Anthracycline-induced cardiotoxicity in children with cancer: strategies for prevention and management

In vitro evaluation of the reductive carbonyl idarubicin metabolism to evaluate inhibitors of the formation of cardiotoxic idarubicinol via carbonyl and aldo-keto reductases

The most important dose-limiting factor of the anthracycline idarubicin is the high risk of cardiotoxicity, in which the secondary alcohol metabolite idarubicinol plays an important role. It is not yet clear which enzymes are most important for the formation of idarubicinol and which inhibitors might be suitable to suppress this metabolic step and thus would be promising concomitant drugs to reduce idarubicin-associated cardiotoxicity. We, therefore, established and validated a mass spectrometry method for intracellular quantification of idarubicin and idarubicinol and investigated idarubicinol formation in different cell lines and its inhibition by known inhibitors of the aldo-keto reductases AKR1A1, AKR1B1, and AKR1C3 and the carbonyl reductases CBR1/3. The enzyme expression pattern differed among the cell lines with dominant expression of CBR1/3 in HEK293 and MCF-7 and very high expression of AKR1C3 in HepG2 cells. In HEK293 and MCF-7 cells, menadione was the most potent inhibitor (IC50 = 1.6 and 9.8 µM), while in HepG2 cells, ranirestat was most potent (IC50 = 0.4 µM), suggesting that ranirestat is not a selective AKR1B1 inhibitor, but also an AKR1C3 inhibitor. Over-expression of AKR1C3 verified the importance of AKR1C3 for idarubicinol formation and showed that ranirestat is also a potent inhibitor of this enzyme. Taken together, our study underlines the importance of AKR1C3 and CBR1 for the reduction of idarubicin and identifies potent inhibitors of metabolic formation of the cardiotoxic idarubicinol, which should now be tested in vivo to evaluate whether such combinations can increase the cardiac safety of idarubicin therapies while preserving its efficacy.

Beta vulgaris-derived exosome-like nanovesicles alleviate chronic doxorubicin-induced cardiotoxicity by inhibiting ferroptosis

Dose-dependent heart failure is a major complication of the clinical use of doxorubicin (Dox), one of the most potent chemotherapeutic agents. Effective adjuvant therapy is required to prevent Dox-induced cardiotoxicity. Currently, plant-derived exosome-like nanovesicle (PELNV) has revealed their salubrious antioxidant and immunological regulating actions in various disease models. In this study, we isolated, purified and characterized Beta vulgaris-derived exosome-like nanovesicle (BELNV). Dox or normal saline was given to HL-1 cells (3 μM) and 8-week C57BL/6N mice (5 mg/kg bodyweight per week for 4 weeks) to establish the in vitro and in vivo model of Dox-induced cardiotoxicity. Administration of BELNV significantly alleviated chronic Dox-induced cardiotoxicity in terms of echocardiographic and histological results. A reduced malondialdehyde (MDA), increased ratio of glutathione (GSH) to oxidized glutathione (GSSG) and levels of system xc- and glutathione peroxidase 4 were observed, indicating that DOX-stimulated ferroptosis was reversed by BELNV. Besides, the safety of BELNV was also validated since no liver, spleen, and kidney toxicity induced by BELNV was observed. These findings provide evidence that BELNV may act as a novel therapeutic biomaterial for patients undergoing adverse effects of Dox, at least partly mediated by inhibiting Dox-induced ferroptosis.

Characteristics and research status among clinical trials in cardio-oncology by bibliometric and visualized analysis

BACKGROUND

We aim to establish the characteristics of published cardio-oncology research of clinical trials by bibliometric analysis and to talk about the prospects and difficulties facing the development of cardio-oncology.

METHODS

Search of data related to clinical trials in cardiac oncology from 1990 to 2022 from the Web of Science core collection. Using CiteSpace to perform co-citation analysis of authors, countries (regions) and institutions, journals and cited journals, cited authors and cited literature, and keywords.

RESULTS

Of the 607 clinical trial studies, the number of papers published per year has increased over time. The regions with the greatest influence were North America (especially the United States) and Europe. Multicenter research has always been the focus of cardio-oncology research, but cross-regional cooperation was still lacking. Myocardial toxicity caused by anthracyclines has received the earliest attention and has been studied for the longest time. Meanwhile, the efficacy and cardiotoxicity of new anticancer drugs always came into focus, but at a slow pace. Few studies on myocardial toxicity were related to the treatment of tumors except breast cancer. Risk factors, heart disease, adverse outcomes, follow-up, and intervention protection were the major hotspots revealed by co-citation cluster.

CONCLUSIONS

There is great potential for the development of clinical trials in cardio-oncology, especially in multicenter cooperation across different regions. Expansion of tumor types, myocardial toxicity of different drugs, and effective interventions in the research direction and design of clinical trials are necessary.

Disruption of histamine/H1R-STAT3-SLC7A11 axis exacerbates doxorubicin-induced cardiac ferroptosis

Doxorubicin (DOX) is widely used in the treatment of various cancers, increasing the great risk of adverse cardiovascular events, while the clinical intervention effect is not ideal. Histamine has been documented to participate in pathophysiological processes of cardiovascular diseases and inflammation-associated carcinogenesis. However, the potential roles of histamine in antitumor-related cardiotoxicity have not been fully elucidated. In this study, cardiomyocytes (hiPSC-CMs, HL-1 cells) and mice were treated with DOX to establish DOX-induced cardiotoxicity (DIC) models. Histidine decarboxylase knockout mice (HDC^-/-) mice and histamine 1 receptor (H₁R) antagonist were used to explore the effect of histamine/H₁R signaling on DIC. Our results demonstrated that histamine deficiency or pharmaceutical inhibition of H₁R accelerated myocardial ferroptosis, which is responsible for the aggravated DIC both in vivo and in vitro, while the supplementation of exogenous histamine reversed these changes. Our data revealed that the dysfunction of histamine/H₁R signaling repressed the activation of transducer and activator of transcription 3 (STAT3), accompanying with decreased expression of solute carrier family7member11 (SLC7A11), a major modulator of ferroptosis. Conclusively, the disruption of histamine/H₁R axis triggered ferroptosis and exacerbated DIC possibly by modulating STAT3-SLC7A11 pathway. Our findings point to a potential therapeutic target for DIC and provide more consideration on the usage of antihistamine drugs.

