Anthracycline-related cardiomyopathy after childhood cancer: role of polymorphisms in carbonyl reductase genes--a report from the Children's Oncology Group

Genetic factors in the pathogenesis of cardio-oncology

In recent years, with advancements in medicine, the survival period of patients with tumours has significantly increased. The adverse effects of tumour treatment on patients, especially cardiac toxicity, have become increasingly prominent. In elderly patients with breast cancer, treatment-related cardiovascular toxicity has surpassed cancer itself as the leading cause of death. Moreover, in recent years, an increasing number of novel antitumour drugs, such as multitargeted agents, antibody‒drug conjugates (ADCs), and immunotherapies, have been applied in clinical practice. The cardiotoxicity induced by these drugs has become more pronounced, leading to a complex and diverse mechanism of cardiac damage. The risks of unintended cardiovascular toxicity are increased by high-dose anthracyclines, immunotherapies, and concurrent radiation, in addition to traditional cardiovascular risk factors such as smoking, hypertension, diabetes, hyperlipidaemia, and obesity. However, these factors do not fully explain why only a subset of individuals experience treatment-related cardiac toxicity, whereas others with similar clinical features do not. Recent studies indicate that genetics play a significant role in susceptibility to the development of cardiovascular toxicity from cancer therapies. These genes are involved in drug metabolism, oxidative damage, cardiac dysfunction, and other processes. Moreover, emerging evidence suggests that epigenetics also plays a role in drug-induced cardiovascular toxicity. We conducted a review focusing on breast cancer as an example to help oncologists and cardiologists better understand the mechanisms and effects of genetic factors on cardiac toxicity. In this review, we specifically address the relationship between genetic alterations and cardiac toxicity, including chemotherapy-related genetic changes, targeted therapy-related genetic changes, and immune therapy-related genetic changes. We also discuss the role of epigenetic factors in cardiac toxicity. We hope that this review will improve the risk stratification of patients and enable therapeutic interventions that mitigate these unintended adverse consequences of life-saving cancer treatments.

Anthracyclines, Diastolic Dysfunction and the road to Heart Failure in Cancer survivors: An untold story

Many cardiovascular diseases are characterized by diastolic dysfunction, which associates with worse clinical outcomes like overall mortality and hospitalization for heart failure (HF). Diastolic dysfunction has also been suspected to represent an early manifestation of cardiotoxicity induced by cancer drugs, with most of the information deriving from patients treated with anthracyclines; however, the prognostic implications of diastolic dysfunction in the anthracycline-treated patient have remained poorly explored or neglected. Here the molecular, pathophysiologic and diagnostic aspects of anthracycline-related diastolic dysfunction are reviewed in the light of HF incidence and phenotype in cancer survivors. We describe that the trajectories of diastolic dysfunction toward HF are influenced by a constellation of patient- or treatment- related factors, such as comorbidities and exposure to other cardiotoxic drugs or treatments, but also by prospective novel opportunities to treat diastolic dysfunction. The importance of a research-oriented multidimensional approach to patient surveillance or treatment is discussed within the framework of what appears to be a distinct pathophysiologic entity that develops early during anthracycline treatment and gradually worsens over the years.

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

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

Risk of anthracycline-induced cardiac dysfunction in adolescent and young adult (AYA) cancer survivors: role of genetic susceptibility loci

There is a known genetic susceptibility to anthracycline-induced cardiac dysfunction in childhood cancer survivors, but this has not been adequately shown in adolescent and young adult (AYA) patients. Our aim was to determine if the previously identified variants associated with cardiac dysfunction in childhood cancer patients affect AYA cancer patients similarly. Forty-five variants were selected for analysis in 253 AYAs previously treated with anthracyclines. We identified four variants that were associated with cardiac dysfunction: SLC10A2:rs7319981 (p = 0.017), SLC22A17:rs4982753 (p = 0.019), HAS3:rs2232228 (p = 0.023), and RARG:rs2229774 (p = 0.050). HAS3:rs2232228 and SLC10A2:rs7319981 displayed significant effects in our AYA cancer survivor population that were in the opposite direction than that reported in childhood cancer survivors. Genetic variants in the host genes were further analyzed for additional associations with cardiotoxicity in AYA cancer survivors. The host genes were then evaluated in a panel of induced pluripotent stem cell-derived cardiomyocytes to assess changes in levels of expression when treated with doxorubicin. Significant upregulation of HAS3 and SLC22A17 expression was observed (p < 0.05), with non-significant anthracycline-responsivity observed for RARG. Our study demonstrates that there is a genetic influence on cardiac dysfunction in AYA cancer patients, but there may be a difference in the role of genetics between childhood and AYA cancer survivors.

Predicting oncology drug-induced cardiotoxicity with donor-specific iPSC-CMs-a proof-of-concept study with doxorubicin

Many oncology drugs have been found to induce cardiotoxicity in a subset of patients, which significantly limits their clinical use and impedes the benefit of lifesaving anticancer treatments. Human induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) carry donor-specific genetic information and have been proposed for exploring the interindividual difference in oncology drug-induced cardiotoxicity. Herein, we evaluated the inter- and intraindividual variability of iPSC-CM-related assays and presented a proof of concept to prospectively predict doxorubicin (DOX)-induced cardiotoxicity (DIC) using donor-specific iPSC-CMs. Our findings demonstrated that donor-specific iPSC-CMs exhibited greater line-to-line variability than the intraindividual variability in impedance cytotoxicity and transcriptome assays. The variable and dose-dependent cytotoxic responses of iPSC-CMs resembled those observed in clinical practice and largely replicated the reported mechanisms. By categorizing iPSC-CMs into resistant and sensitive cell lines based on their time- and concentration-related phenotypic responses to DOX, we found that the sensitivity of donor-specific iPSC-CMs to DOX may predict in vivo DIC risk. Furthermore, we identified a differentially expressed gene, DND microRNA-mediated repression inhibitor 1 (DND1), between the DOX-resistant and DOX-sensitive iPSC-CMs. Our results support the utilization of donor-specific iPSC-CMs in assessing interindividual differences in DIC. Further studies will encompass a large panel of donor-specific iPSC-CMs to identify potential novel molecular and genetic biomarkers for predicting DOX and other oncology drug-induced cardiotoxicity.

Neighborhood factors associated with late effects among survivors of adolescent and young adult cancer

PURPOSE

The purpose of this study is to evaluate the associations between neighborhood income, education, and neighborhood racial composition (measured as a low percentage of white residents) and risk of developing cardiovascular diseases (CVD), diabetes (DM), and severe depression among survivors of AYA cancer and matched non-cancer peers.

