Idarubicin cardiotoxicity: a retrospective study in acute myeloid leukemia and myelodysplasia

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.

Incidence and Risk Factors for Development of Cardiac Toxicity in Adult Patients with Newly Diagnosed Acute Myeloid Leukemia

The incidence of cardiac morbimortality in acute myeloid leukemia (AML) is not well known. We aim to estimate the cumulative incidence (CI) of cardiac events in AML patients and to identify risk factors for their occurrence. Among 571 newly diagnosed AML patients, 26 (4.6%) developed fatal cardiac events, and among 525 treated patients, 19 (3.6%) experienced fatal cardiac events (CI: 2% at 6 months; 6.7% at 9 years). Prior heart disease was associated with the development of fatal cardiac events (hazard ratio (HR) = 6.9). The CI of non-fatal cardiac events was 43.7% at 6 months and 56.9% at 9 years. Age ≥ 65 (HR = 2.2), relevant cardiac antecedents (HR = 1.4), and non-intensive chemotherapy (HR = 1.8) were associated with non-fatal cardiac events. The 9-year CI of grade 1-2 QTcF prolongation was 11.2%, grade 3 was 2.7%, and no patient had grade 4-5 events. The 9-year CI of grade 1-2 cardiac failure was 1.3%, grade 3-4 was 15%, and grade 5 was 2.1%; of grade 1-2, arrhythmia was 1.9%, grade 3-4 was 9.1%, and grade 5 was 1%. Among 285 intensive therapy patients, median overall survival decreased in those experiencing grade 3-4 cardiac events (p < 0.001). We observed a high incidence of cardiac toxicity associated with significant mortality in AML.

Cardiac-Related Lesions in Newly Diagnosed Patients With Acute Leukemia: A Chinese Population-Based Real-World Study

The relationship between newly diagnosed acute leukemia (AL) and heart-related lesions remains unclear. This study aimed to investigate baseline cardiac function and risk of cardiovascular diseases (CVDs) in patients with new-onset AL, and provide data on cardiac management strategies for patients with AL. We retrospectively collected data on baseline characteristics, echocardiography, and biochemical blood indicators (e.g., myocardial enzymes) from 408 patients, 200 with newly diagnosed AL, 103 with coronary artery disease (CAD), and 105 controls from January 1, 2015 to August 31, 2019. The creatine kinase isoenzyme myocardial band, lactate dehydrogenase, highly sensitive troponin-I, and B-type natriuretic peptide levels and left ventricular internal diameter (LVID) were significantly higher in patients with newly diagnosed AL than in the control group. The degree of cardiac damage was lower in newly diagnosed AL patients than in CAD patients. The best predictor of heart damage was LVID (AUC [area under the curve] = 0.709; 95% CI [confidence interval]: 0.637–0.781; p < 0.001), and independent prognostic risk factors were age and ejection fraction (HR [hazard ratio] = 1.636; 95% CI: 1.039–2.575; p = 0.033). The ratio of leukemia blasts among patients with AL was positively correlated with cardiac damage. Our data indicated that newly diagnosed AL patients had certain myocardial damage before treatment. Clinicians need to pay attention to these manifestations, which may be related to the prognosis.

Population-based high-throughput toxicity screen of human iPSC-derived cardiomyocytes and neurons

In this study, we establish a population-based human induced pluripotent stem cell (hiPSC) drug screening platform for toxicity assessment. After recruiting 1,000 healthy donors and screening for high-frequency human leukocyte antigen (HLA) haplotypes, we identify 13 HLA-homozygous "super donors" to represent the population. These "super donors" are also expected to represent at least 477,611,135 of the global population. By differentiating these representative hiPSCs into cardiomyocytes and neurons we show their utility in a high-throughput toxicity screen. To validate hit compounds, we demonstrate dose-dependent toxicity of the hit compounds and assess functional modulation. We also show reproducible in vivo drug toxicity results using mouse models with select hit compounds. This study shows the feasibility of using a population-based hiPSC drug screening platform to assess cytotoxicity, which can be used as an innovative tool to study inter-population differences in drug toxicity and adverse drug reactions in drug discovery applications.

