Late cardiotoxicity after low dose of anthracycline therapy for acute lymphoblastic leukemia in childhood

Prognostic Factors for Cardiotoxicity among Children with Cancer: Definition, Causes, and Diagnosis with Omics Technologies

Improvements in the treatment of childhood cancer have considerably enhanced survival rates over the last decades to over 80% as of today. However, this great achievement has been accompanied by the occurrence of several early and long-term treatment-related complications major of which is cardiotoxicity. This article reviews the contemporary definition of cardiotoxicity, older and newer chemotherapeutic agents that are mainly involved in cardiotoxicity, routine process diagnoses, and methods using omics technology for early and preventive diagnosis. Chemotherapeutic agents and radiation therapies have been implicated as a cause of cardiotoxicity. In response, the area of cardio-oncology has developed into a crucial element of oncologic patient care, committed to the early diagnosis and treatment of adverse cardiac events. However, routine diagnosis and the monitoring of cardiotoxicity rely on electrocardiography and echocardiography. For the early detection of cardiotoxicity, in recent years, major studies have been conducted using biomarkers such as troponin, N-terminal pro b-natriuretic peptide, etc. Despite the refinements in diagnostics, severe limitations still exist due to the increase in the above-mentioned biomarkers only after significant cardiac damage has occurred. Lately, the research has expanded by introducing new technologies and finding new markers using the omics approach. These new markers could be used not only for early detection but also for the early prevention of cardiotoxicity. Omics science, which includes genomics, transcriptomics, proteomics, and metabolomics, offers new opportunities for biomarker discovery in cardiotoxicity and may provide an understanding of the mechanisms of cardiotoxicity beyond traditional technologies.

The Imbalance of p53-Park7 Signaling Axis Induces Iron Homeostasis Dysfunction in Doxorubicin-Challenged Cardiomyocytes

Doxorubicin (DOX)-induced cardiotoxicity (DoIC) is a major side effect for cancer patients. Recently, ferroptosis, triggered by iron overload, is demonstrated to play a role in DoIC. How iron homeostasis is dysregulated in DoIC remains to be elucidated. Here, the authors demonstrate that DOX challenge exhibits reduced contractile function and induction of ferroptosis-related phenotype in cardiomyocytes, evidenced by iron overload, lipid peroxide accumulation, and mitochondrial dysfunction. Compared to Ferric ammonium citrate (FAC) induced secondary iron overload, DOX-challenged cardiomyocytes show a dysfunction of iron homeostasis, with decreased cytoplasmic and mitochondrial iron-sulfur (FeS) cluster-mediated aconitase activity and abnormal expression of iron homeostasis-related proteins. Mechanistically, mass spectrometry analysis identified DOX-treatment induces p53-dependent degradation of Parkinsonism associated deglycase (Park7) which results in iron homeostasis dysregulation. Park7 counteracts iron overload by regulating iron regulatory protein family transcription while blocking mitochondrial iron uptake. Knockout of p53 or overexpression of Park7 in cardiomyocytes remarkably restores the activity of FeS cluster and iron homeostasis, inhibits ferroptosis, and rescues cardiac function in DOX treated animals. These results demonstrate that the iron homeostasis plays a key role in DoIC ferroptosis. Targeting of the newly identified p53-Park7 signaling axis may provide a new approach to prevent DoIC.

Exposure to Doxorubicin Modulates the Cardiac Response to Isoproterenol in Male and Female Mice

Sex is a salient risk factor in the development of doxorubicin-induced cardiotoxicity. Sex differences in the heart's ability to respond to hypertrophic stimuli in doxorubicin-exposed animals have not been reported. We identified the sexual dimorphic effects of isoproterenol in mice pre-exposed to doxorubicin. Male and female intact or gonadectomized C57BL/6N mice underwent five weekly intraperitoneal injections of 4 mg/kg doxorubicin followed by a five-week recovery period. Fourteen days of subcutaneous isoproterenol injections (10 mg/kg/day) were administered after the recovery period. Echocardiography was used to assess heart function one and five weeks after the last doxorubicin injection and on the fourteenth day of isoproterenol treatment. Thereafter, mice were euthanized, and the hearts were weighed and processed for histopathology and gene expression analysis. Doxorubicin did not produce overt cardiac dysfunction in male or female mice before starting isoproterenol treatment. The chronotropic response to a single isoproterenol injection was blunted by doxorubicin, but the inotropic response was maintained in both males and females. Pre-exposure to doxorubicin caused cardiac atrophy in both control and isoproterenol-treated male mice but not in female mice. Counterintuitively, pre-exposure to doxorubicin abrogated isoproterenol-induced cardiac fibrosis. However, there were no sex differences in the expression of markers of pathological hypertrophy, fibrosis, or inflammation. Gonadectomy did not reverse the sexually dimorphic effects of doxorubicin. Additionally, pre-exposure to doxorubicin abrogated the hypertrophic response to isoproterenol in castrated male mice but not in ovariectomized female mice. Therefore, pre-exposure to doxorubicin caused male-specific cardiac atrophy that persisted after isoproterenol treatment, which could not be prevented by gonadectomy.

Cell death regulation in myocardial toxicity induced by antineoplastic drugs

Homeostatic regulation of cardiomyocytes plays a critical role in maintaining normal physiological activity of cardiac tissue. Severe cardiotoxicity can lead to heart disease, including but not limited to arrhythmias, myocardial infarction and cardiac hypertrophy. In recent years, significant progress has been made in developing new therapies for cancer that have dramatically changed the treatment of several malignancies and continue to improve patient survival, but can also lead to serious cardiac adverse effects. Mitochondria are key organelles that maintain homeostasis in myocardial tissue and have been extensively involved in various cardiovascular disease episodes, including ischemic cardiomyopathy, heart failure and stroke. Several studies support that mitochondrial targeting is a major determinant of the cardiotoxic effects triggered by chemotherapeutic agents increasingly used in solid and hematologic tumors. This antineoplastic therapy-induced mitochondrial toxicity is due to different mechanisms, usually altering the mitochondrial respiratory chain, energy production and mitochondrial kinetics, or inducing mitochondrial oxidative/nitrosative stress, ultimately leading to cell death. This review focuses on recent advances in forms of cardiac cell death and related mechanisms of antineoplastic drug-induced cardiotoxicity, including autophagy, ferroptosis, apoptosis, pyroptosis, and necroptosis, explores and evaluates key proteins involved in cardiac cell death signaling, and presents recent advances in cardioprotective strategies for this disease. It aims to provide theoretical basis and targets for the prevention and treatment of pharmacological cardiotoxicity in clinical settings.

Nicorandil Ameliorates Doxorubicin-Induced Cardiotoxicity in Rats, as Evaluated by 7 T Cardiovascular Magnetic Resonance Imaging

PURPOSE

Doxorubicin-induced cardiotoxicity (DIC) is a common side effect of doxorubicin chemotherapy, and a major mechanism of DIC is inflammation. However, no effective method exists to prevent DIC. In the present study, we investigated the cardioprotective effects of nicorandil against DIC using multiparametric cardiac magnetic resonance (CMR) imaging and elucidated the anti-inflammatory properties of nicorandil in rat models.

