast, when co-cultured with MSCs in the presence of DOXO, the proliferation and viability of H9c2 cells increased. Additionally, the expression of p53 and p16 decreased, and increased length of telomere and telomerase activity was also observed. Additionally, the mechanism underlying the anti-senescence function of MSCs was revealed to involve the miR-34a-SIRT1 axis, confirmed by overexpressing miR-34a using a miR-34a mimic or silencing SIRT1 using small interfering RNA, which abolished the anti-senescence effect of MSCs on DOXO-treated H9c2 cells. Taken together, the results of the present study suggest that MSCs may rejuvenate H9c2 cells from a state of DOXO-induced senescence by increasing SIRT1 expression, there by inhibiting miR-34a. Therefore, treatment with MSCs may have important therapeutic implications in the restoration of cardiotoxicity in patients with cancer undergoing treatment with DOXO.

Use of integrated imaging and serum biomarker profiles to identify subclinical dysfunction in pediatric cancer patients treated with anthracyclines

BACKGROUND

Anthracycline induced cardiomyopathy is a major cause of mortality and morbidity among pediatric cancer survivors. It has been postulated that oxidative stress induction and inflammation may play a role in the pathogenesis of this process. Accordingly, the present study performed an assessment of biomarker profiles and functional imaging parameters focused upon potential early determinants of anthracycline induced cardiomyopathy.

METHODS

Patients (10-22 years) were prospectively enrolled between January 2013 and November 2014. Thirteen subjects completed the study and underwent serial cardiac magnetic resonance imaging and plasma biomarker profiling performed 24-48 h after the first anthracycline dose and at set dose intervals. In addition, we collected plasma samples from 62 healthy controls to examine normal plasma biomarker profiles.

RESULTS

Left ventricular ejection fraction (LVEF) decreased from 64.3 ± 6.2 at the first visit to 57.5 ± 3.3 (p = 0.004) 1 year after chemotherapy. A decline in longitudinal strain magnitude occurred at lower cumulative doses. A differential inflammatory/matrix signature emerged in anthracycline induced cardiomyopathy patients compared to normal including increased interleukin-8 and MMP levels. With longer periods of anthracycline dosing, MMP-7, a marker of macrophage proteolytic activation, increased by 165 ± 54% whereas interleukin-10 an anti-inflammatory marker decreased by 75 ± 13% (both p < 0.05). MMP7 correlated with time dependent changes in EF.

CONCLUSIONS

Asymptomatic pediatric patients exposed to anthracycline therapy develop abnormal strain parameters at lower cumulative doses when compared to changes in EF. A differential biomarker signature containing both inflammatory and matrix domains occur early in anthracycline treatment. Dynamic changes in these domains occur with increased anthracycline doses and progression to anthracycline induced cardiomyopathy. These findings provide potential prognostic and mechanistic insights into the natural history of anthracycline induced cardiomyopathy.

TRIAL REGISTRATION NUMBER

NCT03211520 Date of Registration February 13, 2017, retrospectively registered.

Ethanol-induced cardiomyocyte toxicity implicit autophagy and NFkB transcription factor

Chronic ethanol (EtOH) consumption causes early detrimental consequences in many tissues including the myocardium, though the molecular mechanisms leading to the alcoholic cardiomyopathy (ACM) still remain to be elucidated. Here, we studied several biomolecular changes occurring in cardiomyoblasts after their exposure to sublethal concentrations of EtOH and the potential synergistic effect with methylmercury (MM) or doxorubicin (DOXO), which are known to produce direct myocardial dysfunction. In addition, the possible role of autophagic responses and Nuclear Factor kappa-B (NFkB) modulation in early post-alcoholic myocardial damage has been investigated. H9c2 rat cardiomyoblasts were incubated for fifteen days with a sub-lethal concentrations of EtOH (1-1000 μM). In particular, treatment of H9c2 cells with EtOH produced an increase of reactive oxygen species (ROS) and the activation of autophagy. Furthermore, chronic exposure to EtOH, was accompanied by a translocation of NFkB into the nucleus dose-dependently. Finally, co-incubation of EtOH (1-1000 μM) with sublethal concentrations of MM or DOXO showed a prominent apoptotic death of cardiomyoblasts accompanied by ROS overproduction, autophagy activation and by an increased nuclear translocation of NFkB as compared to untreated cells. Thus, EtOH produces early changes in cardiomyoblasts characterized by oxidative stress, reactive autophagy and NFkB modulation at concentrations unable to produce direct cell death. Combination of EtOH with cardiotoxic pollutants or drugs makes the cardiomyocyte vulnerable to exogenous insults leading to apoptosis. These data contribute to better identify molecular mechanisms underlying early stages of alcoholic cardiomyopathy and suggest novel strategies to counteract integrated risk of cardiotoxicity in chronic alcohol consumption.

