Genetics of Anthracycline Cardiomyopathy in Cancer Survivors: JACC: CardioOncology State-of-the-Art Review

Are Sodium-Glucose Cotransporter-2 Inhibitors the Cherry on Top of Cardio-Oncology Care?

The increasing aging of the population combined with improvements in cancer detection and care has significantly improved the survival and quality of life of cancer patients. These benefits are hampered by the increase of cardiovascular diseases being heart failure the most frequent manifestation of cardiotoxicity and becoming the major cause of morbidity and mortality among cancer survivor. Current strategies to prevent cardiotoxicity involves different approaches such as optimal management of CV risk factors, use of statins and/or neurohormonal medications, and, in some cases, even the use of chelating agents. As a class, SGLT2-i have revolutionized the therapeutic horizon of HF patients independently of their ejection fraction or glycemic status. There is an abundance of data from translational and observational clinical studies supporting a potential beneficial role of SGLT2-i in mitigating the cardiotoxic effects of cancer patients receiving anthracyclines. These findings underscore the need for more robust clinical trials to investigate the effect on cardiovascular outcomes of the prophylactic SGLT2-i treatment in patients undergoing cancer treatment.

Variants in structural cardiac genes in patients with cancer therapy-related cardiac dysfunction after anthracycline chemotherapy: a case control study

BACKGROUND

Variants in cardiomyopathy genes have been identified in patients with cancer therapy-related cardiac dysfunction (CTRCD), suggesting a genetic predisposition for the development of CTRCD. The diagnostic yield of genetic testing in a CTRCD population compared to a cardiomyopathy patient cohort is not yet known and information on which genes should be assessed in this population is lacking.

METHODS

We retrospectively included 46 cancer patients with a history of anthracycline induced CTRCD (defined as a decrease in left ventricular ejection fraction (LVEF) to < 50% and a ≥ 10% reduction from baseline by echocardiography). Genetic testing was performed for 59 established cardiomyopathy genes. Only variants of uncertain significance and (likely) pathogenic variants were included. Diagnostic yield of genetic testing was compared with a matched cohort of patients with dilated cardiomyopathy (DCM, n = 46) and a matched cohort of patients without cardiac disease (n = 111).

RESULTS

Average LVEF at time of CTRCD diagnosis was 30.1 ± 11.0%. Patients were 52.9 ± 14.6 years old at time of diagnosis and 30 (65.2%) were female. Most patients were treated for breast cancer or lymphoma, with a median doxorubicin equivalent dose of 300 mg/m2 [112.5-540.0]. A genetic variant, either pathogenic, likely pathogenic or of uncertain significance, was identified in 29/46 (63.0%) of patients with CTRCD, which is similar to the DCM cohort (34/46, 73.9%, p = 0.262), but significantly higher than in the negative control cohort (47/111, 39.6%, p = 0.018). Variants in TTN were the most prevalent in the CTRCD cohort (43% of all variants). All (likely) pathogenic variants identified in the CTRCD cohort were truncating variants in TTN. There were no significant differences in severity of CTRCD and in recovery rate in variant-harbouring individuals versus non-variant harbouring individuals.

CONCLUSIONS

In this case-control study, cancer patients with anthracycline-induced CTRCD have an increased burden of genetic variants in cardiomyopathy genes, similar to a DCM cohort. If validated in larger prospective studies, integration of genetic data in risk prediction models for CTRCD may guide cancer treatment. Moreover, genetic results have important clinical impact, both for the patient in the setting of precision medicine, as for the family members that will receive genetic counselling.

Functional Validation of Doxorubicin-Induced Cardiotoxicity-Related Genes

Background

Genome-wide association studies and candidate gene association studies have identified more than 180 genetic variants statistically associated with anthracycline-induced cardiotoxicity (AIC). However, the lack of functional validation has hindered the clinical translation of these findings.

Objectives

The aim of this study was to functionally validate all genes associated with AIC using human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs).

Methods

Through a systemic literature search, 80 genes containing variants significantly associated with AIC were identified. Additionally, 3 more genes with potential roles in AIC (GSTM1, CBR1, and ERBB2) were included. Of these, 38 genes exhibited expression in human fetal heart, adult heart, and hiPSC-CMs. Using clustered regularly interspaced short palindromic repeats/Cas9-based genome editing, each of these 38 genes was systematically knocked out in control hiPSC-CMs, and the resulting doxorubicin-induced cardiotoxicity (DIC) phenotype was assessed using hiPSC-CMs. Subsequently, functional assays were conducted for each gene knockout on the basis of hypothesized mechanistic implications in DIC.

Results

Knockout of 26 genes increased the susceptibility of hiPSC-CMs to DIC. Notable genes included efflux transporters (ABCC10, ABCC2, ABCB4, ABCC5, and ABCC9), well-established DIC-associated genes (CBR1, CBR3, and RAC2), and genome-wide association study-discovered genes (RARG and CELF4). Conversely, knockout of ATP2B1, HNMT, POR, CYBA, WDR4, and COL1A2 had no significant effect on the in vitro DIC phenotype of hiPSC-CMs. Furthermore, knockout of the uptake transporters (SLC28A3, SLC22A17, and SLC28A1) demonstrated a protective effect against DIC.

Conclusions

The present findings establish a comprehensive platform for the functional validation of DIC-associated genes, providing insights for future studies in DIC variant associations and potential mechanistic targets for the development of cardioprotective drugs.