Detection of doxorubicin-induced cardiotoxicity using myocardial T1 and T2 relaxation times in childhood acute lymphoblastic leukemia survivors

Doxorubicin leads to dose-dependent cardiotoxicity in childhood acute lymphoblastic leukemia (ALL) survivors. The first aim was to propose a contour-based estimation of T1 and T2 relaxation times based on the myocardial area, while our second aim was to evaluate native T1, post-gadolinium T1 and T2 relaxation time sensitivity to detect myocardial changes. A total of 84 childhood ALL survivors were stratified in regard to their prognostic risk groups: standard risk (SR), n = 20), high-risk with and without dexrazoxane (HR + DEX, n = 39 and HR, n = 25). Survivors' mean age was of 22.0 ± 6.9 years, with a mean age at cancer diagnosis of 8.0 ± 5.2 years. CMR acquisitions were performed on a 3 T MRI system and included an ECG-gated 3(3)3(3)5 MOLLI sequence for T1 mapping and an ECG-gated T2-prepared TrueFISP sequence for T2 mapping. Myocardial contours were semi-automatically segmented using an interactive implementation of cubic Bezier curves. We found excellent repeatability between operators for native T1 (ICC = 0.91), and good repeatability between operators for post-gadolinium T1 (ICC = 0.84) and T2 (ICC = 0.79). Bland and Altman tests demonstrated a strong agreement between our contour-based method and images analyzed using the CVI42 software on the measure of native T1, post-gadolinium T1, and T2. No significant differences between survivors' prognostic risk groups in native T1 were reported, while we observed significant differences between survivors' prognostic risk groups in post-gadolinium T1 and T2. Significant differences were observed between male and female survivors. Differences between groups were also observed in partition coefficients, but no significant differences were observed between male and female survivors. The use of CMR parameters with native T1, post-gadolinium T1, and T2 allowed to show that survivors at a high-risk prognostic were more exposed to doxorubicin-related cardiotoxicity than those who were at a standard risk prognostic or who received dexrazoxane treatments.

Empagliflozin Significantly Prevents the Doxorubicin-induced Acute Cardiotoxicity via Non-antioxidant Pathways

Empagliflozin (EMPA) is a SGLT-2 inhibitor that has positive effects on cardiovascular outcomes. In this study, we aim to evaluate the possible protective effects of EMPA against doxorubicin (DOX)-induced acute cardiotoxicity. Non-diabetic Sprague-Dawley rats were randomized into four groups. The control group received serum physiologic (1 ml), the EMPA group received EMPA, the DOX group was administered cumulatively 18 mg/kg body weight DOX. The DOX+EMPA group was administered DOX and EMPA. In the DOX group, LVDED (P < 0.05) and LVSED (P < 0.01), QTc interval (P < 0.001), the ratio of karyolysis and karyorrhexis (P < 0.001) and infiltrative cell proliferation (P < 0.001) were found to be higher than; EF, FS and normal cell morphology were lower than the control group (P < 0.001). In the DOX+EMPA group, LVEDD (P < 0.05) and LVESD (P < 0.01) values, QTc interval (P < 0.001), karyolysis and karyorrhexis ratios (P < 0.001) and infiltrative cell proliferation were lower (P < 0.01); normal cell morphology and EF were higher compared to the DOX group (P < 0.001). Our results showed that empagliflozin significantly ameliorated DOX-induced acute cardiotoxicity.

Acute and Delayed Doxorubicin-Induced Myocardiotoxicity Associated with Elevation of Cardiac Biomarkers, Depletion of Cellular Antioxidant Enzymes, and Several Histopathological and Ultrastructural Changes

Doxorubicin (DOX; Adricin) is an anthracycline antibiotic, which is an efficient anticancer chemotherapeutic agent that targets many types of adult and pediatric tumors, such as breast cancer, leukemia, and lymphomas. However, use of DOX is limited due to its cardiotoxic effects. This study sequentially investigated the mechanistic pathways of the cardiotoxic process of DOX in rats at different post-treatment periods using cumulative dose, which is used in therapeutic regimes. In this regard, 56 male albino rats were used for the experiment. The experimental animals were divided into seven groups (n = 8/group) based on dose and sacrifice schedule as follows: G1 (2 mg/kg body weight [BW] and sacrificed at day 4), G2 (4 mg/kg BW and sacrificed at day 8), G3 (6 mg/kg BW and sacrificed at day 15), G4 (8 mg/kg BW and sacrificed at day 30), G5 (10 mg/kg BW and sacrificed at day 60), G6 (10 mg/kg BW and sacrificed at day 90), and G7 (10 mg/kg BW and sacrificed at day 120). As expected, G1, G2, and G3-treated groups revealed features of acute toxic myocarditis associated with degenerative and necrotic changes in myocytes, mitochondrial damage, elevation of cardiac biomarkers, and depletion of cellular antioxidant enzymes. However, these changes increased in severity with subsequent treatment with the same dose until reaching a cumulative dose of 10 mg/kg BW for 30 d. Furthermore, after a cumulative dose of 10 mg/kg BW with a withdrawal period of 2–3 months, various predominant changes in chronicity were reported, such as disorganization and atrophy of myocytes, condensation and atrophy of mitochondria, degranulation of mast cells, and fibrosis with occasional focal necrosis, indicating incomplete elimination of DOX and/or its metabolites. Altogether, these data provide interesting observations associated with the cardiotoxic process of DOX in rats that would help understand the accompanying changes underlying the major toxic effects of the drug. Future research is suggested to explore more about the dose-dependent mechanisms of such induced toxicity of DOX that would help determine the proper doses and understand the resulting cardiomyopathy.

Importance of cardio-oncology. How to detect suclinical heart failure

Today one of the main causes of mortality is cancer. Survival in cancer patients has increased from 1970 (25%) to the present (80%). Following the introduction of anthracyclines as a cancer treatment since 1960-70, more than 60% of patients are treated with these agents, although chemotherapeutic exposure leads to cardiovascular diseases as the main cause of mortality in surviving patients. of cancer in the 21st Century. There are multiple factors that increase the sensitivity of anthracyclic-induced cardiotoxicity. In 1970 the gold standard for the detection of ventricular dysfunction was endomyocardial biopsy, subsequently the detection and management of cardiotoxicity was guided by symptoms, in 1981 the detection of cardiotoxicity was reported with the determination of the ejection fraction of the left ventricle (LVEF), by 2D echocardiography. Currently, the 3D echocardiogram for LVEF and systolic and diastolic volumes have presented a high correlation of the values obtained by magnetic resonance imaging for the evaluation of cardiac function. Today strain, strain-rate and speckle tracking echocardiography are used to determine regional and global myocardial function. For a comprehensive assessment, these results can be complemented with cardiac biomarkers (troponins) and electrocardiographic changes. In this way, subclinical heart failure can be detected and timely treatment can be given.

Erythrocytes as Carriers: From Drug Delivery to Biosensors

Drug delivery using natural biological carriers, especially erythrocytes, is a rapidly developing field. Such erythrocytes can act as carriers that prolong the drug's action due to its gradual release from the carrier; as bioreactors with encapsulated enzymes performing the necessary reactions, while remaining inaccessible to the immune system and plasma proteases; or as a tool for targeted drug delivery to target organs, primarily to cells of the reticuloendothelial system, liver and spleen. To date, erythrocytes have been studied as carriers for a wide range of drugs, such as enzymes, antibiotics, anti-inflammatory, antiviral drugs, etc., and for diagnostic purposes (e.g. magnetic resonance imaging). The review focuses only on drugs loaded inside erythrocytes, defines the main lines of research for erythrocytes with bioactive substances, as well as the advantages and limitations of their application. Particular attention is paid to in vivo studies, opening-up the potential for the clinical use of drugs encapsulated into erythrocytes.

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.