Cardiotoxicity of anthracycline (ANT) treatment in children with malignant tumors

OBJECTIVE

To investigate the cardiotoxicity indexes in children with malignant tumors after the administration of anthracycline (ANT) chemotherapy.

MATERIALS AND METHODS

Data from 131 children with malignant tumors who were treated using ANT chemotherapy at our hospital from January 2011 to December 2015 were collected to analyze the serologic indexes (such as N-terminal pro-brain natriuretic peptide [NT-proBNP] and isoenzyme of creatine kinase [CK-MB]) and changes in corrected QT interval(QT-c) and left ventricular ejection fraction (LVEF) before and after treatment with different ANT cumulative doses.

RESULTS

General clinical data revealed that 2 of the 131 children developed clinical cardiotoxicity. The ANT cumulative dose range was 12-697 mg/m². All patients were divided into three groups according to the ANT cumulative dose: group 1 (<100 mg/m²), 2 (≥100 and <200 mg/m²), and 3 (≥200 mg/m²). Although NT-proBNP and LVEF among the three groups differed significantly after chemotherapy (p = 0.022 and 0.035, respectively), no significance was noted for CK-MB and QT-c among the three groups after chemotherapy (p = 0.190 and p = 0.084, respectively). Multiple linear regression analysis revealed that the ANT cumulative dose had the most significant impact on NT-proBNP (standardized coefficient 0.423, p = 0). Pearson correlation analysis revealed that ANT cumulative dose was positively correlated with NT-proBNP post-treatment (correlation coefficient 0.423), but LVEF was negatively correlated with NT-proBNP after chemotherapy (correlation coefficient -0.542).

CONCLUSIONS

NT-proBNP showed significant changes when the ANT dose was >200 mg/m². Post-treatment serum NT-proBNP was linearly correlated with ANT cumulative dose, hence strictly controlling the ANT cumulative dose and monitoring serum NT-proBNP may have certain clinical significance in predicting cardiotoxicity.

Macrophage migration inhibitory factor rescues mesenchymal stem cells from doxorubicin-induced senescence though the PI3K-Akt signaling pathway

Doxorubicin (DOXO), an anthracycline antibiotic, is a commonly used anticancer drug. Despite its widespread usage, the therapeutic effects of DOXO are limited by its cardiotoxicity. Mesenchymal stem cell (MSC)-based therapies have had positive outcomes in the treatment of DOXO-induced cardiac damage; however, DOXO exerts toxic effects on MSCs, decreasing the effectiveness of MSC therapy. Macrophage migration inhibitory factor (MIF) promotes MSC survival and rejuvenation, and thus is a promising candidate to protect MSCs against DOXO-induced injury. The present study revealed that DOXO induced the senescence of MSCs, resulting in decreased proliferation, viability and paracrine effects. However, pretreatment with MIF improved the proliferation rate, viability, paracrine function, telomere length and telomerase activity of MSCs. Furthermore, the results indicated that the molecular mechanism underlying the anti-senescent function of MIF involved the phosphatidylinositol 3-kinase (PI3K)-RAC-α serine/threonine-protein kinase (Akt) signaling pathway, which MIF activated. In agreement with this finding, silencing Akt was identified to abolish the anti-senescent effect of MIF. In addition, MIF decreased oxidative stress in MSCs, as revealed by the decreased production of reactive oxygen species and malondialdehyde, and the increased activity of superoxide dismutase. These results indicate that MIF can rescue MSCs from a state of DOXO-induced senescence by inhibiting oxidative stress and activating the PI3K-Akt signaling pathway. Thus, treatment with MIF may have an important therapeutic application for the rejuvenation of MSCs in patients with cancer being treated with DOXO.