Cardiac Toxicity From Adjuvant Targeting Treatment for Breast Cancer Post-Surgery

Breast cancer is one of the most prevalent types of cancers worldwide, especially for females. Surgery is the preferred treatment for breast cancer, and various postoperative adjuvant therapies can be reasonably used according to different pathological characteristics, especially traditional radiotherapy, chemotherapy, and endocrine therapy. In recent years, targeting agent therapy has also become one of the selective breast cancer treatment strategies, including anti-HER-2 drugs, CDK4/6 inhibitor, poly ADP-ribose polymerase inhibitor, PI3K/AKT/mTOR pathway inhibitor, ER targeting drugs, and aromatase inhibitor. Because of the different pathologic mechanisms of these adjuvant therapies, each of the strategies may cause cardiotoxicity in clinic. The cardiac adverse events of traditional endocrine therapy, radiotherapy, and chemotherapy for breast cancer have been widely detected in clinic; however, the targeting therapy agents have been paid more attention with the extension of application. This review will summarize the cardiac toxicity of various adjuvant therapies for breast cancer, especially for targeting drug therapy.

Survival of patients with newly diagnosed high-grade myeloid neoplasms who do not meet standard trial eligibility

Few patients with cancer, including those with acute myeloid leukemia and high-grade myeloid neoplasms, participate in clinical trials. Broadening standard eligibility criteria may increase clinical trial participation. In this retrospective single-center analysis, we identified 442 consecutive newly diagnosed patients from 2014 to 2016. Patients were considered “eligible” if they had a performance status 0-2, normal renal and hepatic function, no recent solid tumor, left ventricular ejection fraction (EF) ≥50%, and no history of congestive heart failure (CHF) or myocardial infarction (MI); “ineligible” patients failed to meet one or more of these criteria. We included 372 patients who received chemotherapy. Ineligible patients represented 40% of the population and had a 1.79-fold greater risk of death (95% Confidence Interval [CI]: 1.37-2.33) than eligible patients. Very few patients had cardiac comorbidities, including 2% with low EF, 4% with prior CHF, and 5% with prior MI. In multivariable analysis, ineligibility was associated with decreased survival (Hazard ratio [HR] 1.44; 95% CI: 1.07-1.93). Allogeneic transplantation, performed in 150 patients (40%), was associated with improved survival (HR 0.66, 95% CI: 0.48-0.91). Therefore, standard eligibility characteristics identify a patient population with improved survival. Further treatment options are needed for patients considered ineligible for clinical trials.

Anthraquinones as Inhibitors of SOS RAS-GEF Activity

Recent breakthroughs have reignited interest in RAS GEFs as direct therapeutic targets. To search for new inhibitors of SOS GEF activity, a repository of known/approved compounds (NIH-NACTS) and a library of new marine compounds (Biomar Microbial Technologies) were screened by means of in vitro RAS-GEF assays using purified, bacterially expressed SOS and RAS constructs. Interestingly, all inhibitors identified in our screenings (two per library) shared related chemical structures belonging to the anthraquinone family of compounds. All our anthraquinone SOS inhibitors were active against the three canonical RAS isoforms when tested in our SOS GEF assays, inhibited RAS activation in mouse embryonic fibroblasts, and were also able to inhibit the growth of different cancer cell lines harboring WT or mutant RAS genes. In contrast to the commercially available anthraquinone inhibitors, our new marine anthraquinone inhibitors did not show in vivo cardiotoxicity, thus providing a lead for future discovery of stronger, clinically useful anthraquinone SOS GEF blockers.

Translational Proteomics Analysis of Anthracycline-Induced Cardiotoxicity From Cardiac Microtissues to Human Heart Biopsies

Anthracyclines, including doxorubicin, idarubicin, and epirubicin, are common antitumor drugs as well as well-known cardiotoxic agents. This study analyzed the proteomics alteration in cardiac tissues caused by these 3 anthracyclines analogs. The in vitro human cardiac microtissues were exposed to drugs in 2 weeks; the proteomic data were measured at 7 time points. The heart biopsy data were collected from heart failure patients, in which some patients underwent anthracycline treatment. The anthracyclines-affected proteins were separately identified in the in vitro and in vivo dataset using the WGCNA method. These proteins engage in different cellular pathways including translation, metabolism, mitochondrial function, muscle contraction, and signaling pathways. From proteins detected in 2 datasets, a protein-protein network was established with 4 hub proteins, and 7 weighted proteins from both cardiac microtissue and human biopsies data. These 11 proteins, which involve in mitochondrial functions and the NF-κB signaling pathway, could provide insights into the anthracycline toxic mechanism. Some of them, such as HSPA5, BAG3, and SH3BGRL, are cardiac therapy targets or cardiotoxicity biomarkers. Other proteins, such as ATP5F1B and EEF1D, showed similar responses in both the in vitro and in vivo data. This suggests that the in vitro outcomes could link to clinical phenomena in proteomic analysis.