Teaching the basics of the mechanism of doxorubicin-induced cardiotoxicity: Have we been barking up the wrong tree?

Doxorubicin (DOX), or Adriamycin, an anthracycline antibiotic discovered serendipitously as a chemotherapeutic drug several decades ago, is still one of the most effective drugs for treating various adult and pediatric cancers (breast cancer, Hodgkin's disease, lymphoblastic leukemia). However, one of the major side effects of the continuous use of DOX is dose-dependent, long-term, and potentially lethal cardiovascular toxicity (congestive heart failure and cardiomyopathy) in cancer survivors many years after cessation of chemotherapy. In addition, predisposition to cardiotoxicity varied considerably among individuals. The long-held notion that DOX cardiotoxicity is caused by reactive oxygen species formed from the redox-cycling of DOX semiquinone lacks rigorous proof in a chronic animal model, and administration of reactive oxygen species detoxifying agents failed to reverse DOX-induced cardiac problems. In this review, I discuss the pros and cons of the reactive oxygen species pathway as a primary or secondary mechanism of DOX cardiotoxicity, the role of topoisomerases, and the potential use of mitochondrial-biogenesis-enhancing compounds in reversing DOX-induced cardiomyopathy. New approaches for well-designed clinical trials that repurpose FDA-approved drugs and naturally occurring polyphenolic compounds prophylactically to prevent or mitigate cardiovascular complications in both pediatric and adult cancer survivors are needed. Essentially, the focus should be on enhancing mitochondrial biogenesis to prevent or mitigate DOX-induced cardiotoxicity.

Synergistic inhibition of tumor cell proliferation by metformin and mito-metformin in the presence of iron chelators

We demonstrate that combined treatment with metformin (Met) or its mitochondria-targeted analog, mito-metformin (Mito-Met), and various iron chelators synergistically inhibits proliferation of pancreatic and triple-negative breast cancer cells. Previously, we reported that Met (at millimolar levels) and Mito-Met (at micromolar levels) inhibited pancreatic cancer cell proliferation. Inhibition of mitochondrial complex I and mitochondrial oxidative phosphorylation (OXPHOS) through stimulation of mitochondrial redox signaling was proposed as a key mechanism for decreased cancer cell proliferation. Because of its poor bioavailability, the use of Met as a "stand-alone" antitumor drug has been questioned. Iron chelators such as deferasirox (DFX) and dexrazoxane (DXR) exhibit antiproliferative effects in cancer cells. The potency of Met and Mito-Met was synergistically enhanced in the presence of iron chelators, DFX, N,N'-bis(2-hydroxyphenyl)ethylendiamine-N,N'-diacetic acid (HBED), and deferoxamine (DFO). Met, DXR (also ICRF-187), and DFO are FDA-approved drugs for treating diabetes, decreasing the incidence and severity of cardiotoxicity following chemotherapy, and mitigating iron toxicity, respectively. Thus, the synergistic antiproliferative effects of Met and Met analogs and iron chelators may have significant clinical relevance in cancer treatment. These findings may have implications in other OXPHOS-mediated cancer therapies.

Anthracycline-associated cardiotoxicity in adults: systematic review on the cardioprotective role of beta-blockers

OBJECTIVES

This study aimed at assessing the role of beta-blockers on preventing anthracycline-induced cardiotoxicity in adults.

METHODS

A systematic review was performed on electronic databases, including relevant studies that analysed beta-blockers as cardioprotective agents before the use of anthracyclines by adult oncologic patients.

RESULTS

After application of eligibility and selection criteria, eight articles were considered as high quality, complying with the proposed theme; all eight clinical trials, four of them placebo-controlled, with a total number of 655 patients included. From this sample, 281 (42.9%) used beta-blocker as intervention, and carvedilol was the most frequent (167 patients - 25.5%). Six studies were considered positive regarding the cardioprotection role played by beta-blockers, although only four demonstrated significant difference on left ventricle ejection fraction after chemotherapy on groups that used beta-blockers compared to control groups. Carvedilol and nebivolol, but not metoprolol, had positive results regarding cardioprotection. Other beta-blockers were not analysed in the selected studies.

CONCLUSIONS

Despite the potential cardioprotective effect of beta-blockers, as demonstrated in small and unicentric clinical trials, its routine use on prevention of anthracycline-associated cardiotoxicity demands greater scientific evidence.

Effect of candesartan and metoprolol on myocardial tissue composition during anthracycline treatment: the PRADA trial

Aims

Anthracycline treatment may cause myocyte loss and expansion of the myocardial extracellular volume (ECV) fraction by oedema and fibrosis. We tested the hypotheses that adjuvant treatment for early breast cancer with the anthracycline epirubicin is dose dependently associated with increased ECV fraction and total ECV, as well as reduced total myocardial cellular volume, and that these changes could be prevented by concomitant angiotensin or beta-adrenergic blockade.

Methods and results

PRevention of cArdiac Dysfunction during Adjuvant breast cancer therapy (PRADA) was a 2 × 2 factorial, placebo-controlled, double-blinded trial of candesartan and metoprolol. Sixty-nine women had valid ECV measurements. ECV fraction, total ECV, and total cellular volume were measured by cardiovascular magnetic resonance before and at the completion of anthracycline therapy. ECV fraction increased from 27.5 ± 2.7% to 28.6 ± 2.9% (P = 0.002). A cumulative doxorubicin equivalent dose of 268 mg/m2 was associated with greater increase in ECV fraction than doses <268 mg/m2 (mean change 3.4% [95% confidence interval (CI) 1.2, 5.5] vs. 0.7% [95% CI 0.0, 1.5], P = 0.006), as well as greater increase in total ECV (1.9 mL [95% CI 0.4, 3.5] vs. 0.1 mL [95% CI -0.6, 0.8], P = 0.04). In patients receiving candesartan, total cellular volume decreased (-3.5 mL [95% CI - 4.7, -2.2], P < 0.001) while in patients not receiving candesartan, it remained unchanged (P = 0.45; between group difference P = 0.003).

Conclusions

Anthracycline therapy is associated with dose-dependent increase in ECV fraction and total ECV. Concomitant treatment with candesartan reduces left ventricular total cellular volume.

Association of Interleukin-10 -1082A>G (rs1800896) Polymorphism with Predisposition to Breast Cancer: a Meta-Analysis based on 17 Case-Control Studies

SUMMARY INTRODUCTION The association between the between IL-10 -1082A>G (rs1800896) polymorphism and breast cancer has been evaluated by several number case-control studies. However, these studies might be underpowered to reveal the true association. OBJECTIVE We have performed a comprehensive meta-analysis to investigate the association IL-10 -1082A>G polymorphism and breast cancer. MATERIALS AND METHODS A systematic literature search was conducted using PubMed, Google Scholar, and Web of Science up to September 20, 2017. Data was analysed with CMA software to identify the strength of the association by pooled odds ratios (ORs) with corresponding 95% confidence intervals (CIs). RESULTS A total of 17 case-control studies involving 3275 cases and 3416 controls obtained from database searches were examined. Overall, there was no significant association between IL-10 -1082A>G polymorphism and breast cancer risk under all genetic models. No significant publication bias was found for the five genetic models (G vs. A OR = 1.184, 95% CI = 0.895-1.180, p= 0.230; GG vs. AA: OR = 1.430, 95% CI = 0.927-2.204, p= 0.106; GA vs. AA: OR = 0.966, 95% CI = 0.765-1.221, p= 0.774; GG+GA vs. AA: OR = 0.957, 95% CI = 0.697-1.314, p= 0.786; and GG vs. GA+AA: OR = 1.221, 95% CI = 0.981-1.518, p= 0.073). Moreover, there was no significant association between the IL-10 -1082A>G polymorphism and breast cancer risk by ethnicity. CONCLUSION Our findings indicated that IL-10 -1082A>G (rs1800896) polymorphism might not be a risk factor for the development of breast cancer.