Factors enhancing the migration and the homing of mesenchymal stem cells in experimentally induced cardiotoxicity in rats

Doxorubicin is an effective anti-neoplastic drug but its use is limited by its cardiotoxicity. Administration of mesenchymal stem cells (MSCs) for the management of cardiotoxicity was with poor myocardial homing capacity. With the aim of developing novel techniques to improve the migration of MSCs, we tested whether valproate and electric fields (EFs) direct the migration of MSCs towards the damaged myocardium. The study included five groups of female albino rats. The first group included 10 healthy rats as normal control group. The remaining 40 female rats received doxorubicin for induction of acute cardiotoxicity. Four rats were sacrificed for histopathological confirmation of cardiotoxicity. The remaining rats were equally divided into subsequent four groups. The second group included nine rats that did not receive further treatment (positive control group). The third group included nine rats which received intravenous bone marrow derived mesenchymal stem cells (BM-MSCs) after cardiotoxicity induction. The fourth group included nine rats which received BM-MSCs plus sodium valporate after cardiotoxicity induction. The fifth group included nine rats which received BM-MSCs plus sodium valporate after cardiotoxicity induction and were exposed to an electrical stimulation (ES). Blood samples were taken from all groups at the end of the study to estimate creatine kinase-MB (CK-MB), aspartate transaminase (AST) and lactate dehydrogenase (LDH). Heart tissues from all rats were used for RNA extraction for assessment of sry gene expression. Homing was tested by PKH26 fluorescence in myocardial tissue sections and by sry gene expression. The best biochemical and histopathological improvement in cardiotoxicity was demonstrated in group 5 (rats that received ES and valporate with MSCs). We concluded that EFs and sodium valproate enhance homing ability of MSCs towards the damaged myocardium in doxorubicin induced carditoxicity model. © 2017 IUBMB Life, 69(3):162-169, 2017.

Pharmacokinetic and pharmacodynamic study of doxorubicin in children with cancer: results of a "European Pediatric Oncology Off-patents Medicines Consortium" trial

Purpose

Doxorubicin is a key component in many pediatric oncology treatment regimens; still pharmacology data on which current dosing regimens are based are very limited.

Methods

We conducted a multinational pharmacokinetic study investigating age dependency of doxorubicin metabolism and elimination in children with cancer. One hundred and one patients treated with doxorubicin according to a cancer-specific national or European therapeutic trial were recruited. Doses of doxorubicin ranged from 10.4 to 57.7 mg/m². Blood samples for measurement of doxorubicin and its metabolite doxorubicinol were collected after two administrations, with five samples collected in children <3 years and eight in children ≥3 years. A population pharmacokinetic approach was used for analysis, including pharmacogenetic covariates. Natriuretic peptides and cardiac troponins were measured to evaluate their role as early indicators of cardiotoxicity.

Results

Age dependence of doxorubicin clearance was demonstrated, with children less than 3 years having a statistically significant lower clearance (21.1 ± 5.8 l/h/m²) than older children (26.6 ± 6.7 l/h/m²) (p = 0.0004) after correcting for body surface area. No effect of the investigated genetic polymorphisms on the pharmacokinetics could be observed. Although natriuretic peptides were transiently elevated after each doxorubicin administration and troponin levels increased with increasing doxorubicin exposure, only limited correlation could be observed between their blood levels and doxorubicin pharmacokinetics.

Conclusion

In the European framework of funding and regulatory support, an add-on study to existing therapeutic trials was developed. The pediatric need concerning missing PK data could be addressed with limited burden for the patients. Empirically used dose adaptations for infants were generally found to be justified based on our PK analyses.