Whole Blood Metal Levels in the Setting of an Oncologic Endoprosthesis: Is There Cause for Concern?

BACKGROUND

Massive modular endoprostheses have become a primary means of reconstruction after oncologic resection of a lower extremity tumor. These implants are commonly made with cobalt-chromium alloys that can undergo wear and corrosion, releasing cobalt and chromium ions into the surrounding tissue and blood. However, there are few studies about the blood metal levels in these patients.

QUESTION/PURPOSE

What is the whole blood cobalt and chromium ion level in patients with massive modular endoprostheses?

METHODS

We performed a cross-sectional study of our total joints registry to identify patients with a history of an endoprosthetic reconstruction performed at our institution. Patients who were alive at the time of our review in addition to those undergoing an endoprosthetic reconstruction after an oncologic resection were included. Whole blood samples were obtained from 27 (14 male and 13 female) patients with a history of a lower extremity oncologic endoprosthesis. The median time from surgery to blood collection was 8 years (range 6 months to 32 years). Blood samples were collected and stored in metal-free ethylenediaminetetraacetic acid tubes. Samples were analyzed on an inductively coupled plasma mass spectrometer in an International Organization for Standardization seven-class clean room using polytetrafluoroethylene-coated instruments to reduce the risk of metal contamination. The analytical measuring range was 1 to 200 ng/mL for chromium and cobalt. Cobalt and chromium levels were considered elevated when the blood level was ≥ 1 ppb.

RESULTS

Cobalt levels were elevated in 59% (16 of 27) of patients, and chromium levels were elevated in 26% (seven of 27). In patients with elevated metal ion values, 15 of 17 patients had a reconstruction using a Stryker/Howmedica Global Modular Replacement System implant.

CONCLUSION

Blood metal levels were elevated in patients who received reconstructions using modular oncology endoprostheses Future work is needed to establish appropriate follow-up routines and determine whether and when systemic complications occur because of elevated metal levels and how to potentially address these elevated levels when complications occur. Prospective and retrospective collaboration between multiple centers and specialty societies will be necessary to address these unknown questions in this potentially vulnerable patient group.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Your Heart Function Has Normalized-What Next After TRED-HF?

PURPOSE OF REVIEW

With the widespread implementation of contemporary disease-modifying heart failure therapy, the rates of normalization of ejection fraction are continuously increasing. The TRED-HF trial confirmed that heart failure remission rather than complete recovery is typical in patients with dilated cardiomyopathy who respond to therapy. The present review outlines key points related to the management and knowledge gaps of this growing patient group, focusing on patients with non-ischaemic dilated cardiomyopathy.

RECENT FINDINGS

There is substantial heterogeneity among patients with normalized ejection fraction. The specific etiology is likely to affect the outcome, although a multiple-hit phenotype is frequent and may not be identified without comprehensive characterization. A monogenic or polygenic genetic susceptibility is common. Ongoing pathophysiological processes may be unraveled with advanced cardiac imaging, biomarkers, multi-omics, and machine learning technologies. There are limited studies that have investigated the withdrawal of specific heart failure therapies in these patients. Diuretics may be safely withdrawn if there is no evidence of congestion, while continued therapy with at least some disease-modifying therapy is likely to be required to reduce myocardial workload and sustain remission for the vast majority. Understanding the underlying disease mechanisms of patients with normalized ejection fraction is crucial in identifying markers of myocardial relapse and guiding individualized therapy in the future. Ongoing clinical trials should inform personalized approaches to therapy.

Exploring Frailty in the Intersection of Cardiovascular Disease and Cancer in Older People

Advances in cardiovascular therapies and cancer treatments have resulted in longer patient survival. The coexistence of cancer and cardiovascular disease has been recognized as a complex clinical scenario. In addition to cardiovascular disease, older people with cancer are at greater risk of experiencing multimorbidity and geriatric syndromes, such as frailty. In older people, the concurrent presence of cancer and cardiovascular disease increases the risk of mortality, and the presence of frailty can exacerbate their conditions and hinder treatment effectiveness. Given the significant intersection among frailty, cardiovascular disease, and cancer in older people, this paper aims to provide an overview of the current research in this field and identifies gaps in the research to understand the burden and impact of frailty in these populations. While many studies have examined the prevalence and impact of frailty on adverse outcomes in patients with cancer or cardiovascular disease, evidence of frailty in individuals with both conditions is lacking. There is no universally accepted definition of frailty, which leads to inconsistencies in identifying and measuring frailty in older adults with cardiovascular disease and cancer. The frailty index seems to be a preferred frailty definition in studies of patients with cancer, while the frailty phenotype seems to be more commonly used in cardiovascular research. However, differences in how the frailty index was categorized and in how patients were classified as 'frail' depending on the cut points may have a negative effect on understanding the impact of frailty in the studied populations. This makes it challenging to compare findings across different studies and limits our understanding of the prevalence and impact of frailty in these populations. Addressing these research gaps will contribute to our understanding of the burden of frailty in older people with cardiovascular disease and cancer, and improve clinical care protocols in this vulnerable population.