Anthracycline-Induced Cardiotoxicity: Molecular Insights Obtained from Human-Induced Pluripotent Stem Cell-Derived Cardiomyocytes (hiPSC-CMs)

Anthracyclines are a class of chemotherapy drugs that are highly effective for the treatment of human cancers, but their clinical use is limited by associated dose-dependent cardiotoxicity. The precise mechanisms by which individual anthracycline induces cardiotoxicity are not fully understood. Human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) are emerging as a physiologically relevant model to assess drugs cardiotoxicity. Here, we describe an assay platform by coupling hiPSC-CMs and impedance measurement, which allows real-time monitoring of cardiomyocyte cellular index, beating amplitude, and beating rate. Using this approach, we have performed comparative studies on a panel of four anthracycline drugs (doxorubicin, epirubicin, idarubicin, and daunorubicin) which share a high degree of structural similarity but are associated with distinct cardiotoxicity profiles and maximum cumulative dose limits. Notably, results from our hiPSC-CMs impedance model (dose-dependent responses and EC₅₀ values) agree well with the recommended clinical dose limits for these drugs. Using time-lapse imaging and RNAseq, we found that the differences in anthracycline cardiotoxicity are closely linked to extent of cardiomyocyte uptake and magnitude of activation/inhibition of several cellular pathways such as death receptor signaling, ROS production, and dysregulation of calcium signaling. The results provide molecular insights into anthracycline cardiac interactions and offer a novel assay system to more robustly assess potential cardiotoxicity during drug development.

Common genetic predisposition for heart failure and cancer

Cardiovascular diseases and cancer are major causes of mortality in industrialized societies. They share common risk factors (e.g., genetics, lifestyle, age, infection, toxins, and pollution) and might also mutually promote the onset of the respective other disease. Cancer can affect cardiac function directly while antitumor therapies may have acute- and/or late-onset cardiotoxic effects. Recent studies suggest that heart failure might promote tumorigenesis and tumor progression. In both cancer and cardiovascular diseases, genetic predisposition is implicated in the disease onset and development. In this regard, genetic variants classically associated with cardiomyopathies increase the risk for toxic side effects on the cardiovascular system. Genetic variants associated with increased cancer risk are frequent in patients with peripartum cardiomyopathy complicated by cancer, pointing to a common genetic predisposition for both diseases. Common risk factors, cardiotoxic antitumor treatment, genetic variants (associated with cardiomyopathies and/or cancer), and increased cardiac stress lead us to propose the "multi-hit hypothesis" linking cancer and cardiovascular diseases. In the present review, we summarize the current knowledge on potential connecting factors between cancer and cardiovascular diseases with a major focus on the role of genetic predisposition and its implication for individual therapeutic strategies and risk assessment in the novel field of oncocardiology.

Childhood cancer survivors: The integral role of the cardiologist and cardiovascular imaging

IMPORTANCE

With 80% of childhood cancer survivors (CCS) alive 30 years after diagnosis, preventable causes of death, such as cardiovascular disease resulting from initial cancer therapy, becomes an important metric. This leads to a more pronounced role for cardiologists in the care of CCS.

OBSERVATIONS

While routine cardiovascular screening has been traditionally performed by the hematologist/oncologist or primary care provider, our understanding of cardiovascular disease in CCS has advanced. The measurement of left ventricular ejection fraction (LVEF) can now be complemented with additional assessments of strain, LV mass, right ventricular function, diastolic function, valve function, the pericardium, coronary perfusion, and biomarkers. Risk factor modification, prophylaxis, and timing of treatment are also critical.

CONCLUSIONS AND RELEVANCE

Early cardiovascular screening and treatment in asymptomatic CCS can be nuanced and complex. As a result, there is a renewed opportunity for the cardiologist to play an integral role in the care of CCS.

