Primary cardioprotection with dexrazoxane in patients with childhood cancer who are expected to receive anthracyclines: recommendations from the International Late Effects of Childhood Cancer Guideline Harmonization Group

Pediatric Cardio-Oncology: Screening, Risk Stratification, and Prevention of Cardiotoxicity Associated with Anthracyclines

Anthracyclines have significantly improved the survival of children with malignant tumors, but the associated cardiotoxicity, an effect now under the purview of pediatric cardio-oncology, due to its cumulative and irreversible effects on the heart, limits their clinical application. A systematic screening and risk stratification approach provides the opportunity for early identification and intervention to mitigate, reverse, or prevent myocardial injury, remodeling, and dysfunction associated with anthracyclines. This review summarizes the risk factors, surveillance indexes, and preventive strategies of anthracycline-related cardiotoxicity to improve the safety and efficacy of anthracyclines.

Harmonization of the Upfront Osteosarcoma Treatment Paradigm for Adolescents and Young Adults

Limited guidance exists on streamlining cancer therapy for adolescent and young adult (AYA) patients 15-39 years of age, as much of the current data are extrapolated from pediatric or adult counterparts and can differ significantly between the two care models. Harmonization of standard treatment approaches has the potential to improve outcomes and establish a foundation for the development of future clinical trials. We present our experience harmonizing treatment and supportive care regimens for AYA patients with osteosarcoma receiving treatment with methotrexate, doxorubicin, and cisplatin (MAP) therapy on the pediatric and adult sarcoma services at the Memorial Sloan Kettering Cancer Center.

Aucubin alleviates doxorubicin-induced cardiotoxicity through crosstalk between NRF2 and HIPK2 mediating autophagy and apoptosis

BACKGROUND

Doxorubicin (DOX) is widely used for the treatment of a variety of cancers. However, its clinical application is limited by dose-dependent cardiotoxicity. Recent findings demonstrated that autophagy inhibition and apoptosis of cardiomyocytes induced by oxidative stress dominate the pathophysiology of DOX-induced cardiotoxicity (DIC), however, there are no potential molecules targeting on these.

PURPOSE

This study aimed to explore whether aucubin (AU) acting on inimitable crosstalk between NRF2 and HIPK2 mediated the autophagy, oxidative stress, and apoptosis in DIC, and provide a new and alternative strategy for the treatment of DIC.

METHODS AND RESULTS

We first demonstrated the protection of AU on cardiac structure and function in DIC mice manifested by increased EF and FS values, decreased serum CK-MB and LDH contents and well-aligned cardiac tissue in HE staining. Furthermore, AU alleviated DOX-induced myocardial oxidative stress, mitochondrial damage, apoptosis, and autophagy flux dysregulation in mice, as measured by decreased ROS, 8-OHdG, and TUNEL-positive cells in myocardial tissue, increased SOD and decreased MDA in serum, aligned mitochondria with reduced vacuoles, and increased autophagosomes. In vitro, AU alleviated DOX-induced oxidative stress, autophagy inhibition, and apoptosis by promoting NRF2 and HIPK2 expression. We also identified crosstalk between NRF2 and HIPK2 in DIC as documented by overexpression of NRF2 or HIPK2 reversed cellular oxidative stress, autophagy blocking, and apoptosis aggravated by HIPK2 or NRF2 siRNA, respectively. Simultaneously, AU promoted the expression and nuclear localization of NRF2 protein, which was reversed by HIPK2 siRNA, and AU raised the expression of HIPK2 protein as well, which was reversed by NRF2 siRNA. Crucially, AU did not affect the antitumor activity of DOX against MCF-7 and HepG2 cells, which made up for the shortcomings of previous anti-DIC drugs.

CONCLUSION

These collective results innovatively documented that AU regulated the unique crosstalk between NRF2 and HIPK2 to coordinate oxidative stress, autophagy, and apoptosis against DIC without compromising the anti-tumor effect of DOX in vitro.