Altered Peripheral Blood Gene Expression in Childhood Cancer Survivors With Anthracycline-Induced Cardiomyopathy - A COG-ALTE03N1 Report

Background Anthracycline-induced cardiomyopathy is a leading cause of premature death in childhood cancer survivors, presenting a need to understand the underlying pathogenesis. We sought to examine differential blood-based mRNA expression profiles in anthracycline-exposed childhood cancer survivors with and without cardiomyopathy. Methods and Results We designed a matched case-control study (Children's Oncology Group-ALTE03N1) with mRNA sequencing on total RNA from peripheral blood in 40 anthracycline-exposed survivors with cardiomyopathy (cases) and 64 matched survivors without (controls). DESeq2 identified differentially expressed genes. Ingenuity Pathway Analyses (IPA) and Gene Set Enrichment Analyses determined the potential roles of altered genes in biological pathways. Functional validation was performed by gene knockout in human-induced pluripotent stem cell-derived cardiomyocytes using CRISPR/Cas9 (clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9) technology. Median age at primary cancer diagnosis for cases and controls was 8.2 and 9.7 years, respectively. Thirty-six differentially expressed genes with fold change ≥±2 were identified; 35 were upregulated. IPA identified "hepatic fibrosis" and "iron homeostasis" pathways to be significantly modulated by differentially expressed genes, including toxicology functions of myocardial infarction, cardiac damage, and cardiac dilation. Leading edge analysis from Gene Set Enrichment Analyses identified lactate dehydrogenase A (LDHA) and cluster of differentiation 36 (CD36) genes to be significantly upregulated in cases. Interleukin 1 receptor type 1, 2 (IL1R1, IL1R2), and matrix metalloproteinase 8, 9 (MMP8, MMP9) appeared in multiple canonical pathways. LDHA-knockout human-induced pluripotent stem cell-derived cardiomyocytes showed increased sensitivity to doxorubicin. Conclusions We identified differential mRNA expression profiles in peripheral blood of anthracycline-exposed childhood cancer survivors with and without cardiomyopathy. Upregulation of LDHA and CD36 genes suggests metabolic perturbations in a failing heart. Dysregulation of proinflammatory cytokine receptors IL1R1 and IL1R2 and matrix metalloproteinases, MMP8 and MMP9 indicates structural remodeling that accompanies the clinical manifestation of symptomatic cardiotoxicity.

Zymosan A Improved Doxorubicin-Induced Ventricular Remodeling by Evoking Heightened Cardiac Inflammatory Responses and Healing in Mice

Background Doxorubicin-induced myocardial injury is reflected by the presence of vacuolization in both clinical and animal models. The lack of scar tissue to replace the vacuolizated cardiomyocytes indicates that insufficient cardiac inflammation and healing occurred following doxorubicin injection. Whether improved macrophage activity by zymosan A (zymosan) ameliorates doxorubicin-induced ventricular remodeling in mice is unknown. Methods and Results Mice were intravenously injected with vehicle or doxorubicin (5 mg/kg per week, 4 weeks), and cardiac structure and function were assessed by echocardiography. Two distinct macrophage subsets in hearts following doxorubicin injection were measured at different time points by flow cytometry. Moreover, cardiomyocyte vacuolization, capillary density, collagen content, and ventricular tensile strength were assessed. The therapeutic effect of zymosan (3 mg/kg, single injection) on doxorubicin-induced changes in the aforementioned parameters was determined. At the cellular level, the polarization of monocytes to proinflammatory or reparative macrophages were measured, with or without doxorubicin (0.25 and 0.5 μmol/L). Doxorubicin led to less proinflammatory and reparative macrophage infiltration in the heart in the early phase, with decreased cardiac capillary density and collagen III in the chronic phase. In cell culture, doxorubicin (0.5 μmol/L) repressed macrophage transition toward both proinflammatory and reparative subset. Zymosan enhanced both proinflammatory and reparative macrophage infiltration in doxorubicin-injected hearts, evoking a heightened acute inflammatory response. Zymosan alleviated doxorubicin-induced cardiomyocyte vacuolization in the chronic phase, in parallel with enhanced collagen content, capillary density, and ventricular tensile strength. Conclusions Zymosan improved cardiac healing and ameliorated doxorubicin-induced ventricular remodeling and dysfunction by activating macrophages at an optimal time.

Racial Disparity in Anthracycline-induced Cardiotoxicity in Breast Cancer Patients

Breast cancer has become the most common cancer in the US and worldwide. While advances in early detection and treatment have resulted in a 40% reduction in breast cancer mortality, this reduction has not been achieved uniformly among racial groups. A large percentage of non-metastatic breast cancer mortality is related to the cardiovascular effects of breast cancer therapies. These effects appear to be more prevalent among patients from historically marginalized racial/ethnic backgrounds, such as African American and Hispanic individuals. Anthracyclines, particularly doxorubicin and daunorubicin, are the first-line treatments for breast cancer patients. However, their use is limited by their dose-dependent and cumulative cardiotoxicity, manifested by cardiomyopathy, ischemic heart disease, arrhythmias, hypertension, thromboembolic disorders, and heart failure. Cardiotoxicity risk factors, such as genetic predisposition and preexisting obesity, diabetes, hypertension, and heart diseases, are more prevalent in racial/ethnic minorities and undoubtedly contribute to the risk. Yet, beyond these risk factors, racial/ethnic minorities also face unique challenges that contribute to disparities in the emerging field of cardio-oncology, including socioeconomic factors, food insecurity, and the inability to access healthcare providers, among others. The current review will address genetic, clinical, and social determinants that potentially contribute to this disparity.

