Chemotherapy-Related Cardiac Dysfunction: A Systematic Review of Genetic Variants Modulating Individual Risk

Risk Assessment Prior to Cardiotoxic Anticancer Therapies in 7 Steps

The burdens of cardiovascular (CV) diseases and cardiotoxic side effects of cancer treatment in oncology patients are increasing in parallel. The European Society of Cardiology (ESC) 2022 Cardio-Oncology guidelines recommend the use of standardized risk stratification tools to determine the risk of cardiotoxicity associated with different anticancer treatment modalities and the severity of their complications. The use of the Heart Failure Association-International Cardio-Oncology Society (HFA-ICOS) is essential for assessing risk prior to starting cancer treatment, and validation of these methods has been performed in patients receiving anthracyclines, human epidermal receptor 2 (HER2)-targeted therapies and breakpoint cluster region-abelson oncogene locus (BCR-ABL) inhibitors. The benefits of performing baseline CV risk assessment and stratification include early recognition of cardiotoxicities, personalisation of cancer treatment and monitoring strategies, and allocation of cardioprotection to those at the highest risk. This review summarizes the key points of risk stratification in these patients. The steps include identifying the target population, assessing nonmodifiable and modifiable CV risk factors, reviewing previous oncologic therapies and CV histories, and performing baseline investigations. In summary, this review aims to provide general physicians with a simple 7-step guide that will help steer and navigate them through cardiac risk evaluation of potentially cardiotoxic oncologic treatment strategies.

Non-coding RNAs and their potential exploitation in cancer therapy-related cardiotoxicity

Life expectancy in cancer patients has been extended in recent years, thanks to major breakthroughs in therapeutic developments. However, this also unmasked an increased incidence of cardiovascular diseases in cancer survivors, which is in part attributable to cancer therapy-related cardiovascular toxicity. Non-coding RNAs (ncRNAs) have received much appreciation due to their impact on gene expression. NcRNAs, which include microRNAs, long ncRNAs and circular RNAs, are non-protein-coding transcripts that are involved in the regulation of various biological processes, hence shaping cell identity and behaviour. They have also been implicated in disease development, including cardiovascular diseases, cancer and, more recently, cancer therapy-associated cardiotoxicity. This review outlines key features of cancer therapy-associated cardiotoxicity, what is known about the roles of ncRNAs in these processes and how ncRNAs could be exploited as therapeutic targets for cardioprotection. LINKED ARTICLES: This article is part of a themed issue Non-coding RNA Therapeutics. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v182.2/issuetoc.

The Moderating Role of Genetics on the Effectiveness of the Mindfulness-Based Stress Reduction for Breast Cancer (MBSR(BC)) Program on Cognitive Impairment

BACKGROUND

Genetics may influence symptoms experienced by breast cancer survivors (BCS) by moderating the effects of stress-reducing interventions, including the Mindfulness-Based Stress Reduction (MBSR(BC)) program, to reduce symptom severity. As part of a larger clinical trial, the aim of this study was to evaluate genetic variants as moderators of MBSR(BC) on improvements among BCS in cognitive functioning and symptoms.

METHODS

BCS (n = 128) were randomized to MBSR(BC) or the Breast Cancer Education Support Program. Objective neuropsychological and subjective measures of cognitive performance, and psychological and physical symptoms were collected at baseline, 6, 12, and 26 weeks. Linear mixed models were implemented to identify MBSR(BC)'s effects over time. A total of 22 single nucleotide polymorphisms (SNPs) from 20 genes known to be related to these symptoms were investigated using genomic DNA. These SNPs were tested as moderators of MBSR(BC) program effects.

RESULTS

Results showed MBSR(BC) participants experienced significantly greater benefits in cognitive functioning, however, the level of benefit varied based on one's genetic profile. Effects sizes, consistency across similar measures were investigated. Among 22 candidate SNPs, rs4680 in COMT, rs1800497 in ANKK1, and rs6277 in DRD2 demonstrated the strongest, most consistent positive effects in moderating MBSR(BC)'s impact on cognitive outcomes.

CONCLUSIONS

Although the effects were small, this translational research may potentially identify BCS with genotypes that would be most influenced by the MBSR(BC) program. These results may be used to develop personalized intervention programs tailored to the genetic profile of each breast cancer survivor who received chemotherapy or chemotherapy and radiation.

TRIAL REGISTRATION

ClinicalTrials.gov, https://www.ClinicalTrials.gov Registration Number: NCT02786797.

Cardiotoxicity and pharmacogenetics of doxorubicin in black Zimbabwean breast cancer patients

AIMS

Doxorubicin-induced cardiotoxicity (DIC) is a significant cause of mortality in cancer care. This study was conducted to establish the frequency of DIC in Zimbabwean breast cancer patients on doxorubicin and to test the DIC predictive power of genetic biomarkers.

METHODS

A cohort of 50 Zimbabwean breast cancer patients treated with doxorubicin were followed up for 12 months with serial echocardiography and genotyped for UGTA1A6*4, SLC28A3 and RARG. Eleven per cent of the patients experienced DIC.

RESULTS

The frequencies of SLC28A3 (rs7853758), UGT1A6*4 (rs17863783) and RARG (rs2229774) were 60.7%, 17.9% and 14.3%, respectively. No association between DIC and the three variants was observed.

CONCLUSIONS

This is the first study on the prevalence of DIC and associated genetic biomarker predictive evaluation in Zimbabwean breast cancer patients. The genetic frequencies observed in our study were different to those reported in other populations. A larger sample size with a longer follow-up time will be necessary in future studies.

CELF4 (rs1786814) gene polymorphism and speckle-tracking Echocardiography for cardiovascular complications in childhood cancer survivors

BACKGROUND

Despite a well-known dose-dependent association between the risk of cardiac dysfunction and anthracycline, the risk of cardiac dysfunction for any given anthracycline dose varies between patients. So, we assessed CELF4 (rs1786814) gene polymorphism on anthracycline-related cardiotoxicity in childhood cancer survivors (CCS).

METHODS

This comparative cross-sectional study included 53 CCS who had regular follow-up visits at the Pediatric Oncology Unit, Menoufia University Hospital. CELF4 (rs1786814) gene polymorphism and conventional and speckle-tracking Echocardiography were done for all survivors.

RESULTS

Regarding CELF4 (rs1786814) genotypes, significant differences existed between the studied groups with a predominance of GG homozygous mutation. For Echocardiographic findings, the ejection fraction and end-systolic diameter compared to the control group, were significantly lower in the survivors group. Speckle- tracking Echocardiography showed a significant difference regarding (GLPS-A4C) and (GLPS-LAX), with no significant difference regarding (GLPS-A2C), (GLPS-Avg) and left atrium between the studied groups. Multivariate logistic regression analysis illustrated a statistically significant relation between cumulative anthracycline dose >300 mg/m2 and CLEF4 (rs1786814) genotypes (GG and GA) and the risk of cardiotoxicity with more significance in GG mutation.

CONCLUSION

Early detection of ventricular dysfunction in CCS with subclinical cardiotoxicity with regular follow-up is promising before the development of life-threatening complications.

IMPACT

Early detection of anthracycline-related cardiotoxicity in childhood cancer survivors (CCS) after finishing chemotherapy. CLEF4 (rs1786814) GG variant is more significant in CCS exposed to high-dose anthracycline. GLPS holds promise as an early predictor of late left ventricular dysfunction and subclinical cardiotoxicity in CCS.

