Different dosage schedules for reducing cardiotoxicity in people with cancer receiving anthracycline chemotherapy

Doxorubicin concentrations in bone tumour-relevant tissues after bolus and continuous infusion: a randomized porcine microdialysis study

PURPOSE

Doxorubicin is a widely used chemotherapeutic drug that can be administered intravenously as both a bolus infusion and a continuous infusion. The latter is believed to lower the risk of cardiotoxicity, which is a critical long-term complication of doxorubicin treatment. The local tissue concentrations of doxorubicin will be reflected in both treatment efficacy and toxicity, but very limited information is available. The aim of this study was to measure the concentration of doxorubicin after continuous and bolus infusion in tissue compartments around a typical location of a bone tumour.

METHODS

Sixteen pigs (female, Danish Landrace, mean weight 77 kg) were randomized into two groups of eight. Both groups received an intravenous infusion of 150 mg doxorubicin; Group 1 received a bolus infusion (10-15 min) and Group 2 received a continuous infusion (6 h). Before infusion, microdialysis catheters were placed intravenously and in four bone tumour-relevant tissue compartments (cancellous bone, subcutaneous tissue, synovial fluid of the knee joint and muscle tissue). Sampling was done (n = 15) over 24 h, and venous blood samples were collected as a reference.

RESULTS

Area under the concentration-time curve (AUC0-24 h) for plasma (total concentration) was significantly different between the two groups, while peak drug concentration (Cmax) was significantly higher in two compartments (plasma and synovial fluid of the knee joint) in Group 1 compared to Group 2. Overall, the unbound tissue concentrations were extremely low with values below 0.20 µg/mL.

CONCLUSION

The pharmacokinetic profile for doxorubicin in the investigated tissues is very similar when comparing bolus and 6 h continuous infusion.

Anthracycline-induced cardiotoxicity: mechanisms, monitoring, and prevention

Anthracyclines are the most fundamental and important treatment of several cancers especially for lymphoma and breast cancer. However, their use is limited by a dose-dependent cardiotoxicity which may emerge early at the initiation of anthracycline administration or several years after termination of the therapy. A full comprehending of the mechanisms of anthracycline-induced cardiotoxicity, which has not been achieved and is currently under the efforts, is critical to the advance of developing effective methods to protect against the cardiotoxicity, as well as to early detect and treat it. Therefore, we review the recent progress of the mechanism underlying anthracycline-induced cardiotoxicity, as well as approaches to monitor and prevent this issue.

Deep inspiration breath-hold radiation therapy in left-sided breast cancer patients: a single-institution retrospective dosimetric analysis of organs at risk doses

BACKGROUND

Radiotherapy can induce cardiac injury in left-sided breast cancer cases. Cardiac-sparing irradiation using the deep inspiration breath-hold (DIBH) technique can achieve substantial dose reduction to vulnerable cardiac substructures compared with free breathing (FB). This study evaluated the dosimetric differences between both techniques at a single institution.

METHODS

From 2017 to 2019, 130 patients with left-sided breast cancer underwent breast-conserving surgery (BCS; n = 121, 93.1%) or mastectomy (ME; n = 9, 6.9%) along with axillary lymph node staging (n = 105, 80.8%), followed by adjuvant irradiation in DIBH technique; adjuvant systemic therapy was included if applicable. 106 (81.5%) patients received conventional and 24 (18.5%) hypofractionated irradiation. Additionally, 12 patients received regional nodal irradiation. Computed tomography (CT) scans in FB and DIBH position were performed for all patients. Intrafractional 3D position monitoring of the patient surface in deep inspiration and breath gating was performed using Sentinel and Catalyst HD 3D surface scanning systems (C-RAD, Catalyst, C‑RAD AB, Uppsala, Sweden). Individual coaching and determination of breathing amplitude during the radiation planning CT was performed. Three-dimensional treatment planning was performed using standard tangential treatment portals (6 or 18 MV). The delineation of cardiac structures and both lungs was done in both the FB and the DIBH scan.

RESULTS

All dosimetric parameters for cardiac structures were significantly reduced (p < 0.01 for all). The mean heart dose (Dmean) in the DIBH group was 1.3 Gy (range 0.5-3.6) vs. 2.2 Gy (range 0.9-8.8) in the FB group (p < 0.001). The Dmean for the left ventricle (LV) in DIBH was 1.5 Gy (range 0.6-4.5), as compared to 2.8 Gy (1.1-9.5) with FB (p < 0.001). The parameters for LV (V10 Gy, V15 Gy, V20 Gy, V23 Gy, V25 Gy, V30 Gy) were reduced by about 100% (p < 0.001). The LAD Dmean in the DIBH group was 4.1 Gy (range 1.2-33.3) and 14.3 Gy (range 2.4-37.5) in the FB group (p < 0.001). The median values for LAD such as V15 Gy, V20 Gy, V25 Gy, V30 Gy, and V40 Gy decreased by roughly 100% (p < 0.001). An increasing volume of left lung in the DIBH position resulted in dose sparing of cardiac structures.

CONCLUSION

For all ascertained dosimetric parameters, a significant dose reduction could be achieved in DIBH technique.

Amsacrine-based induction therapy in AML patients with cardiac comorbidities: a retrospective single-center analysis

Intensive chemotherapy is the backbone of induction treatment in patients with acute myeloid leukemia (AML). However, AML patients with concomitant cardiac disease may not be eligible for anthracycline-based therapies. In a small cohort of patients, we have previously shown that anthracycline-free, amsacrine-based chemotherapy TAA (thioguanine, cytarabine, amsacrine) may be as effective as cytarabine/daunorubicin for induction therapy in these patients. In this systematic retrospective single-center analysis, we documented the outcome of 31 patients with significant cardiac comorbidities including coronary heart disease or cardiomyopathy receiving TAA as induction chemotherapy. Median (range) ejection fraction (EF) was 48% (30-67%) in this cohort. Patients with EF below 30% were considered unfit for intensive induction therapy. Event-free survival (EFS), overall survival (OS), and relapse-free survival (RFS) were 1.61, 5.46, and 13.6 months respectively. Poor outcome was primarily related to a high early mortality rate within the first 30 days of therapy, mainly caused by infectious complications. TAA cannot be recommended as a substitute of standard induction for AML patients with significant concomitant cardiac disease. In the era of novel agents, alternative strategies (e.g., hypomethylating agents plus venetoclax) should be considered when anthracycline-based regimens are not suitable.