Modeling Cardiotoxicity in Pediatric Oncology Patients Using Patient-Specific iPSC-Derived Cardiomyocytes Reveals Downregulation of Cardioprotective microRNAs

Anthracyclines are widely used in the treatment of many solid cancers, but their efficacy is limited by cardiotoxicity. As the number of pediatric cancer survivors continues to rise, there has been a concomitant increase in people living with anthracycline-induced cardiotoxicity. Accordingly, there is an ongoing need for new models to better understand the pathophysiological mechanisms of anthracycline-induced cardiac damage. Here we generated induced pluripotent stem cells (iPSCs) from two pediatric oncology patients with acute cardiotoxicity induced by anthracyclines and differentiated them to ventricular cardiomyocytes (hiPSC-CMs). Comparative analysis of these cells (CTX hiPSC-CMs) and control hiPSC-CMs revealed that the former were significantly more sensitive to cell injury and death from the anthracycline doxorubicin (DOX), as measured by viability analysis, cleaved caspase 3 expression, oxidative stress, genomic and mitochondrial damage and sarcomeric disorganization. The expression of several mRNAs involved in structural integrity and inflammatory response were also differentially affected by DOX. Functionally, optical mapping analysis revealed higher arrythmia complexity after DOX treatment in CTX iPSC-CMs. Finally, using a panel of previously identified microRNAs associated with cardioprotection, we identified lower levels of miR-22-3p, miR-30b-5p, miR-90b-3p and miR-4732-3p in CTX iPSC-CMs under basal conditions. Our study provides valuable phenotype information for cellular models of cardiotoxicity and highlights the significance of using patient-derived cardiomyocytes for studying the associated pathogenic mechanisms.

Evaluation of Children with Malignancies for Blood and Marrow Transplantation: A Report from the ASTCT Committee on Practice Guidelines

Evaluation of a candidate for hematopoietic cell transplantation (HCT) is a complex process with substantial intercenter variability. Although literature providing guidance for evaluating the eligibility of adults is well established, similar guidance for children is lacking. To address gaps between adult recommendations and the specific needs of children, we convened a panel of pediatric HCT experts from a wide geographic range of American Society of Transplantation and Cellular Therapy (ASTCT) member institutions to offer recommendations for pediatric-focused pre-HCT evaluation. In this report from the ASTCT Committee on Practice Guidelines, we present a practical framework for evaluating children with malignancies who are candidates for HCT. We also highlight key differences from adults and emphasize areas of unmet need that require additional research to delineate best practices.

Genome-Wide Association Study Identifies ROBO2 as a Novel Susceptibility Gene for Anthracycline-Related Cardiomyopathy in Childhood Cancer Survivors

PURPOSE

Interindividual variability in the dose-dependent association between anthracyclines and cardiomyopathy suggests a modifying role of genetic susceptibility. Few previous studies have examined gene-anthracycline interactions. We addressed this gap using the Childhood Cancer Survivor Study (discovery) and the Children's Oncology Group (COG) study COG-ALTE03N1 (replication).

METHODS

A genome-wide association study (Illumina HumanOmni5Exome Array) in 1,866 anthracycline-exposed Childhood Cancer Survivor Study participants (126 with heart failure) was used to identify single-nucleotide polymorphisms (SNPs) with either main or gene-environment interaction effect on anthracycline-related cardiomyopathy that surpassed a prespecified genome-wide threshold for statistical significance. We attempted replication in a matched case-control set of anthracycline-exposed childhood cancer survivors with (n = 105) and without (n = 160) cardiomyopathy from COG-ALTE03N1.

RESULTS

Two SNPs (rs17736312 [ROBO2]) and rs113230990 (near a CCCTC-binding factor insulator [< 750 base pair]) passed the significance cutoff for gene-anthracycline dose interaction in discovery. SNP rs17736312 was successfully replicated. Compared with the GG/AG genotypes on rs17736312 and anthracyclines ≤ 250 mg/m2, the AA genotype and anthracyclines > 250 mg/m2 conferred a 2.2-fold (95% CI, 1.2 to 4.0) higher risk of heart failure in discovery and an 8.2-fold (95% CI, 2.0 to 34.4) higher risk in replication. ROBO2 encodes transmembrane Robo receptors that bind Slit ligands (SLIT). Slit-Robo signaling pathway promotes cardiac fibrosis by interfering with the transforming growth factor-β1/small mothers against decapentaplegic (Smad) pathway, resulting in disordered remodeling of the extracellular matrix and potentiating heart failure. We found significant gene-level associations with heart failure: main effect (TGF-β1, P = .007); gene*anthracycline interaction (ROBO2*anthracycline, P = .0003); and gene*gene*anthracycline interaction (SLIT2*TGF-β1*anthracycline, P = .009).

CONCLUSION

These findings suggest that high-dose anthracyclines combined with genetic variants involved in the profibrotic Slit-Robo signaling pathway promote cardiac fibrosis via the transforming growth factor-β1/Smad pathway, providing credence to the biologic plausibility of the association between SNP rs17736312 (ROBO2) and anthracycline-related cardiomyopathy.