Precision Cardio-oncology: Update on Omics-Based Diagnostic Methods

OPINION STATEMENT

Cardio-oncology is an emerging interdisciplinary field dedicated to the early detection and treatment of adverse cardiovascular events associated with anticancer treatment, and current clinical management of anticancer-treatment-related cardiovascular toxicity (CTR-CVT) remains limited by a lack of detailed phenotypic data. However, the promise of diagnosing CTR-CVT using deep phenotyping has emerged with the development of precision medicine, particularly the use of omics-based methodologies to discover sensitive biomarkers of the disease. In the future, combining information produced by a variety of omics methodologies could expand the clinical practice of cardio-oncology. In this review, we demonstrate how omics approaches can improve our comprehension of CTR-CVT deep phenotyping, discuss the positive and negative aspects of available omics approaches for CTR-CVT diagnosis, and outline how to integrate multiple sets of omics data into individualized monitoring and treatment. This will offer a reliable technical route for lowering cardiovascular morbidity and mortality in cancer patients and survivors.

Identification of ADME genes polymorphic variants linked to trastuzumab-induced cardiotoxicity in breast cancer patients: Case series of mono-institutional experience

BACKGROUND

Long-term survival induced by anticancer treatments discloses emerging frailty among breast cancer (BC) survivors. Trastuzumab-induced cardiotoxicity (TIC) is reported in at least 5% of HER2+BC patients. However, TIC mechanism remains unclear and predictive genetic biomarkers are still lacking. Interaction between systemic inflammation, cytokine release and ADME genes in cancer patients might contribute to explain mechanisms underlying individual susceptibility to TIC and drug response variability. We present a single institution case series to investigate the potential role of genetic variants in ADME genes in HER2+BC patients TIC experienced.

METHODS

We selected data related to 40 HER2+ BC patients undergone to DMET genotyping of ADME constitutive variant profiling, with the aim to prospectively explore their potential role in developing TIC. Only 3 patients ("case series"), who experienced TIC, were compared to 37 "control group" matched patients cardiotoxicity-sparing. All patients underwent to left ventricular ejection fraction (LVEF) evaluation at diagnosis and during anti-HER2 therapy. Each single probe was clustered to detect SNPs related to cardiotoxicity.

RESULTS

In this retrospective analysis, our 3 cases were homogeneous in terms of clinical-pathological characteristics, trastuzumab-based treatment and LVEF decline. We identified 9 polymorphic variants in 8 ADME genes (UGT1A1, UGT1A6, UGT1A7, UGT2B15, SLC22A1, CYP3A5, ABCC4, CYP2D6) potentially associated with TIC.

CONCLUSION

Real-world TIC incidence is higher compared to randomized clinical trials and biomarkers with potential predictive value aren't available. Our preliminary data, as proof of concept, could suggest a predictive role of pharmacogenomic approach in the identification of cardiotoxicity risk biomarkers for anti-HER2 treatment.

Association between genetic variants of transmembrane transporters and susceptibility to anthracycline-induced cardiotoxicity: Current understanding and existing evidence

Anthracyclines remain the cornerstone of numerous chemotherapeutic protocols, with beneficial effects against haematological malignancies and solid tumours. Unfortunately, the clinical usefulness of anthracyclines is compromised by the development of cardiotoxic side effects, leading to dose limitations or treatment discontinuation. There is no absolute linear correlation between the incidence of cardiotoxicity and the threshold dose, suggesting that genetic factors may modify the association between anthracyclines and cardiotoxicity risk. And the majority of single nucleotide polymorphisms (SNPs) associated with anthracycline pharmacogenomics were identified in the ATP-binding cassette (ABC) and solute carrier (SLC) transporters, generating increasing interest in the pharmacogenetic implications of their genetic variations for anthracycline-induced cardiotoxicity (AIC). This review focuses on the influence of SLC and ABC polymorphisms on AIC and highlights the prospects and clinical significance of pharmacogenetics for individualised preventive approaches.

Anthracycline Toxicity: Light at the End of the Tunnel?

Anthracycline-induced cardiotoxicity (AIC) is a serious and common side effect of anthracycline therapy. Identification of genes and genetic variants associated with AIC risk has clinical potential as a cardiotoxicity predictive tool and to allow the development of personalized therapies. In this review, we provide an overview of the function of known AIC genes identified by association studies and categorize them based on their mechanistic implication in AIC. We also discuss the importance of functional validation of AIC-associated variants in human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) to advance the implementation of genetic predictive biomarkers. Finally, we review how patient-specific hiPSC-CMs can be used to identify novel patient-relevant functional targets and for the discovery of cardioprotectant drugs to prevent AIC. Implementation of functional validation and use of hiPSC-CMs for drug discovery will identify the next generation of highly effective and personalized cardioprotectants and accelerate the inclusion of approved AIC biomarkers into clinical practice.

Identification of novel hypermethylated or hypomethylated CpG sites and genes associated with anthracycline-induced cardiomyopathy

Anthracycline-induced cardiomyopathy is a leading cause of late morbidity in childhood cancer survivors. Aberrant DNA methylation plays a role in de novo cardiovascular disease. Epigenetic processes could play a role in anthracycline-induced cardiomyopathy but remain unstudied. We sought to examine if genome-wide differential methylation at 'CpG' sites in peripheral blood DNA is associated with anthracycline-induced cardiomyopathy. This report used participants from a matched case-control study; 52 non-Hispanic White, anthracycline-exposed childhood cancer survivors with cardiomyopathy were matched 1:1 with 52 survivors with no cardiomyopathy. Paired ChAMP (Chip Analysis Methylation Pipeline) with integrated reference-based deconvolution of adult peripheral blood DNA methylation was used to analyze data from Illumina HumanMethylation EPIC BeadChip arrays. An epigenome-wide association study (EWAS) was performed, and the model was adjusted for GrimAge, sex, interaction terms of age at enrollment, chest radiation, age at diagnosis squared, and cardiovascular risk factors (CVRFs: diabetes, hypertension, dyslipidemia). Prioritized genes were functionally validated by gene knockout in human induced pluripotent stem cell cardiomyocytes (hiPSC-CMs) using CRISPR/Cas9 technology. DNA-methylation EPIC array analyses identified 32 differentially methylated probes (DMP: 15 hyper-methylated and 17 hypo-methylated probes) that overlap with 23 genes and 9 intergenic regions. Three hundred and fifty-four differential methylated regions (DMRs) were also identified. Several of these genes are associated with cardiac dysfunction. Knockout of genes EXO6CB, FCHSD2, NIPAL2, and SYNPO2 in hiPSC-CMs increased sensitivity to doxorubicin. In addition, EWAS analysis identified hypo-methylation of probe 'cg15939386' in gene RORA to be significantly associated with anthracycline-induced cardiomyopathy. In this genome-wide DNA methylation profile study, we observed significant differences in DNA methylation at the CpG level between anthracycline-exposed childhood cancer survivors with and without cardiomyopathy, implicating differential DNA methylation of certain genes could play a role in pathogenesis of anthracycline-induced cardiomyopathy.

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

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

Cardiovascular Toxicity of Proteasome Inhibitors: Underlying Mechanisms and Management Strategies: JACC: CardioOncology State-of-the-Art Review

Proteasome inhibitors (PIs) are the backbone of combination treatments for patients with multiple myeloma and AL amyloidosis, while also indicated in Waldenström's macroglobulinemia and other malignancies. PIs act on proteasome peptidases, causing proteome instability due to accumulating aggregated, unfolded, and/or damaged polypeptides; sustained proteome instability then induces cell cycle arrest and/or apoptosis. Carfilzomib, an intravenous irreversible PI, exhibits a more severe cardiovascular toxicity profile as compared with the orally administered ixazomib or intravenous reversible PI such as bortezomib. Cardiovascular toxicity includes heart failure, hypertension, arrhythmias, and acute coronary syndromes. Because PIs are critical components of the treatment of hematological malignancies and amyloidosis, managing their cardiovascular toxicity involves identifying patients at risk, diagnosing toxicity early at the preclinical level, and offering cardioprotection if needed. Future research is required to elucidate underlying mechanisms, improve risk stratification, define the optimal management strategy, and develop new PIs with safe cardiovascular profiles.