KEY POINTS

Question/Purpose: Review cardiovascular disease and the role of the cardiologist in the care of asymptomatic childhood cancer survivors (CCS).

FINDINGS

Cardiovascular care in CCS benefits from a multi-faceted approach that does not overly rely on LVEF. Meaning: Adequate screening and treatment of cardiovascular disease in asymptomatic CCS may often be optimized by the involvement of a cardiologist.

Long-term cardiac-specific mortality among 44,292 acute myeloid leukemia patients treated with chemotherapy: a population-based analysis

Background: Acute myeloid leukemia (AML) is a common hematological malignancy treated with regimens containing anthracycline, an agent with cardiotoxicity. However, the cardiac-specific mortality in AML patients receiving chemotherapy remains unknown.

Methods: In this population-based study, patients diagnosed with AML between 1973 and 2015 were identified in the Surveillance, Epidemiology, and End Results database. Cumulative mortality by cause of death was calculated. To quantify the excessive cardiac-specific death compared with the general population, standardized mortality ratios (SMRs) were calculated. Multivariate Cox regression analyses were performed to identify risk factors associated with cardiac-specific death and AML-specific death.

Results: A total of 64,679 AML patients were identified between 1973 and 2015; 68.48% of patients (44,292) received chemotherapy. Among all possible competing causes of death, AML was associated with the highest cumulative mortality. The AML patients who received chemotherapy showed excessive cardiac-specific mortality compared with the general population, with an SMR of 6.35 (95% CI: 5.89-6.82). Age, year of diagnosis, sex, and marital status were independently associated with patient prognosis.

Conclusion: Cardiac-specific mortality in AML patients receiving chemotherapy is higher than that in the general population.

Anthracycline‑Induced Cardiac Toxicity: A Clinical Review

Anthracyclines (ATCs) have a great efficacy against many types of cancer and is currently considered a cornerstone in the treatment of numerous pediatric and adult hematological and solid tumors. Great advances have been achieved after the entry of ATC group into the cancer treatment in the early 1960s, and the overall survival ratio has increased from 30% to near 70%. Due to their significant role and great value in cancer therapy, which is persistent to date, ATCs are listed in the World Health Organization model list of essential medicines. The clinical use of ATC such as doxorubicin and daunorubicin can be viewed as a sort of double-edged sword. On the one hand, ATCs play an undisputed key role in the treatment of many neoplastic diseases; on the other hand, the administration of ATC is associated with the risk of severe adverse effects. The most common side effect of the ATC group is cardiotoxicity (CTX), which may limit its use and increases mortality and morbidity rates. The clinical use of ATC is limited by unique maximum total cumulative dose (approximately 350 mg/m2) limiting CTX. ATC CTX is cumulative dose-dependent and is in most of the occasions irreversible. Lowering the cumulative dose has been proved to be useful in minimize the risk of heart failure (HF), but, yet, there is a growing concern that HF might occur following doses that were thought to be safe. The average incidence of HF is around 5% at a cumulative dose of 400 mg/m2 that becomes higher above 500 mg/m2, albeit with substantial individual variation. The newer generations ATC medications such as epirubicin, idarubicin, and mitoxantrone were thought to be safer; however, subsequent clinical studies showed more or less similar toxicity profiles. The use of cardioprotective agents (e.g., dexrazoxane and amifostine) has been associated with improved safety range; however, questions are looming on their effect on ATC antitumor effects. An overwhelming amount of clinical evidence suggests that ATCs are too good to be old. Yet, they would look much better if they caused less harm to the heart when administered as either single agents or in combination with otherwise promising new drugs. In this review article, we present a comprehensive account on the ATC and provide up to date data on their clinical use and toxicity profile. In addition, we provide a contemporary approach on the early detection, diagnosis, and treatment of ATC CTX.

Concise Review: Precision Matchmaking: Induced Pluripotent Stem Cells Meet Cardio-Oncology

As common chemotherapeutic agents are associated with an increased risk of acute and chronic cardiovascular complications, a new clinical discipline, cardio-oncology, has recently emerged. At the same time, the development of preclinical human stem cell-derived cardiovascular models holds promise as a more faithful platform to predict the cardiovascular toxicity of common cancer therapies and advance our understanding of the underlying mechanisms contributing to the cardiotoxicity. In this article, we review the recent advances in preclinical cancer-related cardiotoxicity testing, focusing on new technologies, such as human induced pluripotent stem cell-derived cardiomyocytes and tissue engineering. We further discuss some of the limitations of these technologies and present future directions. Stem Cells Translational Medicine 2019;8:758&767.