METHODS

Male Sprague-Dawley rats received four weekly intraperitoneal doxorubicin doses (4 mg/kg/injection) to establish the DIC model. After treatment with or without nicorandil (3 mg/kg/day) or diazoxide (10 mg/kg/day) orally, all the groups underwent weekly CMR examinations, including cardiac function and strain assessment and T2 mapping, for 6 weeks. Additionally, blood samples and hearts were collected to examine inflammation and histopathology.

RESULTS

According to our results, the earliest DIC CMR parameter in the doxorubicin group was T2 mapping time prolongation compared with the DIC rats treated with nicorandil (doxorubicin+nicorandil group) at week 2. Subsequently, the left ventricular ejection fraction (LVEF) and global peak systolic myocardial strain in the doxorubicin group were significantly reduced, and nicorandil effectively inhibited these effects at week 6. Our results were confirmed by histopathological evaluations. Furthermore, nicorandil treatment had a protective effect against the doxorubicin-induced inflammatory response. Interestingly, similar protective results were obtained using the K_ATP channel opener diazoxide.

CONCLUSION

Collectively, our findings indicate that nicorandil application ameliorates DIC in rats with significantly higher cardiac function and myocardial strain and less fibrosis, apoptosis and inflammatory cytokine production. Nicorandil prevents T2 abnormalities in the early stages of DIC, showing a high clinical value for early nicorandil treatment in chemotherapy patients.

Assessment of Cardiovascular Function in Childhood Leukemia Survivors: The Role of the Right Heart

Childhood acute lymphoblastic leukemia (ALL) survivors who underwent chemotherapy with anthracyclines have an increased cardiovascular risk. The aim of the study was to evaluate left and right cardiac chamber performances and vascular endothelial function in childhood ALL survivors. Fifty-four ALL survivors and 37 healthy controls were enrolled. All patients underwent auxological evaluation, blood pressure measurements, biochemical parameters of endothelial dysfunction, flow-mediated dilatation (FMD) of the brachial artery, mean common carotid intima-media thickness (c-IMT), antero-posterior diameter of the infra-renal abdominal aorta (APAO), and echocardiographic assessment. The ALL subjects had significantly lower FMD (p = 0.0041), higher left (p = 0.0057) and right (p = 0.0021) echocardiographic/Doppler Tei index (the non-invasive index for combined systolic and diastolic ventricular function) as compared to controls. Tricuspid annular plane excursion (TAPSE) was 16.9 ± 1.2 mm vs. 24.5 ± 3.7 mm, p < 0.0001. Cumulative anthracycline doses were related to TAPSE (p < 0.001). The ALL survivors treated with anthracyclines demonstrated systo/diastolic alterations of the right ventricle and reduced endothelial function compared with healthy controls. The early recognition of subclinical cardiac and vascular impairment during follow up is of utmost importance for the cardiologist to implement strategies preventing overt cardiovascular disease considering the growing number of young adults cured after childhood ALL.

Pre-Treatment Left Ventricular Ejection Fraction Assessment and Long-Term Cardiovascular Outcomes in Adolescent and Young Adult Lymphoma Survivors

Purpose: Anthracyclines can cause long-term cardiovascular (CV) morbidity, especially in long-term Adolescent and Young Adult (AYA) lymphoma survivors. Pre-treatment left ventricular ejection fraction (LVEF) evaluation is recommended, although its utility in AYA is not established. We sought to determine the pre-treatment LVEF assessment practices in AYA lymphoma survivors treated with anthracyclines and factors associated with long-term cardiotoxicity. Methods: Through an electronic health records review, we retrospectively identified AYA lymphoma survivors with ≥5 years of follow-up postanthracycline treatment. Pre-treatment and follow-up data were abstracted. CV health conditions were defined as risk factors for CV disease and confirmed CV diagnoses. Survivors who had new CV health conditions at follow-up were compared to those who were not using descriptive statistics and logistic regression. Results: One hundred fifteen AYA lymphoma survivors met the study criteria. Pre-treatment LVEF assessment did not affect chemotherapy decisions. Survivors with pre-treatment CV evaluation had mean follow-up since diagnosis of 8 ± 3.3 years, while survivors without it had 10.3 ± 4.2 years, p < 0.05. Survivors with pre-treatment LVEF assessment received lower cumulative anthracycline dose (240.4 mg/m² vs. 280.1 mg/m², p < 0.05) and fewer cycles of chemotherapy (4.8 ± 1.5 vs. 5.6 ± 1.2, p < 0.05). Body mass index (BMI) category at diagnosis and follow-up, in addition to age were associated with development of new CV health conditions, pre-treatment LVEF evaluation was not. Conclusion: Pre-treatment LVEF assessment for AYA lymphoma survivors does not impact oncologic treatment decisions or development of CV health conditions. It may be more valuable to assess and modify CV risk factors such as BMI for CV disease prevention.

Divergent Cardiac Effects of Angiotensin II and Isoproterenol Following Juvenile Exposure to Doxorubicin

Hypertension is the most significant risk factor for heart failure in doxorubicin (DOX)-treated childhood cancer survivors. We previously developed a two-hit mouse model of juvenile DOX-induced latent cardiotoxicity that is exacerbated by adult-onset angiotensin II (ANGII)-induced hypertension. It is still not known how juvenile DOX-induced latent cardiotoxicity would predispose the heart to pathologic stimuli that do not cause hypertension. Our main objective is to determine the cardiac effects of ANGII (a hypertensive pathologic stimulus) and isoproterenol (ISO, a non-hypertensive pathologic stimulus) in adult mice pre-exposed to DOX as juveniles. Five-week-old male C57BL/6N mice were administered DOX (4 mg/kg/week) or saline for 3 weeks and then allowed to recover for 5 weeks. Thereafter, mice were administered either ANGII (1.4 mg/kg/day) or ISO (10 mg/kg/day) for 14 days. Juvenile exposure to DOX abrogated the hypertrophic response to both ANGII and ISO, while it failed to correct ANGII- and ISO-induced upregulation in the hypertrophic markers, ANP and BNP. ANGII, but not ISO, worsened cardiac function and exacerbated cardiac fibrosis in DOX-exposed mice as measured by echocardiography and histopathology, respectively. The adverse cardiac remodeling in the DOX/ANGII group was associated with a marked upregulation in several inflammatory and fibrotic markers and altered expression of Ace, a critical enzyme in the RAAS. In conclusion, juvenile exposure to DOX causes latent cardiotoxicity that predisposes the heart to a hypertensive pathologic stimulus (ANGII) more than a non-hypertensive stimulus (ISO), mirroring the clinical scenario of worse cardiovascular outcome in hypertensive childhood cancer survivors.

Assessment of late cardiotoxic effects in patients treated for cancer in childhood

Graphical AbstractThe aim was to assess the late cardiotoxic effects in young adults treated for various cancer types in childhood using echocardiography and 24-h ECG Holter monitoring.