RING Finger Protein 10 Regulates AP-1/Meox2 to Mediate Pirarubicin-Induced Cardiomyocyte Apoptosis

Pirarubicin (THP) is one of the classic chemotherapy drugs for cancer treatment. It is often clinically limited because of its cardiotoxicity. The occurrence and development of THP-mediated chemotherapy-related cardiotoxicity (CRC) may be reversed by RING finger protein 10 (RNF10). This study was performed with the aim of evaluating the inhibitory effect of RNF10 on THP-mediated CRC and its molecular mechanism. In vivo, we found that the expression of RNF10 decreased in THP-induced CRC rats, accompanied by Meox2 inhibition and AP-1 activation, resulting in increased cardiomyocyte apoptosis. After small interfering RNA (siRNA) and lentivirus transfection (Lv) of RNF10 in vitro, the expression of RNF10, Meox2, and AP-1 proteins and the degree of cardiomyocyte apoptosis were detected. We found that overexpression of RNF10 in H9C2 cardiomyocytes significantly promoted Meox2 and inhibited AP-1, alleviated apoptosis, and showed further inhibitory activity on THP-induced cardiomyocyte toxicity. Silencing RNF10 showed the opposite result. Our study showed that RNF10 inhibited THP-induced CRC through the activity of Meox2 and AP-1 proteins. RNF10 may be the next drug target for the treatment of CRC and other related cardiovascular diseases.

Cardio oncology: Digital innovations, precision medicine and health equity

The rapid emergence of cardio-oncology has resulted in a rapid growth of cardio-oncology programs, dedicated professional societies sections and committees, and multiple collaborative networks that emerged to amplify the access to care in this new subspecialty. However, most existing data, position statements and guidelines are limited by the lack of availability of large clinical trials to support these recommendations. Furthermore, there are significant challenges regarding proper access to cardio-oncology care and treatment, particularly in marginalized and minority populations. The emergence and evolution of personalized medicine, artificial intelligence (AI), and machine learning in medicine and in cardio-oncology provides an opportunity for a more targeted, personalized approach to cardiovascular complications of cancer treatment. The proper implementation of these new modalities may facilitate a more equitable approach to adequate and universal access to cardio-oncology care, improve health related outcomes, and enable health care systems to eliminate the digital divide. This article reviews and analyzes the current status on these important issues.

Pharmacogenomics in drug-induced cardiotoxicity: Current status and the future

Drug-induced cardiotoxicity (DICT) is an important concern of drug safety in both drug development and clinical application. The clinical manifestations of DICT include cardiomyopathy, arrhythmia, myocardial ischemia, heart failure, and a series of cardiac structural and functional changes. The occurrence of DICT has negative impacts on the life quality of the patients, brings additional social and economic burden. It is important to identify the potential factors and explore the mechanisms of DICT. Traditional cardiovascular risk factors can only partially explain the risk of DICT. Pharmacogenomic studies show accumulated evidence of genetics in DICT and suggest the potential to guide precision therapy to reduce risk of cardiotoxicity. The comprehensive application of technologies such as third-generation sequencing, human induced pluripotent stem (iPS) cells and genome editing has promoted the in-depth understanding of the functional role of susceptible genes in DICT. This paper reviewed drugs that cause DICT, the clinical manifestations and laboratory tests, as well as the related content of genetic variations associated with the risk of DICT, and further discussed the implication of new technologies in pharmacogenomics of DICT.

Translational Genomic Research: The Association between Genetic Profiles and Cognitive Functioning or Cardiac Function Among Breast Cancer Survivors Completing Chemotherapy

Introduction: Emerging evidence suggests that Chemotherapy (CT) treated breast cancer survivors (BCS) who have "risk variants" in genes may be more susceptible to cognitive impairment (CI) and/or poor cardiac phenotypes. The objective of this preliminary study was to examine whether there is a relationship between genetic variants and objective/subjective cognitive or cardiac phenotypes. Methods and Analysis: BCS were recruited from Moffitt Cancer Center, Morsani College of Medicine, AdventHealth Tampa and Sarasota Memorial Hospital. Genomic DNA were collected at baseline for genotyping analysis. A total of 16 single nucleotide polymorphisms (SNPs) from 14 genes involved in cognitive or cardiac function were evaluated. Three genetic models (additive, dominant, and recessive) were used to test correlation coefficients between genetic variants and objective/subjective measures of cognitive functioning and cardiac outcomes (heart rate, diastolic blood pressure, systolic blood pressure, respiration rate, and oxygen saturation). Results: BCS (207 participants) with a mean age of 56 enrolled in this study. The majority were non-Hispanic white (73.7%), married (63.1%), and received both CT and radiation treatment (77.3%). Three SNPs in genes related to cognitive functioning (rs429358 in APOE, rs1800497 in ANKK1, rs10119 in TOMM40) emerged with the most consistent significant relationship with cognitive outcomes. Among five candidate SNPs related to cardiac functioning, rs8055236 in CDH13 and rs1801133 in MTHER emerged with potential significant relationships with cardiac phenotype. Conclusions: These preliminary results provide initial targets to further examine whether BCS with specific genetic profiles may preferentially benefit from interventions designed to improve cognitive and cardiac functioning following CT.

Clinical and genetic predictions of early-onset cardiac toxicity in adjuvant chemotherapy for breast cancer

Aim: To identify clinical and genetic variants associated with early-onset cardiac toxicity with a low cumulative dose of chemotherapy drugs in breast cancer. Methods: A total of 388 recruited patients completed routine blood, liver and kidney function, D-dimer, troponin T, brain natriuretic peptide (BNP) or N-terminal prohormone of BNP, ECG and echocardiography tests before and after adjuvant chemotherapy. 25 single-nucleotide polymorphisms (SNPs) were tested. Results: A total of 277 adjuvant chemotherapy-related cardiac toxicity events were recorded in 180 patients (46.4%). Anthracycline-containing chemotherapy (odds ratio: 1.848; 95% CI: 1.135-3.008; p = 0.014) and the SLC28A3 rs885004 GG genotype (odds ratio: 2.034; 95% CI: 1.189-3.479; p = 0.010) were found to be associated with overall cardiac toxicity. The final predictive risk model consisting of clinical risk factors and SNPs was better than SNP alone (p = 0.006) or clinical risk factor alone (p = 0.065). Conclusion: On the basis of clinical factors, a prediction model with genetic susceptibility factors can better predict early-onset cardiac toxicity.

RARG S427L attenuates the DNA repair response to doxorubicin in induced pluripotent stem cell-derived cardiomyocytes

Doxorubicin is a commonly used chemotherapeutic drug, but its use is limited by doxorubicin-induced cardiotoxicity (DIC), which can lead to irreversible heart failure and death. A missense variant rs2229774 (p.S427L) in the retinoic acid receptor gamma (RARG) gene is associated with increased susceptibility to DIC, but the precise mechanism underlying this association is incompletely understood. We performed molecular dynamic simulations to determine the effect of this variant on RARG structure and then validated these predictions using CRISPR-Cas9-genome-edited, induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs). We found that this variant leads to reduced activation of its target genes in response to doxorubicin, including gene pathways involved in DNA repair and consequently an inability to mediate DNA repair after exposure to doxorubicin. Our findings establish a role of RARG p.S427L in attenuating DNA repair in DIC and provide insight into the pathogenesis of this cardiotoxic effect.