Risk Prediction Models for Myocardial Dysfunction and Heart Failure in Patients with Current or Prior Cancer

PURPOSE OF REVIEW

Cancer patients are at risk for treatment-related myocardial dysfunction and heart failure during or after treatment. Risk prediction models have the potential to play an important role in identifying patients at high or low risk in order to take appropriate measures. Here, we review their current role.

RECENT FINDINGS

More and more risk prediction models are currently being developed. Unfortunately, they vary widely in their ability to identify patients and survivors at risk for myocardial dysfunction or heart failure, from very poor to strong. Part of this variation might be explained by methodological limitations of the models, but due to a lack of reporting it is not possible to completely assess this. There lies great potential in the improvement of the quality and the use of risk prediction models to inform patients and clinicians on the absolute risk of cardiac events in order to guide care.

Towards Patient-Specific Optimization of Neoadjuvant Treatment Protocols for Breast Cancer Based on Image-Guided Fluid Dynamics

OBJECTIVE

This study establishes a fluid dynamics model personalized with patient-specific imaging data to optimize neoadjuvant therapy (i.e., doxorubicin) protocols for breast cancers.

METHODS

Ten patients recruited at the University of Chicago were included in this study. Quantitative dynamic contrast-enhanced and diffusion weighted magnetic resonance imaging data are leveraged to estimate patient-specific hemodynamic properties, which are then used to constrain the mechanism-based drug delivery model. Then, computer simulations of this model yield the subsequent drug distribution throughout the breast. By systematically varying the dosing schedule, we identify an optimized regimen for each patient using the maximum safe therapeutic duration (MSTD), which is a metric balancing treatment efficacy and toxicity.

RESULTS

With an individually optimized dose (range = 12.11-15.11 mg/m2 per injection), a 3-week regimen consisting of a uniform daily injection significantly outperforms all other scheduling strategies (P < 0.001). In particular, the optimal protocol is predicted to significantly outperform the standard protocol (P < 0.001), improving the MSTD by an average factor of 9.93 (range = 6.63 to 14.17).

CONCLUSION

A clinical-mathematical framework was developed by integrating quantitative MRI data, advanced image processing, and computational fluid dynamics to predict the efficacy and toxicity of neoadjuvant therapy protocols, thus enabling the rational identification of an optimal therapeutic regimen on a patient-specific basis.

SIGNIFICANCE

Our clinical-computational approach has the potential to enable optimization of therapeutic regimens on a patient-specific basis and provide guidance for prospective clinical trials aimed at refining neoadjuvant therapy protocols for breast cancers.

Dexrazoxane for preventing or reducing cardiotoxicity in adults and children with cancer receiving anthracyclines

BACKGROUND

This review is the third update of a previously published Cochrane Review. The original review, looking at all possible cardioprotective agents, was split and this part now focuses on dexrazoxane only. Anthracyclines are effective chemotherapeutic agents in the treatment of numerous malignancies. Unfortunately, their use is limited by a dose-dependent cardiotoxicity. In an effort to prevent or reduce this cardiotoxicity, different cardioprotective agents have been studied, including dexrazoxane.

OBJECTIVES

To assess the efficacy of dexrazoxane to prevent or reduce cardiotoxicity and determine possible effects of dexrazoxane on antitumour efficacy, quality of life and toxicities other than cardiac damage in adults and children with cancer receiving anthracyclines when compared to placebo or no additional treatment.

SEARCH METHODS

We searched CENTRAL, MEDLINE and Embase to May 2021. We also handsearched reference lists, the proceedings of relevant conferences and ongoing trials registers.

SELECTION CRITERIA

Randomised controlled trials (RCTs) in which dexrazoxane was compared to no additional therapy or placebo in adults and children with cancer receiving anthracyclines.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed study selection, data extraction, risk of bias and GRADE assessment of included studies. We analysed results in adults and children separately. We performed analyses according to the Cochrane Handbook for Systematic Reviews of Interventions.