Mitochondrial-Targeted Therapy for Doxorubicin-Induced Cardiotoxicity

Anthracyclines, such as doxorubicin, are effective chemotherapeutic agents for the treatment of cancer, but their clinical use is associated with severe and potentially life-threatening cardiotoxicity. Despite decades of research, treatment options remain limited. The mitochondria is commonly considered to be the main target of doxorubicin and mitochondrial dysfunction is the hallmark of doxorubicin-induced cardiotoxicity. Here, we review the pathogenic mechanisms of doxorubicin-induced cardiotoxicity and present an update on cardioprotective strategies for this disorder. Specifically, we focus on strategies that can protect the mitochondria and cover different therapeutic modalities encompassing small molecules, post-transcriptional regulators, and mitochondrial transfer. We also discuss the shortcomings of existing models of doxorubicin-induced cardiotoxicity and explore advances in the use of human pluripotent stem cell derived cardiomyocytes as a platform to facilitate the identification of novel treatments against this disorder.

Juvenile exposure to doxorubicin alters the cardiovascular response to adult-onset psychosocial stress in mice

Childhood cancer survivors have a high risk for premature cardiovascular diseases, mainly due to cardiotoxic cancer treatments such as doxorubicin (DOX). Psychosocial stress is a significant cardiovascular risk factor and an enormous burden in childhood cancer survivors. Although observational studies suggest that psychosocial stress is associated with cardiovascular complications in cancer survivors, there is no translationally relevant animal model to study this interaction. We established a "two-hit" model in which juvenile mice were administered DOX (4 mg/kg/week for 3 weeks), paired to a validated model of chronic subordination stress (CSS) 5 weeks later upon reaching adulthood. Blood pressure, heart rate, and activity were monitored by radio-telemetry. At the end of CSS experiment, cardiac function was assessed by echocardiography. Cardiac fibrosis and inflammation were assessed by histopathologic analysis. Gene expressions of inflammatory and fibrotic markers were determined by PCR. Juvenile exposure to DOX followed by adult-onset CSS caused cardiac fibrosis and inflammation as evident by histopathologic findings and upregulated gene expression of multiple inflammatory and fibrotic markers. Intriguingly, juvenile exposure to DOX blunted CSS-induced hypertension but not CSS-induced tachycardia. There were no significant differences in cardiac function parameters among all groups, but juvenile exposure to DOX abrogated the hypertrophic response to CSS. In conclusion, we established a translationally relevant mouse model of juvenile DOX-induced cardiotoxicity that predisposes to adult-onset stress-induced adverse cardiac remodeling. Psychosocial stress should be taken into consideration in cardiovascular risk stratification of DOX-treated childhood cancer survivors.

Mechanism and prevention strategy of a bidirectional relationship between heart failure and cancer (Review)

The relationship between cancer and heart failure has been extensively studied in the last decade. These studies have focused on describing heart injury caused by certain cancer treatments, including radiotherapy, chemotherapy and targeted therapy. Previous studies have demonstrated a higher incidence of cancer in patients with heart failure. Heart failure enhances an over-activation of the sympathetic nervous system and the renin-angiotensin-aldosterone system, and subsequently promotes cancer development. Other studies have found that heart failure and cancer both have a common pathological origin, flanked by chronic inflammation in certain organs. The present review aims to summarize and describe the recent discoveries, suggested mechanisms and relationships between heart failure and cancer. The current review provides more ideas on clinical prevention strategies according to the pathological mechanism involved.

Role of cardiovascular magnetic resonance in early detection and treatment of cardiac dysfunction in oncology patients

The purpose of this review is to provide an overview of the essential role that cardiovascular magnetic resonance (CMR) has in the field of cardio-oncology. Recent findings: CMR has been increasingly used for early identification of cancer therapy related cardiac dysfunction (CTRCD) due to its precision in detecting subtle changes in cardiac function and for myocardial tissue characterization. Summary: CMR is able to identify subclinical CTRCD in patients receiving potentially cardiotoxic chemotherapy and guide initiation of cardio protective therapy. Multiparametric analysis with myocardial strain, tissue characterization play a critical role in understanding important clinical questions in cardio-oncology.

Age-Related Considerations in Cardio-Oncology

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

p38δ genetic ablation protects female mice from anthracycline cardiotoxicity

The efficacy of an anthracycline antibiotic doxorubicin (DOX) as a chemotherapeutic agent is limited by dose-dependent cardiotoxicity. DOX is associated with activation of intracellular stress signaling pathways including p38 MAPKs. While previous studies have implicated p38 MAPK signaling in DOX-induced cardiac injury, the roles of the individual p38 isoforms, specifically, of the alternative isoforms p38γ and p38δ, remain uncharacterized. We aimed to determine the potential cardioprotective effects of p38γ and p38δ genetic deletion in mice subjected to acute DOX treatment. Male and female wild-type (WT), p38γ-/-, p38δ-/-, and p38γ-/-δ-/- mice were injected with 30 mg/kg DOX and their survival was tracked for 10 days. During this period, cardiac function was assessed by echocardiography and electrocardiography and fibrosis by Picro Sirius Red staining. Immunoblotting was performed to assess the expression of signaling proteins and markers linked to autophagy. Significantly improved survival was observed in p38δ-/- female mice post-DOX relative to WT females, but not in p38γ-/- or p38γ-/-δ-/- male or female mice. The improved survival in DOX-treated p38δ-/- females was associated with decreased fibrosis, increased cardiac output and LV diameter relative to DOX-treated WT females, and similar to saline-treated controls. Structural and echocardiographic parameters were either unchanged or worsened in all other groups. Increased autophagy, as suggested by increased LC3-II level, and decreased mammalian target of rapamycin activation was also observed in DOX-treated p38δ-/- females. p38δ plays a crucial role in promoting DOX-induced cardiotoxicity in female mice by inhibiting autophagy. Therefore, p38δ targeting could be a potential cardioprotective strategy in anthracycline chemotherapy.NEW & NOTEWORTHY This study for the first time identifies the sex-specific roles of the alternative p38γ and p38δ MAPK isoforms in promoting doxorubicin (DOX) cardiotoxicity. We show that p38δ and p38γ/δ systemic deletion was cardioprotective in female but not in male mice. Cardiac structure and function were preserved in DOX-treated p38δ-/- females and autophagy marker was increased.