Molecular mechanisms of anthracycline induced cardiotoxicity: Zebrafish come into play

Anthracyclines are among the most potent chemotherapeutics; however, cardiotoxicity significantly restricts their use. Indeed, anthracycline-induced cardiotoxicity (AIC) fares among the worst types of cardiomyopathy, and may only slowly and partially respond to standard heart failure therapies including β-blockers and ACE inhibitors. No therapy specifically designed to treat anthracycline cardiomyopathy at present, and neither is it known if any such strategy could be developed. To address this gap and to elucidate the molecular basis of AIC with a therapeutic goal in mind, zebrafish has been introduced as an in vivo vertebrate model about a decade ago. Here, we first review our current understanding of the basic molecular and biochemical mechanisms of AIC, and then the contribution of zebrafish to the AIC field. We summarize the generation of embryonic zebrafish AIC models (eAIC) and their use for chemical screening and assessment of genetic modifiers, and then the generation of adult zebrafish AIC models (aAIC) and their use for discovering genetic modifiers via forward mutagenesis screening, deciphering spatial-temporal-specific mechanisms of modifier genes, and prioritizing therapeutic compounds via chemical genetic tools. Several therapeutic target genes and related therapies have emerged, including a retinoic acid (RA)-based therapy for the early phase of AIC and an autophagy-based therapy that, for the first time, is able to reverse cardiac dysfunction in the late phase of AIC. We conclude that zebrafish is becoming an important in vivo model that would accelerate both mechanistic studies and therapeutic development of AIC.

Cardiovascular Side Effects of Anthracyclines and HER2 Inhibitors among Patients with Breast Cancer: A Multidisciplinary Stepwise Approach for Prevention, Early Detection, and Treatment

Cardiovascular (CV) diseases (CVD) are a major cause of long-term morbidity and mortality affecting life expectancy amongst cancer survivors. In recent years, because of the possibility of early diagnosis and the increased efficacy of neo-adjuvant and adjuvant systemic treatments (targeting specific molecular pathways), the high percentage of survival from breast cancer led CVD to become the first cause of death among survivors. Therefore, it is mandatory to adopt cardioprotective strategies to minimize CV side effects and CVD in general in breast cancer patients. Cancer therapeutics-related cardiac dysfunction (CTRCD) is a common group of side effects of chemotherapeutics widely employed in breast cancer (e.g., anthracycline and human epidermal growth factor receptor 2 inhibitors). The aim of the present manuscript is to propose a pragmatic multidisciplinary stepwise approach for prevention, early detection, and treatment of cardiotoxicity in patients with breast cancer.

Cancer therapeutics-related cardiovascular dysfunction: Basic mechanisms and clinical manifestation

Although recent advances in cancer treatment improve cancer prognosis, cancer therapeutics-related cardiovascular dysfunction (CTRCD) significantly contributes to the global burden of cardiovascular disease. CTRCD causes two crucial issues: first, premature treatment interruption or discontinuation of chemotherapy; second, the development of congestive heart failure during and after cancer treatment. Thus, early detection and prompt treatment of CTRCD may improve the prognosis in cancer patients. This review covers representative anticancer drugs, including anthracyclines, human epidermal growth factor 2 inhibitors, tyrosine kinase inhibitors, proteasome inhibitors, and immune checkpoint inhibitors. We focus on the molecular mechanisms of CTRCD and various approaches to diagnosis, prevention, monitoring, and treatment.

Exploring the Cardiotoxicity Spectrum of Anti-Cancer Treatments: Definition, Classification, and Diagnostic Pathways

Early detection and treatment of cancer have led to a noticeable reduction in both mortality and morbidity. However, chemotherapy and radiotherapy could exert cardiovascular (CV) side effects, impacting survival and quality of life, independent of the oncologic prognosis. In this regard, a high clinical index of suspicion is required by the multidisciplinary care team in order to trigger specific laboratory tests (namely natriuretic peptides and high-sensitivity cardiac troponin) and appropriate imaging techniques (transthoracic echocardiography along with cardiac magnetic resonance, cardiac computed tomography, and nuclear testing (if clinically indicated)), leading to timely diagnosis. In the near future, we do expect a more tailored approach to patient care within the respective community along with the widespread implementation of digital health tools.

The Innate Immune System in Cardiovascular Diseases and Its Role in Doxorubicin-Induced Cardiotoxicity

Innate immune cells are the early responders to infection and tissue damage. They play a critical role in the initiation and resolution of inflammation in response to insult as well as tissue repair. Following ischemic or non-ischemic cardiac injury, a strong inflammatory response plays a critical role in the removal of cell debris and tissue remodeling. However, persistent inflammation could be detrimental to the heart. Studies suggest that cardiac inflammation and tissue repair needs to be tightly regulated such that the timely resolution of the inflammation may prevent adverse cardiac damage. This involves the recognition of damage; activation and release of soluble mediators such as cytokines, chemokines, and proteases; and immune cells such as monocytes, macrophages, and neutrophils. This is important in the context of doxorubicin-induced cardiotoxicity as well. Doxorubicin (Dox) is an effective chemotherapy against multiple cancers but at the cost of cardiotoxicity. The innate immune system has emerged as a contributor to exacerbate the disease. In this review, we discuss the current understanding of the role of innate immunity in the pathogenesis of cardiovascular disease and dox-induced cardiotoxicity and provide potential therapeutic targets to alleviate the damage.