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RARG p.S427L is predicted to alter the stability of the C terminus of the protein

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The RARG p.S427L variant has impaired ability to activate its target genes

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This variant attenuates the DNA repair response to doxorubicin

Cardiovascular Health Status And Genetic Risk In Survivors of Childhood Neuroblastoma and Nephroblastoma Treated With Doxorubicin: Protocol of the Pharmacogenetic Part of the LESS-Anthra Cross-Sectional Cohort Study

BACKGROUND

In childhood cancer survivors (survival of 5 years or more after diagnosis), cardiac toxicity is the most common nonmalignant cause of death attributed to treatment-related consequences. Identifying patients at risk of developing late cardiac toxicity is therefore crucial to improving treatment outcomes. The use of genetic markers has been proposed, together with clinical risk factors, to predict individual risk of cardiac toxicity from cancer therapies, such as doxorubicin.

OBJECTIVE

The primary aim of this study is to evaluate the value of multimarker genetic testing for RARG rs2229774, UGT1A6 rs17863783, and SLC28A3 rs7853758 for predicting doxorubicin-induced cardiotoxicity. The secondary aim is to replicate previously described associations of candidate genetic markers with doxorubicin-induced cardiotoxicity. Moreover, we will evaluate the prevalence of cardiovascular dysfunction in childhood cancer survivors after neuroblastoma or nephroblastoma.

METHODS

This is the pharmacogenetic substudy of the research project Structural Optimization for Children With Cancer After Anthracycline Therapy (LESS-Anthra). We invited 2158 survivors of childhood neuroblastoma or nephroblastoma treated with doxorubicin according to the trial protocols of SIOP 9/GPOH, SIOP 93-01/GPOH, SIOP 2001/GPOH, NB 90, NB 97, or NB 2004 to participate in this prospective cross-sectional cohort study. The study participants underwent a cardiological examination and were asked to provide a blood or saliva sample for genotyping. The study participants' health statuses and cardiovascular diagnoses were recorded using a questionnaire completed by the cardiologist. Digital echocardiographic data were centrally evaluated to determine the contractile function parameters. Medical data on the tumor diagnosis and treatment protocol were taken from the study documentation. Survivors were screened for variants of several candidate genes by TaqMan genotyping.

RESULTS

This study includes 657 survivors treated with doxorubicin for childhood cancer, the largest German cohort assembled to date to investigate cardiovascular late effects. Data analyses are yet to be completed.

CONCLUSIONS

This study will define the genetic risk related to 3 marker genes proposed in a pharmacogenetic guideline for risk assessment. Moreover, the results of this study will show the prevalence of cardiovascular dysfunction in survivors of pediatric neuroblastoma or nephroblastoma who were treated with doxorubicin. The results will help to improve primary treatment and follow-up care, thus reducing cardiovascular late effects in the growing population of childhood cancer survivors.

TRIAL REGISTRATION

German Clinical Trials Register DRKS00015084; https://www.drks.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00015084.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/27898.

Pharmacogenomic study of anthracycline-induced cardiotoxicity in Mexican pediatric patients

Background: The aim of this study was to evaluate the association between well-defined genetic risk variants in SLC28A3, RARG and UGT1A6 and anthracycline-induced cardiotoxicity in Mexican pediatric patients. Methods: We tested a cohort of 79 children treated with anthracyclines for the presence of SLC28A3-rs7853758, RARG-rs2229774 and UGT1A6-rs17863783. Results: The SLC28A3-rs7853758 variant was more frequent in this cohort, while the UGT1A6-rs17863783 and RARG-rs2229774 variants were present at lower frequencies. A clinically important decrease of fractional shortening was associated with SLC28A3-rs7853758 variant. Conclusion: In this cohort, 39.2% of patients carried the protective SLC28A3 variant. A small number of tested patients have the risk variants of UGT1A6 and RARG. None of the patients shared the two risk variants.

Cardiotoxicity and Chemotherapy-The Role of Precision Medicine

Cancer and cardiovascular disease are the leading causes of death in the United Kingdom. Many systemic anticancer treatments are associated with short- and long-term cardiotoxicity. With improving cancer survival and an ageing population, identifying those patients at the greatest risk of cardiotoxicity from their cancer treatment is becoming a research priority and has led to a new subspecialty: cardio-oncology. In this concise review article, we discuss cardiotoxicity and systemic anticancer therapy, with a focus on chemotherapy. We also discuss the challenge of identifying those at risk and the role of precision medicine as we strive for a personalised approach to this clinical scenario.

Future Perspectives of Cardiovascular Biomarker Utilization in Cancer Survivors: A Scientific Statement From the American Heart Association

Improving cancer survival represents the most significant effect of precision medicine and personalized molecular and immunologic therapeutics. Cardiovascular health becomes henceforth a key determinant for the direction of overall outcomes after cancer. Comprehensive tissue diagnostic studies undoubtedly have been and continue to be at the core of the fight against cancer. Will a systemic approach integrating circulating blood-derived biomarkers, multimodality imaging technologies, strategic panomics, and real-time streams of digitized physiological data overcome the elusive cardiovascular tissue diagnosis in cardio-oncology? How can such a systemic approach be personalized for application in day-to-day clinical work, with diverse patient populations, cancer diagnoses, and therapies? To address such questions, this scientific statement approaches a broad definition of the biomarker concept. It summarizes the current literature on the utilization of a multitude of established cardiovascular biomarkers at the intersection with cancer. It identifies limitations and gaps of knowledge in the application of biomarkers to stratify the cardiovascular risk before cancer treatment, monitor cardiovascular health during cancer therapy, and detect latent cardiovascular damage in cancer survivors. Last, it highlights areas in biomarker discovery, validation, and clinical application for concerted efforts from funding agencies, scientists, and clinicians at the cardio-oncology nexus.

CELF Family Proteins in Cancer: Highlights on the RNA-Binding Protein/Noncoding RNA Regulatory Axis

Post-transcriptional modifications to coding and non-coding RNAs are unquestionably a pivotal way in which human mRNA and protein diversity can influence the different phases of a transcript's life cycle. CELF (CUGBP Elav-like family) proteins are RBPs (RNA-binding proteins) with pleiotropic capabilities in RNA processing. Their responsibilities extend from alternative splicing and transcript editing in the nucleus to mRNA stability, and translation into the cytoplasm. In this way, CELF family members have been connected to global alterations in cancer proliferation and invasion, leading to their identification as potential tumor suppressors or even oncogenes. Notably, genetic variants, alternative splicing, phosphorylation, acetylation, subcellular distribution, competition with other RBPs, and ultimately lncRNAs, miRNAs, and circRNAs all impact CELF regulation. Discoveries have emerged about the control of CELF functions, particularly via noncoding RNAs, and CELF proteins have been identified as competing, antagonizing, and regulating agents of noncoding RNA biogenesis. On the other hand, CELFs are an intriguing example through which to broaden our understanding of the RBP/noncoding RNA regulatory axis. Balancing these complex pathways in cancer is undeniably pivotal and deserves further research. This review outlines some mechanisms of CELF protein regulation and their functional consequences in cancer physiology.