MAIN RESULTS

For this update, we identified 548 unique records. We included three additional RCTs: two paediatric and one adult. Therefore, we included a total of 13 eligible RCTs (five paediatric and eight adult). The studies enrolled 1252 children with leukaemia, lymphoma or a solid tumour and 1269 participants, who were mostly diagnosed with breast cancer. In adults, moderate-quality evidence showed that there was less clinical heart failure with the use of dexrazoxane (risk ratio (RR) 0.22, 95% confidence interval (CI) 0.11 to 0.43; 7 studies, 1221 adults). In children, we identified no difference in clinical heart failure risk between treatment groups (RR 0.20, 95% CI 0.01 to 4.19; 3 studies, 885 children; low-quality evidence). In three paediatric studies assessing cardiomyopathy/heart failure as the primary cause of death, none of the children had this outcome (1008 children, low-quality evidence). In the adult studies, different definitions for subclinical myocardial dysfunction and clinical heart failure combined were used, but pooled analyses were possible: there was a benefit in favour of the use of dexrazoxane (RR 0.37, 95% CI 0.24 to 0.56; 3 studies, 417 adults and RR 0.46, 95% CI 0.33 to 0.66; 2 studies, 534 adults, respectively, moderate-quality evidence). In the paediatric studies, definitions of subclinical myocardial dysfunction and clinical heart failure combined were incomparable, making pooling impossible. One paediatric study showed a benefit in favour of dexrazoxane (RR 0.33, 95% CI 0.13 to 0.85; 33 children; low-quality evidence), whereas another study showed no difference between treatment groups (Fischer exact P = 0.12; 537 children; very low-quality evidence). Overall survival (OS) was reported in adults and overall mortality in children. The meta-analyses of both outcomes showed no difference between treatment groups (hazard ratio (HR) 1.04, 95% 0.88 to 1.23; 4 studies; moderate-quality evidence; and HR 1.01, 95% CI 0.72 to 1.42; 3 studies, 1008 children; low-quality evidence, respectively). Progression-free survival (PFS) was only reported in adults. We subdivided PFS into three analyses based on the comparability of definitions, and identified a longer PFS in favour of dexrazoxane in one study (HR 0.62, 95% CI 0.43 to 0.90; 164 adults; low-quality evidence). There was no difference between treatment groups in the other two analyses (HR 0.95, 95% CI 0.64 to 1.40; 1 study; low-quality evidence; and HR 1.18, 95% CI 0.97 to 1.43; 2 studies; moderate-quality evidence, respectively). In adults, there was no difference in tumour response rate between treatment groups (RR 0.91, 95% CI 0.79 to 1.04; 6 studies, 956 adults; moderate-quality evidence). We subdivided tumour response rate in children into two analyses based on the comparability of definitions, and identified no difference between treatment groups (RR 1.01, 95% CI 0.95 to 1.07; 1 study, 206 children; very low-quality evidence; and RR 0.92, 95% CI 0.84 to 1.01; 1 study, 200 children; low-quality evidence, respectively). The occurrence of secondary malignant neoplasms (SMN) was only assessed in children. The available and worst-case analyses were identical and showed a difference in favour of the control group (RR 3.08, 95% CI 1.13 to 8.38; 3 studies, 1015 children; low-quality evidence). In the best-case analysis, the direction of effect was the same, but there was no difference between treatment groups (RR 2.51, 95% CI 0.96 to 6.53; 4 studies, 1220 children; low-quality evidence). For other adverse effects, results also varied. None of the studies evaluated quality of life. If not reported, the number of participants for an analysis was unclear.

AUTHORS' CONCLUSIONS

Our meta-analyses showed the efficacy of dexrazoxane in preventing or reducing cardiotoxicity in adults treated with anthracyclines. In children, there was a difference between treatment groups for one cardiac outcome (i.e. for one of the definitions used for clinical heart failure and subclinical myocardial dysfunction combined) in favour of dexrazoxane. In adults, no evidence of a negative effect on tumour response rate, OS and PFS was identified; and in children, no evidence of a negative effect on tumour response rate and overall mortality was identified. The results for adverse effects varied. In children, dexrazoxane may be associated with a higher risk of SMN; in adults this was not addressed. In adults, the quality of the evidence ranged between moderate and low; in children, it ranged between low and very low. Before definitive conclusions on the use of dexrazoxane can be made, especially in children, more high-quality research is needed. We conclude that if the risk of cardiac damage is expected to be high, it might be justified to use dexrazoxane in children and adults with cancer who are treated with anthracyclines. However, clinicians and patients should weigh the cardioprotective effect of dexrazoxane against the possible risk of adverse effects, including SMN, for each individual. For children, the International Late Effects of Childhood Cancer Guideline Harmonization Group has developed a clinical practice guideline.

Current Status and Trends of Research on Anthracycline-Induced Cardiotoxicity from 2002 to 2021: A Twenty-Year Bibliometric and Visualization Analysis

Anthracyclines constitute the cornerstone of numerous chemotherapy regimens for various cancers. However, the clinical application of anthracyclines is significantly limited to their dose-dependent cardiotoxicity. A comprehensive understanding of the current status of anthracycline-induced cardiotoxicity is necessary for in-depth research and optimal clinical protocols. Bibliometric analysis is widely applied in depicting development trends and tracking frontiers of a specific field. The present study is aimed at revealing the status and trends of anthracycline-induced cardiotoxicity during the past two decades by employing bibliometric software including R-bibliometric, VOSviewer, and CiteSpace. A total of 3504 publications concerning anthracycline-induced cardiotoxicity from 2002 to 2021 were collected from the Web of Science Core Collection database. Results showed significant growth in annual yields from 90 records in 2002 to 304 papers in 2021. The United States was the most productive country with the strongest collaboration worldwide in the field. Charles University in the Czech Republic was the institution that contributed the most papers, while 7 of the top 10 productive institutions were from the United States. The United States Department of Health and Human Services and the National Institutes of Health are the two agencies that provide financial support for more than 50% of sponsored publications. The research categories of included publications mainly belong to Oncology and Cardiac Cardiovascular Systems. The Journal of Clinical Oncology had a comprehensive impact on this research field with the highest IF value and many publications. Simunek Tomas from Charles University contributed the most publications, while Lipshultz Steven E. from the State University of New York possessed the highest H-index. In addition, the future research frontiers of anthracycline-induced cardiotoxicity might include early detection, pharmacogenomics, molecular mechanism, and cardiooncology. The present bibliometric analysis may provide a valuable reference for researchers and practitioners in future research directions.

Cardioprotective Strategies for Doxorubicin-induced Cardiotoxicity: Present and Future

The improvement of drugs and protocols of chemotherapeutic treatment has led to improved outcomes and survival in patients with cancer. But along with this, at first glance a positive point, there was another interdisciplinary problem, which is the need for early detection and treatment of developing cardiotoxicity when taking chemotherapy drugs. The study of cardioprotective strategies has recently become increasingly relevant, due to the fact that many patients who have successfully undergone treatment for cancer have a high risk of developing or are at high risk of death from cardiovascular diseases. One of the main drugs for the treatment of a number of oncological diseases is an anthracycline – type antibiotic-doxorubicin. This review briefly examines the risk factors and pathophysiological mechanisms underlying anthracycline cardiotoxicity. The current possibilities of cardioprotection of anthracycline cardiotoxicity are considered in detail, and some promising targets and drugs for improving cardioprotective strategies are discussed.