Genetic Susceptibility and Mechanisms Underlying the Pathogenesis of Anthracycline-Associated Cardiotoxicity

Anthracyclines are chemotherapeutic agents widely used to treat a variety of cancers, and these drugs have revolutionized our management of cancer patients. The dose-dependent cardiotoxicity of anthracyclines, however, remains one of the leading causes of chemotherapy treatment-associated mortality in cancer survivors. Patient threshold doses leading to anthracycline-induced cardiotoxicity (AIC) are highly variable among affected patients. This variability is largely ascribed to genetic variants in individuals' genomes. Here, we briefly discuss the prevailing mechanisms underlying the pathogenesis of AIC, and then, we review the genetic variants, mostly identified through human genetic approaches and identified in cancer survivors. The identification of all genetic susceptibilities and elucidation of underlying mechanisms of AIC can help improve upfront risk prediction assessment for potentially severe cardiotoxicity disease and provide valuable insights into the understanding of AIC pathophysiology, which can be further leveraged to develop targeted pharmacogenetic therapies for those at high risk.

Upregulation of Endothelin-1 May Predict Chemotherapy-Induced Cardiotoxicity in Women with Breast Cancer

As survival in breast cancer patients from newer therapies increases, concerns for chemotherapy-induced cardiotoxicity (CIC) have offset some of these benefits, manifesting as a decline in left ventricular ejection fraction (LVEF). Patients receiving anthracycline-based chemotherapy followed by trastuzumab are at risk for CIC. Previous research evaluating whether clinical biomarkers predict cardiotoxicity has been inconsistent. Recently, angiotensin II type 1 receptor (ATR1) and endothelin 1 (ET1) have been shown to play a role in breast tumor growth. We evaluated ATR1 and ET1 expression in breast cancer tissue and its association with CIC. A total of 33 paraffin-embedded breast tissue specimens from women with breast cancer treated with anthracycline-based chemotherapy and trastuzumab were analyzed by immunohistochemistry (IHC) and qRT-PCR. We found that ET1 expression was increased in patients with an LVEF ≤ 50% (p = 0.032) with a lower LVEF correlating with higher ET1 expression (r = 0.377, p = 0.031). In patients with a change in LVEF of greater than 10%, greater ET1 expression was noted compared to those without a change in LVEF (p = 0.017). Increased ET1 expression in breast tumor tissue is associated with reduced LVEF. Future studies need to examine whether ET1 may be a tissue biomarker that helps predict the risk of developing CIC in women with breast cancer.

Novel Therapeutics for Anthracycline Induced Cardiotoxicity

Anthracyclines remain an essential component of the treatment of many hematologic and solid organ malignancies, but has important implications on cardiovascular disease. Anthracycline induced cardiotoxicity (AIC) ranges from asymptomatic LV dysfunction to highly morbid end- stage heart failure. As cancer survivorship improves, the detection and treatment of AIC becomes more crucial to improve patient outcomes. Current treatment modalities for AIC have been largely extrapolated from treatment of conventional heart failure, but developing effective therapies specific to AIC is an area of growing research interest. This review summarizes the current evidence behind the use of neurohormonal agents, dexrazoxane, and resynchronization therapy in AIC, evaluates the clinical outcomes of advanced therapy and heart transplantation in AIC, and explores future horizons for treatment utilizing gene therapy, stem cell therapy, and mechanism-specific targets.

Cardio-Oncology: A Myriad of Relationships Between Cardiovascular Disease and Cancer

Cardiovascular disease (CVD) and cancer are the leading causes of death worldwide. With an increasing number of the elderly population, and early cancer screening and treatment, the number of cancers cases are rising, while the mortality rate is decreasing. However, the number of cancer survivors is increasing yearly. With the prolonged life span of cancer patients, the adverse effects of anti-tumor therapy, especially CVD, have gained enormous attention. The incidence of cardiovascular events such as cardiac injury or cardiovascular toxicity is higher than malignant tumors' recurrence rate. Numerous clinical studies have also shifted their focus from the study of a single disease to the interdisciplinary study of oncology and cardiology. Previous studies have confirmed that anti-tumor therapy can cause CVD. Additionally, the treatment of CVD is also related to the tumors incidence. It is well established that the increased incidence of CVD in cancer patients is probably due to an unmodified unhealthy lifestyle among cancer survivors or cardiotoxicity caused by anti-cancer therapy. Nevertheless, some patients with CVD have a relatively increased cancer risk because CVD and malignant tumors are highly overlapping risk factors, including gender, age, hypertension, diabetes, hyperlipidemia, inflammation, and obesity. With advancements in the diagnosis and treatment, many patients simultaneously suffer from CVD and cancer, and most of them have a poor prognosis. Therefore, clinicians should understand the relationship between CVD and tumors, effectively identify the primary and secondary prevention for these diseases, and follow proper treatment methods.

RS4673 and pon1 level in blood plasma - new prospects in prediction and early diagnostics of anthracycline-mediated cardiotoxicity