Electronic supplementary material

The online version of this article (doi:10.1007/s00280-016-3174-8) contains supplementary material, which is available to authorized users.

Sex-related differential susceptibility to doxorubicin-induced cardiotoxicity in B6C3F1 mice

Sex is a risk factor for development of cardiotoxicity, induced by the anti-cancer drug, doxorubicin (DOX), in humans. To explore potential mechanisms underlying differential susceptibility to DOX between sexes, 8-week old male and female B6C3F₁ mice were dosed with 3mg/kg body weight DOX or an equivalent volume of saline via tail vein once a week for 6, 7, 8, and 9 consecutive weeks, resulting in 18, 21, 24, and 27mg/kg cumulative DOX doses, respectively. At necropsy, one week after each consecutive final dose, the extent of myocardial injury was greater in male mice compared to females as indicated by higher plasma concentrations of cardiac troponin T at all cumulative DOX doses with statistically significant differences between sexes at the 21 and 24mg/kg cumulative doses. A greater susceptibility to DOX in male mice was further confirmed by the presence of cytoplasmic vacuolization in cardiomyocytes, with left atrium being more vulnerable to DOX cardiotoxicity. The number of TUNEL-positive cardiomyocytes was mostly higher in DOX-treated male mice compared to female counterparts, showing a statistically significant sex-related difference only in left atrium at 21mg/kg cumulative dose. DOX-treated male mice also had an increased number of γ-H2A.X-positive (measure of DNA double-strand breaks) cardiomyocytes compared to female counterparts with a significant sex effect in the ventricle at 27mg/kg cumulative dose and right atrium at 21 and 27mg/kg cumulative doses. This newly established mouse model provides a means to identify biomarkers and access potential mechanisms underlying sex-related differences in DOX-induced cardiotoxicity.

Late Cardiotoxicity: Issues for Childhood Cancer Survivors

OPINION STATEMENT

Cardiovascular-related morbidity is a substantial health burden in survivors of childhood cancers. This burden is gaining importance as this population increases through advancements in therapy. Anthracyclines are commonly used agents that are known to cause late cardiotoxicity. Cardiotoxicity is also increased by other risk factors, such as concurrent radio- or chemotherapy, younger age at diagnosis, female sex, comorbidities, lifestyle factors, and genetic factors, such as hemochromatosis gene mutations. Treatment of late cardiotoxicity depends on the type of cardiac abnormalities and consists of pharmacotherapy, mechanical support, or heart transplantation. Because cardiotoxicity is progressive and often irreversible, prevention, risk reduction, and early detection are of utmost importance. The cardioprotectant dexrazoxane decreases anthracycline cardiotoxicity. Screening for other risk factors at the time of diagnosis may identify risk that when present, if used to tailor therapy, may reduce the severity of cardiac damage. The effects of exercise and other lifestyle changes in reducing the cardiovascular diseases in cancer survivors are unclear. However, it may be beneficial to encourage survivors to engage in physical activity tailored to survivor medical status, but with close monitoring.

Growth-differentiation Factor-15 and Tissue Doppler Imaging in Detection of Anthracycline-induced Cardiomyopathy During Therapy of Childhood Cancers

OBJECTIVES

The aim of this study was to evaluate the importance of growth-differentiation factor-15 (GDF-15) levels and tissue Doppler imaging (TDI) in the early detection of anthracycline-induced cardiomyopathy during the treatment of childhood cancers.

PATIENTS AND METHODS

Twenty patients (13 males and 7 females) newly diagnosed with childhood cancer whose treatment protocol included anthracycline were included in the study. Echocardiography, including M-mode, pulse Doppler, and TDI, was performed after the first anthracycline treatment at cumulative doses of 100, 200, and 300 mg/m and at least 6 months after the last treatment. GDF-15 and troponin-I were also measured at these time points.