Preventing and Treating Anthracycline Cardiotoxicity: New Insights

Anthracyclines are the cornerstone of many chemotherapy regimens for a variety of cancers. Unfortunately, their use is limited by a cumulative dose-dependent cardiotoxicity. Despite more than five decades of research, the biological mechanisms underlying anthracycline cardiotoxicity are not completely understood. In this review, we discuss the incidence, risk factors, types, and pathophysiology of anthracycline cardiotoxicity, as well as methods to prevent and treat this condition. We also summarize and discuss advances made in the last decade in the comprehension of the molecular mechanisms underlying the pathology.

microRNA-377 Signaling Modulates Anticancer Drug-Induced Cardiotoxicity in Mice

Doxorubicin (DOX, an anthracycline) is a widely used chemotherapy agent against various forms of cancer; however, it is also known to induce dose-dependent cardiotoxicity leading to adverse complications. Investigating the underlying molecular mechanisms and strategies to limit DOX-induced cardiotoxicity might have potential clinical implications. Our previous study has shown that expression of microRNA-377 (miR-377) increases in cardiomyocytes (CMs) after cardiac ischemia-reperfusion injury in mice, but its specific role in DOX-induced cardiotoxicity has not been elucidated. In the present study, we investigated the effect of anti-miR-377 on DOX-induced cardiac cell death, remodeling, and dysfunction. We evaluated the role of miR-377 in CM apoptosis, its target analysis by RNA sequencing, and we tested the effect of AAV9-anti-miR-377 on DOX-induced cardiotoxicity and mortality. DOX administration in mice increases miR-377 expression in the myocardium. miR-377 inhibition in cardiomyocyte cell line protects against DOX-induced cell death and oxidative stress. Furthermore, RNA sequencing and Gene Ontology (GO) analysis revealed alterations in a number of cell death/survival genes. Intriguingly, we observed accelerated mortality and enhanced myocardial remodeling in the mice pretreated with AAV9-anti-miR-377 followed by DOX administration as compared to the AAV9-scrambled-control-pretreated mice. Taken together, our data suggest that in vitro miR-377 inhibition protects against DOX-induced cardiomyocyte cell death. On the contrary, in vivo administration of AAV9-anti-miR-377 increases mortality in DOX-treated mice.

Influence of Ile655Val polymorphism on trastuzumab-induced cardiotoxicity in early-stage HER2 positive breast cancer

Trastuzumab has improved the prognosis of HER2 positive breast cancer, but cardiotoxicity remains a concern. We aimed to identify risk factors for trastuzumab-induced cardiotoxicity, with an emphasis on the HER2 Ile655Val single nucleotide polymorphism. This single-center case-control study included 1056 patients with early-stage HER2 positive breast cancer that received adjuvant trastuzumab. Cardiotoxicity was defined as a decline in left ventricular ejection fraction (LVEF) > 15% in patients without previous cardiomyopathy, or > 10% in patients with baseline LVEF of < 50%. Patient characteristics and cardiac parameters were compared in 78 (7.38%) cases and 99 randomly assigned controls, and the polymorphism was genotyped using real-time polymerase chain reaction. Cardiotoxicity was independently associated with advanced age (P = 0.024), lower body mass index (P = 0.023), left breast involvement (P = 0.001), N3 status (P = 0.004), diabetes (P = 0.016), and a family history of coronary artery disease (P = 0.019). Genotype distribution was as follows: A/A (Ile/Ile) was found in 111 (62.7%) patients, A/G (Ile/Val) in 60 (33.9%) patients, and G/G (Val/Val) in 6 (3.4%) patients. The genotype was not associated with cardiotoxicity or the severity of heart failure, reversibility, and recovery time. We found no association between the HER2 Ile655Val polymorphism and trastuzumab-induced cardiotoxicity; therefore, we do not recommend routine cardiotoxicity-risk stratification using this polymorphism.

Potential Gene Association Studies of Chemotherapy-Induced Cardiotoxicity: A Systematic Review and Meta-Analysis

Chemotherapy is widely used in the treatment of cancer patients, but the cardiotoxicity induced by chemotherapy is still a major concern to most clinicians. Currently, genetic methods have been used to detect patients with high risk of chemotherapy-induced cardiotoxicity (CIC), and our study evaluated the correlation between genomic variants and CIC. The systematic literature search was performed in the PubMed, Cochrane Central Register of Controlled Trials (CENTRAL), China Biology Medicine disc (CBMdisc), the Embase database, China National Knowledge Internet (CNKI) and Wanfang database from inception until June 2020. Forty-one studies were identified that examined the relationship between genetic variations and CIC. And these studies examined 88 different genes and 154 single nucleotide polymorphisms (SNPs). Our study indicated 6 variants obviously associated with the increased risk for CIC, including CYBA rs4673 (pooled odds ratio, 1.93; 95% CI, 1.13–3.30), RAC2 rs13058338 (2.05; 1.11–3.78), CYP3A5 rs776746 (2.15; 1.00–4.62) ABCC1 rs45511401 (1.46; 1.05–2.01), ABCC2 rs8187710 (2.19; 1.38–3.48), and HER2-Ile655Val rs1136201 (2.48; 1.53–4.02). Although further studies are required to validate the diagnostic and prognostic roles of these 6 variants in predicting CIC, our study emphasizes the promising benefits of pharmacogenomic screening before chemotherapy to minimize the CIC.

A focused review on CB2 receptor-selective pharmacological properties and therapeutic potential of β-caryophyllene, a dietary cannabinoid

The endocannabinoid system (ECS), a conserved physiological system emerged as a novel pharmacological target for its significant role and potential therapeutic benefits ranging from neurological diseases to cancer. Among both, CB1 and CB2R types, CB2R have received attention for its pharmacological effects as antioxidant, anti-inflammatory, immunomodulatory and antiapoptotic that can be achieved without causing psychotropic adverse effects through CB1R. The ligands activate CB2R are of endogenous, synthetic and plant origin. In recent years, β-caryophyllene (BCP), a natural bicyclic sesquiterpene in cannabis as well as non-cannabis plants, has received attention due to its selective agonist property on CB2R. BCP has been well studied in a variety of pathological conditions mediating CB2R selective agonist property. The focus of the present manuscript is to represent the CB2R selective agonist mediated pharmacological mechanisms and therapeutic potential of BCP. The present narrative review summarizes insights into the CB2R-selective pharmacological properties and therapeutic potential of BCP such as cardioprotective, hepatoprotective, neuroprotective, nephroprotective, gastroprotective, chemopreventive, antioxidant, anti-inflammatory, and immunomodulator. The available evidences suggest that BCP, can be an important candidate of plant origin endowed with CB2R selective properties that may provide a pharmacological rationale for its pharmacotherapeutic application and pharmaceutical development like a drug. Additionally, given the wide availability in edible plants and dietary use, with safety, and no toxicity, BCP can be promoted as a nutraceutical and functional food for general health and well-being. Further, studies are needed to explore pharmacological and pharmaceutical opportunities for therapeutic and preventive applications of use of BCP in human diseases.

Monitoring of Metabolic Syndrome and Cardiovascular Disease in Childhood Cancer Survivors

Advances in cancer treatment have significantly improved childhood cancer survival, although metabolic syndrome and cardiovascular disease are common long-term complications that may occur years after treatment. Childhood cancer survivors may not receive appropriate follow-up due to lack of communication between oncologists and primary care physicians, or, from lack of awareness of possible long-term metabolic and cardiovascular complications after cancer treatment. We, therefore, reviewed current evidence on long-term effects of cancer therapy, and appropriate monitoring for long-term treatment effects in childhood cancer survivors that could lead to early detection and prompt treatment to prevent future cardiovascular events.

Cardiac Energetics Before, During, and After Anthracycline-Based Chemotherapy in Breast Cancer Patients Using 31P Magnetic Resonance Spectroscopy: A Pilot Study

Purpose: To explore the utility of phosphorus magnetic resonance spectroscopy (³¹P MRS) in identifying anthracycline-induced cardiac toxicity in patients with breast cancer.

Methods: Twenty patients with newly diagnosed breast cancer receiving anthracycline-based chemotherapy had cardiac magnetic resonance assessment of left ventricular ejection fraction (LVEF) and ³¹P MRS to determine myocardial Phosphocreatine/Adenosine Triphosphate Ratio (PCr/ATP) at three time points: pre-, mid-, and end-chemotherapy. Plasma high sensitivity cardiac troponin-I (cTn-I) tests and electrocardiograms were also performed at these same time points.