METHODS

Two-year survivors of AYA cancers diagnosed at age 15-39 yrs at Kaiser Permanente Southern California (diagnosed 2000-2012) and individually matched (1:13) non-cancer subjects were included. The development of CVD, DM, and severe depression was ascertained via electronic health records. Neighborhood characteristics were obtained from census-based geocoded data. Cox regression evaluated associations between neighborhood characteristics and the health outcomes of interest among both the cancer survivors and the non-cancer comparison cohort and effect modification by cancer survivor status on these relationships.

RESULTS

Among cancer survivors (n = 6774), living in mostly non-white neighborhoods, was associated with risk of CVD (hazard ratio (HR) = 1.54 (95% CI 1.00-2.36)), while lower education level (HR = 1.41 (95% CI 1.02-1.94)) was associated with risk of severe depression. None of the neighborhood characteristics were associated with risk of DM. Effect modification was found for neighborhood education and risk of DM and severe depression.

CONCLUSION

When jointly considered, cancer survivors who resided in the most disadvantaged neighborhoods were at the highest risk of developing these health outcomes compared to other subgroups.

IMPLICATIONS FOR CANCER SURVIVORS

Our findings may inform screening strategy and addressing social determinants of health among AYA cancer survivors.

How I treat long-term survivors of childhood acute leukemia

ABSTRACT

The population of survivors of childhood leukemia who reach adulthood is growing due to improved therapy. However, survivors are at risk of long-term complications. Comprehensive follow-up programs play a key role in childhood leukemia survivor care. The major determinant of long-term complications is the therapeutic burden accumulated over time. Relapse chemotherapy, central nervous system irradiation, hematopoietic stem cell transplantation, and total body irradiation are associated with greater risk of long-term complications. Other parameters include clinical characteristics such as age and sex as well as environmental, genetic, and socioeconomic factors, which can help stratify the risk of long-term complications and organize follow-up program. Early diagnosis improves the management of several late complications such as anthracycline-related cardiomyopathy, secondary cancers, metabolic syndrome, development defects, and infertility. Total body irradiation is the treatment associated with worse long-term toxicity profile with a wide range of complications. Patients treated with chemotherapy alone are at a lower risk of long-term complications, although the optimal long-term follow-up remains unclear. Novel immunotherapies and targeted therapy are generally associated with a better short-term safety profile but still require careful long-term toxicity monitoring. Advances in understanding genetic susceptibility to long-term complications could enable tailored therapeutic strategies for leukemia treatment and optimized follow-up programs.

Improved Cardiomyopathy Risk Prediction Using Global Longitudinal Strain and N-Terminal-Pro-B-Type Natriuretic Peptide in Survivors of Childhood Cancer Exposed to Cardiotoxic Therapy

PURPOSE

To leverage baseline global longitudinal strain (GLS) and N-terminal-pro-B-type natriuretic peptide (NT-proBNP) to identify childhood cancer survivors with a normal left ventricular ejection fraction (LVEF) at highest risk of future treatment-related cardiomyopathy.

METHODS

St Jude Lifetime Cohort participants ≥5 years from diagnosis, at increased risk for cardiomyopathy per the International Guideline Harmonization Group (IGHG), with an LVEF ≥50% on baseline echocardiography (n = 1,483) underwent measurement of GLS (n = 1,483) and NT-proBNP (n = 1,052; 71%). Multivariable Cox regression models estimated hazard ratios (HRs) and 95% CIs for postbaseline cardiomyopathy (modified Common Terminology Criteria for Adverse Events ≥grade 2) incidence in association with echocardiogram-based GLS (≥-18) and/or NT-proBNP (>age-sex-specific 97.5th percentiles). Prediction performance was assessed using AUC in models with and without GLS and NT-proBNP and compared using DeLong's test for IGHG moderate- and high-risk individuals treated with anthracyclines.

RESULTS

Among survivors (median age, 37.6; range, 10.2-70.4 years), 162 (11.1%) developed ≥grade 2 cardiomyopathy 5.1 (0.7-10.0) years from baseline assessment. The 5-year cumulative incidence of cardiomyopathy for survivors with and without abnormal GLS was, respectively, 7.3% (95% CI, 4.7 to 9.9) versus 4.4% (95% CI, 3.0 to 5.7) and abnormal NT-proBNP was 9.9% (95% CI, 5.8 to 14.1) versus 4.7% (95% CI, 3.2 to 6.2). Among survivors with a normal LVEF, abnormal baseline GLS and NT-proBNP identified anthracycline-exposed, IGHG-defined moderate-/high-risk survivors at a four-fold increased hazard of postbaseline cardiomyopathy (HR, 4.39 [95% CI, 2.46 to 7.83]; P < .001), increasing to a HR of 14.16 (95% CI, 6.45 to 31.08; P < .001) among survivors who received ≥250 mg/m2 of anthracyclines. Six years after baseline, AUCs for individual risk prediction were 0.70 for models with and 0.63 for models without GLS and NT-proBNP (P = .022).

CONCLUSION

GLS and NT-proBNP should be considered for improved identification of survivors at high risk for future cardiomyopathy.

A Comprehensive Review of Cancer Drug-Induced Cardiotoxicity in Blood Cancer Patients: Current Perspectives and Therapeutic Strategies

OPINION STATEMENT

Cardiotoxicity has emerged as a serious outcome catalyzed by various therapeutic targets in the field of cancer treatment, which includes chemotherapy, radiation, and targeted therapies. The growing significance of cancer drug-induced cardiotoxicity (CDIC) and radiation-induced cardiotoxicity (CRIC) necessitates immediate attention. This article intricately unveils how cancer treatments cause cardiotoxicity, which is exacerbated by patient-specific risks. In particular, drugs like anthracyclines, alkylating agents, and tyrosine kinase inhibitors pose a risk, along with factors such as hypertension and diabetes. Mechanistic insights into oxidative stress and topoisomerase-II-B inhibition are crucial, while cardiac biomarkers show early damage. Timely intervention and prompt treatment, especially with specific agents like dexrazoxane and beta-blockers, are pivotal in the proactive management of CDIC.