Pediatric Chemotherapy Drugs Associated With Cardiotoxicity

Pediatric cancers are a common cause of childhood morbidity. As a result, chemotherapeutic regimens have been designed to target childhood cancers. These medications are necessary to treat pediatric cancers, however, oncology management options are accompanied by multiple negative and potentially fatal adverse effects. Although anthracyclines are the most commonly used chemotherapeutic agents associated with cardiotoxicity, we also explore other chemotherapeutic drugs used in children that can potentially affect the heart. Genetic variations resulting in single nucleotide polymorphism (SNP) have the propensity to modify the cardiotoxic effects of the chemotherapy drugs. The clinical presentation of the cardiac effects can vary from arrhythmias and heart failure to completely asymptomatic. A range of imaging studies and laboratory investigations can protect the heart from severe outcomes. The physiology of the heart and the effect of drugs in children vary vividly from adults; therefore, it is crucial to study the cardiotoxic effect of chemotherapy drugs in the pediatric population. This review highlights the potential contributing factors for cardiotoxicity in the pediatric population and discusses the identification and management options.

Anthracycline-induced cardiotoxicity: mechanisms of action, incidence, risk factors, prevention, and treatment

Anthracycline is a mainstay in treatment of many cancers including lymphoma and breast cancer among many others. However, anthracycline treatment can be cardiotoxic. Although anthracycline-induced cardiotoxicity is dose dependent, it can also occur early at the onset of treatment and even up to several years following completion of treatment. This review article focuses on the understanding of mechanisms of anthracycline-induced cardiotoxicity, the treatments, and recommended follow-up and preventive approaches.

Anthracycline-related cardiotoxicity in older patients with acute myeloid leukemia: a Young SIOG review paper

The incidence of acute myeloid leukemia (AML) increases with age. Intensive induction chemotherapy containing cytarabine and an anthracycline has been part of the upfront and salvage treatment of AML for decades. Anthracyclines are associated with a significant risk of cardiotoxicity (especially anthracycline-related left ventricular dysfunction [ARLVD]). In the older adult population, the higher prevalence of cardiac comorbidities and risk factors may further increase the risk of ARLVD. In this article of the Young International Society of Geriatric Oncology group, we review the prevalence of ARLVD in patients with AML and factors predisposing to ARLVD, focusing on older adults when possible. In addition, we review the assessment of cardiac function and management of ARLVD during and after treatment. It is worth noting that only a minority of clinical trials focus on alternative treatment strategies in patients with mildly declined left ventricular ejection fraction or at a high risk for ARLVD. The limited evidence for preventive strategies to ameliorate ARLVD and alternative strategies to anthracycline use in the setting of cardiac comorbidities are discussed. Based on extrapolation of findings from younger adults and nonrandomized trials, we recommend a comprehensive baseline evaluation of cardiac function by imaging, cardiac risk factors, and symptoms to risk stratify for ARLVD. Anthracyclines remain an appropriate choice for induction although careful risk-stratification based on cardiac disease, risk factors, and predicted chemotherapy-response are warranted. In case of declined left ventricular ejection fraction, alternative strategies should be considered.

Resistance training improves cardiac function and cardiovascular autonomic control in doxorubicin-induced cardiotoxicity

Doxorubicin (DOX) is an anticancer chemotherapy drug that is widely used in clinical practice. It is well documented that DOX impairs baroreflex responsiveness and left ventricular function and enhances sympathetic activity, cardiac sympathetic afferent reflexes and oxidative stress, which contribute to hemodynamic deterioration. Because resistance training (RT)-induced cardioprotection has been observed in other animal models, the objective of this study was to assess the effects of RT during DOX treatment on hemodynamics, arterial baroreflex, cardiac autonomic tone, left ventricular function and oxidative stress in rats with DOX-induced cardiotoxicity. Male Wistar rats were submitted to a RT protocol (3 sets of 10 repetitions, 40% of one-repetition maximum (1RM) of intensity, 3 times per week, for 8 weeks). The rats were separated into 3 groups: sedentary control, DOX sedentary (2.5 mg/kg of DOX intraperitoneal injection, once a week, for 6 weeks) and DOX + RT. After training or time control, the animals were anesthetized and 2 catheters were implanted for hemodynamic, arterial baroreflex and cardiac autonomic tone. Another group of animals was used to evaluate left ventricular function. We found that RT in DOX-treated rats decreased diastolic arterial pressure, heart rate, sympathetic tone and oxidative stress. In addition, RT increased arterial baroreflex sensitivity, vagal tone and left ventricular developed pressure in rats with DOX-induced cardiotoxicity. In summary, RT is a useful non-pharmacological strategy to attenuate DOX-induced cardiotoxicity.

Genetic Polymorphisms Affecting Cardiac Biomarker Concentrations in Children with Cancer: an Analysis from the "European Paediatric Oncology Off-patents Medicines Consortium" (EPOC) Trial

BACKGROUND AND OBJECTIVES

Doxorubicin plays an essential role in the treatment of paediatric cancers. Defining genotypes with a higher risk for developing anthracycline-induced cardiotoxicity could help to reduce cardiotoxicity.

METHODS

Data originated from a phase II study assessing the pharmacokinetics of doxorubicin in 100 children. Studied patients (0-17 years) were treated for solid tumours or leukaemia. Two cycles of doxorubicin were studied. Concentrations of natriuretic peptides proANP, BNP and NT-proBNP and cardiac troponins T and I were measured at five time points before, during and after two cycles of doxorubicin treatment. Genotypes of 17 genetic polymorphisms in genes encoding for anthracycline metabolizing enzymes and drug transporters were determined for each patient. We analysed the influence of genotypes on cardiac biomarker concentrations at different time points by a Kruskal-Wallis test. To perform a pairwise comparison significant genetic polymorphisms with more than two genotypes were analysed by a post hoc test.

RESULTS

The Kruskal-Wallis tests and the post hoc-tests showed a significant association for seven genetic polymorphisms (ABCB1-rs1128503, ABCB1-rs1045642, ABCC1-rs4148350, CBR3-rs8133052, NQO2-in/del, SLC22A16-rs714368 and SLC22A16-rs6907567) with the concentration of at least one biomarker at one or more time points. We could not identify any polymorphism with a consistent effect on any biomarker over the whole treatment period.