Screening for in-vivo regional contractile defaults to predict the delayed Doxorubicin Cardiotoxicity in Juvenile Rat

Anthracyclines are key chemotherapeutic agents used in various adult and pediatric cancers, however, their clinical use is limited due to possible congestive heart failure (HF) caused by acute and irreversible cardiotoxicity. Currently, there is no method to predict the future development of the HF in these patients. In order to identify early biomarkers to predict anthracycline cardiotoxicity in long-term survivors of childhood cancer, this longitudinal study aimed to analyze early and late in-vivo regional myocardial anthracycline-induced cardiotoxicity, related to in-vitro cardiac myocytes dysfunction, in a juvenile rat model. Methods: Young male Wistar rats (4 weeks-old) were treated with different cumulative doses of doxorubicin (7.5, 10 or 12.5 mg/kg) or NaCl (0.9%) once a week for 6 weeks by intravenous injection. Cardiac function was evaluated in-vivo by conventional (left ventricular ejection fraction, LVEF) and regional two-dimensional (2D) speckle tracking echocardiography over the 4 months after the last injection. The animals were assigned to preserved (pEF) or reduced EF (rEF) groups at the end of the protocol and were compared to controls. Results: We observed a preferential contractile dysfunction of the base of the heart, further altered in the posterior segment, even in pEF group. The first regional alterations appeared 1 month after chemotherapy. Functional investigation of cardiomyocytes isolated from the LV base 1 month after doxorubicin treatment showed that early in-vivo contractile alterations were associated with both decreased myofilament Ca²⁺ sensitivity and length-dependent activation. Changes in post-translational modifications (phosphorylation; S-glutathionylation) and protein degradation of the cardiac myosin binding protein-C may contribute to these alterations. Conclusion: Our data suggest that screening of the contractile defaults of the base of the heart by regional 2D strain echocardiography is useful to detect subclinical myocardial dysfunction prior to the development of delayed anthracycline-induced cardiomyopathy in pediatric onco-cardiology.

The use of cardiovascular magnetic resonance as an early non-invasive biomarker for cardiotoxicity in cardio-oncology

Contemporary cancer therapy has resulted in significant survival gains for patients. However, many current and emerging cancer therapies have an associated risk of cardiotoxicity, either acutely or later in life. Regular cardiac screening and surveillance is recommended for patients undergoing treatment for cancer, with emphasis on the early detection of cardiotoxicity before irreversible complications develop. Cardiovascular magnetic resonance imaging is able to accurately assess cardiac structure, function, and perform advanced myocardial tissue characterisation, including perfusion, features which may facilitate the diagnosis and management of cardiotoxicity in cancer survivors. This review outlines the current standards for the diagnosis and screening of cardiotoxicity, with particular focus on current and future applications of cardiovascular magnetic resonance imaging.

Acute and Chronic Effects of Cancer Drugs on the Cardiovascular System

Several cancer treatments cause cardiotoxicity that can lead to heart failure, coronary artery disease, arrhythmia, and pericardial disease. In this review, representative cases of heart failure following cardiotoxicity caused by trastuzumab, anthracycline, and hematopoietic stem cell transplantation are described with case notes. Additionally, other important points regarding cardiotoxicity related to heart failure are reported. During and after potentially cardiotoxic therapy, periodic cardiac examinations are recommended to detect any cardiovascular disorders; these are ameliorated if appropriately diagnosed at an earlier stage. It is important for cardiologists and oncologists to understand the pathophysiology of representative cardiovascular disease cases following cancer treatment.

Magnetic Driven Nanocarriers for pH-Responsive Doxorubicin Release in Cancer Therapy

Doxorubicin is one of the most widely used anti-cancer drugs, but side effects and selectivity problems create a demand for alternative drug delivery systems. Herein we describe a hybrid magnetic nanomaterial as a pH-dependent doxorubicin release carrier. This nanocarrier comprises magnetic iron oxide cores with a diameter of 10 nm, enveloped in a hybrid material made of siliceous shells and ĸ-carrageenan. The hybrid shells possess high drug loading capacity and a favorable drug release profile, while the iron oxide cores allows easy manipulation via an external magnetic field. The pH responsiveness was assessed in phosphate buffers at pH levels equivalent to those of blood (pH 7.4) and tumor microenvironment (pH 4.2 and 5). The nanoparticles have a loading capacity of up to 12.3 wt.% and a release profile of 80% in 5 h at acidic pH versus 25% at blood pH. In vitro drug delivery tests on human breast cancer and non-cancer cellular cultures have shown that, compared to the free drug, the loaded nanocarriers have comparable antiproliferative effect but a less intense cytotoxic effect, especially in the non-cancer cell line. The results show a clear potential for these new hybrid nanomaterials as alternative drug carriers for doxorubicin.

Cranial Irradiation in Childhood Acute Lymphoblastic Leukemia Is Related to Subclinical Left Ventricular Dysfunction and Reduced Large Artery Compliance in Cancer Survivors

Long-term survivors of acute lymphoblastic leukemia (ALL), the most common childhood malignancy, are at remarkably increased risk of heart failure (HF) in middle age, most likely due anthracycline cardiotoxicity. The role of cranial radiation therapy (CRT) in the development of left ventricular (LV) dysfunction, a predecessor of overt HF, remains unclear. Our aim was to compare LV function and systemic arterial properties according to past CRT in young adult survivors of anthracycline-treated ALL. We studied young adult survivors of childhood ALL at a median of 16 years from diagnosis treated with anthracycline-based chemotherapy, with (n = 12) or without (n = 30) CRT. In addition to fractional shortening (FS) and ejection fraction (EF), LV function was quantified by tissue Doppler imaging of the mitral annulus. Aortic strain/distensibility and arterial compliance were derived from echocardiography and simultaneously recorded pulse pressure. Despite similar FS and EF, peak mitral annular systolic velocity (median (interquartile range): 9.0 (7.5–10.0) vs. 10.0 (8.8–11.5) cm/s, p = 0.05), and early diastolic velocity (13.8 (13.0–14.8) vs. 15.5 (14.0–17.3), p = 0.01) were decreased after chemotherapy combined with CRT compared to chemotherapy without CRT. Systemic arterial compliance was lower in post-CRT subjects (1.0 (0.8–1.2 vs. 1.4 (1.1–1.7) mL/mmHg, p = 0.002). Aortic strain and distensibility were similar regardless of prior CRT. In conclusion, lower arterial compliance and subclinical LV dysfunction may be possible late consequences of past CRT in adult survivors of childhood ALL. Whether arterial stiffening is associated with future HF development in CRT-exposed ALL survivors remains to be investigated.

Co-administration of resveratrol with doxorubicin in young mice attenuates detrimental late-occurring cardiovascular changes

Aims

Doxorubicin (DOX) is among the most effective chemotherapies used in paediatric cancer patients. However, the clinical utility of DOX is offset by its well-known cardiotoxicity, which often does not appear until later in life. Since hypertension significantly increases the risk of late-onset heart failure in childhood cancer survivors, we investigated whether juvenile DOX exposure impairs the ability to adapt to angiotensin II (Ang II)-induced hypertension later in life and tested a treatment that could prevent this.

Methods and results

Five-week-old male mice were administered a low dose of DOX (4 mg/kg) or saline once a week for 3 weeks and then allowed to recover for 5 weeks. Following the 5-week recovery period, mice were infused with Ang II or saline for 2 weeks. In another cohort, mice were fed chow containing 0.4% resveratrol 1 week before, during, and 1 week after the DOX administrations. One week after the last DOX administration, p38 mitogen-activated protein kinase (MAPK) was activated in hearts of DOX-treated mice demonstrating molecular signs of cardiac stress; yet, there was no change in cardiac function between groups. However, DOX-treated mice failed to develop compensatory cardiac hypertrophy in response to Ang II-induced hypertension later in life. Of importance, mice receiving DOX with resveratrol co-administration displayed normalization in p38 MAPK activation in the heart and a restored capacity for cardiac hypertrophy in response to Ang II-induced hypertension.