Possible roles of genetic variations in chemotherapy related cardiotoxicity in pediatric acute lymphoblastic leukemia and osteosarcoma

Background

The treatment of acute lymphoblastic leukemia (ALL) and osteosarcoma (OSC) is very effective: the vast majority of patients recover and survive for decades. However, they still need to face serious adverse effects of chemotherapy. One of these is cardiotoxicity which may lead to progressive heart failure in the long term. Cardiotoxicity is contributed mainly to the use of anthracyclines and might have genetic risk factors. Our goal was to test the association between left ventricular function and genetic variations of candidate genes.

Methods

Echocardiography data from medical records of 622 pediatric ALL and 39 OSC patients were collected from the period 1989–2015. Fractional shortening (FS) and ejection fraction (EF) were determined, 70 single nucleotide polymorphisms (SNPs) in 26 genes were genotyped. Multivariate logistic regression and multi-adjusted general linear model were performed to investigate the influence of genetic polymorphisms on the left ventricular parameters. Bayesian network based Bayesian multilevel analysis of relevance (BN-BMLA) method was applied to test for the potential interaction of the studied cofactors and SNPs.

Results

Our results indicate that variations in ABCC2, CYP3A5, NQO1, SLC22A6 and SLC28A3 genes might influence the left ventricular parameters. CYP3A5 rs4646450 TT was 17% among ALL cases with FS lower than 28, and 3% in ALL patients without pathological FS (p = 5.60E-03; OR = 6.94 (1.76–27.39)). SLC28A3 rs7853758 AA was 12% in ALL cases population, while only 1% among controls (p = 6.50E-03; OR = 11.56 (1.98–67.45)). Patients with ABCC2 rs3740066 GG genotype had lower FS during the acute phase of therapy and 5–10 years after treatment (p = 7.38E-03, p = 7.11E-04, respectively). NQO1 rs1043470 rare T allele was associated with lower left ventricular function in the acute phase and 5–10 years after the diagnosis (p = 4.28E-03 and 5.82E-03, respectively), and SLC22A6 gene rs6591722 AA genotype was associated with lower mean FS (p = 1.71E-03), 5–10 years after the diagnosis.

Conclusions

Genetic variants in transporters and metabolic enzymes might modulate the individual risk to cardiac toxicity after chemotherapy.

Electronic supplementary material

The online version of this article (10.1186/s12885-018-4629-6) contains supplementary material, which is available to authorized users.

An initial health economic evaluation of pharmacogenomic testing in patients treated for childhood cancer with anthracyclines

BACKGROUND

Anthracyclines are a class of highly effective chemotherapeutic drugs commonly used to treat cancer patients. Anthracyclines, however, are associated with the development of serious adverse reactions, including anthracycline-induced cardiotoxicity (ACT). It is not possible, within current practice, to accurately individualize treatment to minimize risk.

PROCEDURE

Recently, genetic variants have been associated with the risk of ACT in children. Building on these findings and the related genetic test, a predictive model was developed which classifies pediatric patients by their risk of developing ACT. We assessed the value of this ACT-predictive risk classification in addressing ACT.

RESULTS

With current care, the estimated average lifetime cost of ACT is $8,667 per anthracycline-treated patient and approximately 7% of patients are expected to die from ACT. The projected impact of the information from the new predictive model is a 17% reduction in the risk of mortality from ACT and savings of about 6%: lives saved and lower costs.

CONCLUSION

The newly identified genetic variants associated with the risk of ACT provide information that allows a more reliable prediction of the risk of ACT for a given patient and can be obtained at a very moderate cost, which is expected to lead to meaningful progress in reducing harm and costs associated with ACT.

RGD-mediated delivery of small-molecule drugs

Conjugates of cytotoxic agents with RGD peptides (Arg-Gly-Asp) addressed to α_νβ₃, α₅β₁ and α_νβ₆ integrin receptors overexpressed by cancer cells, have recently gained attention as potential selective anticancer chemotherapeutics. In this review, the design and the development of RGD conjugates coupled to different small molecules including known cytotoxic drugs and natural products will be discussed.

Increased proapoptotic activity of electron beam irradiated doxorubicin and epirubicin in multidrug-resistant human leukemic cells

This study evaluated the effect of electron beam irradiation on the cytotoxic activity of anthracycline antibiotics such as doxorubicin (DOX), epirubicin (EPI), and dunorubicin (DAU) in human acute lymphoblastic leukemia cell line CCRF-CEM and its multidrug-resistant variant CCRF-VCR1000 cell line characterized by the overexpression of ABCB1 gene. Drugs were irradiated at doses of 10 and 25 kGy. Data from EPR studies proved that the highest concentration of free radicals was found in DOX and that the number of stable free radicals is always greater after irradiation. In in vitro studies, a higher cytotoxic activity of irradiated DOX and EPI in multidrug-resistant CCRF-VCR1000 cells was observed. This tendency was maintained during the storage at 4 °C for 90 days. Changes in CCRF-CEM cells' viability were not dependent on the irradiation status and its dose and were only drug-concentration dependent in all measurement time points. It was proved that increased potency of 25 kGy e-beam irradiated drugs results from their enhanced proapoptotic activity. Apoptotic cell death observed in CCRF-VCR1000 cells treated with irradiated drugs was caspase-8, -9, and -3 dependent and related to the increased Bax/Bcl-2 ratio. No significant differences in the effects of irradiated and non-irradiated drugs on p53 and NFκB transcription factor level and their translocation to the nucleus were noted. Increased activity of the irradiated drugs was not dependent on ABCB1 level.

Cardiotoxicity of anthracycline therapy: current perspectives

Anthracyclines, especially doxorubicin and daunorubicin, are the drugs of first choice in the treatment of patients with hematologic malignancies, soft-tissue sarcomas, and solid tumors. Unfortunately, the use of anthracyclines is limited by their dose-dependent and cumulative cardiotoxicity. The molecular mechanism responsible for anthracycline-induced cardiotoxicity remains poorly understood, although experimental and clinical studies have shown that oxidative stress plays the main role. Hence, antioxidant agents, especially dexrazoxane, and also other drug classes (statins, β-blockers) proved to have a beneficial effect in protecting against anthracycline-induced cardiotoxicity. According to previous clinical trials, the major high-risk factors for anthracycline-induced cardiotoxicity are age, body weight, female gender, radiotherapy, and other diseases such as Down syndrome, familial dilated cardiomyopathy, diabetes and hypertension. Consequently, further studies are needed to elucidate the molecular pathogenesis of anthracycline-induced cardiotoxicity and also to discover new cardioprotective agents against anthracycline-induced cardiotoxicity.