Novel molecular mechanisms of doxorubicin cardiotoxicity: latest leading-edge advances and clinical implications

Doxorubicin (Dox) is among the most widely used cancer chemotherapeutic drugs. The clinical use of Dox is, however, limited due to its cardiotoxicity. Studies over the past several decades have suggested various mechanisms of Dox-induced cardiotoxicity (DIC). Among them are oxidative stress, topoisomerase inhibition, and mitochondrial damage. Several novel molecular targets and signaling pathways underlying DIC have emerged over the past few years. The most notable advances include discovery of ferroptosis as a major form of cell death in Dox cytotoxicity, and elucidation of the involvement of cardiogenetics and regulatory RNAs as well as multiple other targets in DIC. In this review, we discuss these advances, focusing on latest cutting-edge research discoveries from mechanistic studies reported in influential journals rather than surveying all research studies available in the literature.

The Importance and Essentiality of Natural and Synthetic Chelators in Medicine: Increased Prospects for the Effective Treatment of Iron Overload and Iron Deficiency

The supply and control of iron is essential for all cells and vital for many physiological processes. All functions and activities of iron are expressed in conjunction with iron-binding molecules. For example, natural chelators such as transferrin and chelator-iron complexes such as haem play major roles in iron metabolism and human physiology. Similarly, the mainstay treatments of the most common diseases of iron metabolism, namely iron deficiency anaemia and iron overload, involve many iron-chelator complexes and the iron-chelating drugs deferiprone (L1), deferoxamine (DF) and deferasirox. Endogenous chelators such as citric acid and glutathione and exogenous chelators such as ascorbic acid also play important roles in iron metabolism and iron homeostasis. Recent advances in the treatment of iron deficiency anaemia with effective iron complexes such as the ferric iron tri-maltol complex (feraccru or accrufer) and the effective treatment of transfusional iron overload using L1 and L1/DF combinations have decreased associated mortality and morbidity and also improved the quality of life of millions of patients. Many other chelating drugs such as ciclopirox, dexrazoxane and EDTA are used daily by millions of patients in other diseases. Similarly, many other drugs or their metabolites with iron-chelation capacity such as hydroxyurea, tetracyclines, anthracyclines and aspirin, as well as dietary molecules such as gallic acid, caffeic acid, quercetin, ellagic acid, maltol and many other phytochelators, are known to interact with iron and affect iron metabolism and related diseases. Different interactions are also observed in the presence of essential, xenobiotic, diagnostic and theranostic metal ions competing with iron. Clinical trials using L1 in Parkinson's, Alzheimer's and other neurodegenerative diseases, as well as HIV and other infections, cancer, diabetic nephropathy and anaemia of inflammation, highlight the importance of chelation therapy in many other clinical conditions. The proposed use of iron chelators for modulating ferroptosis signifies a new era in the design of new therapeutic chelation strategies in many other diseases. The introduction of artificial intelligence guidance for optimal chelation therapeutic outcomes in personalised medicine is expected to increase further the impact of chelation in medicine, as well as the survival and quality of life of millions of patients with iron metabolic disorders and also other diseases.

Pharmacological activation of GPX4 ameliorates doxorubicin-induced cardiomyopathy

Due to the cardiotoxicity of doxorubicin (DOX), its clinical application is limited. Lipid peroxidation caused by excessive ferrous iron is believed to be a key molecular mechanism of DOX-induced cardiomyopathy (DIC). Dexrazoxane (DXZ), an iron chelator, is the only drug approved by the FDA for reducing DIC, but it has many side effects and cannot be used as a preventive drug in clinical practice. Single-nucleus RNA sequencing (snRNA-seq) analysis identified myocardial and epithelial cells that are susceptible to DOX-induced ferroptosis. The glutathione peroxidase 4 (GPX4) activator selenomethione (SeMet) significantly reduced polyunsaturated fatty acids (PUFAs) and oxidized lipid levels in vitro. Consistently, SeMet significantly decreased DOX-induced lipid peroxidation in H9C2 cells and mortality in C57BL/6 mice compared to DXZ, ferrostatin-1, and normal saline. SeMet can effectively reduce serum markers of cardiac injury in C57BL/6 mice and breast cancer patients. Depletion of the GPX4 gene in C57BL/6 mice resulted in an increase in polyunsaturated fatty acid (PUFA) levels and eliminated the protective effect of SeMet against DIC. Notably, SeMet exerted antitumor effects on breast cancer models with DOX while providing cardiac protection for the same animal without detectable toxicities. These findings suggest that pharmacological activation of GPX4 is a valuable and promising strategy for preventing the cardiotoxicity of doxorubicin.