First-dose idarubicin cardiomyopathy: a case of new heart failure after induction chemotherapy for acute myeloid leukaemia

Anthracyclines are an effective chemotherapy agent. However, very few cases of idarubicin-induced cardiomyopathy exist. Herein, we describe a case of first-dose idarubicin-related acute heart failure in a woman with a history of myelodysplastic syndrome converted to acute myeloid leukaemia.

Equipotent doses of daunorubicin and idarubicin for AML: a meta-analysis of clinical trials versus in vitro estimation

In the treatment of acute myeloid leukemia (AML), the "7 + 3"-based strategy, combining cytarabine 100-200 mg/m² for 7 days with an anthracycline for 3 days, remains the standard of care for younger and medically fit patients. Daunorubicin (DNR) and idarubicin (IDA) are the two anthracyclines most commonly used. DNR and IDA are used interchangeably with different conversion factors, as there is no high-level evidence on the equipotency of these two agents for AML treatment. To determine the equipotent doses of DNR and IDA, we first systematically reviewed studies directly comparing the clinical outcomes of AML induction therapy utilizing DNR and IDA. We found 15 articles that met our inclusion criteria and compared time-to-event survival end points as well as complete remission rates post-induction. The DNR:IDA equipotency ratio was estimated at 5.90 with 95% confidence interval (CI) 1.7-20.7. To validate the estimate from our meta-analysis biologically, we conducted in vitro tests comparing anti-AML activity of DNR and IDA against six AML cell lines and two primary AML cells from patients with different cytogenetic and molecular characteristics. Based on these in vitro data, the equipotency dose ratio between DNR and IDA was 4.06 with 95% CI 3.64-4.49. Combining the estimates from the meta-analysis and the in vitro data using inverse-variance weighting, the current best estimate of the DNR:IDA equipotent ratio is 4.1 with 95% CI 3.9-4.3. This estimate, however, is largely driven by the in vitro chemo-sensitivity data. Given clinical studies demonstrating the safety of IDA at higher doses, our work implies that dose intensification of IDA could be investigated in future clinical trials in AML.

Cardiovascular adverse events associated with oral antineoplastic therapy

OBJECTIVE

To identify in the literature the cardiovascular adverse events resulting from oral antineoplastic therapy.

METHOD

Integrative review of the literature through the SCOPUS, Scientific Electronic Library Online (SciELO), Cumulative Index to Nursing and Allied Health Literature (CINAHL), Medical Literature Analysis and Retrieval System Online (MEDLINE) databases. The antineoplastic, cardiotoxicity, cardiovascular system and adverse reaction descriptors were used in Portuguese, English and Spanish. We selected 23 articles published between 1985 and 2015.

RESULTS

Twenty studies were related to cardiac events and eleven to peripheral vascular events. The most frequent adverse cardiac events were reduced left ventricular ejection fraction, myocardial infarction, changes in the electrocardiogram, heart failure and angina, whereas peripheral vascular events were hypertension and thromboembolism.

CONCLUSION

Oral antineoplastic therapy is associated with different adverse events, including cardiac and peripheral vascular events.

Chemotherapeutic-Induced Cardiovascular Dysfunction: Physiological Effects, Early Detection-The Role of Telomerase to Counteract Mitochondrial Defects and Oxidative Stress

Although chemotherapeutics can be highly effective at targeting malignancies, their ability to trigger cardiovascular morbidity is clinically significant. Chemotherapy can adversely affect cardiovascular physiology, resulting in the development of cardiomyopathy, heart failure and microvascular defects. Specifically, anthracyclines are known to cause an excessive buildup of free radical species and mitochondrial DNA damage (_mtDNA) that can lead to oxidative stress-induced cardiovascular apoptosis. Therefore, oncologists and cardiologists maintain a network of communication when dealing with patients during treatment in order to treat and prevent chemotherapy-induced cardiovascular damage; however, there is a need to discover more accurate biomarkers and therapeutics to combat and predict the onset of cardiovascular side effects. Telomerase, originally discovered to promote cellular proliferation, has recently emerged as a potential mechanism to counteract mitochondrial defects and restore healthy mitochondrial vascular phenotypes. This review details mechanisms currently used to assess cardiovascular damage, such as C-reactive protein (CRP) and troponin levels, while also unearthing recently researched biomarkers, including circulating _mtDNA, telomere length and telomerase activity. Further, we explore a potential role of telomerase in the mitigation of mitochondrial reactive oxygen species and maintenance of _mtDNA integrity. Telomerase activity presents a promising indicator for the early detection and treatment of chemotherapy-derived cardiac damage.