RESULTS

The median age of the patients was 14 years (range, 3 to 18 y). The median cumulative anthracycline dose was 220 mg/m (range, 60 to 400 mg/m). Conventional pulse wave and pulse wave tissue Doppler methods revealed significant differences in the right ventricular myocardial performance indices of the patients who received cumulative anthracycline doses of 300 mg/m compared with their indices at least 6 months after the last treatment. The serum GDF-15 levels after the cumulative anthracycline dose of 200 mg/m were also higher than the patients' pretreatment levels.

CONCLUSIONS

Doppler/TDI and GDF-15 levels may be used in the early determination of anthracycline-induced cardiomyopathy during the treatment of childhood cancers.

Two-Dimensional Speckle Tracking Echocardiography Detects Subclinical Left Ventricular Systolic Dysfunction among Adult Survivors of Childhood, Adolescent, and Young Adult Cancer

Two-dimensional speckle tracking echocardiography (2DSTE) provides a sensitive measure of left ventricular (LV) systolic function and may aid in the diagnosis of cardiotoxicity. 2DSTE was performed in a cross-sectional study of 134 patients (mean age: 31.4 ± 8.8 years; 55% male; mean time since diagnosis: 15.4 ± 9.4 years) previously treated with anthracyclines (mean cumulative dose: 320 ± 124 mg/m(2)), with (n = 52) or without (n = 82) mediastinal radiotherapy. The prevalence of LV systolic dysfunction, defined as fractional shortening < 27%, LV ejection fraction (LVEF) < 55%, and global longitudinal strain (GLS) ≤ 16%, was 5.2%, 6.0%, and 23.1%, respectively. Abnormal GLS was observed in 24 (18%) patients despite a normal LVEF. Indices of LV systolic function were similar regardless of anthracycline dose. However, GLS was worse (18.0 versus 19.0, p = 0.003) and prevalence of abnormal GLS was higher (36.5% versus 14.6%, p = 0.004) in patients treated with mediastinal radiotherapy. Mediastinal radiotherapy was associated with reduced GLS (p = 0.040) after adjusting for sex, age, and cumulative anthracycline dose. In adult survivors of childhood, adolescent, and young adult cancer, 2DSTE frequently detects LV systolic dysfunction despite a normal LVEF and may be useful for the long-term cardiac surveillance of adult cancer survivors.

Cardiac Diseases Following Childhood Cancer Treatment

Background—

Cardiac disease (CD) is one of the major side effects of childhood cancer therapy, but until now little has been known about the relationship between the heart radiation dose (HRD) received during childhood and the risk of CD.

Methods and Results—

The cohort comprised 3162 5-year survivors of childhood cancer. Chemotherapy information was collected and HRD was estimated. There were 347 CDs in 234 patients, 156 of them were rated grade ≥3. Cox and Poisson regression models were used. The cumulative incidence of any type of CD at 40 years of age was 11.0% (95% confidence interval [CI], 9.5–12.7) and 7·4% (95% CI, 6.2–8.9) when only the CDs of grade ≥3 were considered. In comparison with patients who received no anthracycline and either no radiotherapy or an HRD<0·1Gy, the risk was multiplied by 18·4 (95% CI, 7.1–48.0) in patients who had received anthracycline and no radiotherapy or a HRD <0.1Gy, by 60.4 (95% CI, 22.4–163.0) in those who had received no anthracycline and an HRD≥30Gy, and 61.5 (95% CI, 19.6–192.8) in those who had received both anthracycline and an HRD≥30Gy.

Conclusions—

Survivors of childhood cancers treated with radiotherapy and anthracycline run a high dose-dependent risk of developing CD. CDs develop earlier in patients treated with anthracycline than in those treated without it.