CONCLUSIONS

In this study of patients treated with doxorubicin for different tumour entities, seven genetic polymorphisms possibly influencing the pharmacokinetics and pharmacodynamics of doxorubicin could lead occasionally to differences in the concentration of cardiac biomarkers. Since, the role of cardiac biomarkers for monitoring anthracycline-induced cardiotoxicity has not yet been clarified, further trials with a long follow-up time are required to assess the impact of these genetic polymorphisms on chemotherapy-related cardiotoxicity.

TRIAL REGISTRATION

EudraCT number: 2009-011454-17.

Possible Susceptibility Genes for Intervention against Chemotherapy-Induced Cardiotoxicity

Recent therapeutic advances have significantly improved the short- and long-term survival rates in patients with heart disease and cancer. Survival in cancer patients may, however, be accompanied by disadvantages, namely, increased rates of cardiovascular events. Chemotherapy-related cardiac dysfunction is an important side effect of anticancer therapy. While advances in cancer treatment have increased patient survival, treatments are associated with cardiovascular complications, including heart failure (HF), arrhythmias, cardiac ischemia, valve disease, pericarditis, and fibrosis of the pericardium and myocardium. The molecular mechanisms of cardiotoxicity caused by cancer treatment have not yet been elucidated, and they may be both varied and complex. By identifying the functional genetic variations responsible for this toxicity, we may be able to improve our understanding of the potential mechanisms and pathways of treatment, paving the way for the development of new therapies to target these toxicities. Data from studies on genetic defects and pharmacological interventions have suggested that many molecules, primarily those regulating oxidative stress, inflammation, autophagy, apoptosis, and metabolism, contribute to the pathogenesis of cardiotoxicity induced by cancer treatment. Here, we review the progress of genetic research in illuminating the molecular mechanisms of cancer treatment-mediated cardiotoxicity and provide insights for the research and development of new therapies to treat or even prevent cardiotoxicity in patients undergoing cancer treatment. The current evidence is not clear about the role of pharmacogenomic screening of susceptible genes. Further studies need to done in chemotherapy-induced cardiotoxicity.

Cardiac Disease in Childhood Cancer Survivors: Risk Prediction, Prevention, and Surveillance: JACC CardioOncology State-of-the-Art Review

Cardiac diseases in the growing population of childhood cancer survivors are of major concern. Cardiotoxicity as a consequence of anthracyclines and chest radiotherapy continues to be relevant in the modern treatment era. Mitoxantrone has emerged as an important treatment-related risk factor and evidence on traditional cardiovascular risk factors in childhood cancer survivors is accumulating. International surveillance guidelines have been developed with the aim to detect and manage cardiac diseases early and prevent symptomatic disease. There is growing interest in risk prediction models to individualize prevention and surveillance. This State-of-the-Art Review summarizes literature from a systematic PubMed search focused on cardiac diseases after treatment for childhood cancer. Here, we discuss the prevalence, risk factors, prevention, risk prediction, and surveillance of cardiac diseases in survivors of childhood cancer.

Can we optimise doxorubicin treatment regimens for children with cancer? Pharmacokinetic simulations and a Delphi consensus procedure

BACKGROUND

Despite its cardiotoxicity doxorubicin is widely used for the treatment of paediatric malignancies. Current treatment regimens appear to be suboptimal as treatment strategies vary and do not follow a clear pharmacological rationale. Standardisation of dosing strategies in particular for infants and younger children is required but is hampered by scarcely defined exposure-response relationships. The aim is to provide a rational dosing concept allowing for a reduction of variability in systemic therapy intensity and subsequently unforeseen side effects.

METHODS

Doxorubicin plasma concentrations in paediatric cancer patients were simulated for different treatment schedules using a population pharmacokinetic model which considers age-dependent differences in doxorubicin clearance. Overall drug exposure and peak concentrations were assessed. Simulation results were used to support a three round Delphi consensus procedure with the aim to clarify the pharmacological goals of doxorubicin dosing in young children. A group of 28 experts representing paediatric trial groups and clinical centres were invited to participate in this process.

RESULTS

Pharmacokinetic simulations illustrated the substantial differences in therapy intensity associated with current dosing strategies. Consensus among the panel members was obtained on a standardised a priori dose adaptation that individualises doxorubicin doses based on age and body surface area targeting uniform drug exposure across children treated with the same protocol. Further, a reduction of peak concentrations in very young children by prolonged infusion was recommended.

CONCLUSIONS

An approach to standardise current dose modification schemes in young children is proposed. The consented concept takes individual pharmacokinetic characteristics into account and involves adaptation of both the dose and the infusion duration potentially improving the safety of doxorubicin administration.

Cardiotoxicity of Anthracyclines

Cardiotoxicity is a feared side effect that may limit the clinical use of anthracyclines. It may indeed affect the quality of life and survival of patients with cancer, regardless of oncological prognosis. This paper provides an overview of anthracycline-induced cardiotoxicity in terms of definition, classification, incidence, risk factors, possible mechanisms, diagnosis, and treatment. We also report effective strategies for preventing cardiotoxicity. In addition, we discuss limiting current approaches, the need for a new classification, and early cardiotoxicity detection and treatment. Probably, anthracycline-induced cardiotoxicity is a continuous phenomenon that starts from myocardial cell injury; it is followed by left ventricular ejection fraction (LVEF) and, if not diagnosed and cured early, progressively leads to symptomatic heart failure. Anthracycline-induced cardiotoxicity can be detected at a preclinical phase. The role of biomarkers, in particular troponins, in identifying subclinical cardiotoxicity and its therapy with angiotensin-converting enzyme inhibitors (mainly enalapril) to prevent LVEF reduction is a recognized and effective strategy. If cardiac dysfunction has already occurred, partial or complete LVEF recovery may still be obtained in case of early detection of cardiotoxicity and prompt heart failure treatment.

Diagnostic tools for early detection of cardiac dysfunction in childhood cancer survivors: Methodological aspects of the Dutch late effects after childhood cancer (LATER) cardiology study

BACKGROUND

Cancer therapy-related cardiac dysfunction and heart failure are major problems in long-term childhood cancer survivors (CCS). We hypothesize that assessment of more sensitive echo- and electrocardiographic measurements, and/or biomarkers will allow for improved recognition of patients with cardiac dysfunction before heart failure develops, and may also identify patients at lower risk for heart failure.