DL-3-n-butylphthalide attenuates doxorubicin-induced acute cardiotoxicity via Nrf2/HO-1 signaling pathway

Doxorubicin (DOX) is a widely used chemotherapeutic drug known to cause dose-dependent myocardial toxicity, which limits its clinical potential. DL-3-n-butylphthalide (NBP), a substance extracted from celery seed species, has a number of pharmacological properties, such as antioxidant, anti-inflammatory, and anti-apoptotic actions. However, whether NBP can protect against DOX-induced acute myocardial toxicity is still unclear. Therefore, this study was designed to investigate the potential protective effects of NBP against DOX-induced acute myocardial injury and its underlying mechanism. By injecting 15 mg/kg of DOX intraperitoneally, eight-week-old male C57BL6 mice suffered an acute myocardial injury. The treatment group of mice received 80 mg/kg NBP by gavage once daily for 14 days. To mimic the cardiotoxicity of DOX, 1uM DOX was administered to H9C2 cells in vitro. In comparison to the DOX group, the results showed that NBP improved cardiac function and decreased serum levels of cTnI, LDH, and CK-MB. Additionally, HE staining demonstrated that NBP attenuated cardiac fibrillar lysis and breakage in DOX-treated mouse hearts. Western blotting assay and immunofluorescence staining suggested that NBP attenuated DOX-induced oxidative stress, apoptosis, and inflammation both in vivo and in vitro. Mechanistically, NBP significantly upregulated the Nrf2/HO-1 signaling pathway, while the Nrf2 inhibitor ML385 prevented NBP from protecting the myocardium from DOX-induced myocardial toxicity in vitro. In conclusion, Our results indicate that NBP alleviates DOX-induced myocardial toxicity by activating the Nrf2/HO-1 signaling pathway.

Anticancer therapy-induced adverse drug reactions in children and preventive and control measures

In recent years, considerable achievements have been made in pediatric oncology with the innovation and development of antitumor drugs. However, compared to adults, children as a special group have not yet matured fully in terms of liver and kidney function. Moreover, pediatric patients are prone to more adverse drug reactions (ADRs) from the accumulation of antineoplastic drugs due to their smaller body size and larger body surface area. Chemotherapy-related ADRs have become a non-negligible factor that affects cancer remission. To date, studies on ADRs in pediatric cancer patients have emerged internationally, but few systematic summaries are available. Here, we reviewed the various systemic ADRs associated with antitumor drugs in children and adolescent patients, as well as the advances in strategies to cope with ADRs, which consisted of neurotoxicity, hematological toxicity, cardiotoxicity, ADRs of the respiratory system and gastrointestinal system and urinary system, ADRs of the skin and its adnexa, allergic reactions, and other ADRs. For clinicians and researchers, understanding the causes, symptoms, and coping strategies for ADRs caused by anticancer treatments will undoubtedly benefit more children.

Association of European Paediatric and Congenital Cardiology practical recommendations for surveillance and prevention of cardiac disease in childhood cancer survivors: the importance of physical activity and lifestyle changes From the Association of European Paediatric and Congenital Cardiology Working Group Sports Cardiology, Physical Activity and Prevention, Working Group Adult Congenital Heart Disease, Working Group Imaging and Working Group Heart Failure

BACKGROUND

Childhood cancer survivors are at increased risk of developing cardiovascular diseases, presenting as the main causes of morbidity and mortality within this group. Besides the usual primary and secondary prevention in combination with screening during follow-up, the modifiable lifestyle factors of physical activity, nutrition, and body weight have not yet gained enough attention regarding potential cardiovascular risk reduction.

OBJECTIVE

These practical recommendations aim to provide summarised information and practical implications to paediatricians and health professionals treating childhood cancer survivors to reduce the risk of cardiovascular late effects.

METHODS

The content derives from either published guidelines or expert opinions from Association of European Paediatric and Congenital Cardiology working groups and is in accordance with current state-of-the-art.

RESULTS

All usual methods of prevention and screening regarding the risk, monitoring, and treatment of occurring cardiovascular diseases are summarised. Additionally, modifiable lifestyle factors are explained, and clear practical implications are named.