In vitro evaluation of the reductive carbonyl idarubicin metabolism to evaluate inhibitors of the formation of cardiotoxic idarubicinol via carbonyl and aldo-keto reductases

The most important dose-limiting factor of the anthracycline idarubicin is the high risk of cardiotoxicity, in which the secondary alcohol metabolite idarubicinol plays an important role. It is not yet clear which enzymes are most important for the formation of idarubicinol and which inhibitors might be suitable to suppress this metabolic step and thus would be promising concomitant drugs to reduce idarubicin-associated cardiotoxicity. We, therefore, established and validated a mass spectrometry method for intracellular quantification of idarubicin and idarubicinol and investigated idarubicinol formation in different cell lines and its inhibition by known inhibitors of the aldo-keto reductases AKR1A1, AKR1B1, and AKR1C3 and the carbonyl reductases CBR1/3. The enzyme expression pattern differed among the cell lines with dominant expression of CBR1/3 in HEK293 and MCF-7 and very high expression of AKR1C3 in HepG2 cells. In HEK293 and MCF-7 cells, menadione was the most potent inhibitor (IC50 = 1.6 and 9.8 µM), while in HepG2 cells, ranirestat was most potent (IC50 = 0.4 µM), suggesting that ranirestat is not a selective AKR1B1 inhibitor, but also an AKR1C3 inhibitor. Over-expression of AKR1C3 verified the importance of AKR1C3 for idarubicinol formation and showed that ranirestat is also a potent inhibitor of this enzyme. Taken together, our study underlines the importance of AKR1C3 and CBR1 for the reduction of idarubicin and identifies potent inhibitors of metabolic formation of the cardiotoxic idarubicinol, which should now be tested in vivo to evaluate whether such combinations can increase the cardiac safety of idarubicin therapies while preserving its efficacy.

Role of HDL cholesterol in anthracycline-induced subclinical cardiotoxicity: a prospective observational study in patients with diffuse large B-cell lymphoma treated with R-CHOP

OBJECTIVES

Anthracycline-induced cardiotoxicity is a debilitating cardiac dysfunction for which there are no effective treatments, making early prevention of anthracycline-induced subclinical cardiotoxicity (AISC) crucial. High-density lipoprotein cholesterol (HDL-C) plays a role in cardioprotection, but its impact on AISC remains unclear. Our study aims to elucidate the protective capacity of HDL-C in AISC in patients with diffuse large B-cell lymphoma (DLBCL) treated with R-CHOP (cyclophosphamide, vincristine, doxorubicin, prednisone and rituximab).

DESIGN

Prospective observational study.

SETTING

Conducted in China from September 2020 to September 2022.

PARTICIPANTS

70 chemotherapy-naïve patients newly diagnosed with DLBCL who were scheduled to receive the standard dose of R-CHOP; 60 participants included in a case-control study (DOI: 10.1186/s12885-022-10085-6).

PRIMARY OUTCOME MEASURES

Serum biomarkers, 2D speckle tracking echocardiography and conventional echocardiography were measured at baseline, at the end of the third and sixth cycles of R-CHOP and 6 and 12 months after chemotherapy.

RESULTS

24 patients experienced AISC, while 10 did not. 36 patients were lost to follow-up and death. Cox regression analysis showed that higher levels of HDL-C were associated with a significantly lower risk of AISC (unadjusted HR=0.24, 95% CI 0.09 to 0.67, p=0.006; adjusted HR=0.27, 95% CI 0.09 to 0.79, p=0.017). Patients without AISC had a more stable and higher HDL-C level during the follow-up period. HDL-C levels significantly decreased from the end of the third cycle of chemotherapy to the end of the sixth cycle of chemotherapy in all patients (p=0.034), and particularly in the AISC group (p=0.003). The highest level of HDL-C was significantly higher in patients without AISC than in those with AISC (1.52±0.49 vs 1.22±0.29, p=0.034).

CONCLUSIONS

Our study suggests that higher HDL-C levels may associate with lower AISC risk in patients with DLBCL treated with R-CHOP. HDL-C could be a cardioprotective target, but further research is needed to confirm its benefits and limitations.

STUDY REGISTRATION NUMBER

Study registration number: ChiCTR2100054721.

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.

Subsequent primary neoplasms after childhood cancer therapy - design and description of the German nested case-control study STATT-SCAR

BACKGROUND

Subsequent primary neoplasms (SPN) are among the most severe late effects and the second most frequent cause of death in childhood cancer patients. In this paper we introduce method and properties of the STATT-SCAR study (Second Tumor After Tumor Therapy, Second Cancer After Radiotherapy), which is a joint nested matched case-control study to evaluate the impact of chemotherapy (STATT) as well as radiotherapy (SCAR) on the risk of developing a SPN.

METHODS

Based on the cohort of the German childhood cancer registry (GCCR), we selected patients diagnosed with a first neoplasm before age 15 or younger between 1980 and 2014. We selected those with a SPN at least half a year after the first neoplasm, and matched up to four controls to each case. Therapy data were acquired from various sources, including clinical study centers and treating hospitals. To analyze the impact of radiotherapy, organ doses were estimated by using reconstructed treatment plans. The effect of chemotherapy was analyzed using substance groups summarized after isotoxic dose conversion.

RESULTS

1244 cases with a SPN were identified and matched with 4976 controls. Treatment data were acquired for 83% of all match groups (one case and at least one control). Based on preliminary analyses, 98% of all patients received chemotherapy and 54% of all patients were treated with radiotherapy.

CONCLUSIONS

Based on our data, detailed analyses of dose response relationships and treatment element combinations are possible, leading to a deeper insight into SPN risks after cancer treatments.

TRIAL REGISTRATION

The study is registered at the German clinical trial register (DRKS) under number DRKS00017847 [45].

Prevalence, patterns, and determinants of multimorbidity among childhood and adult cancer survivors: A systematic review

Development of multimorbidity is common among cancer survivors due to their previous cancer, treatments, or changes in lifestyle. We summarized evidence on the prevalence, patterns, and determinants of multimorbidity among childhood and adult cancer survivors. We searched PubMed and EMBASE databases for articles reporting prevalence, patterns, and determinants of multimorbidity in cancer survivors. Finally, 23/500 articles were included. There was a large variation in the prevalence of multimorbidity (13-89%) among cancer survivors. Bone marrow transplantation, radiation, female sex, lower level of physical activity, increasing age, minority ethnicity, low-income, and low-education were associated with a higher prevalence of multimorbidity. Patterns of multimorbidity were both concordant and discordant. In conclusion, multimorbidity is highly prevalent and a major concern among cancer survivors. A personalized care plan that takes into account the identified risk may be beneficial to reduce the burden of multimorbidity and improve the quality of life among cancer survivors.

Gene-Level Analysis of Anthracycline-Induced Cardiomyopathy in Cancer Survivors: A Report From COG-ALTE03N1, BMTSS, and CCSS

Background

Anthracyclines are highly effective in treating cancer, albeit with increased cardiomyopathy risk. Although risk is attributed to associations with single nucleotide polymorphisms (SNPs), multiple SNPs on a gene and their interactions remain unexamined.

Objectives

This study examined gene-level associations with cardiomyopathy among cancer survivors using whole-exome sequencing data.