The purpose of this study was to research the effectiveness of molecular genetic tests based on the determination of the rs4673 CYBA polymorphism (c.242C>T) and the level of paraoxonase 1 (PON1) in the blood plasma of patients with breast cancer (BC) for predicting and diagnosing anthracycline-mediated cardiotoxicity (AMC). The genotyping of rs4673 CYBA (c.242C>T) and the study of the PON1 level in the blood plasma of 280 patients of the Caucasian type with a histologically verified diagnosis of breast cancer, who received complex treatment on the basis of the National Medical Research Center of Oncology, were carried out. Based on the results of observation for at least 8 months, two groups were identified: group 1 (257 people) without diagnosed cardiovascular changes; group 2 (23 people) - patients with subacute and early chronic AMC. It was found that carriers of the rs4673 polymorphism increase the likelihood of developing AMC by 6.8 times (p = 0.001). In the blood plasma of both groups of patients, an increase in the level of PON1 was described after the fourth course compared to the initial level (group 1 - p = 0.036, group 2 - p = 0.048). The level of the studied enzyme was higher in the blood plasma of patients with diagnosed AMC compared with patients without cardiovascular complications (before chemotherapy - p = 0.001, after the fourth course - p = 0.023). The test based on the measurement of the concentration of PON1 in the blood plasma of patients after the fourth course of chemotherapy was distinguished by high quality metrics: sensitivity - 100%, specificity - 70.8%, area under the ROC-curve (AUC) - 0.825 with a threshold level of PON1 equal to 2, 9 ng/μL. The presence of the T/T genotype caused a high level of PON1 in the blood plasma after the fourth course of chemotherapy (p = 0.012). The results of our work are of undoubted practical importance, since they allow us to obtain data on the prognosis and diagnosis of a patient in a short time, which can later be verified using clinical and instrumental methods.

Potential Applications for Targeted Gene Therapy to Protect Against Anthracycline Cardiotoxicity: JACC: CardioOncology Primer

Anthracyclines are associated with risk of significant dose-dependent cardiotoxicity. Conventional heart failure therapies have neither ameliorated declining cardiac function nor addressed the underlying cause. Gene therapy may confer long-term cardioprotection by rendering the heart resistant to anthracyclines after 1 treatment, although the optimal therapeutic target remains to be elucidated. Recombinant adeno-associated virus is now clinically approved for the treatment of lipoprotein lipase deficiency, spinal muscular atrophy, and hereditary transthyretin amyloidosis. High-throughput methods allow selection of recombinant adeno-associated virus capsids that facilitate efficient gene delivery to specific target cells. Vector safety is enhanced by incorporating cardiac-specific promoters into vector design and localizing delivery to reduce off-target risk. Any cardioprotective transgene may bear a degree of risk as they may play as yet unknown roles, which require careful assessment using clinically relevant models. The innovative technologies outlined here make gene therapy a promising proof of principle, with potential further application to nonanthracycline chemotherapeutics.

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Protection against anthracycline cardiotoxicity may be achieved by gene delivery to the heart.

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The optimal cardioprotective target gene remains to be identified.

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Targeted gene expression in human myocytes can now be achieved with advances in AAV vectorology.

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It is critical to minimize risk of off-target effects which may impede anthracycline oncotherapy.

Cardiotoxicity in pediatric lymphoma survivors

INTRODUCTION

Over the past five decades, the diagnosis and management of children with various malignancies have improved tremendously. As a result, an increasing number of children are long-term cancer survivors. With improved survival, however, has come an increased risk of treatment-related cardiovascular complications that can appear decades later.

AREAS COVERED

This review discusses the pathophysiology, epidemiology and effects of treatment-related cardiovascular complications from anthracyclines and radiotherapy in pediatric lymphoma survivors. There is a paucity of evidence-based recommendations for screening for and treatment of cancer therapy-induced cardiovascular complications. We discuss current preventive measures and strategies for their treatment.

EXPERT OPINION

Significant cardiac adverse effects occur due to radiation and chemotherapy received by patients treated for lymphoma. Higher lifetime cumulative doses, female sex, longer follow-up, younger age, and preexisting cardiovascular disease are associated with a higher incidence of cardiotoxicity. With deeper understanding of the mechanisms of these adverse cardiac effects and identification of driver mutations causing these effects, personalized cancer therapy to limit cardiotoxic effects while ensuring an adequate anti-neoplastic effect would be ideal. In the meantime, expanding the use of cardioprotective agents with the best evidence such as dexrazoxane should be encouraged and further studied.

Leveraging Clinical Informatics Tools to Extract Cumulative Anthracycline Exposure, Measure Cardiovascular Outcomes, and Assess Guideline Adherence for Children With Cancer

PURPOSE

Cardiovascular disease is a significant cause of late morbidity and mortality in survivors of childhood cancer. Clinical informatics tools could enhance provider adherence to echocardiogram guidelines for early detection of late-onset cardiomyopathy.

METHODS

Cancer registry data were linked to electronic health record data. Structured query language facilitated the construction of anthracycline-exposed cohorts at a single institution. Primary outcomes included the data quality from automatic anthracycline extraction, sensitivity of International Classification of Disease coding for heart failure, and adherence to echocardiogram guideline recommendations.

RESULTS

The final analytic cohort included 385 pediatric oncology patients diagnosed between July 1, 2013, and December 31, 2018, among whom 194 were classified as no anthracycline exposure, 143 had low anthracycline exposure (< 250 mg/m²), and 48 had high anthracycline exposure (≥ 250 mg/m²). Manual review of anthracycline exposure was highly concordant (95%) with the automatic extraction. Among the unexposed group, 15% had an anthracycline administered at an outside institution not captured by standard query language coding. Manual review of echocardiogram parameters and clinic notes yielded a sensitivity of 75%, specificity of 98%, and positive predictive value of 68% for International Classification of Disease coding of heart failure. For patients with anthracycline exposure, 78.5% (n = 62) were adherent to guideline recommendations for echocardiogram surveillance. There were significant association with provider adherence and race and ethnicity (P = .047), and 50% of patients with Spanish as their primary language were adherent compared with 90% of patients with English as their primary language (P = .003).