Anti-Tumor Effects of Bak-Proteoliposomes against Glioblastoma

Despite palliative treatments, glioblastoma (GBM) remains a devastating malignancy with a mean survival of about 15 months after diagnosis. Programmed cell-death is de-regulated in almost all GBM and the re-activation of the mitochondrial apoptotic pathway through exogenous bioactive proteins may represent a powerful therapeutic tool to treat multidrug resistant GBM. We have reported that human Bak protein integrated in Liposomes (LB) was able, in vitro, to activate the mitochondrial apoptotic pathway in colon cancer cells. To evaluate the anti-tumor effects of LB on GBM, MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assays and Western blot analysis were performed on GL26 murine cell line. LB treatment shows a dose-dependent inhibition of cell viability, followed by an up-regulation of Bax and a down-modulation of JNK1 proteins. In GL26-bearing mice, two different routes of administration were tested: intra-tumor and intravenous. Biodistribution, tumor growth and animal survival rates were followed. LB show long-lasting tumor accumulation. Moreover, the intra-tumor administration of LB induces tumor growth delay and total tumor regression in about 40% of treated mice, while the intravenous injection leads to a significant increased life span of mice paralleled by an increased tumor cells apoptosis. Our findings are functional to the design of LB with potentiated therapeutic efficacy for GBM.

Mesenchymal stem cell therapy for doxorubicin cardiomyopathy: hopes and fears

Chemotherapy has made an essential contribution to cancer treatment in recent decades despite its adverse effects. As cancer survivors have increased, concern about ex-patient lifespan has become more important too. Doxorubicin is an effective anti-neoplastic drug that produces a cardiotoxic effect. Cancer survivors who received doxorubicin became more vulnerable to cardiac disease than the normal population did. Many efforts have been made to prevent cardiac toxicity in patients with cancer. However, current therapies cannot guarantee permanent cardiac protection. One of their main limitations is that they do not promote myocardium regeneration. In this review, we summarize and discuss the promising use of mesenchymal stem cells for cardio-protection or cardio-regeneration therapies and consider their regenerative potential without leaving aside their controversial effects on tumor progression.

Current Views on Anthracycline Cardiotoxicity in Childhood Cancer Survivors

Owing to their high efficacy, anthracycline antibiotics are included in numerous chemotherapeutic regimens used-often in combination with radiation therapy and/or surgery-in treatment of solid tumours and blood malignancies, both in children and adults. However, the efficacy of modern cancer treatments, owing to which the population of cancer survivors has been on the rise in recent years, may be limited by the risk of serious complications involving multiple organs and systems, including the cardiovascular system. Being an important side effect of anthracyclines, cardiotoxicity may limit the efficacy of cancer therapies in the acute phase (i.e. during the treatment) and induce the long-term sequelae, observed years after treatment completion in childhood cancer survivors. It is very important to understand the cardiotoxicity-associated mechanisms and to determine its risk factors in order to develop and/or improve the effective countermeasures. Based on published data, the paper provides an outline of current views on anthracycline cardiotoxicity and discusses such aspects as molecular mechanisms of cardiotoxicity and its clinical manifestations as well as the new preventive strategies and diagnostic techniques used for the assessment of cardiovascular abnormalities. The widespread awareness of cancer treatment-related cardiotoxicity among the healthcare professionals may significantly improve the quality of life of the childhood cancer survivors.

The tell-tale heart: molecular and cellular responses to childhood anthracycline exposure

Since the modern era of cancer chemotherapy that began in the mid-1940s, survival rates for children afflicted with cancer have steadily improved from 10% to current rates that approach 80% (60). Unfortunately, many long-term survivors of pediatric cancer develop chemotherapy-related health effects; 25% are afflicted with a severe or life-threatening medical condition, with cardiovascular disease being a primary risk (96). Childhood cancer survivors have markedly elevated incidences of stroke, congestive heart failure (CHF), coronary artery disease, and valvular disease (96). Their cardiac mortality is 8.2 times higher than expected (93). Anthracyclines are a key component of most curative chemotherapeutic regimens used in pediatric cancer, and approximately half of all childhood cancer patients are exposed to them (78). Numerous epidemiologic and observational studies have linked childhood anthracycline exposure to an increased risk of developing cardiomyopathy and CHF, often decades after treatment. The acute toxic effects of anthracyclines on cardiomyocytes are well described; however, myocardial tissue is comprised of additional resident cell types, and events occurring in the cardiomyocyte do not fully explain the pathological processes leading to late cardiomyopathy and CHF. This review will summarize the current literature regarding the cellular and molecular responses to anthracyclines, with an important emphasis on nonmyocyte cardiac cell types as well as those that mediate the myocardial injury response.