Methods

For discovery, 278 childhood cancer survivors (129 cases; 149 matched control subjects) from the COG (Children's Oncology Group) study ALTE03N1 were included. Logic regression (machine learning) was used to identify gene-level SNP combinations for 7,212 genes and ordinal logistic regression to estimate gene-level associations with cardiomyopathy. Models were adjusted for primary cancer, age at cancer diagnosis, sex, race/ethnicity, cumulative anthracycline dose, chest radiation, cardiovascular risk factors, and 3 principal components. Statistical significance threshold of 6.93 × 10-6 accounted for multiple testing. Three independent cancer survivor populations (COG study, BMTSS [Blood or Marrow Transplant Survivor Study] and CCSS [Childhood Cancer Survivor Study]) were used to replicate gene-level associations and examine SNP-level associations from discovery genes using ordinal logistic, conditional logistic, and Cox regression models, respectively.

Results

Median age at cancer diagnosis for discovery cases and control subjects was 6 years and 8 years, respectively. Gene-level association for P2RX7 (OR: 0.10; 95% CI: 0.04-0.27; P = 2.19 × 10-6) was successfully replicated (HR: 0.65; 95% CI: 0.47-0.90; P = 0.009) in the CCSS cohort. Additional signals were identified on TNIK, LRRK2, MEFV, NOBOX, and FBN3. Individual SNPs across all discovery genes, except FBN3, were replicated.

Conclusions

In our study, SNP sets having 1 or no copies of P2RX7 variant alleles were associated with reduced risk of cardiomyopathy, presenting a potential therapeutic target to mitigate cardiac outcomes in cancer survivors.

Circulating Biomarkers for Monitoring Chemotherapy-Induced Cardiotoxicity in Children

Most commonly diagnosed cancer pathologies in the pediatric population comprise leukemias and cancers of the nervous system. The percentage of cancer survivors increased from approximatively 50% to 80% thanks to improvements in medical treatments and the introduction of new chemotherapies. However, as a consequence, heart disease has become the main cause of death in the children due to the cardiotoxicity induced by chemotherapy treatments. The use of different cardiovascular biomarkers, complementing data obtained from electrocardiogram, echocardiography cardiac imaging, and evaluation of clinical symptoms, is considered a routine in clinical diagnosis, prognosis, risk stratification, and differential diagnosis. Cardiac troponin and natriuretic peptides are the best-validated biomarkers broadly accepted in clinical practice for the diagnosis of acute coronary syndrome and heart failure, although many other biomarkers are used and several potential markers are currently under study and possibly will play a more prominent role in the future. Several studies have shown how the measurement of cardiac troponin (cTn) can be used for the early detection of heart damage in oncological patients treated with potentially cardiotoxic chemotherapeutic drugs. The advent of high sensitive methods (hs-cTnI or hs-cTnT) further improved the effectiveness of risk stratification and monitoring during treatment cycles.

Cardiac electrical abnormalities in childhood acute lymphoblastic leukemia survivors: a systematic review

PURPOSE

The aim was to provide evidence about the prevalence, incidence, and risk factors of cardiac electrical abnormalities in childhood acute lymphoblastic leukemia (ALL) survivors.

METHODS

We included all original studies reporting the incidence and/or prevalence of cardiac electrical abnormalities and/or risk factors associated with cardiac electrical abnormalities in childhood ALL survivors (< 21 years old at the time of their initial cancer diagnosis) who were post-treatment. Searches of the databases PubMed, Ovid MEDLINE(R) and Epub Ahead of Print, In-Process, In-Data-Review & Other Non-Indexed Citations, Daily and Versions(R), Ovid All EBM Reviews, Ovid Embase, and ISI Web of Science were completed in May 2023. The risk of bias was assessed using the standard JBI critical appraisal checklists.

RESULTS

The 11 studies included in this review (N = 1,264 participants) evaluated various parameters, including different cardiac electrical abnormalities. Five studies reported heart rate abnormalities (0-68%), six reported repolarization disorders (0-30%), two reported depolarization disorders (0-1%), seven reported rhythm disturbances or abnormalities (0-100%), four reported conduction disorders (0-10%), and three reported unclassified abnormalities (1-38%). No risk factors were reported.

CONCLUSIONS

Electrical heart problems have been observed in childhood ALL survivors after completion of treatment. Large prospective studies in childhood ALL survivors, clear definitions of cardiac electrical abnormalities, and comparison with a control group are warranted.

IMPLICATIONS FOR CANCER SURVIVORS

Cardiac electrical abnormalities induced by chemotherapy-related cardiotoxicity in the growing population of childhood ALL survivors need to be better characterized to ensure better long-term follow-up and improve overall survival rate.

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

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

Clinical Care for People Who Survive Childhood Cancer: A Review

Importance

An estimated 15 000 children and adolescents aged 0 to 19 years are diagnosed with cancer each year in the US, and more than 85% survive for at least 5 years. By 45 years of age, approximately 95% of people who survive childhood cancer will develop a significant health problem related to the childhood cancer diagnosis or its treatment.

Observations

Approximately 500 000 people currently alive in the US have survived childhood cancer. The most common severe or life-threatening chronic health problems related to childhood cancer or its treatment are endocrine disorders such as hypothyroidism or growth hormone deficiency (44%), subsequent neoplasms such as breast cancer or thyroid cancer (7%), and cardiovascular disease such as cardiomyopathy or congestive heart failure, coronary artery disease, and cerebrovascular disease (5.3%). Medical conditions related to a cancer diagnosis during childhood or adolescence are most commonly caused by the radiation therapy and the chemotherapies used to treat cancer and may develop at varying lengths of time after exposure to these treatments. Individuals at highest risk for developing treatment-related health problems include patients with brain cancer treated with cranial irradiation (approximately 70% develop severe or life-threatening health problems) and allogeneic hematopoietic stem cell transplant recipients (approximately 60% develop severe or life-threatening health problems). Individuals at the lowest risk for developing treatment-related health problems include those who survived solid tumors (such as Wilms tumor) treated with surgical resection alone or with minimal chemotherapy, for whom the prevalence of subsequent health problems is similar to people who did not have cancer during childhood or adolescence. People diagnosed with childhood cancer in the 1990s who survived for at least 5 years after the cancer diagnosis have a shorter lifespan (by about 9 years) vs children who were not diagnosed with cancer in the 1990s.

Conclusions and Relevance

Approximately 500 000 individuals currently alive in the US have survived childhood cancer. The most common adverse effects in individuals who survived childhood cancer are endocrine disorders, subsequent neoplasms, and cardiovascular disease. There is a need for clinicians and patients to have heightened awareness of these complications.