Results: Phosphocreatine/Adenosine Triphosphate did not change significantly between pre- and mid-chemo (2.16 ± 0.46 vs. 2.00 ± 0.56, p = 0.80) and pre- and end-chemo (2.16 ± 0.46 vs. 2.17 ± 0.86, p = 0.99). Mean LVEF reduced significantly by 5.1% between pre- and end-chemo (61.4 ± 4.4 vs. 56.3 ± 8.1 %, p = 0.02). Change in PCr/ATP ratios from pre- to end-chemo correlated inversely with changes in LVEF over the same period (r = −0.65, p = 0.006). Plasma cTn-I increased progressively during chemotherapy from pre- to mid-chemo (1.35 ± 0.81 to 4.40 ± 2.64 ng/L; p = 0.01) and from mid- to end-chemo (4.40 ± 2.64 to 18.33 ± 13.23 ng/L; p = 0.001).

Conclusions: In this small cohort pilot study, we did not observe a clear change in mean PCr/ATP values during chemotherapy despite evidence of increased plasma cardiac biomarkers and reduced LVEF. Future similar studies should be adequately powered to take account of patient drop-out and variable changes in PCr/ATP and could include T1 and T2 mapping.

Regulated cell death pathways in doxorubicin-induced cardiotoxicity

Doxorubicin is a chemotherapeutic drug used for the treatment of various malignancies; however, patients can experience cardiotoxic effects and this has limited the use of this potent drug. The mechanisms by which doxorubicin kills cardiomyocytes has been elusive and despite extensive research the exact mechanisms remain unknown. This review focuses on recent advances in our understanding of doxorubicin induced regulated cardiomyocyte death pathways including autophagy, ferroptosis, necroptosis, pyroptosis and apoptosis. Understanding the mechanisms by which doxorubicin leads to cardiomyocyte death may help identify novel therapeutic agents and lead to more targeted approaches to cardiotoxicity testing.

Subtle cardiac dysfunction in lymphoma patients receiving low to moderate dose chemotherapy

Left ventricular (LV) global peak systolic longitudinal strain (GLS) is a sensitive measurement for detecting subtle LV systolic dysfunction and a powerful prognostic predictor. However, the clinical implication of LV GLS in lymphoma patients receiving cancer therapy remains unknown. We prospectively enrolled 74 lymphoma patients (57.9 ± 17.0 years old, 57% male). We performed echocardiographic studies after the 3rd and 6th cycles and 1 year after chemotherapy and a cardiopulmonary exercise test upon completion of 3 cycles of anticancer therapy. Cancer therapy-related cardiac dysfunction (CTRCD) was defined as a ≥ 15% relative reduction in GLS value from baseline. The primary outcome was a composite of all-cause mortality and heart failure events. Thirty-six patients (49%) had CTRCD (LV GLS: baseline vs. after 3rd cycle of therapy: 20.1 ± 2.6 vs. 17.5 ± 2.3%, p < 0.001). CTRCD was detected after the 3rd cycle of anticancer therapy. CTRCD patients had impaired exercise capacity (minute oxygen consumption/kg, CTRCD vs. CTRCD (-): 13.9 ± 3.1 vs. 17.0 ± 3.9 ml/kg/min, p = 0.02). More primary outcome events occurred in the CTRCD group (hazard ratio 3.21; 95% confidence interval 1.04–9.97; p = 0.03). LV GLS could detect subtle but clinically significant cardiac dysfunction in lymphoma patients in the early stage of anticancer therapy. CTRCD may be associated with not only a reduced exercise capacity but also a worse prognosis.

A New RBPs-Related Signature Predicts the Prognosis of Colon Adenocarcinoma Patients

The dysregulation of RNA binding proteins (RBPs) is closely related to tumorigenesis and development. However, the role of RBPs in Colon adenocarcinoma (COAD) is still poorly understood. We downloaded COAD’s RNASeq data from the Cancer Genome Atlas (TCGA) database, screened the differently expressed RBPs in normal tissues and tumor, and constructed a protein interaction network. COAD patients were randomly divided into a training set (N = 315) and a testing set (N = 132). In the training set, univariate Cox analysis identified 12 RBPs significantly related to the prognosis of COAD. By multivariate COX analysis, we constructed a prognostic model composed of five RBPs (CELF4, LRRFIP2, NOP14, PPARGC1A, ZNF385A) based on the lowest Akaike information criterion. Each COAD patient was scored according to the model formula. Further analysis showed that compared with the low-risk group, the overall survival rate (OS) of patients in the high-risk group was significantly lower. The area under the curve of the time-dependent receiver operator characteristic (ROC) curve was 0.722 in the training group and 0.738 in the test group, which confirmed a good prediction feature. In addition, a nomogram was constructed based on clinicopathological characteristics and risk scores. C-index and calibration curve proved the accuracy in predicting the 1-, 3-, and 5-year survival rates of COAD patients. In short, we constructed a superior prognostic and diagnostic signature composed of five RBPs, which indicates new possibilities for individualized treatment of COAD patients.

Clinical Trial in a Dish: Using Patient-Derived Induced Pluripotent Stem Cells to Identify Risks of Drug-Induced Cardiotoxicity

Drug-induced cardiotoxicity is a significant clinical issue, with many drugs in the market being labeled with warnings on cardiovascular adverse effects. Treatments are often prematurely halted when cardiotoxicity is observed, which limits their therapeutic potential. Moreover, cardiotoxicity is a major reason for abandonment during drug development, reducing available treatment options for diseases and creating a significant financial burden and disincentive for drug developers. Thus, it is important to minimize the cardiotoxic effects of medications that are in use or in development. To this end, identifying patients at a higher risk of developing cardiovascular adverse effects for the drug of interest may be an effective strategy. The discovery of human induced pluripotent stem cells has enabled researchers to generate relevant cell types that retain a patient's own genome and examine patient-specific disease mechanisms, paving the way for precision medicine. Combined with the rapid development of pharmacogenomic analysis, the ability of induced pluripotent stem cell-derivatives to recapitulate patient-specific drug responses provides a powerful platform to identify subsets of patients who are particularly vulnerable to drug-induced cardiotoxicity. In this review, we will discuss the current use of patient-specific induced pluripotent stem cells in identifying populations who are at risk to drug-induced cardiotoxicity and their potential applications in future precision medicine practice. Graphic Abstract: A graphic abstract is available for this article.

Diagnosis and Risk Prediction of Dilated Cardiomyopathy in the Era of Big Data and Genomics

Dilated cardiomyopathy (DCM) is a leading cause of heart failure and life-threatening ventricular arrhythmias (LTVA). Work-up and risk stratification of DCM is clinically challenging, as there is great heterogeneity in phenotype and genotype. Throughout the last decade, improved genetic testing of patients has identified genotype-phenotype associations and enhanced evaluation of at-risk relatives leading to better patient prognosis. The field is now ripe to explore opportunities to improve personalised risk assessments. Multivariable risk models presented as "risk calculators" can incorporate a multitude of clinical variables and predict outcome (such as heart failure hospitalisations or LTVA). In addition, genetic risk scores derived from genome/exome-wide association studies can estimate an individual's lifetime genetic risk of developing DCM. The use of clinically granular investigations, such as late gadolinium enhancement on cardiac magnetic resonance imaging, is warranted in order to increase predictive performance. To this end, constructing big data infrastructures improves accessibility of data by using electronic health records, existing research databases, and disease registries. By applying methods such as machine and deep learning, we can model complex interactions, identify new phenotype clusters, and perform prognostic modelling. This review aims to provide an overview of the evolution of DCM definitions as well as its clinical work-up and considerations in the era of genomics. In addition, we present exciting examples in the field of big data infrastructures, personalised prognostic assessment, and artificial intelligence.