Low-Dose Anthracycline and Risk of Heart Failure in a Pharmacokinetic Model of Human Myocardium Exposure: Analog Specificity and Role of Secondary Alcohol Metabolites

Cumulative doses of doxorubicin and other antitumor anthracyclines may cause heart failure (HF). Cardiotoxicity is determined by cardiac exposure to anthracyclines and to more toxic secondary alcohol metabolites that are formed inside cardiomyocytes or diffuse from the bloodstream. Concerns exist that HF might be caused by cumulative anthracycline doses that were thought to be safe. Patients with gain-of-function polymorphism of carbonyl reductase 3 (CBR3), which converts anthracyclines to secondary alcohol metabolites, would be at a higher risk of HF. Recently, a pharmacokinetic model was developed that simulated clinical exposure of human myocardium to anthracyclines and incorporated simulations of CBR3 polymorphism. It was shown that HF risk could occur after lower doxorubicin doses than previously reported, particularly for patients with CBR3 polymorphism. In this study, we show that also daunorubicin and idarubicin, but not epirubicin, might cause HF after reportedly safe cumulative doses. CBR3 polymorphism increased HF risk from daunorubicin and idarubicin to a greater extent as compared with doxorubicin. This was caused by daunorubicin and idarubicin forming higher levels of toxic metabolites in human myocardium; moreover, daunorubicin and idarubicin metabolites diffused from plasma and accumulated in cardiac tissue, whereas doxorubicin metabolite did not. CBR3 polymorphism did not aggravate HF risk from epirubicin, which was caused by the very low levels of formation of its toxic metabolite. These results support concerns about HF risk from low-dose anthracycline, characterize the analog specificity of HF risk, and illuminate the role of secondary alcohol metabolites.

Cardiotoxicity from anthracycline and cardioprotection in paediatric cancer patients

Notwithstanding the steady progress in survival rates of children and adolescents suffering from cancer, the benefits associated with chemotherapy do not come without risks involving multiple organs and systems, including the cardiovascular apparatus. Anthracyclines-often administered in combination with radiation therapy and/or surgery-are the most used chemotherapeutic compounds in order to treat tumours and blood malignancies even in paediatric age. Being an important side-effect of anthracyclines, carduitoxicity may limit their efficacy during the treatment and induce long-term sequelae, observed even many years after therapy completion. The purpose of this review was to perform an overview about all the possible strategies to prevent and/or limit the anthracyclines adverse side-effects for the cardiovascular system in childhood cancer survivors.

Cardiotoxicity of anticancer treatments: Epidemiology, detection, and management

Answer questions and earn CME/CNE Cancer and heart disease are the leading causes of morbidity and mortality in the industrialized world. Modern treatment strategies have led to an improvement in the chances of surviving a diagnosis of cancer; however, these gains can come at a cost. Patients may experience adverse cardiovascular events related to their cancer treatment or as a result of an exacerbation of underlying cardiovascular disease. With longer periods of survival, late effects of cancer treatment may become clinically evident years or decades after completion of therapy. Current cancer therapy incorporates multiple agents whose deleterious cardiac effects may be additive or synergistic. Cardiac dysfunction may result from agents that can result in myocyte destruction, such as with anthracycline use, or from agents that appear to transiently affect left ventricular contractility. In addition, cancer treatment may be associated with other cardiac events, such as severe treatment-induced hypertension and vasospastic and thromboembolic ischemia, as well as rhythm disturbances, including QTc prolongation, that may be rarely life-threatening. Early and late effects of chest radiation can lead to radiation-induced heart disease, including pericardial disease, myocardial fibrosis, cardiomyopathy, coronary artery disease, valvular disease, and arrhythmias, in the setting of myocardial fibrosis. The discipline of cardio-oncology has developed in response to the combined decision making necessary to optimize the care of cancer patients, whether they are receiving active treatment or are long-term survivors. Strategies to prevent or mitigate cardiovascular damage from cancer treatment are needed to provide the best cancer care. This review will focus on the common cardiovascular issues that may arise during or after cancer therapy, the detection and monitoring of cardiovascular injury, and the best management principles to protect against or minimize cardiotoxicity during the spectrum of cancer treatment strategies. CA Cancer J Clin 2016;66:309-325. © 2016 American Cancer Society.