OBJECTIVE

To describe the methodology of the Dutch LATER cardiology study (LATER CARD).

METHODS

The LATER CARD study is a cross-sectional study in long-term CCS treated with (potentially) cardiotoxic cancer therapies and sibling controls. We will evaluate 1) the prevalence and associated (treatment related) risk factors of subclinical cardiac dysfunction in CCS compared to sibling controls and 2) the diagnostic value of echocardiography including myocardial strain and diastolic function parameters, blood biomarkers for cardiomyocyte apoptosis, oxidative stress, cardiac remodeling and inflammation and ECG or combinations of them in the surveillance for cancer therapy-related cardiac dysfunction. From 2017 to 2020 we expect to include 1900 CCS and 500 siblings.

CONCLUSIONS

The LATER CARD study will provide knowledge on different surveillance modalities for detection of cardiac dysfunction in long-term CCS at risk for heart failure. The results of the study will enable us to improve long-term follow-up surveillance guidelines for CCS at risk for heart failure.

[Curing cancer and protecting the heart : Challenges in cardio-oncology in the era of modern tumor treatment]

Recent advances in the medical oncological treatment options for cancer have led to a clear improvement in the survival rate worldwide; however, many of the recently developed new drugs are directly or indirectly associated with cardiovascular side effects. Cardiovascular diseases are already the most frequent non-cancerous cause of death in tumor patients. Prevention, early detection of these complications, correct management and timely initiation of specific cardiac medical treatment are the key for an improvement of the cardiovascular prognosis. This article provides an overview and comprehensive summary of the possible cardiotoxic side effects of important oncological therapies and offers possible practical strategies with respect to risk stratification, cardiological follow-up care and management approaches for chemotherapy-induced left ventricular dysfunction.

Pediatric Cardio-Oncology: Development of Cancer Treatment-Related Cardiotoxicity and the Therapeutic Approach to Affected Patients

OPINION STATEMENT

The past 5 decades have seen significant improvements in outcomes for pediatric patients with cancer. Unfortunately, children and adolescents who have been treated for cancer are five to six times more likely to develop cardiovascular disease as a result of their therapies. Cardiovascular disease may manifest in a plethora of ways, from asymptomatic ventricular dysfunction to end-stage heart failure, hypertension, arrhythmia, valvular disease, early coronary artery disease, or peripheral vascular disease. A number of treatment modalities are implicated in pediatric and adult populations, including anthracyclines, radiation therapy, alkylating agents, targeted cancer therapies (small molecules and antibody therapies), antimetabolites, antimicrotubule agents, immunotherapy, interleukins, and chimeric antigen receptor T cells. For some therapies, such as anthracyclines, the mechanism of injury is elucidated, but for many others it is not. While a few protective strategies exist, in many cases, observation and close monitoring is the only defense against developing end-stage cardiovascular disease. Because of the variety of potential outcomes after cancer therapy, a one-size-fits-all approach is not appropriate. Rather, a good working relationship between oncology and cardiology to assess the risks and benefits of various therapies and planning for appropriate surveillance is the best model. When disease is identified, any of a number of therapies may be appropriate; however, in the pediatric and adolescent population supportive data are limited.

Chronic doxorubicin administration impacts satellite cell and capillary abundance in a muscle-specific manner

Anthracycline chemotherapies are effective at reducing disease recurrence and mortality in cancer patients. However, these drugs also contribute to skeletal muscle wasting and dysfunction. The purpose of this study was to assess the impact of chronic doxorubicin (DOX) administration on satellite cell and capillary densities in different skeletal muscles. We hypothesized that DOX would reduce satellite cell and capillary densities of the soleus (SOL) and extensor digitorum longus (EDL) muscles, along with muscle fiber size. Ovariectomized female Sprague-Dawley rats were randomized to receive three bi-weekly intraperitoneal injections of DOX (4 mg∙kg-1 ; cumulative dose 12 mg∙kg-1 ) or vehicle (VEH; saline). Animals were euthanized 5d following the last injection and the SOL and EDL were dissected and prepared for immunohistochemical and RT-qPCR analyses. Relative to VEH, CSA of the SOL and EDL fibers were 26% and 33% smaller, respectively, in DOX (P < 0.05). In the SOL, satellite cell and capillary densities were 39% and 35% lower, respectively, in DOX (P < 0.05), whereas in the EDL satellite cell and capillary densities were unaffected by DOX administration (P > 0.05). Proliferating satellite cells were unaffected by DOX in the SOL (P > 0.05). In the SOL, MYF5 mRNA expression was increased in DOX (P < 0.05), while in the EDL MGF mRNA expression was reduced in DOX (P < 0.05). Chronic DOX administration is associated with reduced fiber size in the SOL and EDL; however, DOX appeared to reduce satellite cell and capillary densities only in the SOL. These findings highlight that therapeutic targets to protect skeletal muscle from DOX may vary across muscles.

Involvement of cytosolic and mitochondrial iron in iron overload cardiomyopathy: an update

Iron overload cardiomyopathy (IOC) is a major cause of death in patients with diseases associated with chronic anemia such as thalassemia or sickle cell disease after chronic blood transfusions. Associated with iron overload conditions, there is excess free iron that enters cardiomyocytes through both L- and T-type calcium channels thereby resulting in increased reactive oxygen species being generated via Haber-Weiss and Fenton reactions. It is thought that an increase in reactive oxygen species contributes to high morbidity and mortality rates. Recent studies have, however, suggested that it is iron overload in mitochondria that contributes to cellular oxidative stress, mitochondrial damage, cardiac arrhythmias, as well as the development of cardiomyopathy. Iron chelators, antioxidants, and/or calcium channel blockers have been demonstrated to prevent and ameliorate cardiac dysfunction in animal models as well as in patients suffering from cardiac iron overload. Hence, either a mono-therapy or combination therapies with any of the aforementioned agents may serve as a novel treatment in iron-overload patients in the near future. In the present article, we review the mechanisms of cytosolic and/or mitochondrial iron load in the heart which may contribute synergistically or independently to the development of iron-associated cardiomyopathy. We also review available as well as potential future novel treatments.