Cardiotoxicity in children with cancer treated with anthracyclines: A position statement on dexrazoxane

Cardiovascular disease is the leading cause of non-malignant morbidity and mortality in childhood cancer survivors (CCSs). Anthracyclines are included in many treatment regimens for paediatric cancer, but unfortunately, these compounds are cardiotoxic. One in 10 CCSs who has received an anthracycline will develop a symptomatic cardiac event over time. Given the crucial need to mitigate anthracycline-related cardiotoxicity (ARC), the authors critically examined published data to identify effective cardioprotective strategies. Based on their expert analysis of contemporary literature data, it was concluded that consideration should be given for routine use of dexrazoxane in children with cancer who are at risk of ARC.

Remote Ischemic Conditioning in Pediatric Cancer Patients Receiving Anthracycline Chemotherapy: A Sham-Controlled Single-Blind Randomized Trial

Background

Anthracycline cardiotoxicity is a concern in survivors of childhood cancers. Recent evidence suggests that remote ischemic conditioning (RIC) may offer myocardial protection.

Objectives

This randomized sham-controlled single-blind study tested the hypothesis that RIC may reduce myocardial injury in pediatric cancer patients receiving anthracycline chemotherapy.

Methods

We performed a phase 2 sham-controlled single-blind randomized controlled trial to determine the impact of RIC on myocardial injury in pediatric cancer patients receiving anthracycline-based chemotherapy. Patients were randomized to receive RIC (3 cycles of 5-minute inflation of a blood pressure cuff placed over 1 limb to 15 mm Hg above systolic pressure) or sham intervention. The intervention was applied within 60 minutes before initiation of the first dose and before up to 4 cycles of anthracycline therapy. The primary outcome was the plasma high-sensitivity cardiac troponin T (hs-cTnT) level. The secondary outcome measures included echocardiographic indexes of left ventricular systolic and diastolic function and the occurrence of cardiovascular events.

Results

A total of 68 children 10.9 ± 3.9 years of age were randomized to receive RIC (n = 34) or sham (n = 34) intervention. Plasma levels of hs-cTnT showed a progressive increase across time points in the RIC (P < 0.001) and sham (P < 0.001) groups. At each of the time points, there were no significant differences in hs-cTnT levels or LV tissue Doppler and strain parameters between the 2 groups (all P > 0.05). None of the patients developed heart failure or cardiac arrhythmias.

Conclusions

RIC did not exhibit cardioprotective effects in childhood cancer patients receiving anthracycline-based chemotherapy. (Remote Ischaemic Preconditioning in Childhood Cancer [RIPC]; NCT03166813).

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.

Replication of genetic associations of chemotherapy-related cardiotoxicity in the adjuvant NSABP B-31 clinical trial

Background

The cardiotoxic effects of doxorubicin, trastuzumab, and other anticancer agents are well known, but molecular genetic testing is lacking for the early identification of patients at risk for therapy-related cardiac toxicity.

Methods

Using the Agena Bioscience MassARRAY system, we genotyped TRPC6 rs77679196, BRINP1 rs62568637, LDB2 rs55756123, RAB22A rs707557, intergenic rs4305714, LINC01060 rs7698718, and CBR3 rs1056892 (V244M) (previously associated with either doxorubicin or trastuzumab-related cardiotoxicity in the NCCTG N9831 trial of anthracycline-based chemotherapy ± trastuzumab) in 993 patients with HER2+ early breast cancer from the NSABP B-31 trial of adjuvant anthracycline-based chemotherapy ± trastuzumab. Association analyses were performed with outcomes of congestive heart failure (N = 29) and maximum decline in left ventricular ejection fraction (LVEF) using logistic and linear regression models, respectively, under an additive model with age, baseline LVEF, and previous use of hypertensive medications as covariates.

Results

Associations of maximum decline in LVEF in the NCCTG N9831 patients did not replicate in the NSABP B-31 patients. However, TRPC6 rs77679196 and CBR3 rs1056892 were significantly associated with congestive heart failure, p < 0.05, with stronger associations observed in patients treated with chemotherapy only (no trastuzumab) or in the combined analysis of all patients relative to those patients treated with chemotherapy + trastuzumab.

Conclusions

TRPC6 rs77679196 and CBR3 rs1056892 (V244M) are associated with doxorubicin-induced cardiac events in both NCCTG N9831 and NSABP B-31. Other variants previously associated with trastuzumab-related decline in LVEF failed to replicate between these studies.

Equivalent doses for anticancer agents used in pediatric oncology: A literature review and evaluation of a novel approach for conversion factors

BACKGROUND

Epidemiological research on late effects of therapy shows the necessity to aggregate chemotherapy agents to substance classes. This requires using conversion factors by substance classes.

AIMS

The aim of this study was to identify previously used conversion factors from the literature, to present a novel approach for additional factors, and to compare these approaches.

METHODS AND RESULTS

A literature review was performed, which identified two main principles of deriving conversion factors: effect-equivalence and equimolar. Thirty-five articles presenting effect equivalence-based factors in the widest sense were found in the literature. Ten articles presented the equimolar approach which can be applied to almost all chemotherapy substances. Based on a comprehensive list of treatment protocols used in German pediatric oncology, we derived alternative conversion factors from typical doses. We compared the conversion factors using Pearson correlation coefficients and linear regression. At least two types of conversion factor were available for each of the 49 substances included. The equivalent effect-based and the typical dose-based factors were highly correlated with a regression coefficient close to 1. The equimolar factors are independent.

CONCLUSIONS

For substances for which no conversion factor based on some type of effect equivalence has been published so far, a factor based on a typical doses-approach may be used in epidemiological late effects research. Doses aggregated based on the equimolar approach may not be compatible with doses aggregated based on equivalent effects.

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.

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

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

Risk Factors for Heart Failure Among Pan-European Childhood Cancer Survivors: A PanCareSurFup and ProCardio Cohort and Nested Case-Control Study

PURPOSE

Heart failure (HF) is a potentially life-threatening complication of treatment for childhood cancer. We evaluated the risk and risk factors for HF in a large European study of long-term survivors. Little is known of the effects of low doses of treatment, which is needed to improve current treatment protocols and surveillance guidelines.

METHODS

This study includes the PanCareSurFup and ProCardio cohort of ≥ 5-year childhood cancer survivors diagnosed between 1940 and 2009 in seven European countries (N = 42,361). We calculated the cumulative incidence of HF and conducted a nested case-control study to evaluate detailed treatment-related risk factors.

RESULTS

The cumulative incidence of HF was 2% (95% CI, 1.7 to 2.2) by age 50 years. The case-control study (n = 1,000) showed that survivors who received a mean heart radiation therapy (RT) dose of 5 to < 15 Gy have an increased risk of HF (odds ratio, 5.5; 95% CI, 2.5 to 12.3), when compared with no heart RT. The risk associated with doses 5 to < 15 Gy increased with exposure of a larger heart volume. In addition, the HF risk increased in a linear fashion with higher mean heart RT doses. Regarding total cumulative anthracycline dose, survivors who received ≥ 100 mg/m² had a substantially increased risk of HF and survivors treated with a lower dose showed no significantly increased risk of HF. The dose-response relationship appeared quadratic with higher anthracycline doses.