The Role of Pharmacogenomics in Contemporary Cardiovascular Therapy: A position statement from the European Society of Cardiology Working Group on Cardiovascular Pharmacotherapy

There is a strong and ever-growing body of evidence regarding the use of pharmacogenomics to inform cardiovascular pharmacology. However, there is no common position taken by international cardiovascular societies to unite diverse availability, interpretation and application of such data, nor is there recognition of the challenges of variation in clinical practice between countries within Europe. Aside from the considerable barriers to implementing pharmacogenomic testing and the complexities of clinically actioning results, there are differences in the availability of resources and expertise internationally within Europe. Diverse legal and ethical approaches to genomic testing and clinical therapeutic application also require serious thought. As direct-to-consumer genomic testing becomes more common, it can be anticipated that data may be brought in by patients themselves, which will require critical assessment by the clinical cardiovascular prescriber. In a modern, pluralistic and multi-ethnic Europe, self-identified race/ethnicity may not be concordant with genetically detected ancestry and thus may not accurately convey polymorphism prevalence. Given the broad relevance of pharmacogenomics to areas such as thrombosis and coagulation, interventional cardiology, heart failure, arrhythmias, clinical trials, and policy/regulatory activity within cardiovascular medicine, as well as to genomic and pharmacology subspecialists, this position statement attempts to address these issues at a wide-ranging level.

Differences between familial and sporadic dilated cardiomyopathy: ESC EORP Cardiomyopathy & Myocarditis registry

AIMS

Dilated cardiomyopathy (DCM) is a complex disease where genetics interplay with extrinsic factors. This study aims to compare the phenotype, management, and outcome of familial DCM (FDCM) and non-familial (sporadic) DCM (SDCM) across Europe.

METHODS AND RESULTS

Patients with DCM that were enrolled in the prospective ESC EORP Cardiomyopathy & Myocarditis Registry were included. Baseline characteristics, genetic testing, genetic yield, and outcome were analysed comparing FDCM and SDCM; 1260 adult patients were studied (238 FDCM, 707 SDCM, and 315 not disclosed). Patients with FDCM were younger (P < 0.01), had less severe disease phenotype at presentation (P < 0.02), more favourable baseline cardiovascular risk profiles (P ≤ 0.007), and less medication use (P ≤ 0.042). Outcome at 1 year was similar and predicted by NYHA class (HR 0.45; 95% CI [0.25-0.81]) and LVEF per % decrease (HR 1.05; 95% CI [1.02-1.08]. Throughout Europe, patients with FDCM received more genetic testing (47% vs. 8%, P < 0.01) and had higher genetic yield (55% vs. 22%, P < 0.01).

CONCLUSIONS

We observed that FDCM and SDCM have significant differences at baseline but similar short-term prognosis. Whether modification of associated cardiovascular risk factors provide opportunities for treatment remains to be investigated. Our results also show a prevalent role of genetics in FDCM and a non-marginal yield in SDCM although genetic testing is largely neglected in SDCM. Limited genetic testing and heterogeneity in panels provides a scaffold for improvement of guideline adherence.

Epigenetic Changes Associated With Anthracycline-Induced Cardiotoxicity

Advances in cancer treatment have significantly improved the survival of patients with cancer, but, unfortunately, many of these treatments also have long-term complications. Cancer treatment-related cardiotoxicities are becoming a significant clinical problem that a new discipline, Cardio-Oncology, was established to advance the cardiovascular care of patients with growing cancer populations. Anthracyclines are a class of chemotherapeutic agents used to treat many cancers in adults and children. Their clinical use is limited by anthracycline-induced cardiotoxicity (AIC), which can lead to heart failure. Early-onset cardiotoxicity appears within a year of treatment, whereas late-onset cardiotoxicity occurs > 1 year and even up to decades after treatment completion. The pathophysiology of AIC was hypothesized to be caused by generation of reactive oxygen species that lead to lipid peroxidation, defective mitochondrial biogenesis, and DNA damage of the cardiomyocytes. The accumulation of anthracycline metabolites was also proposed to cause mitochondrial damage and the induction of cardiac cell apoptosis, which induces arrhythmias, contractile dysfunction, and cardiomyocyte death. This paper will provide a general overview of cardiotoxicity focusing on the effect of anthracyclines and their epigenetic molecular mechanisms on cardiotoxicity.

Machine Learning Identifies Clinical and Genetic Factors Associated With Anthracycline Cardiotoxicity in Pediatric Cancer Survivors

Background

Despite known clinical risk factors, predicting anthracycline cardiotoxicity remains challenging.

Objectives

This study sought to develop a clinical and genetic risk prediction model for anthracycline cardiotoxicity in childhood cancer survivors.

Methods

We performed exome sequencing in 289 childhood cancer survivors at least 3 years from anthracycline exposure. In a nested case-control design, 183 case patients with reduced left ventricular ejection fraction despite low-dose doxorubicin (≤250 mg/m²), and 106 control patients with preserved left ventricular ejection fraction despite doxorubicin >250 mg/m² were selected as extreme phenotypes. Rare/low-frequency variants were collapsed to identify genes differentially enriched for variants between case patients and control patients. The expression levels of 5 top-ranked genes were evaluated in human induced pluripotent stem cell–derived cardiomyocytes, and variant enrichment was confirmed in a replication cohort. Using random forest, a risk prediction model that included genetic and clinical predictors was developed.

Results

Thirty-one genes were differentially enriched for variants between case patients and control patients (p < 0.001). Only 42.6% case patients harbored a variant in these genes compared to 89.6% control patients (odds ratio: 0.09; 95% confidence interval: 0.04 to 0.17; p = 3.98 × 10^–15). A risk prediction model for cardiotoxicity that included clinical and genetic factors had a higher prediction accuracy and lower misclassification rate compared to the clinical-only model. In vitro inhibition of gene-associated pathways (PI3KR2, ZNF827) provided protection from cardiotoxicity in cardiomyocytes.

Conclusions

Our study identified variants in cardiac injury pathway genes that protect against cardiotoxicity and informed the development of a prediction model for delayed anthracycline cardiotoxicity, and it also provided new targets in autophagy genes for the development of cardio-protective drugs. (Preventing Cardiac Sequelae in Pediatric Cancer Survivors [PCS2]; NCT01805778)

Cardiotoxicity of Novel Targeted Hematological Therapies

Chemotherapy-related cardiac dysfunction, also known as cardiotoxicity, is a group of drug-related adverse events negatively affecting myocardial structure and functions in patients who received chemotherapy for cancer treatment. Clinical manifestations can vary from life-threatening arrythmias to chronic conditions, such as heart failure or hypertension, which dramatically reduce quality of life of cancer survivors. Standard chemotherapy exerts its toxic effect mainly by inducing oxidative stress and genomic instability, while new targeted therapies work by interfering with signaling pathways important not only in cancer cells but also in myocytes. For example, Bruton’s tyrosine kinase (BTK) inhibitors interfere with class I phosphoinositide 3-kinase isoforms involved in cardiac hypertrophy, contractility, and regulation of various channel forming proteins; thus, off-target effects of BTK inhibitors are associated with increased frequency of arrhythmias, such as atrial fibrillation, compared to standard chemotherapy. In this review, we summarize current knowledge of cardiotoxic effects of targeted therapies used in hematology.

Is there scope for better individualisation of anthracycline cancer chemotherapy?

Anthracyclines are used to treat solid and haematological cancers, particularly breast cancers, lymphomas and childhood cancers. Myelosuppression and cardiotoxicity are the primary toxicities that limit treatment duration and/or intensity. Cardiotoxicity, particularly heart failure, is a leading cause of morbidity and mortality in cancer survivors. Cumulative anthracycline dose is a significant predictor of cardiotoxicity risk, suggesting a role for anthracycline pharmacokinetic variability. Population pharmacokinetic modelling in children has shown that doxorubicin clearance in the very young is significantly lower than in older children, potentially contributing to their higher risk of cardiotoxicity. A model of doxorubicin clearance based on body surface area and age offers a patient-centred dose-adjustment strategy that may replace the current disparate initial-dose selection tools, providing a rational way to compensate for pharmacokinetic variability in children aged <7 years. Population pharmacokinetic models in adults have not adequately addressed older ages, obesity, hepatic and renal dysfunction, and potential drug-drug interactions to enable clinical application. Although candidate gene and genome-wide association studies have investigated relationships between genetic variability and anthracycline pharmacokinetics or clinical outcomes, there have been few clinically significant reproducible associations. Precision-dosing of anthracyclines is currently hindered by lack of clinically useful pharmacokinetic targets and models that predict cumulative anthracycline exposures. Combined with known risk factors for cardiotoxicity, the use of advanced echocardiography and biomarkers, future validated pharmacokinetic targets and predictive models could facilitate anthracycline precision dosing that truly maximises efficacy and provides individualised early intervention with cardioprotective therapies in patients at risk of cardiotoxicity.