Cardio-oncology: management of cardiovascular toxicity

Traditional chemotherapeutic agents and newer targeted therapies for cancer have the potential to cause cardiovascular toxicities. These toxicities can result in arrhythmias, heart failure, vascular toxicity, and even death. It is important for oncologists and cardiologists to understand the basic diagnostic and management strategies to employ when these toxicities occur. While anti-neoplastic therapy occasionally must be discontinued in this setting, it can often be maintained with caution and careful monitoring. In the second of this two-part review series, we focus on the management of cardiovascular toxicity from anthracyclines, HER2/ErbB2 inhibitors, immune checkpoint inhibitors, and vascular endothelial growth factor inhibitors.

Cardio-toxicity in childhood cancer survivors "Cure is not enough"

The number of pediatric cancer survivors is growing, and they are getting older. Therapy-induced cardiotoxicity therefore is debated as an ongoing problem. Recognition of the side effects in the use of anthracyclines and radiation as well as the patients' clinical condition and comorbidities leads back as far as the beginning of systematic cancer treatment in children in the 1980s. Since, numerous case reports, meta-analyses and retrospective surveys were published worldwide. However, randomized clinical trials with standardized protocols yet fail to be designed. This article gives an overview of the recent reports and emphasizes on the heterogeneity of the different approaches. A standardized work-up which may identify the patient at risk-including the patient's history and condition, individual genetic dispositions, dosage and method of drug application, consideration of co-medication, radiation therapy and dose, standardized imaging methods-is the main proposition of our report. The fusion of already established sources, e.g., data of different registries or study centers, might help to create preventive strategies for and a better understanding of patients with therapy induced cardiomyopathy.

The breast cancer patient in the cardioncology unit

The breakthroughs of breast cancer management have led to a significant improvement in patient survival. However, to obtain this outcome a considerable price has been paid regarding cardiovascular side effects. Indeed, cardiovascular disease is the main cause of mortality in patients with breast cancer over fifty years of age, contributing more than cancer mortality in older cancer survivors. Thus, the identification and the management of patients with breast cancer at risk for cardiovascular events has become critical in order to reduce morbidity and mortality from cardiovascular toxicity due to cancer therapy, which may blunt its effectiveness. Today, cardioncology is a novel and recognized medical discipline, which aims to encourage a close interaction between cardiology and oncology, explore new strategies, collect evidence-based indications, and develop interdisciplinary expertise with the ultimate goal of minimize the risk of developing cardiovascular disease during and after anticancer therapy, prevent the breast cancer patient cured today from becoming the heart patient of tomorrow, and avoiding the possibility that pre-existent cardiac disease be a barrier leading to a reduction of a patient's therapeutic opportunities. In this review we discussed the advantages of a cardioncology approach in terms of risk stratification, monitoring for early diagnosis, prevention, and early treatment of cardiotoxicity.

Cardio-oncology: an overview on outpatient management and future developments

Recent advances in the early detection and treatment of cancer have led to increasing numbers of cancer survivors worldwide. Nonetheless, despite major improvements in the outcome of these patients, long-term side effects of radio- and chemotherapy affect both patient survival and quality of life, independent of the oncological prognosis. Chemotherapy-related cardiac dysfunction is one of the most notorious short-term side effects of anticancer treatment, occurring in ~10% of patients. Progression to overt heart failure carries a strikingly poor prognosis with a 2-year mortality rate of 60%. Early detection of left ventricular damage by periodic monitoring and prompt initiation of heart failure treatment is key in improving cardiovascular prognosis. To meet the growing demand for a specialised interdisciplinary approach for the prevention and management of cardiovascular complications induced by cancer treatment, a new discipline termed cardio-oncology has evolved. However, an uniform, multidisciplinary approach is currently lacking in the Netherlands. This overview provides an introduction and comprehensive summary of this emerging discipline and offers a practical strategy for the outpatient management of this specific patient population.

A Multiscale Physiologically-Based Pharmacokinetic Model for Doxorubicin to Explore its Mechanisms of Cytotoxicity and Cardiotoxicity in Human Physiological Contexts

PURPOSE

The mechanisms underlying doxorubicin cytotoxicity and cardiotoxicity were broadly explored but remain incompletely understood. A multiscale physiologically-based pharmacokinetic (PBPK) model was developed to assess doxorubicin dispositions at levels of system, tissue interstitial, cell, and cellular organelles. This model was adopted to explore the mechanisms-of-action/toxicity of doxorubicin in humans.

METHODS

The PBPK model was developed by analyzing data from mice and the model was verified by scaling up to predict doxorubicin multiscale dispositions in rats and humans. The multiscale dispositions of doxorubicin in human heart and tumors were explicitly simulated to elucidate the potential mechanisms of its cytotoxicity and cardiotoxicity.

RESULTS

The developed PBPK model was able to adequately describe doxorubicin dispositions in mice, rats and humans. In humans, prolonged infusion, a dosing regimen with less cardiotoxicity, was predicted with substantially reduced free doxorubicin concentrations at human heart interstitium, which were lower than the concentrations associated with oxidative stress. However, prolonged infusion did not reduce doxorubicin-DNA adduct at tumor nucleus, consistent with clinical observations that prolonged infusion did not compromise anti-tumor effect, indicating that one primary anti-tumor mechanism was DNA torsion.

CONCLUSIONS

A multiscale PBPK model for doxorubicin was developed and further applied to explore its cytotoxic and cardiotoxic mechanisms.