CONCLUSION

Survivors who received a mean heart RT dose of ≥ 5 Gy have an increased risk of HF. The risk associated with RT increases with larger volumes exposed. Survivors treated with < 100 mg/m² total cumulative anthracycline dose have no significantly increased risk of HF. These new findings might have consequences for new treatment protocols for children with cancer and for cardiomyopathy surveillance guidelines.

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.

Study on influencing factors of anthracycline-induced subclinical cardiotoxicity in DLBCL patients administered (R)-CHOP

Background

Anthracycline-induced cardiotoxicity is an irreversible cardiac cell injury. Therefore, it’s very important to identify influencing factors of anthracycline-induced subclinical cardiotoxicity (AISC). This study was designed to analyze the influencing factors of AISC in patients with diffuse large B-cell lymphoma (DLBCL) treated with the (R)-CHOP chemotherapy regimen.

Methods

This is an ongoing observational prospective clinical trial. All patients underwent conventional echocardiography and speckle tracking echocardiography at the time of enrollment and during treatment. Changes of global longitudinal peak systolic strain were assessed after 3 cycles of (R)-CHOP chemotherapy, and patients were divided into the AISC and No-AISC groups. Demographic data, clinical variables, and biochemical variables were measured. Regression models, receiver operating characteristic curve analysis, and difference values were used to explore the relationships between variables and AISC.

Results

Among 70 patients who completed 3 cycles of (R)-CHOP chemotherapy, 26 developed AISC. In multiple logistic regression, HDL-C (P = 0.047), ApoA1 (P = 0.022), TG (P = 0.029) and e’ (P = 0.008) were associated with AISC. The combination of HDL-C and NT-proBNP had the highest area under curves (AUC) for the diagnosis of AISC than HDL-C and NT-proBNP alone (AUC = 0.752, 95%CI: 0.63–0.87, P = 0.001). Between the No-AISC and AISC groups, there was no significant difference in HDL-C, ApoA1, and e’ at baseline and after 3 cycles of chemotherapy, respectively. The dynamic changes of HDL-C, ApoA1, and e’ from baseline to the end of the 3^rd cycle of chemotherapy showed statistically significant differences.

Conclusions

HDL-C, ApoA1, TG, and e’ are independent predictive factors in DLBCL cases treated with the (R)-CHOP chemotherapy regimen. The combination of HDL-C and NT-proBNP may improve the predictive ability for AISC in patients with DLBCL administered 3 cycles of (R)-CHOP chemotherapy. Dynamic changes of HDL-C, ApoA1, and e’ may be meaningful for predicting AISC.

Trial registration

Our study was registered in the Chinese Clinical Trial Registry (Approval ID. ChiCTR2100054721 http://www.chictr.org.cn/showproj.aspx?proj=145082).

Leveraging Clinical Trial Populations and Data from the Children's Oncology Group for Cancer Survivorship Research

Children and adolescents diagnosed with cancer can now expect an average 85% 5-year overall survival, with significant improvements in longer-term morbidity and mortality reported over the past several decades. However, the long-term impact of therapeutic agents and modalities introduced in recent years remains unclear and will require dedicated follow-up in the years ahead. The Children's Oncology Group (COG), a part of the NCI's National Clinical Trials Network, with over 200 sites across North America and beyond, enrolls more than 10,000 patients onto research protocols annually, inclusive of first-line clinical trials and nontherapeutic studies. COG provides a platform to conduct survivorship research with several unique strengths: (i) a huge catchment to ascertain relatively rare but important adverse events, (ii) study populations that are otherwise too rare to study in smaller consortia, including access to highly diverse patient populations, (iii) long-term follow-up of clinical trial populations linked to the original trial data, and (iv) a natural platform for intervention research. Enhancements in COG infrastructure facilitate survivorship research, including a COG patient registry (Project:EveryChild), availability of a long-term follow-up tracking resource, and successful deployment of various remote-based study procedures to reduce the burden on participants and participating institutions.

Cardioprotective Strategies from Cardiotoxicity in Cancer Patients: A Comprehensive Review

Cardiotoxicity is a significant complication of chemotherapeutic agents in cancer patients. Cardiovascular incidents including LV dysfunction, heart failure (HF), severe arrhythmias, arterial hypertension, and death are associated with high morbidity and mortality. Risk stratification of cancer patients prior to initiation of chemotherapy is crucial, especially in high-risk patients for cardiotoxicity. The early identification and management of potential risk factors for cardiovascular side effects seems to contribute to the prevention or minimization of cardiotoxicity. Screening of cancer patients includes biomarkers such as cTnI and natriuretic peptide and imaging measurements such as LV function, global longitudinal strain, and cardiac MRI. Cardioprotective strategies have been investigated over the last two decades. These strategies for either primary or secondary prevention include medical therapy such as ACE inhibitors, ARBs, b-blockers, aldosterone antagonists, statins and dexrazoxane, physical therapy, and reduction of chemotherapeutic dosages. However, data regarding dosages, duration of medical therapy, and potential interactions with chemotherapeutic agents are still limited. Collaboration among oncologists, cardiologists, and cardio-oncologists could establish management cardioprotective strategies and approved follow-up protocols in patients with cancer receiving chemotherapy.

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.

Detecting subclinical anthracycline therapy-related cardiac dysfunction in patients attending Uganda Cancer Institute

Aims: To investigate the incidence of anthracycline therapy-related cardiac dysfunction (ATRCD) and its predictors among Ugandan cancer patients. Patients & methods: The study recruited 207 cancer patients who were followed for 6 months after ending anthracycline therapy. Global longitudinal strain and troponin-I were the diagnostic tools. Results & conclusions: The cumulative incidences of subclinical and clinical ATRCD were 35.0 and 8.8% respectively. The predictors of clinical ATRCD were HIV infection (hazard ratio [HR]: 3.04; 95% CI: 1.26-7.32; p = 0.013), lower baseline global longitudinal strain (HR: 0.61; 95% CI: 0.53-0.71; p < 0.001) and development of subclinical ATRCD at the end of anthracycline therapy (HR: 6.61; 95% CI: 2.60-16.82; p < 0.001). Cardiac surveillance at baseline and at ending of anthracycline therapy is essential to identify high-risk patients.