Conclusion

We have developed a juvenile mouse model of DOX-induced cardiotoxicity that displays no immediate overt physiological dysfunction; but, leads to an impaired ability of the heart to adapt to hypertension later in life. We also show that co-administration of resveratrol during DOX treatment was sufficient to normalize molecular markers of cardiotoxicity and restore the ability of the heart to undergo adaptive remodelling in response to hypertension later in life.

Bidirectional Relationship Between Cancer and Heart Failure: Old and New Issues in Cardio-oncology

The main focus of cardio-oncology has been the prevention and treatment of the cardiac toxicity of chemotherapy and radiotherapy. Furthermore, several targeted therapies have been associated with unexpected cardiotoxic side-effects. Recently, epidemiological studies reported a higher incidence of cancer in patients with heart failure (HF) compared with individuals without HF. On this basis, it has been proposed that HF might represent an oncogenic condition. This hypothesis is supported by preclinical studies demonstrating that hyperactivation of the sympathetic nervous system and renin-angiotensin-aldosterone system, which is a hallmark of HF, promotes cancer growth and dissemination. Another intriguing possibility is that the co-occurrence of HF and cancer is promoted by a common pathological milieu characterised by a state of chronic low-grade inflammation, which predisposes to both diseases. In this review, we provide an overview of the mechanisms underlying the bidirectional relationship between HF and cancer.

The role of irradiated heart and left ventricular volumes in heart failure occurrence after childhood cancer

BACKGROUND

Paediatric cancer survivors have a high risk of developing cardiac diseases, and the most frequent cardiac disease is heart failure (HF). The radiation dose-volume effects in the heart and cardiac substructures have not been explored in childhood cancer survivors (CCS). Therefore, the role of irradiated heart volume in the occurrence of HF among this population remains unclear. The aims of this study were to determine the doses and irradiated volumes of the heart and left ventricle (LV) related to the risk of HF in CCS and to investigate the impact of anthracycline exposure on this risk.

METHODS AND RESULTS

A case-control study nested in the French Childhood Cancer Survivors Study cohort. The mean heart and left ventricular doses and volumes indicators were estimated by reconstruction of individual treatments. A total of 239 HF cases and 1042 matched controls were included. The median age of HF diagnosis was 25.1 years. The median volume of the heart that received ≥ 30 Gy was 61.1% for cases and 16.9% for controls. In patients who did not receive anthracycline, the risk of HF was increased 3.6-fold when less than 10% of the LV received ≥ 30 Gy when compared to patients who were not exposed to any cardiac radiation and anthracycline.

CONCLUSIONS

Small irradiated volumes of the heart or LV were significantly associated with HF risk. To the author's knowledge, this is the first study to report a dose-response relationship based on dose-volume indicators in CCS, which can be translated efficiently into current clinical practice.

Biomarkers for the detection of apparent and subclinical cancer therapy-related cardiotoxicity

Progress in cancer therapy over the past decades improved long-term survival but increased cancer therapy-related cardiotoxicity. Many novel treatment options have been implemented with yet incompletely characterized cardiovascular side effects including heart failure, coronary artery disease, arrhythmias, valvular disease, venous thromboembolism and myocarditis. Diagnosis of potential cardiotoxic side effects is essential for an optimal treatment but remains challenging. Cardiac biomarkers troponin and brain natriuretic peptide/N-terminal proBNP (BNP/NT-proBNP) have been extensively studied in heart failure and acute coronary syndromes. Emerging evidence implicates a significant role in the detection of cardiotoxicity and guidance of therapy in cancer patients. Elevated troponin or BNP/NT-proBNP levels were associated with increased all-cause mortality in cancer patients and have been shown to predict manifest heart failure. BNP/NT-proBNP may be useful for the prediction of cancer therapy-related heart failure and response to heart failure therapy in adult and pediatric cancer patients while troponin can indicate acute myocardial infarction in patients with cancer therapy-related risk for coronary artery disease. Furthermore, troponin may be used for the identification of immune checkpoint inhibitor-related myocarditis with very high sensitivity. Finally, even D-dimer levels have been shown to improve risk stratification and diagnosis in cancer-associated venous thromboembolism. This review aims to summarize the current knowledge about biomarkers in cancer therapy-related cardiotoxicity. We also outline possible clinical recommendations for the detection and treatment of subclinical and clinically apparent cardiotoxic effects using biomarkers.

Clinical and preclinical evidence of sex-related differences in anthracycline-induced cardiotoxicity

Anthracyclines are very effective chemotherapeutic agents that are widely used to treat pediatric and adult cancer patients. Unfortunately, the clinical utility of anthracyclines is limited by cardiotoxicity. There are several established risk factors for anthracycline-induced cardiotoxicity (AIC), including total cumulative dose, very young and very old age, concomitant use of other cardiotoxic agents, and concurrent mediastinal radiation. However, the role of sex as a risk factor for AIC is not well defined. In pediatric cancer patients, most studies support the notion that female sex is a significant risk factor for AIC. Conversely, there is anecdotal evidence that female sex protects against AIC in adult cancer patients. The lack of consistency in study designs and the different definitions of cardiotoxicity preclude reaching consensus regarding the role of sex as a risk factor for AIC in both pediatric and adult cancer patients. Therefore, more clinical research using reliable techniques such as cardiac magnetic resonance imaging is needed to determine if there truly are sex differences in AIC. In adult preclinical rodent studies, however, there is unequivocal evidence that female sex confers significant protection against AIC, with a possible protective effect of female sex hormones and/or a detrimental role of the male sex hormones. Although findings of these rodent studies may not perfectly mirror the clinical scenario in adult anthracycline-treated cancer patients, understanding the mechanisms of this significant sexual dimorphism may reveal important cardioprotective mechanisms that can be therapeutically targeted.

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.

Chemotherapy-related cardiac dysfunction: grey area in type I and type II classification

PURPOSE OF REVIEW

The main aim of this review is to address and challenge an old nomenclature of reversible versus irreversible chemotherapy-induced cardiomyopathy.

RECENT FINDINGS

Chemotherapy-related cardiac dysfunction (CRCD) has been often characterized as type I or type II. Type I CRCD (e.g., anthracycline) represents a group of chemotherapeutic agents that has often been correlated with irreversible cardiac dysfunction. Conversely, type II CRCD (e.g., trastuzumab) represents a group of anticancer agents that has been considered as reversible. Recent evidence suggests that this nomenclature may not hold true, thus affecting clinical prognosis as well as timely management. It is prudent to address this concern so that physicians are armed with appropriate information, thus providing our oncological patients with informed care. The purpose is to highlight the grey area in this dichotomous classification.

SUMMARY

Type I CRCD can be reversible if cardioprotective medications are administered in a timely manner. Conversely, a small proportion of type II CRCD may develop irreversible dysfunction and therefore, will require a long-term follow-up. Therefore, every case should be dealt on an individual basis and an appropriate prognosis should be given to patients based on the clinical evidence on hand.