Doxorubicin cardiotoxicity and target cells: a broader perspective

The cardiotoxicity of doxorubicin is becoming an interdisciplinary point of interest given a growing population of cancer survivors. The complex and not completely understood pathogenesis of this complication makes difficult to design successful preventive or curative measures. Although cardiomyocyte has been considered a classical cellular target, other cells including various types of undifferentiated cells are involved in myocardial homeostasis. Such perspective may shed light on previously unrecognized aspects of cardiotoxicity and promote new experimental and clinical cardioprotective strategies. In this review, different cellular targets of doxorubicin are discussed with the focus on cardiac progenitor cells, oxidative stress, DNA damage, senescence and apoptosis all of which contribute to their compromised functional properties.

Cardiac magnetic resonance imaging for the assessment of the myocardium after doxorubicin-based chemotherapy

OBJECTIVES

Doxorubicin is associated with a cumulative dose-dependent nonischemic cardiomyopathy. Cardiac magnetic resonance imaging (cMRI) is able to examine both structural and functional components of the myocardium. Our aim was to assess the myocardial changes in non-Hodgkin lymphoma patients undergoing doxorubicin-based chemotherapy using cMRI.

MATERIALS AND METHODS

cMRI examination was performed before and 3 months after chemotherapy. Experienced investigators interpreted each cMRI, and were blinded to all data. Left ventricular ejection fractions (LVEF), cardiac deformation, and delayed gadolinium enhancement (GD-DE) were quantified for each cMRI. The change between LVEF, GD-GE, and cardiac deformation parameters were compared between the 2 cMRI studies. A Δ LVEF≥10% was considered clinically relevant. The findings of GD-GE or changes in myocardial strain were analyzed as independent variables.

RESULTS

All 10 patients enrolled received a cumulative dose of doxorubicin of 300 mg/m. A comparison of pretreatment and posttreatment cMRI demonstrated 5 (50%) patients with a ≥10% decrease in LVEF (median, -8.4%; range, 1% to -17%; P=0.004). Three patients had at least 1 new or progressive segment of GD-DE. The global circumferential strain was significantly lower in patients after treatment, as compared with values before treatment (P=0.018) and to normal controls (P=0.046). Patients after treatment also had significantly lower global longitudinal strain than controls (P=0.035), and longitudinal strain values that tended to decrease compared with pretreatment values (P=0.073).

DISCUSSION

Our data suggests that cMRI has the ability to assess both early structural and functional myocardial changes in association with doxorubicin-based chemotherapy.

Chemotherapy-related Cardiomyopathy

Advances in chemotherapeutic agents have resulted in significantly improved cancer survival rates. Cardiac toxicity, however, has emerged as a leading cause of morbidity, both during and years after treatment. One of the most common manifestations of cardiotoxicity is that of heart failure and left ventricular systolic dysfunction. In this review, current opinions and guidelines in this field are discussed, with particular focus on the most common culprits, the anthracyclines, and the monoclonal antibody, trastuzumab.

Hematopoietic stem cell transplantation in patients with systolic dysfunction: can it be done?