A review of the risks of long-term consequences associated with components of the CHOP chemotherapy regimen

A common chemotherapy regimen in post-transplant lymphoproliferative disease (PTLD) following solid organ transplants (SOT) is cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP). This study reviews the quantitative evidence for long-term consequences associated with components of CHOP identified from the Children's Oncology Group Long-Term Follow-Up Guidelines. Cited references were screened using prespecified criteria (English, systematic review, randomized controlled trial n > 100, observation study n > 100, case series n > 20). Relevant data were extracted and synthesized. Of 61 studies, 66% were retrospective cohort studies, 28% were in the US, and 95% enrolled pediatric patients. No study focused specifically on the CHOP regimen. Long-term consequences for CHOP components observed in >3 studies included cardiac toxicity (n = 14), hormone deficiencies/infertility (n = 14), secondary leukemia (n = 7), osteonecrosis (n = 6), and bladder cancer (n = 4). These effects are significant, impact a high percentage of patients, and occur as early as one year after treatment. Although none of the studies focused specifically on the CHOP regimen, 30%, 23%, and 15% evaluated alkylating agents (e.g. cyclophosphamide), anthracyclines (e.g. doxorubicin), and corticosteroids (e.g. prednisone), respectively. All three product classes had a dose-dependent risk of long-term consequences with up to 13.2-fold, 27-fold, 16-fold, 14.5-fold, and 6.2-fold increase in risk of heart failure, early menopause, secondary leukemia, bladder cancer, and osteonecrosis, respectively. Lymphoma patients had significantly elevated risks of cardiac toxicity (up to 12.2-fold), ovarian failure (up to 3.8-fold), and osteonecrosis (up to 6.7-fold). No studies were found in PTLD or SOT. Safe and effective PTLD treatments that potentially avoid these long-term consequences are urgently needed.

Contribution of Genome-Wide Polygenic Score to Risk of Coronary Artery Disease in Childhood Cancer Survivors

Background

Adverse cardiovascular outcomes such as coronary artery disease (CAD) are the leading noncancer causes of morbidity and mortality among childhood cancer survivors.

Objectives

The aim of this study was to assess the role of a genome-wide polygenic score (GPS) for CAD, well validated in the general population, and its interplay with cancer-related risk factors among childhood cancer survivors.

Methods

In a cohort study of 2,472 5-year childhood cancer survivors from the St. Jude Lifetime Cohort, the association between the GPS and the risk of CAD was performed using Cox regression models adjusted for age at cancer diagnosis, sex, cumulative dose of anthracyclines, and mean heart radiation dose.

Results

Among survivors of European ancestry, the GPS was significantly associated with the risk of CAD (HR per 1 SD of the GPS: 1.25; 95% CI: 1.04-1.49; P = 0.014). Compared with the first tertile, survivors in the upper tertile had a greater risk of CAD (1.51-fold higher HR of CAD [95% CI: 0.96-2.37; P = 0.074]), although the difference was not statistically significant. The GPS-CAD association was stronger among survivors diagnosed with cancer at age <10 years exposed to >25 Gy heart radiation (HR top vs. bottom tertile of GPS: 15.49; 95% CI: 5.24-45.52; P_trend = 0.005) but not among those diagnosed at age ≥10 years (P_trend ≥ 0.77) and not among those diagnosed at age <10 years exposed to ≤25 Gy heart radiation (P_trend = 0.23). Among high-risk survivors, defined by an estimated relative hazard ≥3.0 from fitted Cox models including clinical risk factors alone, the cumulative incidence of CAD at 40 years from diagnosis was 29% (95% CI: 13%-45%). After incorporating the GPS into the model, the cumulative incidence increased to 48% (95% CI: 26%-69%).

Conclusions

Childhood cancer survivors are at risk for premature CAD. A GPS may help identify those who may benefit from targeted screening and personalized preventive interventions.

The Prevalence of Pharmacogenomics Variants and Their Clinical Relevance Among the Pakistani Population

Background:

Pharmacogenomics (PGx), forming the basis of precision medicine, has revolutionized traditional medical practice. Currently, drug responses such as drug efficacy, drug dosage, and drug adverse reactions can be anticipated based on the genetic makeup of the patients. The pharmacogenomic data of Pakistani populations are limited. This study investigates the frequencies of pharmacogenetic variants and their clinical relevance among ethnic groups in Pakistan.

Methods:

The Pharmacogenomics Knowledge Base (PharmGKB) database was used to extract pharmacogenetic variants that are involved in medical conditions with high (1A + 1B) to moderate (2A + 2B) clinical evidence. Subsequently, the allele frequencies of these variants were searched among multiethnic groups of Pakistan (Balochi, Brahui, Burusho, Hazara, Kalash, Pashtun, Punjabi, and Sindhi) using the 1000 Genomes Project (1KGP) and ALlele FREquency Database (ALFRED). Furthermore, the published Pharmacogenomics literature on the Pakistani population was reviewed in PubMed and Google Scholar.

Results:

Our search retrieved (n = 29) pharmacogenetic genes and their (n = 44) variants with high to moderate evidence of clinical association. These pharmacogenetic variants correspond to drug-metabolizing enzymes (n = 22), drug-metabolizing transporters (n = 8), and PGx gene regulators, etc. (n = 14). We found 5 pharmacogenetic variants present at >50% among 8 ethnic groups of Pakistan. These pharmacogenetic variants include CYP2B6 (rs2279345, C; 70%-86%), CYP3A5 (rs776746, C; 64%-88%), FLT3 (rs1933437, T; 54%-74%), CETP (rs1532624, A; 50%-70%), and DPP6 (rs6977820, C; 61%-86%) genes that are involved in drug response for acquired immune deficiency syndrome, transplantation, cancer, heart disease, and mental health therapy, respectively.

Conclusions:

This study highlights the frequency of important clinical pharmacogenetic variants (1A, 1B, 2A, and 2B) among multi-ethnic Pakistani populations. The high prevalence (>50%) of single nucleotide pharmacogenetic variants may contribute to the drug response/diseases outcome. These PGx data could be used as pharmacogenetic markers in the selection of appropriate therapeutic regimens for specific ethnic groups of Pakistan.

Genetics of Anthracycline-Associated Cardiotoxicity

Anthracyclines are a major component of chemotherapies used in many pediatric and adult malignancies. Anthracycline-associated cardiotoxicity (ACT) is a dose-dependent adverse effect that has substantial impact on morbidity and mortality. Therefore, the identification of genetic variants associated with increased risk of ACT has the potential for significant clinical impact to improve patient care. The goal of this review is to summarize the current evidence supporting genetic variants associated with ACT, identify gaps and limitations in current knowledge, and propose future directions for incorporating genetics into clinical practice for patients treated with anthracyclines. We will discuss mechanisms of ACT that could be illuminated by genetics and discuss clinical applications for the cardiologist/cardio-oncologist.