Cardiovascular Complications of Cancer Therapy: Best Practices in Diagnosis, Prevention, and Management: Part 1

Modern cancer therapy has successfully cured many cancers and converted a terminal illness into a chronic disease. Because cancer patients often have coexisting heart diseases, expert advice from cardiologists will improve clinical outcome. In addition, cancer therapy can also cause myocardial damage, induce endothelial dysfunction, and alter cardiac conduction. Thus, it is important for practicing cardiologists to be knowledgeable about the diagnosis, prevention, and management of the cardiovascular complications of cancer therapy. In this first part of a 2-part review, we will review cancer therapy-induced cardiomyopathy and ischemia. This review is based on a MEDLINE search of published data, published clinical guidelines, and best practices in major cancer centers. With the number of cancer survivors expanding quickly, the time has come for cardiologists to work closely with cancer specialists to prevent and treat cancer therapy-induced cardiovascular complications.

Heart failure following blood cancer therapy in pediatric and adult populations

AIM

The link between chemotherapy treatment and cardiotoxicity is well established, particularly for adults with blood cancers. However, it is less clear for children. This analysis aimed to compare the trajectory and mortality of children and adults who received chemotherapy for blood cancers and were subsequently hospitalized for heart failure.

METHODS

Linked data from the Queensland Cancer Registry, Death Registry and Hospital Administration records for initial chemotherapy and later heart failure were reviewed (1996-2009). Of all identified blood cancer patients (N = 23 434), 8339 received chemotherapy, including 817 children (aged ≤18 years at time of cancer diagnosis) and 7522 adults. Time-varying Cox proportional hazards regression models were used to compare the characteristics and survival between the two groups.

RESULTS

Of those who were subsequently hospitalized for heart failure, 70% of children and 46% of adults had the index admission within 12 months of their cancer diagnosis. Of these, 53% of the pediatric heart failure population and 71% of the adult heart failure population died within the study period. Following adjustment for age, sex and chemotherapy admissions, children with heart failure had an increased mortality risk compared to their non-heart failure counterparts, a difference which was much greater than that between the adult groups.

CONCLUSION

The impact of heart failure on children previously treated for blood cancer is more severe than for adults, with earlier morbidity and greater mortality. Improved strategies are needed for the prevention and management of cardiotoxicity in this population.

Customized laboratory TLR4 and TLR2 detection method from peripheral human blood for early detection of doxorubicin-induced cardiotoxicity

Cancer treatments can have significant cardiovascular adverse effects that can cause cardiomyopathy and heart failure with reduced survival benefit and considerable decrease in the use of antineoplastic therapy. The purpose of this study is to assess the role of TLR2 and TLR4 gene expression as an early marker for the risk of doxorubicin-induced cardiomyopathy in correlation with early diastolic dysfunction in patients treated with doxorubicin. Our study included 25 consecutive patients who received treatment with doxorubicin for hematological malignancies (leukemia, lymphomas or multiple myeloma), aged 18-65 years, with a survival probability>6 months and with left ventricular ejection fraction>50%. Exclusion criteria consisted of the following: previous anthracycline therapy, previous radiotherapy, history of heart failure or chronic renal failure, atrial fibrillation, and pregnancy. In all patients, in fasting state, a blood sample was drawn for the assessment of TLR2 and TLR4 gene expression. Gene expression was assessed by quantitative reverse transcription PCR (qRT-PCR) using blood collection, RNA isolation, cDNA reverse transcription, qRT-PCR and quantification of the relative expression. At enrollment, all patients were evaluated clinically; an ECG and an echocardiography were performed. The average amount of gene expression units was 0.113 for TLR4 (range 0.059-0.753) and 0.218 for TLR2 (range 0.046-0.269). The mean mRNA extracted quantity was 113 571 ng/μl. As for the diastolic function parameters, criteria for diastolic dysfunction were present after 6 months in 16 patients (64%). In these patients, the mean values for TLR4 were 0.1198625 and for TLR2 were 0.16454 gene expression units. As for the diastolic function parameters, criteria for diastolic dysfunction were present after 6 months in 16 patients (64%). In these patients, the mean value for TLR2 was 0.30±0.19 and for TLR4 was 0.15±0.04. The corresponding values for the patients who did not develop diastolic dysfunction were 0.16±0.07 for TLR2 (P=0.01) and 0.11±0.10 for TLR4 (P=0.2). Our study suggests that TLR4 and TLR2 expression is higher in patients under doxorubicin therapy who develop diastolic dysfunction. This may suggest a predisposition to myocardial involvement, a higher sensitivity to doxorubicin cardiac effects.

Cardiac dysfunction in cancer survivors unmasked during exercise

BACKGROUND

The cardiac dysfunction associated with anthracycline-based chemotherapy cancer treatment can exist subclinically for decades before overt presentation. Stress echocardiography, the measurement of left ventricular (LV) deformation and arterial haemodynamic evaluation, has separately been used to identify subclinical cardiovascular (CV) dysfunction in several patient groups including those with hypertension and diabetes. The purpose of the present cross-sectional study was to determine whether the combination of these techniques could be used to improve the characterisation of subclinical CV dysfunction in long-term cancer survivors previously treated with anthracyclines.

MATERIALS AND METHODS

Thirteen long-term cancer survivors (36 ± 10 years) with prior anthracycline exposure (11 ± 8 years posttreatment) and 13 age-matched controls were recruited. Left ventricular structure, function and deformation were assessed using echocardiography. Augmentation index was used to quantify arterial haemodynamic load and was measured using applanation tonometry. Measurements were taken at rest and during two stages of low-intensity incremental cycling.

RESULTS

At rest, both groups had comparable global LV systolic, diastolic and arterial function (all P > 0·05); however, longitudinal deformation was significantly lower in cancer survivors (-18 ± 2 vs. -20 ± 2, P < 0·05). During exercise, this difference between groups persisted and further differences were uncovered with significantly lower apical circumferential deformation in the cancer survivors (-24 ± 5 vs. -29 ± 5, -29 ± 5 vs. 35 ± 8 for first and second stage of exercise respectively, both P < 0·05).

CONCLUSION

In contrast to resting echocardiography, the measurement of LV deformation at rest and during exercise provides a more comprehensive characterisation of subclinical LV dysfunction. Larger studies are required to determine the clinical relevance of these preliminary findings.

Medium-term assessment of cardiac function in pediatric cancer survivors. Comparison of different echocardiographic methods, cardiac MRI and cardiac biomarker testing in adolescent cancer survivors

PURPOSE

To evaluate the feasibility and correlation of 3D echocardiography (echo) and cardiac biomarkers with cardiac MRI, in surveillance of cardiac function for cancer survivors.

METHODS

Subjects ≥10 years of age who have survived >2 years after completion of cancer treatment from a single center were enrolled. Cardiac MRI and 3D echo images were obtained on the same day when routine echo was obtained. On the same day, along with annual routine blood test, cardiac biomarkers N-terminal pro-B-type natriuretic peptide levels (NT-proBNP) and troponin-I levels were also measured.