Synthesis, crystal structure from PXRD of a MnII(purp)2complex, interaction with DNA at different temperatures and pH and lack of stimulated ROS formation by the complex

Mn^II(purpurin)₂crystal structure done from PXRD is the second report on hydroxy-9,10-anthraquinone with a 3d-transition metal. DNA binding of complex is better and ROS generation less than purpurin. Complex maintains biological activity of purpurin.

Intensified home haemodialysis for managing severe cardiac failure

BACKGROUND

Conventional thrice weekly haemodialysis (HD) provides adequate dialysis to prevent mortality, but morbidity is prevalent in both the paediatric and adult population. There has been growing interest in the potential of intensive dialysis regimes entering the realm of optimal dialysis, with superior health and quality of life outcomes.

CASE DIAGNOSIS/TREATMENT

We present the case of a 13-year-old girl who had bilateral nephrectomies as a result of bilateral Wilms tumors. In the third year of treatment with conventional HD, she presented with symptomatic progressive cardiac failure, presumably secondary to anthracycline-induced cardiomyopathy. Consequently, she was taken off the renal transplant list and became increasingly dependent on frequent in-centre dialysis sessions to manage her symptoms. Five months after switching to a frequent and extended home HD regime, we observed a tremendous improvement in her health and well-being, with complete reversal of her cardiac dysfunction.

CONCLUSIONS

Home HD is a practically viable option in children with severe cardiac dysfunction. Gentler, more intensive dialysis will draw out and improve the ureamic component of heart disease. This may translate into improved cardiac function.

Influence of ionic strength on the interaction of THA and its Cu(ii) complex with DNA helps to explain studies on various breast cancer cells

Purpurin, a structural analogue of anthracycline anticancer drugs, was used to understand how environmental changes affect its biophysical interactions with DNA and along with its Cu(ii) complex, the activity it shows on breast cancer cells.

Managing chemotherapy-related cardiotoxicity in survivors of childhood cancers

In the US, children diagnosed with cancer are living longer, but not without consequences from the same drugs that cured their cancer. In these patients, cardiovascular disease is the leading cause of non-cancer-related morbidity and mortality. Although this review focuses on anthracycline-related cardiomyopathy in childhood cancer survivors, the global lifetime risk of other cardiovascular diseases such as atherosclerosis, arrhythmias and intracardiac conduction abnormalities, hypertension, and stroke also are increased. Besides anthracyclines, newer molecularly targeted agents, such as vascular endothelial growth factor receptor and tyrosine kinase inhibitors, also have been associated with acute hypertension, cardiomyopathy, and increased risk of ischemic cardiac events and arrhythmias, and are summarized here. This review also covers other risk factors for chemotherapy-related cardiotoxicity (including both modifiable and non-modifiable factors), monitoring strategies (including both blood and imaging-based biomarkers) during and following cancer treatment, and discusses the management of cardiotoxicity (including prevention strategies such as cardioprotection by use of dexrazoxane).

Hemodynamic and biochemical alterations in dogs with lymphoma after induction of chemotherapy

Background

Doxorubicin is a common antineoplastic agent with dose‐dependent cardiotoxic adverse effects, and pre‐existing myocardial dysfunction is a contraindication to its use.

Objectives

To systematically define the hemodynamic and biochemical alterations in dogs undergoing chemotherapy for newly diagnosed lymphoma and assess the reversibility of these alterations with fluid administration.

Animals

Twenty‐one client‐owned dogs with newly diagnosed lymphoma were evaluated 1 week after induction of chemotherapy. Underlying degenerative valve disease was exclusionary. Eighteen healthy age‐ and weight‐matched dogs were used as controls.

Methods

Physical examination, blood pressure by Doppler, echocardiography, and biochemical evaluation (routine serum biochemistry, plasma renin activity and aldosterone concentrations, plasma and urine osmolalities, and urine electrolyte concentrations) were measured in dogs with lymphoma and compared to controls. Dogs with lymphoma received crystalloids IV at 6 mL/kg/h for 24 hours. All variables were reassessed at 4 and 24 hours. Deuterium oxide dilution and bromide dilution were used to determine total body water and extracellular water space, respectively.

Results

Baseline echocardiograms showed significantly smaller chamber dimensions in dogs with lymphoma compared to controls. These changes were reversed by fluid administration. Systolic blood pressure and urine sodium concentration were significantly increased, and bromide dilution space, PCV, urine specific gravity, and urine potassium concentration were significantly decreased compared to controls.

Conclusion and Clinical Importance

Echocardiographic and biochemical abnormalities in dogs with lymphoma appear consistent with volume depletion, and may be the result of systemic hypertension and subsequent pressure natriuresis.

Synthesis, crystal structure, DNA interaction and in vitro anticancer activity of a Cu(ii) complex of purpurin: dual poison for human DNA topoisomerase I and II

Although generation of reactive oxygen species (ROS) by anthracycline anticancer drugs is essential for anti-tumor activity, they make these drugs cardiotoxic.

Primary nephrectomy and intraoperative tumor spill: report from the Children's Oncology Group (COG) renal tumors committee

PURPOSE

Initial Children's Oncology Group (COG) management for Wilms' tumor (WT) consists of primary nephroureterectomy with lymph node sampling. While this provides accurate staging to define further treatment, it may result in intraoperative spill (IOS), which is associated with higher recurrence rates and therefore requires more intensive therapy. The purpose of this study is to determine current rates and identify factors which may predispose a patient to IOS.

METHODS

The study population was drawn from the AREN03B2 renal tumor banking and classification study of the Children's Oncology Group. All children with a first time occurrence of a renal mass were eligible for the study. At the time of enrollment and prior to risk stratification, the institution is required to submit operative notes, pathology specimens, a chest computed tomography scan (CT), and a contrast-enhanced CT or magnetic resonance imaging (MRI) of the abdomen and pelvis for central imaging review. These data are then used to determine an initial risk classification and therapeutic protocol eligibility. Patients who had a unilateral nephroureterectomy for favorable histology WT underwent further review to assure data accuracy and to clarify details regarding the spill. Analyses were performed using chi square and logistic regression. Odd ratios (OR) are shown with 95% confidence intervals.

RESULTS

There were 1,131 primary nephrectomies for unilateral WT with an IOS rate of 9.7% with an additional 1.8% having possible tumor spill during renal vein or IVC tumor thrombectomy. IOS correlated with diameter (>12 cm, p<0.0001) and laterality (right, p=0.0414). Simple logistic regression indicated that IOS increased 2.7% [p=0.0240, OR 1.027 (1.004, 1.052)] with each 1 cm increase in diameter (3 - 21 cm) and 4.7% [p=0.0147 OR 1.047 (1.009, 1.086)] with each 100 g increase in weight (80 - 1800 g). Multiple logistic regression indicated that laterality [right p=0.048, OR 1.46 (1.004, 2.110)] and weight (p=0.03, OR 1.039 (1.003, 1.075) were predictive of IOS when diameter was included as a continuous variable. Diameter as a binary variable was highly prognostic of IOS (p=0.0002), while laterality and weight were not significant.