CONCLUSION

Modifiable lifestyle factors should definitely be considered as a cost-effective and complementary approach to already implemented follow-up care programs in cardio-oncology, which can be actively addressed by the survivors themselves. However, treating physicians are strongly encouraged to support survivors to develop and maintain a healthy lifestyle, including physical activity as one of the major influencing factors. This article summarises relevant background information and provides specific practical recommendations on how to advise survivors to increase their level of physical activity.

Drug Selection and Posology, Optimal Therapies and Risk/Benefit Assessment in Medicine: The Paradigm of Iron-Chelating Drugs

The design of clinical protocols and the selection of drugs with appropriate posology are critical parameters for therapeutic outcomes. Optimal therapeutic protocols could ideally be designed in all diseases including for millions of patients affected by excess iron deposition (EID) toxicity based on personalised medicine parameters, as well as many variations and limitations. EID is an adverse prognostic factor for all diseases and especially for millions of chronically red-blood-cell-transfused patients. Differences in iron chelation therapy posology cause disappointing results in neurodegenerative diseases at low doses, but lifesaving outcomes in thalassemia major (TM) when using higher doses. In particular, the transformation of TM from a fatal to a chronic disease has been achieved using effective doses of oral deferiprone (L1), which improved compliance and cleared excess toxic iron from the heart associated with increased mortality in TM. Furthermore, effective L1 and L1/deferoxamine combination posology resulted in the complete elimination of EID and the maintenance of normal iron store levels in TM. The selection of effective chelation protocols has been monitored by MRI T2* diagnosis for EID levels in different organs. Millions of other iron-loaded patients with sickle cell anemia, myelodysplasia and haemopoietic stem cell transplantation, or non-iron-loaded categories with EID in different organs could also benefit from such chelation therapy advances. Drawbacks of chelation therapy include drug toxicity in some patients and also the wide use of suboptimal chelation protocols, resulting in ineffective therapies. Drug metabolic effects, and interactions with other metals, drugs and dietary molecules also affected iron chelation therapy. Drug selection and the identification of effective or optimal dose protocols are essential for positive therapeutic outcomes in the use of chelating drugs in TM and other iron-loaded and non-iron-loaded conditions, as well as general iron toxicity.

Pharmacotherapy for Cancer Treatment-Related Cardiac Dysfunction and Heart Failure in Childhood Cancer Survivors

The number of childhood cancer survivors is increasing rapidly. According to American Association for Cancer Research, there are more than 750,000 childhood cancer survivors in the United States and Europe. As the number of childhood cancer survivors increases, so does cancer treatment-related cardiac dysfunction (CTRCD), leading to heart failure (HF). It has been reported that childhood cancer survivors who received anthracyclines are 15 times more likely to have late cancer treatment-related HF and have a 5-fold higher risk of death from cardiovascular (CV) disease than the general population. CV disease is the leading cause of death in childhood cancer survivors. The increasing need to manage cancer survivor patients has led to the rapid creation and adaptation of cardio-oncology. Cardio-oncology is a multidisciplinary science that monitors, treats, and prevents CTRCD. Many guidelines and position statements have been published to help diagnose and manage CTRCD, including those from the American Society of Clinical Oncology, the European Society of Cardiology, the Canadian Cardiovascular Society, the European Society of Medical Oncology, the International Late Effects of Childhood Cancer Guideline Harmonization Group, and many others. However, there remains a gap in identifying high-risk patients likely to develop cardiomyopathy and HF in later life, thus reducing primary and secondary measures being instituted, and when to start treatment when there is echocardiographic evidence of left ventricular (LV) dysfunctions without symptoms of HF. There are no randomized controlled clinical trials for treatment for CTRCD leading to HF in childhood cancer survivors. The treatment of HF due to cancer treatment is similar to the guidelines for general HF. This review describes the latest pharmacologic therapy for preventing and treating LV dysfunction and HF in childhood cancer survivors based on expert consensus guidelines and extrapolating data from adult HF trials.