RESULTS

Cardiac MRI was feasible in all 50 subjects. Three-dimensional echo and 2D echo images were of poor quality in four subjects. With a median duration of remission of 10 years, there were four subjects with mild LV dysfunction (cardiac MRI LV EF of<53%). None had MRI EF <50%, and nine subjects had LVEF <55%. M-mode echo overestimated EF more than 2D and 3D echo. Two-dimensional and 3D echo methods had much tighter limits of agreement for LV EF. For measurement of LVEF, 3D echo had a lower % error than 2D echo or M-mode echo. One subject had an abnormal troponin-I level and another one had an elevated NT-proBNP.

CONCLUSIONS

Three-dimensional echo can be performed in most adolescent cancer survivors, and it correlates well with MRI. Further large-scale research is required in assessing utility of cardiac biomarkers in pediatric cancer survivors.

Radiation reduction and faster acquisition times with SPECT gated blood pool scans using a high-efficiency cardiac SPECT camera

BACKGROUND

Planar gated blood pool scans are an established method for the evaluation of left ventricular ejection fraction (LVEF) but the camera technology used for these studies has not significantly changed in decades. The purpose of this study was to determine the diagnostic accuracy of new high-efficiency SPECT gated blood pool scans compared to traditional scans and determine if they can be performed with lower radiation doses or faster acquisition times.

METHODS

Patients undergoing a planar gated blood pool scan on a Na-I SPECT camera who consented to participate were subsequently imaged for 5 minutes in "List Mode" using a high-efficiency SPECT camera. LVEF was calculated for both the planar study and at 1, 2, 3, 4, and 5 minutes of acquisition on the high-efficiency camera. Counts acquired in the field of view, counts in the cardiac blood pool and LVEF were compared.

RESULTS

A total of 46 patients were analyzed (48% male, mean age 55 years, and BMI 27.6 kg/m(2)) who received an average Tc-99m dose of 20.3 mCi (5.3 mSv), 17 (37%) with abnormal LVEF's. The Na-I camera averaged 24,514 counts/min/mCi in the field of view and 8662 counts/min/mCi in the cardiac blood pool while the high-efficiency camera averaged 65,219 counts/min/mCi and 41,427 counts/min/mCi, respectively. Compared to the planar calculation of LVEF, 1-minute SPECT LVEF was on average 8.6 ± 10.7 higher, 2 minutes 3.5 ± 7.6 higher, 3 minutes 2.9 ± 8.5 higher, 4 minutes 2.5 ± 7.0 higher, and 5 minutes 1.1 ± 6.2 higher. Good correlation was seen between the SPECT LVEF's and the planar LVEF's across all acquisition times with correlation coefficients of 0.74-0.93.

CONCLUSIONS

High-efficiency SPECT technology can reduce radiation exposure to patients during gated blood pool imaging or decrease acquisition time while maintaining diagnostic accuracy. Based on the improved count sensitivity with high-efficiency SPECT, a 50% reduction in injected activity may be achievable while maintaining short imaging times of 5 minutes, with further reduction possible at longer imaging times.

"Smart" nickel oxide based core-shell nanoparticles for combined chemo and photodynamic cancer therapy

We report "smart" nickel oxide nanoparticles (NOPs) as multimodal cancer therapy agent. Water-dispersible and light-sensitive NiO core was synthesized with folic acid (FA) connected bovine serum albumin (BSA) shell on entrapped doxorubicin (DOX). The entrapped drug from NOP-DOX@BSA-FA was released in a sustained way (64 hours, pH=5.5, dark conditions) while a robust release was found under red light exposure (in 1/2 hour under λmax=655 nm, 50 mW/cm(2), at pH=5.5). The cell viability, thiobarbituric acid reactive substances and diphenylisobenzofuran assays conducted under light and dark conditions revealed a high photodynamic therapy potential of our construct. Furthermore, we found that the combined effect of DOX and NOPs from NOP-DOX@BSA-FA resulted in cell death approximately eightfold high compared to free DOX. We propose that NOP-DOX@BSA-FA is a potential photodynamic therapy agent and a collective drug delivery system for the systemic administration of cancer chemotherapeutics resulting in combination therapy.

Secondary Solid Organ Neoplasm in Patients with Acute Lymphoblastic Leukemia: A Nationwide Population-Based Study in Taiwan

Background

Acute lymphoblastic leukemia (ALL) is more common in children than in adults. Secondary neoplasms (SNs) in childhood ALL have been widely reported. However, only one study has demonstrated SNs in adult ALL. Because of the poorer survival of adult ALL, the incidence might be underestimated.

Objective

To evaluate the incidence and risk factors of secondary solid organ neoplasms among adult and child ALL patients.

Methods

Newly diagnosed ALL patients between 1997 and 2011 were recruited from the Taiwan National Health Insurance database. Those who had antecedent or combined malignancies were excluded. Standardized incidence ratios (SIRs) were analyzed to compare the risk of our cohort to general population in the same age, sex and calendar year. Risk factors for SN development were analyzed by Cox proportional hazards models. Effects of treatments were treated as time-dependent variables.

Results

The 15-year cumulative incidence of SN was 1.9% and 8.4% in 1,381 child and 2,154 adult ALL patients, respectively. The SIR was significantly increased in child ALL (SIR 6.06), but not in adult ALL (SIR 1.16). The SIRs of follow-up periods were 5.14, 2.24, .87 and .71 at ≥ 10 years, 5–10 years, 1–5 years and 0–1, respectively. Overall, 15 SNs developed, and CNS tumors (SIR 11.56) were the most common type. Multivariate analysis showed that age ≥ 20 years (hazard ratio [HR] 5.04), end-stage renal disease (HR 18.98) and cranial irradiation (HR 8.12) were independent risk factors for cancer development.

Conclusions

When compared with the general population, child ALL shows a increased risk of developing SNs. CNS tumors are the most common type, and cranial irradiation is an independent risk factor. With longer follow-up, the risk of SNs increases. Hence, physicians need to pay more attention on the risk of developing SNs in long-term ALL survivors with risk factors.

Mechanisms of Cardiotoxicity of Cancer Chemotherapeutic Agents: Cardiomyopathy and Beyond

Tremendous strides have been made in the treatment of various oncological diseases such that patients are surviving longer and are having better quality of life. However, the success has been tainted by the iatrogenic cardiac toxicities. This is especially concerning in the younger population who are facing cardiac disease such as heart failure in their 30s and 40s as the consequence of the anthracycline's side effects (used for childhood leukemia and lymphoma). This resulted in the awareness of cardiotoxic effects of anticancer drugs and emergence of a new discipline: oncocardiology. Since then, numerous anticancer drugs have been correlated to cardiomyopathy. Additionally, other cardiovascular effects have been identified, which includes but is not limited to myocardial infarction, thrombosis, hypertension, arrhythmias, and pulmonary hypertension. In this review we examine some of the anticancer agents that mitigate cardiotoxicity and present current knowledge of molecular mechanism(s). The aim of the review is to ignite awareness of emerging cardiotoxic effects as new generations of anticancer agents are being tested in clinical trials and introduced as part of the therapeutic armamentarium to our oncological patients.

Echocardiographic Detection of Cardiac Dysfunction in Childhood Cancer Survivors: How Long Is Screening Required?