CONCLUSIONS

Intraoperative tumor spill occurs in about one out of every ten cases of primary nephroureterectomies for WT. Right-sided and larger tumors are at higher risk of IOS.

ABCC1 polymorphisms in anthracycline-induced cardiotoxicity in childhood acute lymphoblastic leukaemia

Anthracyclines are potent cytostatic drugs, the correct dosage being critical to avoid possible cardiac side effects. ABCC1 [ATP-binding cassette, sub-family C, member 1; also denoted as MRP1 (multidrug resistance-associated protein 1)] is expressed in the heart and takes part in the detoxification and protection of cells from the toxic effects of xenobiotics, including anthracyclines. Our objective was to search for associations between LV (left ventricular) function and single-nucleotide polymorphisms of the ABCC1 gene in children receiving anthracycline chemotherapy. Data of 235 paediatric patients with acute lymphoblastic leukaemia was analysed. Patients were followed-up by echocardiography (median follow-up 6.3 years). Nine polymorphisms in the ABCC1 gene were genotyped. The ABCC1 rs3743527TT genotype and rs3743527TT–rs246221TC/TT genotype combination were associated with lower LVFS (left ventricular fractional shortening) after chemotherapy. The results suggest that genetic variants in the ABCC1 gene influence anthracycline-induced LV dysfunction.

Flavaglines alleviate doxorubicin cardiotoxicity: implication of Hsp27

Background

Despite its effectiveness in the treatment of various cancers, the use of doxorubicin is limited by a potentially fatal cardiomyopathy. Prevention of this cardiotoxicity remains a critical issue in clinical oncology. We hypothesized that flavaglines, a family of natural compounds that display potent neuroprotective effects, may also alleviate doxorubicin-induced cardiotoxicity.

Methodology/Principal Findings

Our in vitro data established that a pretreatment with flavaglines significantly increased viability of doxorubicin-injured H9c2 cardiomyocytes as demonstrated by annexin V, TUNEL and active caspase-3 assays. We demonstrated also that phosphorylation of the small heat shock protein Hsp27 is involved in the mechanism by which flavaglines display their cardioprotective effect. Furthermore, knocking-down Hsp27 in H9c2 cardiomyocytes completely reversed this cardioprotection. Administration of our lead compound (FL3) to mice attenuated cardiomyocyte apoptosis and cardiac fibrosis, as reflected by a 50% decrease of mortality.

Conclusions/Significance

These results suggest a prophylactic potential of flavaglines to prevent doxorubicin-induced cardiac toxicity.

Effect of telmisartan in limiting the cardiotoxic effect of daunorubicin in rats

Objectives

Studies have suggested that angiotensin receptor blockers may exert a protective role towards doxorubicin-induced cardiotoxicity, but they have not been extensively investigated in this area. We therefore investigated whether the co-treatment of telmisartan, an angiotensin (Ang II) type-1 receptor blocker, might offer protection against daunorubicin cardiotoxic properties in rats.

Methods

Daunorubicin was administered at 3 mg/kg/day every other day for 12 days. Telmisartan was administered orally every day for 12 days.

Key findings

Daunorubicin-treated rats showed cardiac toxicity, evidenced by worsening cardiac function, evaluated by haemodynamic status and echocardiography, elevation of malondialdehyde level and a decreased level of total glutathione peroxidase activity in the heart tissue. These changes were reversed by treatment with telmisartan. Furthermore, telmisartan also downregulated matrix metalloproteinase-2 expression, attenuated the increased protein expression of p22phox, p47phox, p67phox, nuclear factor kappa B and Nox4 in heart tissue, and reduced oxidative-stress-induced DNA damage, which was evaluated by the expression of 8-hydroxydeoxyguanosine. Moreover, telmisartan reduced the myocardial apoptosis induced by daunorubicin.

Conclusions

The present study indicates that telmisartan may improve cardiac function by inhibiting the action of Ang II via AT-1R, which reverses oxidative stress and myocardial apoptosis. This suggests a beneficial effect of telmisartan treatment in the prevention of daunorubicin-induced cardiotoxicity.

Protective effect of carvedilol on daunorubicin-induced cardiotoxicity and nephrotoxicity in rats

Daunorubicin (DNR) is one of the anthracycline anti-tumor agents widely used in the treatment of acute myeloid leukemia. However, the clinical use of DNR has been limited by its undesirable systemic toxicity, especially in the heart and kidney. This study was designed to test the effectiveness of carvedilol, a nonselective beta-blocker against DNR-induced cardiotoxicity and nephrotoxicity. Rats were treated with a cumulative dose of 9 mg/kg body weight DNR (i.v.). Carvedilol was administered orally every day for 6 weeks. DNR rats showed cardiac and nephrotoxicities as evidenced by worsening cardiac and kidney functions, which were evaluated by hemodynamic and echocardiographic studies, and by measuring protein in urine, levels of urea and creatinine in serum, lipid profiles, malondialdeyde level and the total level of glutathione peroxidase activity in both heart and kidney tissues. These changes were reversed by treatment with carvedilol, which resulted in significant improvement in the cardio-renal function. Furthermore, carvedilol down-regulated matrix metalloproteinase-2 expression in the heart, increased nephrin expression in the kidney, and attenuated the increased protein expression of NADPH oxidase subunits in heart and kidney. Moreover, carvedilol reduced myocardial and renal apoptosis and improved the histopathological changes in heart and kidney induced by DNR. In conclusion, the present study demonstrated a beneficial effect of carvedilol treatment in the prevention of DNR-induced cardiotoxicity and nephrotoxicity by reversing the oxidative stress and apoptosis.

Survivorship: childhood cancer survivors

Late effects of therapy for childhood cancer are frequent and serious. Fortunately, many late effects are also modifiable. Proactive and anticipatory risk-based care can reduce the frequency and severity of treatment-related morbidity. The primary care clinician should be an integral component in risk-based care of survivors. Continued communication between the "late effects" staff at the cancer center and the primary care clinician is essential for optimum care of this high-risk population.

Molecular pathogenetic mechanisms and new therapeutic perspectives in anthracycline-induced cardiomyopathy

Anthracyclines are among the most powerful drugs for the treatment of oncologic diseases both in childhood and in adulthood. Nevertheless, their major antineoplastic efficacy can be seriously impaired by collateral toxic cardiac effects causing cardiomyopathy with chronic heart failure that is refractory to conventional medical therapy.

This article reports possible subcellular molecular alterations of anthracycline-induced cardiomyopathy (reactive oxygen species formation, apoptosis, inflammatory signalling, altered expression of cardiomyocytes specific genes, etc) and indicates some new therapeutic perspectives resulting from a better understanding of the molecular pathogenetic mechanisms.