Cardiotoxicity and cardioprotection in childhood cancer

Children diagnosed with cancer are now living longer as a result of advances in treatment. However, some commonly used anticancer drugs, although effective in curing cancer, can also cause adverse late effects. The cardiotoxic effects of anthracycline chemotherapy, such as doxorubicin, and radiation can cause persistent and progressive cardiovascular damage, emphasizing a need for effective prevention and treatment to reduce or avoid cardiotoxicity. Examples of risk factors for cardiotoxicity in children include higher anthracycline cumulative dose, higher dose of radiation, younger age at diagnosis, female sex, trisomy 21 and black race. However, not all who are exposed to toxic treatments experience cardiotoxicity, suggesting the possibility of a genetic predisposition. Cardioprotective strategies under investigation include the use of dexrazoxane, which provides short- and long-term cardioprotection in children treated with doxorubicin without interfering with oncological efficacy, the use of less toxic anthracycline derivatives and nutritional supplements. Evidence-based monitoring and screening are needed to identify early signs of cardiotoxicity that have been validated as surrogates of subsequent clinically significant cardiovascular disease before the occurrence of cardiac damage, in patients who may be at higher risk.

Evaluation of traditional and novel measures of cardiac function to detect anthracycline-induced cardiotoxicity in survivors of childhood cancer

PURPOSE

Cardiovascular disease is the leading noncancer cause of death among survivors of childhood cancer. Ejection fraction (EF) and fractional shortening (FS) are common echocardiographic measures of cardiac function, but newer imaging modalities may provide additional information about preclinical disease. This study aimed to evaluate these modalities in detection of anthracycline-induced cardiac toxicity.

METHODS

We compared mean radial displacement, EF, and FS among 17 adult survivors of childhood cancer exposed to ≥ 300 mg/m(2) of anthracyclines to 17 age- and sex-matched healthy controls. Survivors with a history of cardiac-directed radiation, diabetes, or heart disease were excluded.

RESULTS

Survivors (35% male), mostly with history of treatment for a solid tumor, had a median age at diagnosis of 15 years (1-20) and 27 years (18-50) at evaluation. Median anthracycline exposure was 440 (range 300-645) mg/m(2). FS (35.5 vs. 39.6%, p < 0.01) and radial displacement (5.6 vs. 6.7 mm, p = 0.02) were significantly lower in survivors compared to controls, respectively. Although the mean EF was lower in survivors versus controls (55.4 vs. 59.7%), it was not statistically significant (p = 0.057). All echocardiographic measures were inversely associated with anthracycline dose, though radial displacement was no longer significantly correlated with anthracycline dose after controlling for survival time (p = 0.07), while EF remained correlated (p = 0.003).

IMPLICATIONS FOR CANCER SURVIVORS

Radial displacement, EF, and FS are lower in childhood cancer survivors compared to controls. In this study, radial displacement added no new information beyond the traditional measures, but clinical utility remains undetermined and requires further longitudinal study.

Topoisomerase 2β: a promising molecular target for primary prevention of anthracycline-induced cardiotoxicity

Anthracyclines are powerful chemotherapy agents that are still widely used today. However, their clinical use is limited by the development of dose-dependent cardiotoxicity. Recently, we showed that topoisomerase 2β (Top2β) is required for anthracycline to induce DNA double-strand breaks and changes in the transcriptome, leading to mitochondrial dysfunction and generation of reactive oxygen species. Furthermore, deleting Top2β from cardiomyocytes prevented the development of anthracycline-induced cardiotoxicity in mice. On the basis of this molecular insight, new strategies should be developed to prevent anthracycline-induced cardiotoxicity. First, Top2α-specific anthracyclines should be tested to determine whether they will spare the heart. Second, Top2β should be studied as a potential biomarker to predict risk of developing cardiotoxicity before anthracycline treatment. Third, inhibiting and deleting Top2β in the heart should also be tested as primary prevention strategies. We propose that Top2β is a promising molecular target that can be used to design interventions to prevent anthracycline-induced cardiotoxicity.