Improving quality and quantity of life for childhood cancer survivors globally in the twenty-first century

The contributions of cooperative groups to performing large-cohort clinical trials and long-term survivorship studies have facilitated advances in treatment, supportive care and, ultimately, survival for patients with paediatric cancers. As a result, the number of childhood cancer survivors in the USA alone is expected to reach almost 580,000 by 2040. Despite these substantial improvements, childhood cancer survivors continue to have an elevated burden of chronic disease and an excess risk of early death compared with the general population and therefore constitute a large, medically vulnerable population for which delivery of high-quality, personalized care is much needed. Data from large survivorship cohorts have enabled the identification of compelling associations between paediatric cancers, cancer therapy and long-term health conditions. Effectively translating these findings into clinical care that improves the quality and quantity of life for survivors remains an important focus of ongoing research. Continued development of well-designed clinical studies incorporating dissemination and implementation strategies with input from patient advocates and other key stakeholders is crucial to overcoming these gaps. This Review highlights the global progress made and future efforts that will be needed to further increase the quality and quantity of life-years gained for childhood cancer survivors.

Cardiotoxicity of breast cancer chemotherapy

Breast cancer is one of the leading causes of malignancy affecting women in the United States. Although many effective treatments are available, most come with notable side effects that providers and patients must take into consideration. Various classes of chemotherapeutic agents, including anthracyclines and human epidermal growth factor receptor-2 antagonists, are known to be toxic to myocardial tissue. In this review article, we discuss what is reported in the literature regarding the cardiotoxicity of these agents as well as how to monitor and prevent cardiac injury and dysfunction.

Iron Load Toxicity in Medicine: From Molecular and Cellular Aspects to Clinical Implications

Iron is essential for all organisms and cells. Diseases of iron imbalance affect billions of patients, including those with iron overload and other forms of iron toxicity. Excess iron load is an adverse prognostic factor for all diseases and can cause serious organ damage and fatalities following chronic red blood cell transfusions in patients of many conditions, including hemoglobinopathies, myelodyspasia, and hematopoietic stem cell transplantation. Similar toxicity of excess body iron load but at a slower rate of disease progression is found in idiopathic haemochromatosis patients. Excess iron deposition in different regions of the brain with suspected toxicity has been identified by MRI T2* and similar methods in many neurodegenerative diseases, including Alzheimer's disease and Parkinson's disease. Based on its role as the major biological catalyst of free radical reactions and the Fenton reaction, iron has also been implicated in all diseases associated with free radical pathology and tissue damage. Furthermore, the recent discovery of ferroptosis, which is a cell death program based on free radical generation by iron and cell membrane lipid oxidation, sparked thousands of investigations and the association of iron with cardiac, kidney, liver, and many other diseases, including cancer and infections. The toxicity implications of iron in a labile, non-protein bound form and its complexes with dietary molecules such as vitamin C and drugs such as doxorubicin and other xenobiotic molecules in relation to carcinogenesis and other forms of toxicity are also discussed. In each case and form of iron toxicity, the mechanistic insights, diagnostic criteria, and molecular interactions are essential for the design of new and effective therapeutic interventions and of future targeted therapeutic strategies. In particular, this approach has been successful for the treatment of most iron loading conditions and especially for the transition of thalassemia from a fatal to a chronic disease due to new therapeutic protocols resulting in the complete elimination of iron overload and of iron toxicity.

The Vital Role Played by Deferiprone in the Transition of Thalassaemia from a Fatal to a Chronic Disease and Challenges in Its Repurposing for Use in Non-Iron-Loaded Diseases

The iron chelating orphan drug deferiprone (L1), discovered over 40 years ago, has been used daily by patients across the world at high doses (75-100 mg/kg) for more than 30 years with no serious toxicity. The level of safety and the simple, inexpensive synthesis are some of the many unique properties of L1, which played a major role in the contribution of the drug in the transition of thalassaemia from a fatal to a chronic disease. Other unique and valuable clinical properties of L1 in relation to pharmacology and metabolism include: oral effectiveness, which improved compliance compared to the prototype therapy with subcutaneous deferoxamine; highly effective iron removal from all iron-loaded organs, particularly the heart, which is the major target organ of iron toxicity and the cause of mortality in thalassaemic patients; an ability to achieve negative iron balance, completely remove all excess iron, and maintain normal iron stores in thalassaemic patients; rapid absorption from the stomach and rapid clearance from the body, allowing a greater frequency of repeated administration and overall increased efficacy of iron excretion, which is dependent on the dose used and also the concentration achieved at the site of drug action; and its ability to cross the blood-brain barrier and treat malignant, neurological, and microbial diseases affecting the brain. Some differential pharmacological activity by L1 among patients has been generally shown in relation to the absorption, distribution, metabolism, elimination, and toxicity (ADMET) of the drug. Unique properties exhibited by L1 in comparison to other drugs include specific protein interactions and antioxidant effects, such as iron removal from transferrin and lactoferrin; inhibition of iron and copper catalytic production of free radicals, ferroptosis, and cuproptosis; and inhibition of iron-containing proteins associated with different pathological conditions. The unique properties of L1 have attracted the interest of many investigators for drug repurposing and use in many pathological conditions, including cancer, neurodegenerative conditions, microbial conditions, renal conditions, free radical pathology, metal intoxication in relation to Fe, Cu, Al, Zn, Ga, In, U, and Pu, and other diseases. Similarly, the properties of L1 increase the prospects of its wider use in optimizing therapeutic efforts in many other fields of medicine, including synergies with other drugs.