BACKGROUND

Childhood cancer survivors treated with anthracycline chemotherapy are at an increased risk of long-term cardiac toxicity, and guidelines recommend that exposed survivors undergo echocardiography every 1-5 years. However, it is unclear whether survivors should undergo echocardiographic screening indefinitely, or if a period of echocardiographic stability indicates that screening is no longer necessary. The objective of this study was to evaluate the outcomes of echocardiographic screening to aid in the refinement of existing guidelines.

METHODS

We retrospectively analyzed the results of echocardiographic screening in a cohort of adult survivors of childhood cancer treated with anthracyclines and/or cardiac radiation therapy. Interval regression analysis was performed to identify predictors of single-episode or sustained abnormal echocardiograms.

RESULTS

The cohort constituted 333 survivors, with median follow-up time of 15.8 years post-treatment (range: 5.0-47.9), and median age at treatment of 8 years (range: 1.5-18). Forty-nine survivors had an abnormal echocardiogram (14.7%), and 29 (8.7%) had reproducible abnormal findings. An ongoing continual increase in the incidence of sustained echocardiographic abnormality was seen among patients treated with >250 mg/m(2) doxorubicin at age <5 years, reaching 43% by 20 years of therapy. In contrast, no sustained abnormal echocardiographic findings arose after 10 years of therapy in survivors treated with <250 mg/m(2) at age ≥5 years.

CONCLUSIONS

Single-episode echocardiographic abnormalities are often not reproduced in subsequent evaluations. The duration of echocardiographic screening for childhood cancer survivors should be reassessed for patients who received lower doses of anthracycline after age 5.

Impaired exercise capacity and left ventricular function in long-term adult survivors of childhood acute lymphoblastic leukemia

BACKGROUND

Survivors of childhood acute lymphoblastic leukemia (ALL) are at risk for late cardiotoxic effects of cancer treatment, but conflicting evidence exists on the effects of anthracyclines on left ventricular (LV) diastolic function and exercise capacity.

PROCEDURE

We performed a cross-sectional study with comprehensive echocardiography in 138 adult survivors of childhood ALL, median 23.4 years after diagnosis. Pulsed tissue Doppler measurements of early diastolic mitral annular velocities (e') were used for the assessment of diastolic function, and compared to 138 matched controls. Of the survivors, 133 also performed ergospirometry measuring peak oxygen uptake (VO2 max). Associations between cancer treatment, LV function, and VO2 max were analyzed.

RESULTS

The survivor group had lower e' values than controls (e' septal 11.0 vs. 12.6 cm/s, P < 0.001), but the difference was confined to the subgroup of anthracycline treated survivors (median cumulative dose 120 mg/m(2) ). Anthracycline exposure was inversely correlated with e' (regression coefficient -1.581, P=0.009). Reduced VO2 max/kg occurred in 47% of the survivors, but more often in anthracycline treated survivors (56%) than anthracycline naïve survivors (17%, P<0.001). Anthracycline exposure was inversely correlated with VO2 max/kg (regression coefficient -3.084, P = 0.05 in multivariate analysis). Furthermore, associations were observed between measures of LV function and VO2 max/kg, and e' was the best predictor of VO2 max/kg (standardized coefficient 0.355, P < 0.001 in multivariate analysis).

CONCLUSIONS

Adult survivors of childhood ALL have increased risk for impaired LV diastolic function and impaired exercise capacity, both associated with previous anthracycline exposure. Furthermore, there is an association between LV diastolic function and exercise capacity.

Identifying cancer patients at risk for cardiotoxicity

Improvements in therapies have significantly changed survival of cancer patients. However, the clinical history and oncologic treatment put cancer patients at higher risk for developing cardiovascular problems. Anthracyclines, but also the targeted therapy and angiogenesis inhibitors, are all treatments associated with cardiotoxicity. The most common adverse event is a reduction in left ventricular ejection fraction that may progress to overt heart failure. Recognition of a cardiac impairment during or after a potential cardiotoxic treatment requires a stringent assessment of clinical symptoms and signs of heart failure associated with an evaluation of the left ventricular ejection fraction, which, however, detects the damage already installed. Circulating cardiac biomarkers are promising in detecting cardiotoxicity and will likely change the approach for identifying patients at risk.

Evaluation of cardiotoxicity by tissue Doppler imaging in childhood leukemia survivors treated with low-dose anthracycline

Improvement in long-term survival in patients with acute childhood leukemia has led to the need for monitorization of chemotherapy-related morbidity and mortality. This study included 60 patients with acute lymphoblastic leukemia that were in remission for at least 2 years and 30 healthy controls. Systolic and diastolic function of myocardium was evaluated using conventional echocardiography and tissue Doppler imaging of the left ventricle, interventricular septum and right ventricle. Median age of patients was 11.7 years (range 10-14.9 years), and the median duration of remission was 4 years (range 2.5-5 years). All patients were treated with a low cumulative dose of adriamycin (100 mg/m(2)) according to the St. Jude Total-XIIIA protocol. The ejection fraction (EF) and fractional shortening were normal in the patient and control groups, even though EF values were significantly lower in the patients (69.5 ± 2.3 vs. 72.7 ± 3 %, P < 0.01). Myocardial systole (S m), early diastole (E m) and late diastole (A m) velocities in all segments of the myocardium were significantly lower in the patient group (P < 0.01 for all segments). Cardiotoxicity was noted in all segments of the myocardium in the patient group, despite the fact that they were all treated with a low cumulative dose of adriamycin. Based on these findings, we think that there is no safe dose for anthracyclines and periodic echocardiographic evaluation of both the left and right ventricles must be performed in all patients treated with anthracyclines, even at low doses.

Sodium ferulate protects against daunorubicin-induced cardiotoxicity by inhibition of mitochondrial apoptosis in juvenile rats

Daunorubicin (DNR) is a widely used chemotherapeutic agent; however, its clinical use is limited because of its cardiotoxicity. This study was aimed to investigate the protective effect of sodium ferulate (SF), an effective component from traditional Chinese herbs, against DNR-induced cardiotoxicity in juvenile rats. DNR was administered intraperitoneally to rats at the dosage of 2.5 mg·kg(-1)·wk(-1) for 5 consecutive weeks (cumulative dose of 12.5 mg/kg) or in combination with intraperitoneal injection of SF at 50 mg·kg(-1)·d(-1) over a period of 30 days. The animals were killed 6 days after the last injection of DNR. SF significantly ameliorated the DNR-induced cardiac dysfunction, structural damage of the myocardium, and release of lactate dehydrogenase and creatine kinase. Treatment with SF also reversed DNR-induced oxidative stress as evidenced by a decrease in malondialdehyde levels with a concomitant increase in myocardical superoxide dismutase activities. Furthermore, SF afforded significant cardioprotection against DNR-induced apoptosis in vivo and effectively suppressed the complex mitochondrion-dependent apoptotic signaling triggered by DNR. This study indicates that SF may improve cardiac function by inhibition of oxidative stress and apoptosis, thus providing a beneficial effect on the prevention of DNR-induced cardiotoxicity.

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.