Doxorubicin inactivates myocardial cytochrome c oxidase in rats: cardioprotection by Mito-Q

Doxorubicin (DOX) is used for treating various cancers. Its clinical use is, however, limited by its dose-limiting cardiomyopathy. The exact mechanism of DOX-induced cardiomyopathy still remains unknown. The goals were to investigate the molecular mechanism of DOX-induced cardiomyopathy and cardioprotection by mitoquinone (Mito-Q), a triphenylphosphonium-conjugated analog of coenzyme Q, using a rat model. Rats were treated with DOX, Mito-Q, and DOX plus Mito-Q for 12 weeks. The left ventricular function as measured by two-dimensional echocardiography decreased in DOX-treated rats but was preserved during Mito-Q plus DOX treatment. Using low-temperature ex vivo electron paramagnetic resonance (EPR), a time-dependent decrease in heme signal was detected in heart tissues isolated from rats administered with a cumulative dose of DOX. DOX attenuated the EPR signals characteristic of the exchange interaction between cytochrome c oxidase (CcO)-Fe(III) heme a3 and CuB. DOX and Mito-Q together restored these EPR signals and the CcO activity in heart tissues. DOX strongly downregulated the stable expression of the CcO subunits II and Va and had a slight inhibitory effect on CcO subunit I gene expression. Mito-Q restored CcO subunit II and Va expressions in DOX-treated rats. These results suggest a novel cardioprotection mechanism by Mito-Q during DOX-induced cardiomyopathy involving CcO.

Long-term consequences of drugs on the paediatric cardiovascular system

Many pharmacological and toxicological actions of drugs in children cannot be fully predicted from adult clinical experience or from standard non-clinical toxicology studies. Numerous drugs have direct or indirect pharmacological effects on the heart and are prescribed for children of all ages. Toxicity or secondary effects may be immediate or delayed for years after drug exposure has ceased. Originally, the aim of this review was to compile information on the effect of specific drugs on the post-natal development of the cardiovascular system and to examine long-term follow-up of the use of cardio-active drugs in children. The limited database of published information caused the original question to evolve into an examination of the medical literature for three areas of information: (i) whether vulnerable developmental windows have been identified that reflect the substantial functional development that the cardiovascular system undergoes after birth; (ii) what is known about pharmacological perturbation of development; and (iii) what the likelihood is of drug exposure during childhood. We examined different scenarios for exposure including random, isolated exposure, conditions historically associated with adults, primary or secondary cardiac disease, psychiatric and neurological conditions, asthma, cancer and HIV. Except for random, isolated drug exposures, each category of possible exposure contained numerous drugs known to have either primary or secondary effects on the cardiovascular system or to influence factors associated with atherosclerosis. It is likely that a significant number of children will be prescribed drugs having either direct or indirect effects upon the immature cardiovascular system. A confounding factor is the simultaneous use of over-the-counter medications and herbal or nutraceutical preparations that a patient, parent or guardian does not mention to a prescribing physician. Metabolism is also important in assessing drug effects in children. Differences in body water : body fat ratio, age-related gastrointestinal absorption, distribution, excretion, renal function and drug metabolizing capabilities make it possible for children to have a different metabolite profile for a drug compared with adults. There is little examination of drug effects on the interdependent processes of cardiac maturation and less examination of metabolite effects. It is difficult to identify delayed toxicities in children as these adverse events may take years to manifest with many patients lost to follow-up. Clearly this is an area of study where intermediate endpoints and surrogate markers would be of great benefit. Pharmacogenomics may be useful in providing markers of increased risk or susceptibility. A perspective must be kept in balancing the possibility of a problem with the very real benefits that many children experience from the use of these pharmaceuticals.

Anandamide Preserves Cardiac Function and Geometry in an Acute Doxorubicin Cardiotoxicity Rat Model

We investigated the use of the endocannabinoid anandamide as a means of cardioprotection against doxorubicin-induced cardiac dysfunction. Male rats received doxorubicin with or without anandamide pretreatment. Cardiac function was assessed in vivo using transthoracic echocardiography and ex vivo using the isolated working heart 5 days posttreatment. Doxorubicin administration without anandamide pretreatment resulted in a decline in fractional shortening (P < .05) and left ventricular wall thickness when compared to controls (P < .05). Ex vivo cardiac function analysis revealed a reduction in left ventricular developed pressure in hearts from animals receiving doxorubicin without anandamide pretreatment when compared to controls (P < .05). Left ventricles from animals receiving anandamide pretreatment before doxorubicin administration did not exhibit depressed fractional shortening, ventricular wall thickness, or developed pressure when compared to controls (P > .05). These results suggest that a potential therapy for doxorubicin-induced cardiotoxicity involves targeting the endogenous cannabinoid system.

Early detection of doxorubicin cardiomyopathy using two-dimensional strain echocardiography

Doxorubicin is one of the most effective chemotherapeutic agents; however, it causes dose-dependent cardiomyopathy that may lead to heart failure. Conventional measures of ventricular function, such as fractional shortening, are insensitive in detecting early doxorubicin cardiomyopathy. We tested whether novel two-dimensional radial strain echocardiography (2DSE) can detect early doxorubicin injury following chronic administration in a rat model. 14 male Sprague Dawley rats (240 to 260 g) received doxorubicin 2.5 mg/k i.v. per wk for 10 (n=4) or 12 wk (n=10); 17 controls received saline (10 wk, n=7 and 12 wk, n=10). Serial 2DSE from 0 to 12 wk was done at the mid left ventricle using Vivid 7 echo (General Electric, Waukesha, WI, USA). With Q analysis software, radial strain was obtained. From the two-dimensional (2D) image, anatomical M-mode through the anterior/inferior walls was used to measure fractional shortening. Fibrosis (Masson's trichrome) and caspase-3 activity were measured from excised hearts. Radial strain was lower in the doxorubicin group (12 wk: 26.7+/-3 versus 38.3+/-2.6%, p=0.006), with significant difference by 8 wk whereas fractional shortening was lower with doxorubicin only after 12 wk (30.2+/-1.7 versus 37.6+/-1.4%, p=0.02). Doxorubicin group had lower cardiac mass (0.85+/-0.09 versus 1.14+/-0.04 g, p=0.001), higher caspase-3 activity (1.95+/-0.2 fold increase over control, p<0.0001) and fibrosis (3.9 +/- 0.7 versus 0.7+/-0.1%, p=0.005). Radial strain was related directly to cardiac mass (r=0.61, p=0.0007) and inversely to caspase-3 activity (r= -0.5, p=0.005). 2-dimensional radial strain echocardiography is useful in the early detection of doxorubicin cardiac injury and the reduction in radial strain is associated with histologic markers of doxorubicin cardiomyopathy.

Use of cardiac markers to assess the toxic effects of anthracyclines given to children with cancer: a systematic review

AIM

To evaluate the effectiveness of cardiac markers to quantify anthracycline-induced cardiotoxicity in children with cancer.

METHODS

Systematic review using a priori methods.