Imaging of early modification in cardiomyopathy: the doxorubicin-induced model

Doxorubicin chemotherapy is effective and widely used to treat acute lymphoblastic leukemia. However, its effectiveness is hampered by a wide spectrum of dose-dependent cardiotoxicity including both morphological and functional changes, affecting primarily the myocardium. Non-invasive imaging techniques are used for the diagnosis and monitoring of these cardiotoxic effects. The purpose of this review is to summarize and compare the most common imaging techniques used in early detection and therapeutic monitoring of doxorubicin-induced cardiotoxicity and the suggested mechanisms of such side effects. Imaging techniques using echocardiography including conventional 2D and 3D echocardiography along with MRI sequences including Tagging, Cine, and quantitative MRI in detecting early myocardial damage are also reviewed. As there is a multitude of reported indices and imaging methods to assess particular functional alterations, we limit this review to the most relevant techniques based on their clinical application and their potential to early detection of doxorubicin-induced cardiotoxic effects.

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.

Cardioprotective effect of early dexrazoxane use in anthracycline treated pediatric patients

Anthracyclines play a major role in chemotherapeutic regimens for a variety of pediatric cancers, but produce undesirable dose-related cardiotoxicity. Dexrazoxane reduces early myocardial injury during anthracycline treatment, but data remain insufficient to fully understand its cardioprotective effectiveness in treating pediatric cancers and additional research is necessary to find efficient methods of dexrazoxane administration. Therefore, we retrospectively evaluated the cardioprotective effect of dexrazoxane against anthracyclines in 258 pediatric cancer patients who had received any anthracyclines from January 1997 to May 2005 at a tertiary teaching hospital in Korea. The results of this study suggest that the early use of dexrazoxane protects against the development of cardiotoxicity during anthracycline treatment in pediatric cancer patients. Further studies involving larger pediatric cancer patients are needed to evaluate the cardioprotective effect of dexrazoxane at higher cumulative doses of anthracyclines and on late-onset cardiotoxicity in long-term survivors.

New policies to address the global burden of childhood cancers

Childhood cancer is a major global health issue. Every year, almost 100 000 children die from cancer before the age of 15 years, more than 90% of them in resource-limited countries. Here, we review the key policy issues for the delivery of better care, research, and education of professionals and patients. We present a key list of time-limited proposals focusing on change to health systems and research and development. These include sector and system reforms to make care affordable to all, policies to promote growth of civil society around both cancer and Millennium Development Goals, major improvements to public health services (particularly the introduction of national cancer plans), improved career development, and increased remuneration of specialist health-care workers and government support for childhood cancer registries. Research and development proposals focus on sustainable funding, the establishment of more research networks, and clinical research specifically targeted at the needs of low-income and middle-income countries. Finally, we present proposals to address the need for clinical trial innovation, the complex dichotomy of regulations, and the threats to the availability of data for childhood cancers.

Cardiotoxicity in childhood cancer survivors: strategies for prevention and management

Advances in cancer treatment have greatly improved survival rates of children with cancer. However, these same chemotherapeutic or radiologic treatments may result in long-term health consequences. Anthracyclines, chemotherapeutic drugs commonly used to treat children with cancer, are known to be cardiotoxic, but the mechanism by which they induce cardiac damage is still not fully understood. A higher cumulative anthracycline dose and a younger age of diagnosis are only a few of the many risk factors that identify the children at increased risk of developing cardiotoxicity. While cardiotoxicity can develop at anytime, starting from treatment initiation and well into adulthood, identifying the best cardioprotective measures to minimize the long-term damage caused by anthracyclines in children is imperative. Dexrazoxane is the only known agent to date, that is associated with less cardiac dysfunction, without reducing the oncologic efficacy of the anthracycline doxorubicin in children. Given the serious long-term health consequences of cancer treatments on survivors of childhood cancers, it is essential to investigate new approaches to improving the safety of cancer treatments.