Dexrazoxane and Long-Term Heart Function in Survivors of Childhood Cancer

PURPOSE

For survivors of childhood cancer treated with doxorubicin, dexrazoxane is cardioprotective for at least 5 years. However, longer-term data are lacking.

METHODS

Within the Children's Oncology Group and the Dana Farber Cancer Institute's Childhood Acute Lymphoblastic Leukemia Consortium, we evaluated four randomized trials of children with acute lymphoblastic leukemia or Hodgkin lymphoma, who received doxorubicin with or without dexrazoxane, and a nonrandomized trial of patients with osteosarcoma who all received doxorubicin with dexrazoxane. Cumulative doxorubicin doses ranged from 100 to 600 mg/m2 across these five trials, and dexrazoxane was administered uniformly (10:1 mg/m2 ratio) as an intravenous bolus before doxorubicin. Cardiac function was prospectively assessed in survivors from these trials, plus a matched group of survivors of osteosarcoma treated with doxorubicin without dexrazoxane. Two-dimensional echocardiograms and blood biomarkers were analyzed centrally in blinded fashion. Multivariate analyses adjusted for demographic characteristics, cumulative doxorubicin dose, and chest radiotherapy determined the differences and associations by dexrazoxane status.

RESULTS

From 49 participating institutions, 195 participants were assessed at 18.1 ± 2.7 years since cancer diagnosis (51% dexrazoxane-exposed; cumulative doxorubicin dose 297 ± 91 mg/m2). Dexrazoxane administration was associated with superior left ventricular fractional shortening (absolute difference, +1.4% [95% CI, 0.3 to 2.5]) and ejection fraction (absolute difference, +1.6% [95% CI, 0.0 to 3.2]), and lower myocardial stress per B-type natriuretic peptide (-6.7 pg/mL [95% CI, -10.6 to -2.8]). Dexrazoxane was associated with a reduced risk of having lower left ventricular function (fractional shortening < 30% or ejection fraction < 50%; odds ratio, 0.24 [95% CI, 0.07 to 0.81]). This protective association was primarily seen in those treated with cumulative doxorubicin doses ≥ 250 mg/m2.

CONCLUSION

Among young adult-aged survivors of childhood cancer, dexrazoxane was associated with a cardioprotective effect nearly 20 years after initial anthracycline exposure.

Systematic review and updated recommendations for cardiomyopathy surveillance for survivors of childhood, adolescent, and young adult cancer from the International Late Effects of Childhood Cancer Guideline Harmonization Group

Survivors of childhood, adolescent, and young adult cancer, previously treated with anthracycline chemotherapy (including mitoxantrone) or radiotherapy in which the heart was exposed, are at increased risk of cardiomyopathy. Symptomatic cardiomyopathy is typically preceded by a series of gradually progressive, asymptomatic changes in structure and function of the heart that can be ameliorated with treatment, prompting specialist organisations to endorse guidelines on cardiac surveillance in at-risk survivors of cancer. In 2015, the International Late Effects of Childhood Cancer Guideline Harmonization Group compiled these guidelines into a uniform set of recommendations applicable to a broad spectrum of clinical environments with varying resource availabilities. Since then, additional studies have provided insight into dose thresholds associated with a risk of asymptomatic and symptomatic cardiomyopathy, have characterised risk over time, and have established the cost-effectiveness of different surveillance strategies. This systematic Review and guideline provides updated recommendations based on the evidence published up to September, 2020.