RESULTS

Seven studies, all with methodological limitations, were identified. One RCT suggests that cardiac troponin can be used to assess the effectiveness of the cardio-protective agent dexrazoxane. Cohort studies suggest that atrial natriuretic peptide and brain (B-type) natriuretic peptide are elevated in some subgroups of patients compared with healthy children; NT-pro-BNP levels are significantly elevated in children with cardiac dysfunction compared with those without; serum lipid peroxide is higher in children who have received doxorubicin compared with children not receiving doxorubicin; there are no differences in carnitine levels between children treated with doxorubicin and a healthy control group.

CONCLUSIONS

The limited evidence makes conclusions difficult. Research is needed to fill this important evidence gap and link short-term changes in cardiac markers to longer-term cardiac damage.

Mapping genes that contribute to daunorubicin-induced cytotoxicity

Daunorubicin is an anthracycline antibiotic agent used in the treatment of hematopoietic malignancies. Toxicities associated with this agent include myelosuppression and cardiotoxicity; however, the genes or genetic determinants that contribute to these toxicities are unknown. We present an unbiased genome-wide approach that incorporates heritability, whole-genome linkage analysis, and linkage-directed association to uncover genetic variants contributing to the sensitivity to daunorubicin-induced cytotoxicity. Cell growth inhibition in 324 Centre d' Etude du Polymorphisme Humain lymphoblastoid cell lines (24 pedigrees) was evaluated following treatment with daunorubicin for 72 h. Heritability analysis showed a significant genetic component contributing to the cytotoxic phenotypes (h2 = 0.18-0.63 at 0.0125, 0.025, 0.05, 0.1, 0.2, and 1.0 mumol/L daunorubicin and at the IC50, the dose required to inhibit 50% cell growth). Whole-genome linkage scans at all drug concentrations and IC50 uncovered 11 regions with moderate peak LOD scores (> 1.5), including 4q28.2 to 4q32.3 with a maximum LOD score of 3.18. The quantitative transmission disequilibrium tests were done using 31,312 high-frequency single-nucleotide polymorphisms (SNP) located in the 1 LOD confidence interval of these 11 regions. Thirty genes were identified as significantly associated with daunorubicin-induced cytotoxicity (P < or = 2.0 x 10(-4), false discovery rate < or = 0.1). Pathway and functional gene ontology analysis showed that these genes were overrepresented in the phosphatidylinositol signaling system, axon guidance pathway, and GPI-anchored proteins family. Our findings suggest that a proportion of susceptibility to daunorubicin-induced cytotoxicity may be controlled by genetic determinants and that analysis using linkage-directed association studies with dense SNP markers can be used to identify the genetic variants contributing to cytotoxicity.

Impact of cumulative anthracycline dose, preparative regimen and chronic graft-versus-host disease on pulmonary and cardiac function in children 5 years after allogeneic hematopoietic stem cell transplantation: a prospective evaluation on behalf of the EBMT Pediatric Diseases and Late Effects Working Parties

This prospective study focused on risk factors and clinical outcome of pulmonary and cardiac late effects after allogeneic hematopoietic stem cell transplantation (allo-HSCT). We prospectively evaluated 162 children by pulmonary function tests (PFTs) and cardiac shortening fraction (SF) before allo-HSCT and yearly up to the 5th year of follow-up. The 5-year cumulative incidence of lung and cardiac impairment was 35 (hazard rate=0.03) and 26% (hazard rate=0.06), respectively. Patients presenting abnormal PFTs and SF at last follow-up were 19 and 13%, respectively, with a median Lansky performance status of 90% (70-100). Chronic graft-versus-host disease (c-GVHD) was the major risk factor for reduced lung function in univariate (P=0.02) and multivariate analysis (P=0.02). Total body irradiation (TBI) alone and TBI together with pre-transplant anthracycline administration were significant risk factors for reduced cardiac function in univariate analysis, only (P=0.04 and 0.004, respectively). In conclusion, our prospective study demonstrates an asymptomatic post-allo-HSCT deterioration of pulmonary and cardiac function in some long-term survivors, who had been transplanted in childhood, and thus emphasizes the need for lifelong cardiopulmonary monitoring and the development of new strategies both to reduce pre-transplant cardiotoxic regimens and to treat more efficiently c-GVHD.

A precise pharmacodynamic study showing the advantage of a marked reduction in cardiotoxicity in continuous infusion of doxorubicin

We have already shown that the antileukemic activity of daunorubicin that had been reported to be dependent on the area under the concentration - time curve (AUC) was actually peak concentration (Cmax) dependent. The antitumor activity of doxorubicin (DXR) has also been reported to be dependent on AUC, whereas its cumulative cardiotoxicity has been reported to be Cmax dependent. In this study, we evaluated whether the antileukemic and cardiotoxic effects of DXR were AUC or Cmax dependent, and compared their cytotoxic effects, utilizing the computer-controlled in vitro pharmacokinetic simulation system or a conventional culture system for a leukemic cell line and measuring the intracellular ATP amount or the proportion of beating cells for the cardiotoxicity. In leukemic cells, the cytotoxic rate decreased as the simulated infusion time or exposure time increased with the same AUC value in the simulation and conventional culture system (P < 0.05 and <0.01, respectively). The intracellular ATP and proportion of beating cells also increased with prolonged DXR exposure time with the same constant concentration - time product value (P < 0.05 and <0.0001, respectively) in heart cells. These results indicated that both the antileukemic effects and the cardiotoxicity were Cmax dependent. However, a comparison of the two showed that cardiotoxicity was more Cmax dependent than the antileukemic effect. These results suggested that the continuous infusion treatment schedule of DXR may have the clinical advantage of reducing cardiotoxicity more markedly than the antileukemic effect.

Treatment of stage I, IIA, IIIA1 pediatric Hodgkin disease with doxorubicin, bleomycin, vincristine and etoposide (DBVE) and radiation: a Pediatric Oncology Group (POG) study

PURPOSE

The objectives of this study were to evaluate the feasibility of reducing therapy, while maintaining treatment efficacy, in the context of a cooperative group clinical trial that allowed for clinical staging in early stage Hodgkin disease (HD).

PATIENTS AND METHODS

Between August 1992 and December 1993, 51 eligible children < or =21 years of age, 31 male and 20 female, were enrolled in this study which was designed for low stage (IA, IIA, IIIA1) HD. Laparotomy and surgical staging was optional. Five postpubertal patients with Stage IA and IIA disease received only involved-field radiation therapy. The other 46 patients, who form the basis of this report, received combined modality therapy consisting of four courses of doxorubicin, bleomycin, vincristine, and etoposide (DBVE) followed by 2,550 cGy involved-field irradiation.

RESULTS

With a median follow-up of 8.4 years, the 6-year overall and event-free survival rates for the 46 patients treated with combination therapy were 98 +/- 2% and 91 +/- 5%, respectively. All patients achieved remission after completion of therapy. There have been four recurrences and a remission death due to gunshot wound. Combined modality therapy was well tolerated. Predominant side effects were gastrointestinal and hemopoietic. There have been no clinically significant cardio-pulmonary side effects so far.

CONCLUSION

In clinically staged children with early-stage HD, DBVE and low-dose involved-field irradiation was effective therapy with tolerable side effects and reduced potential for long-term adverse events.