Case Report: Diffuse Large B Cell Lymphoma After Cardiac Transplantation due to Anthracycline-Induced Dilated Cardiomyopathy in Pediatric Acute Lymphoblastic Leukemia

Anthracycline is a first-line chemotherapy drug used to treat childhood acute leukemia, which may cause cardiac toxicity including common arrhythmia, valve disease, pericardial effusion, and even rare cardiomyopathy and cardiac failure. We reported a 2-year-old boy who was treated irregularly for acute lymphoblastic leukemia with daunorubicin. After 26 months, his left ventricular ejection fraction decreased to 40% and progressively decreased to 20–30%. Then he successfully received a heart transplant and the myocardium was confirmed with dilated cardiomyopathy. Eight months after cardiac transplantation, he was admitted again for left neck mass and was diagnosed with monomorphic diffuse large B cell lymphoma associated with Epstein-Barr virus infection by biopsy. We present this case to highlight the importance of standard chemotherapy of daunorubicin, clinical prevention, and monitoring of anthracycline-induced cardiotoxicity in acute lymphoblastic leukemia children to ensure their good prognosis and long-term life quality.

Cardiotoxicity of Anticancer Drugs: Molecular Mechanisms and Strategies for Cardioprotection

Chemotherapy and targeted therapies have significantly improved the prognosis of oncology patients. However, these antineoplastic treatments may also induce adverse cardiovascular effects, which may lead to acute or delayed onset of cardiac dysfunction. These common cardiovascular complications, commonly referred to as cardiotoxicity, not only may require the modification, suspension, or withdrawal of life-saving antineoplastic therapies, with the risk of reducing their efficacy, but can also strongly impact the quality of life and overall survival, regardless of the oncological prognosis. The onset of cardiotoxicity may depend on the class, dose, route, and duration of administration of anticancer drugs, as well as on individual risk factors. Importantly, the cardiotoxic side effects may be reversible, if cardiac function is restored upon discontinuation of the therapy, or irreversible, characterized by injury and loss of cardiac muscle cells. Subclinical myocardial dysfunction induced by anticancer therapies may also subsequently evolve in symptomatic congestive heart failure. Hence, there is an urgent need for cardioprotective therapies to reduce the clinical and subclinical cardiotoxicity onset and progression and to limit the acute or chronic manifestation of cardiac damages. In this review, we summarize the knowledge regarding the cellular and molecular mechanisms contributing to the onset of cardiotoxicity associated with common classes of chemotherapy and targeted therapy drugs. Furthermore, we describe and discuss current and potential strategies to cope with the cardiotoxic side effects as well as cardioprotective preventive approaches that may be useful to flank anticancer therapies.

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.

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.

Pediatric Cardio-Oncology Medicine: A New Approach in Cardiovascular Care

Survival for pediatric patients diagnosed with cancer has improved significantly. This achievement has been made possible due to new treatment modalities and the incorporation of a systematic multidisciplinary approach for supportive care. Understanding the distinctive cardiovascular characteristics of children undergoing cancer therapies has set the underpinnings to provide comprehensive care before, during, and after the management of cancer. Nonetheless, we acknowledge the challenge to understand the rapid expansion of oncology disciplines. The limited guidelines in pediatric cardio-oncology have motivated us to develop risk-stratification systems to institute surveillance and therapeutic support for this patient population. Here, we describe a collaborative approach to provide wide-ranging cardiovascular care to children and young adults with oncology diseases. Promoting collaboration in pediatric cardio-oncology medicine will ultimately provide excellent quality of care for future generations of patients.

POLRMT as a Novel Susceptibility Gene for Cardiotoxicity in Epirubicin Treatment of Breast Cancer Patients

Anthracyclines are among the most used chemotherapeutic agents in breast cancer (BC). However their use is hampered by anthracycline-induced cardiotoxicity (AIC). The currently known clinical and genetic risk factors do not fully explain the observed inter-individual variability and only have a limited ability to predict which patients are more likely to develop this severe toxicity. To identify novel predictive genes, we conducted a two-stage genome-wide association study in epirubicin-treated BC patients. In the discovery phase, we genotyped over 700,000 single nucleotide variants in a cohort of 227 patients. The most interesting finding was rs62134260, located 4kb upstream of POLRMT (OR = 5.76, P = 2.23 × 10-5). We replicated this association in a validation cohort of 123 patients (P = 0.021). This variant regulates the expression of POLRMT, a gene that encodes a mitochondrial DNA-directed RNA polymerase, responsible for mitochondrial gene expression. Individuals harbouring the risk allele had a decreased expression of POLRMT in heart tissue that may cause an impaired capacity to maintain a healthy mitochondrial population in cardiomyocytes under stressful conditions, as is treatment with epirubicin. This finding suggests a novel molecular mechanism involved in the development of AIC and may improve our ability to predict patients who are at risk.

Targeting the redox imbalance in mitochondria: A novel mode for cancer therapy

Changes in reactive oxygen species (ROS) levels affect many aspects of cell behavior. During carcinogenesis, moderate ROS production modifies gene expression to alter cell function, elevating metabolic activity and ROS. To avoid extreme ROS-activated death, cancer cells increase antioxidative capacity, regulating sustained ROS levels that promote growth. Anticancer therapies are exploring inducing supranormal, cytotoxic oxidative stress levels either inhibiting antioxidative capacity or promoting excess ROS to selectively destroy cancer cells, triggering mechanisms such as apoptosis, autophagy, necrosis, or ferroptosis. This review exemplifies pro-oxidants (natural/synthetic/repurposed drugs) and their clinical significance as cancer therapies providing revolutionary approaches.

Pediatric Chemotherapy Drugs Associated With Cardiotoxicity

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

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.

RARG variant predictive of doxorubicin-induced cardiotoxicity identifies a cardioprotective therapy

Doxorubicin is an anthracycline chemotherapy agent effective in treating a wide range of malignancies, but its use is limited by dose-dependent cardiotoxicity. A recent genome-wide association study identified a SNP (rs2229774) in retinoic acid receptor-γ (RARG) as statistically associated with increased risk of anthracycline-induced cardiotoxicity. Here, we show that human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) from patients with rs2229774 and who suffered doxorubicin-induced cardiotoxicity (DIC) are more sensitive to doxorubicin. We determine that the mechanism of this RARG variant effect is mediated via suppression of topoisomerase 2β (TOP2B) expression and activation of the cardioprotective extracellular regulated kinase (ERK) pathway. We use patient-specific hiPSC-CMs as a drug discovery platform, determining that the RARG agonist CD1530 attenuates DIC, and we confirm this cardioprotective effect in an established in vivo mouse model of DIC. This study provides a rationale for clinical prechemotherapy genetic screening for rs2229774 and a foundation for the clinical use of RARG agonist treatment to protect cancer patients from DIC.