Improving cardiotoxicity prediction in cancer treatment: integration of conventional circulating biomarkers and novel exploratory tools

Early detection strategies and improvements in cancer treatment have dramatically reduced the cancer mortality rate in the United States (US). However, cardiovascular (CV) side effects of cancer therapy are frequent among the 17 million cancer survivors in the US today, and cardiovascular disease (CVD) has become the second leading cause of morbidity and mortality among cancer survivors. Circulating biomarkers are ideal for detecting and monitoring CV side effects of cancer therapy. Here, we summarize the current state of clinical studies on conventional serum and plasma CVD biomarkers to detect and prevent cardiac injury during cancer treatment. We also review how novel exploratory tools such as genetic testing, human stem cell-derived cardiomyocytes, Omics technologies, and artificial intelligence can elucidate underlying molecular and genetic mechanisms of CV injury and to improve predicting cancer therapy-related cardiotoxicity (CTRC). Current regulatory requirements for biomarker qualifications are also addressed. We present generally applicable lessons learned from published studies, particularly on how to improve reproducibility. The combination of conventional circulating biomarkers and novel exploratory tools will pave the way for precision medicine and improve the clinical practice of prediction, detection, and management of CTRC.

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

Anthracyclines are an integral part of chemotherapy regimens used to treat a variety of childhood-onset and adult-onset cancers. However, the development of cardiac dysfunction and heart failure often compromises the clinical utility of anthracyclines. The risk of cardiac dysfunction increases with anthracycline dose. This anthracycline-cardiac dysfunction association is modified by several demographic and clinical factors, such as age at anthracycline exposure (<4 years and ≥65 years); female sex; chest radiation; presence of cardiovascular risk factors (diabetes, hypertension); and concurrent use of cyclophosphamide, paclitaxel, and trastuzumab. However, the clinical variables alone yield modest predictive power in detecting cardiac dysfunction. Recently, attention has focused on the molecular basis of anthracycline-related cardiac dysfunction, providing an initial understanding of the mechanism of anthracycline-related cardiomyopathy. This review describes the current state of knowledge with respect to the pathogenesis of anthracycline-related cardiomyopathy and identifies the critical next steps to mitigate this problem.

Early- and late anthracycline-induced cardiac dysfunction: echocardiographic characterization and response to heart failure therapy

Background

Anthracycline-induced cardiac dysfunction (ACD) is a notorious side effect of anticancer treatment. It has been described as a phenomenon of a continuous progressive decline of cardiac function, eventually leading to dilated cardiomyopathy (DCM). This progressive nature suggests that patients with a delayed ACD diagnosis have greater compromise of cardiac function and more adverse remodeling, with a poor response to heart failure (HF) treatment. This study aimed to delineate the impact of a delayed ACD diagnosis on echocardiographic characteristics and response to HF treatment.

Methods and results

From the population of our cardio-oncology outpatient clinic, 92 ACD patients were included in this study (age 51.6 ± 16.2 years, median cumulative anthracycline dose 329 [200–329] mg/m²), and a median follow-up of 25.0 [9.6–37.2] months after ACD diagnosis. Median time to ACD diagnosis for patients diagnosed early (< 1 year) and late (> 1 year) was 4.0 vs. 47.7 months respectively. There were no echocardiographic differences between patients diagnosed early vs. late (LVEF 43.6 ± 4.9% vs. 43.0 ± 6.2% and iEDV 63.6 vs. 62.9 mL/m²). Eighty-three percent of patients presented with mild LV dysfunction and in 79% the LV was not dilated. Patients diagnosed early were more likely to have (partial) recovery of cardiac function upon HF treatment initiation (p = 0.015).

Conclusions

In the setting of a cardio-oncology outpatient clinic, patients with ACD presented with a hypokinetic non-dilated cardiomyopathy, rather than typical DCM. Timing of ACD diagnosis did not impact HF disease severity. However, in patients receiving an early diagnosis, cardiac function was more likely to recover upon HF treatment.

Cancer Therapeutics-Related Cardiac Dysfunction - Insights From Bench and Bedside of Onco-Cardiology

Improvements in the long-term survival of cancer patients have led to growing awareness of the clinical importance of cancer therapeutics-related cardiac dysfunction (CTRCD), which can have a considerable effect on the prognosis and quality of life of cancer patients and survivors. Under such circumstances, onco-cardiology/cardio-oncology has emerged as a new discipline, with the aim of best managing cardiovascular complications, including CTRCD. Despite the recent accumulation of epidemiological and clinical information regarding CTRCD, the molecular mechanisms underlying the pathogenesis of CTRCD by individual drugs remain to be determined. To achieve the goal of preventing cardiovascular complications in cancer patients and survivors, it is important to elucidate the pathogenic mechanisms and to establish diagnostic strategies with risk prediction and mechanism- and evidence-based therapies against CTRCD.

Variation in RARG increases susceptibility to doxorubicin-induced cardiotoxicity in patient specific induced pluripotent stem cell-derived cardiomyocytes

Doxorubicin is a potent anticancer drug used to treat a variety of cancer types. However, its use is limited by doxorubicin-induced cardiotoxicity (DIC). A missense variant in the RARG gene (S427L; rs2229774) has been implicated in susceptibility to DIC in a genome wide association study. The goal of this study was to investigate the functional role of this RARG variant in DIC. We used induced pluripotent stem cell derived cardiomyocytes (iPSC-CMs) from patients treated with doxorubicin. iPSC-CMs from individuals who experienced DIC (cases) showed significantly greater sensitivity to doxorubicin compared to iPSC-CMs from doxorubicin-treated individuals who did not develop DIC (controls) in cell viability and optical mapping experiments. Using CRISPR/Cas9, we generated isogenic cell lines that differed only at the RARG locus. Genetic correction of RARG-S427L to wild type resulted in reduced doxorubicin-induced double stranded DNA breaks, reactive oxygen species production, and cell death. Conversely, introduction of RARG-S427L increased susceptibility to doxorubicin. Finally, genetic disruption of the RARG gene resulted in protection from cell death due to doxorubicin treatment. Our findings suggest that the presence of RARG-S427L increases sensitivity to DIC, establishing a direct, causal role for this variant in DIC.

Cardiovascular Consequences of Skeletal Muscle Impairments in Breast Cancer

Breast cancer survivors suffer from disproportionate cardiovascular disease risk compared to age-matched controls. Beyond direct cardiotoxic effects due to treatments such as chemotherapy and radiation, breast-cancer-related reductions in skeletal muscle mass, quality and oxidative capacity may further contribute to cardiovascular disease risk in this population by limiting the ability to engage in aerobic exercise—a known promoter of cardiovascular health. Indeed, 20–30% decreases in peak oxygen consumption are commonly observed in breast cancer survivors, which are indicative of exercise intolerance. Thus, breast-cancer-related skeletal muscle damage may reduce exercise-based opportunities for cardiovascular disease risk reduction. Resistance training is a potential strategy to improve skeletal muscle health in this population, which in turn may enhance the capacity to engage in aerobic exercise and reduce cardiovascular disease risk.