CONCLUSION

Extraction of treatment exposures from the electronic health record through clinical informatics and integration with cancer registry data represents a feasible approach to assess cardiovascular disease outcomes and adherence to guideline recommendations for survivors.

Cardiac complications associated with hematopoietic stem-cell transplantation

Advances in chemotherapy and supportive therapy have resulted in improved clinical outcomes in patients with hematological malignancies undergoing hematopoietic stem-cell transplantation (HSCT). However, the association between HSCT and early- and late-onset cardiotoxicity remains controversial as these cardiac complications, including acute heart failure and arrhythmia, such as atrial fibrillation, can occasionally be lethal. Although the overall pathophysiology has not been elucidated, initial/salvage chemotherapy before HSCT, such as anthracycline-combined regimens, conditioning regimens, thoracic radiotherapy, and pre-existing personal risk factors, could be associated with an increased risk of cardiac events. Routine monitoring of cardiac function using global longitudinal strain or left ventricular ejection fraction in echocardiogram and serum biomarkers could be an option to detect early changes in cardiac status before irreversible cardiac complications develop. While beta-blockers and angiotensin-converting enzyme inhibitors are commonly used for cardioprotection, their clinical benefit has not been fully established in HSCT-associated cardiotoxicity. In the future, genetic analysis to reveal individual vulnerability to cardiotoxicity and prospective trials assessing the clinical benefit of early interventions, including novel agents such as angiotensin receptor-neprilysin inhibitor, are warranted. Collaboration between oncologists and cardiologists is crucial to establishing a strategy to prevent cardiac complications.

Cardiometabolic risk in childhood cancer survivors

The Italian Cancer Registry Association has estimated that for the five-year period 2016-2020, in line with the previous five years, approximately 7,000 neoplasms have been diagnosed among children and 4,000 among adolescents. Leukemias, brain tumors and lymphomas together account for more than two-thirds of all pediatric cancers. Fortunately, the five-years survival rate has progressively improved reaching 80% thanks to the continuing improvement of therapeutic protocols but the vast majority of these cancer survivors will have at least one chronic health condition by 40 years of age. Long-term complications concern various organs and systems and have a multifactorial etiopathogenesis. Obesity, diabetes and metabolic syndrome represent chronic diseases that affect life expectancy. Cardiovascular risk partly linked to therapies and genetic susceptibility and partly linked to the presence of obesity, diabetes and metabolic syndrome predispose childhood cancer survivors to heart failure, coronary artery disease, valvular disease, arrhythmia. Hence the cardio- metabolic risk of childhood cancer survivors can have a significant impact on their lives, families, and on society at-large. It is therefore very important to know the risk factors that predispose to the development of cardio-metabolic pathologies in childhood cancer survivors, the possible primary and secondary prevention strategies, the methods of surveillance and the therapeutic approaches.

Disruption of MAP7D1 Gene Function Increases the Risk of Doxorubicin-Induced Cardiomyopathy and Heart Failure

Doxorubicin is a cornerstone chemotherapeutic drug widely used to treat various cancers; its dose-dependent cardiomyopathy, however, is one of the leading causes of treatment-associated mortality in cancer survivors. Patients' threshold doses leading to doxorubicin-induced cardiomyopathy (DIC) and heart failure are highly variable, mostly due to genetic variations in individuals' genomes. However, genetic susceptibility to DIC remains largely unidentified. Here, we combined a genetic approach in the zebrafish (Danio rerio) animal model with a genome-wide association study (GWAS) in humans to identify genetic susceptibility to DIC and heart failure. We firstly reported the cardiac and skeletal muscle-specific expression and sarcomeric localization of the microtubule-associated protein 7 domain-containing protein 1b (Map7d1b) in zebrafish, followed by expression validation in mice. We then revealed that disruption of the map7d1b gene function exaggerated DIC effects in adult zebrafish. Mechanistically, the exacerbated DIC are likely conveyed by impaired autophagic degradation and elevated protein aggregation. Lastly, we identified 2 MAP7D1 gene variants associated with cardiac functional decline and heart failure in cancer patients who received doxorubicin therapy. Together, this study identifies MAP7D1 as a clinically relevant susceptibility gene to DIC and heart failure, providing useful information to stratify cancer patients with a high risk of incurring severe cardiomyopathy and heart failure after receiving chemotherapy.

Heart Failure With Targeted Cancer Therapies: Mechanisms and Cardioprotection

Oncology has seen growing use of newly developed targeted therapies. Although this has resulted in dramatic improvements in progression-free and overall survival, challenges in the management of toxicities related to longer-term treatment of these therapies have also become evident. Although a targeted approach often exploits the differences between cancer cells and noncancer cells, overlap in signaling pathways necessary for the maintenance of function and survival in multiple cell types has resulted in systemic toxicities. In particular, cardiovascular toxicities are of important concern. In this review, we highlight several targeted therapies commonly used across a variety of cancer types, including HER2 (human epidermal growth factor receptor 2)+ targeted therapies, tyrosine kinase inhibitors, immune checkpoint inhibitors, proteasome inhibitors, androgen deprivation therapies, and MEK (mitogen-activated protein kinase kinase)/BRAF (v-raf murine sarcoma viral oncogene homolog B) inhibitors. We present the oncological indications, heart failure incidence, hypothesized mechanisms of cardiotoxicity, and potential mechanistic rationale for specific cardioprotective strategies.