Molecular iodine/doxorubicin neoadjuvant treatment impair invasive capacity and attenuate side effect in canine mammary cancer

Background

Mammary cancer has a high incidence in canines and is an excellent model of spontaneous carcinogenesis. Molecular iodine (I₂) exerts antineoplastic effects on different cancer cells activating re-differentiation pathways. In co-administration with anthracyclines, I₂ impairs chemoresistance installation and prevents the severity of side effects generated by these antineoplastic drugs. This study is a random and double-blind protocol that analyzes the impact of I₂ (10 mg/day) in two administration schemes of Doxorubicin (DOX; 30 mg/m2) in 27 canine patients with cancer of the mammary gland. The standard scheme (sDOX) includes four cycles of DOX administered intravenously for 20 min every 21 days, while the modified scheme (mDOX) consists of more frequent chemotherapy (four cycles every 15 days) with slow infusion (60 min). In both schemes, I₂ or placebo (colored water) was supplemented daily throughout the treatment.

Results

mDOX attenuated the severity of adverse events (VCOG-CTCAE) in comparison with the sDOX group. The overall tumor response rate (RECIST criteria) for all dogs was 18% (interval of reduction 48–125%), and no significant difference was found between groups. I₂ supplementation enhances the antineoplastic effect in mDOX, exhibiting a significant decrease in the tumor epithelial fraction, diminished expression of chemoresistance (MDR1 and Survivin) and invasion (uPA) markers and enhanced expression of the differentiation factor known as peroxisome proliferator-activated receptors type gamma (PPARγ). Significant tumor lymphocytic infiltration was also observed in both I₂-supplemented groups. The ten-month survival analysis showed that the entire I₂ supplementation (before and after surgery) induced 67–73% of disease-free survival, whereas supplementation in the last period (only after surgery) produced 50% in both schemes.

Conclusions

The mDOX+I₂ scheme improves the therapeutic outcome, diminishes the invasive capacity, attenuates the adverse events and increases disease-free survival. These data led us to propose mDOX+I₂ as an effective treatment for canine mammary cancer.

The duration of anthracycline infusion should be at least one hour in children with cancer: A clinical practice guideline

We aimed to provide recommendations on the infusion duration of anthracycline chemotherapy agents in children with cancer. This study also serves as a practice example of the essential steps that need to be taken when using a previously published systematic review to develop a high-quality clinical practice guideline. Although evidence was scarce and included adult studies, the panel was able (using the Grading of Recommendations Assessment, Development and Evaluation evidence-to-decision framework) to recommend in favor of an anthracycline infusion duration of at least 1 hr (strong recommendation, very low to moderate quality of evidence). Recommending a precise optimal prolonged infusion duration was currently not possible.

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.

Treatment pathway of bone sarcoma in children, adolescents, and young adults

When pediatric, adolescent, and young adult patients present with a bone sarcoma, treatment decisions, especially after relapse, are complex and require a multidisciplinary approach. This review presents scenarios commonly encountered in the therapy of bone sarcomas with the goal of objectively presenting a consensus, multidisciplinary management approach. Little variation was found in the authors' group with respect to local control or systemic therapy. Clinical trials were universally prioritized in all settings. Decisions regarding relapse therapies in the absence of a clinical trial had very minor variations initially, but a consensus was reached after a literature review and discussion. This review presents a concise document and figures as a starting point for evidence‐based care for patients with these rare diseases. This framework allows prospective decision making and prioritization of clinical trials. It is hoped that this framework will inspire and focus future clinical research and thus lead to new trials to improve efficacy and reduce toxicity. Cancer 2017;123:2206–2218. © 2017 American Cancer Society.

This review presents a pathway for the management of common clinical scenarios that arise in the treatment of bone sarcomas in children, adolescents, and young adults. Clinical trials should be prioritized when they are available, and for those times when trials are unavailable, a consensus, multidisciplinary management approach to bone sarcomas is presented.

Slow infusion rate of doxorubicin induces higher pro-inflammatory cytokine production

Different infusion rates of doxorubicin (DOX) have been used for treating human malignancies. Organ toxicity after DOX infusion is a major issue in treatment disruption. However, whether different DOX infusion rates induce different toxicity is still unknown. In this study, we examined the toxicity effects of different DOX infusion rates in the early phase of organ toxicity. Thirty-six rats were randomly divided into 5-, 15-, and 30-min infusion rate groups. A single dose of DOX (8.3 mg/kg, I.V.) was administered at different infusion rates. Blood samples were collected from the femoral artery at 1, 3, 6, 9, 12, 18, 24, 36, and 48 h after DOX administration. The blood cell count and blood biochemistry were analyzed. The liver, kidney, and heart were removed for pathological examinations after the rats were sacrificed. Our findings show that the 30-min group had higher injury markers in the liver (glutamic oxaloacetic transaminase and glutamic pyruvic transaminase), kidneys (blood urea nitrogen and creatinine), and heart (creatine phosphokinase-MB and lactate dehydrogenase), and had higher tumor necrosis factor-alpha and interleukin 6 levels than did the other groups. The 30-min group also had more severe damage according to the pathological examinations. In conclusion, slower infusion of DOX induced a higher inflammatory response and greater organ damage.

How I treat acute myeloid leukemia presenting with preexisting comorbidities

Acute myeloid leukemia (AML) is a devastating disease with an incidence that progressively increases with advancing age. Currently, only ∼40% of younger and 10% of older adults are long-term survivors. If untreated, the overall prognosis of AML remains dismal. Initiation of therapy at diagnosis is usually urgent. Barriers to successful therapy for AML are the attendant toxicities directly related to chemotherapy or those associated with inevitable aplasia. Organ dysfunction often further complicates such toxicities and may even be prohibitive. There are few guidelines to manage such patients and the fear of crossing the medico-legal abyss may dominate. Such clinical scenarios provide particular challenges and require experience for optimal management. Herein, we discuss select examples of common pretreatment comorbidities, including cardiomyopathy, ischemic heart disease; chronic renal failure, with and without dialysis; hepatitis and cirrhosis; chronic pulmonary insufficiency; and cerebral vascular disease. These comorbidities usually render patients ineligible for clinical trials and enormous uncertainty regarding management reigns, often to the point of withholding definitive therapy. The scenarios described herein emphasize that with appropriate subspecialty support, many AML patients with comorbidities can undergo therapy with curative intent and achieve successful long-term outcome.