Hematopoietic cell transplantation (HCT) is a potential cure for certain hematologic malignancies. However, because of risks of complications and mortality, this treatment option is limited to patients with minimal comorbidities. We performed a retrospective cohort study evaluating the impact of pre-HCT systolic dysfunction on outcomes. We identified 49 subjects with systolic dysfunction, defined as left ventricular ejection fraction (LVEF) < 50% and 49 controls (matched by age, gender, conditioning regimen, and HCT donor number; all with LVEF ≥ 50%) undergoing HCT at the University of Minnesota between 2002 and 2012. Treatment complications, use of beta-blockers and angiotensin-converting enzyme inhibitors, and overall survival (OS) after HCT out to 24 months were analyzed. The median LVEF was 45% (range, 27.5% to 49%) for the study group and 60% (range, 50% to 69%) for controls. The majority of patients in both groups (81.6%) received reduced-intensity conditioning (RIC). Treatment-related mortality (TRM) at day 100 was identical, with a cumulative incidence of 14% in the study (95% confidence interval [CI], 5% to 24%) versus 14% in controls (95% CI, 5% to 24%) (P = .89). Two-year OS was similar in the study group (53%; 95% CI, 38% to 66%) versus controls (61%; 95% CI, 46% to 73%) (P = .34). LVEF ≥ 43% was associated with improved OS at 1 year (hazard ratio [HR], .36; 95% CI, .15 to .87; P = .02). There was no significant difference in the incidence of non-life-threatening cardiac complications (12.2% in cases versus 8.2% in controls, P = .50) or serious (life-threatening or fatal) cardiac complications (4.1% in cases versus 2.0% in controls, P = .56). Pre-existing coronary artery disease was associated with increased TRM at 100 days (HR, 4.35; 95% CI, 1.24 to 15.32; P = .02). Cardiac medication use had no effect on TRM. Our study demonstrates that patients with asymptomatic borderline systolic dysfunction can safely undergo HCT with RIC. Coronary artery disease remains a risk factor for increased TRM. Patients with borderline systolic dysfunction can safely undergo HCT, but may need particular vigilance for potential hemodynamic or ischemic cardiac complications.

A phase I study using bortezomib with weekly idarubicin for treatment of elderly patients with acute myeloid leukemia

We report the results of a phase I study with four dose levels of bortezomib in combination with idarubicin. Eligible patients were newly diagnosed with acute myeloid leukemia (AML) age ≥60 years, or any adult with relapsed AML. Bortezomib was given twice weekly at 0.8, 1.0, or 1.2 mg/m(2) with once weekly idarubicin 10 mg/m(2) for four weeks. Twenty patients were treated: 13 newly diagnosed (median age 68, range 61-83) and 7 relapsed (median age 58, range 40-77). Prior myelodysplastic syndrome (MDS) was documented in 10/13 (77%) newly diagnosed and 1/7 (14%) relapsed patients; the three newly diagnosed patients without prior MDS had dyspoietic morphology. Two dose-limiting toxicities occurred at the initial dose level (bortezomib 0.8 mg/m(2) and idarubicin 10 mg/m(2)); idarubicin was reduced to 8 mg/m(2) without observing subsequent dose-limiting toxicities. The maximum tolerated dose in this study was bortezomib 1.2 mg/m(2) and idarubicin 8 mg/m(2). Common adverse events included: neutropenic fever, infections, constitutional symptoms, and gastrointestinal symptoms. No subjects experienced neurotoxicity. Most patients demonstrated hematologic response as evidenced by decreased circulating blasts. Four patients (20%) achieved complete remission. There was one treatment-related death. The combination of bortezomib and idarubicin in this mostly poor-risk, older AML group was well tolerated and did not result in high mortality. This trial was registered at www.clinicaltrials.gov as #NCT00382954.

Treatment-related cardiotoxicity in survivors of childhood cancer

Treatment advances and higher participation rates in clinical trials have rapidly increased the number of survivors of childhood cancer. However, chemotherapy and radiation treatments are cardiotoxic and can cause cardiomyopathy, conduction defects, myocardial infarction, hypertension, stroke, pulmonary oedema, dyspnoea and exercise intolerance later in life. These cardiotoxic effects are often progressive and irreversible, emphasizing a need for effective prevention and treatment to reduce or avoid cardiotoxicity. Medical interventions, such as angiotensin-converting enzyme inhibitors, β-blockers, and growth hormone therapy, might be used to treat cardiotoxicity in childhood cancer survivors. Preventative strategies should include the use of dexrazoxane, which provides cardioprotection without reducing the oncological efficacy of doxorubicin chemotherapy; less-toxic anthracycline derivatives and the use of antioxidant nutritional supplements might also be beneficial. Continuous-infusion doxorubicin provides no benefit over bolus infusion in children. Identifying patient-related (for example, obesity and hypertension) and drug-related (for example, cumulative dose) risk factors for cardiotoxicity could help tailor treatments to individual patients. However, all survivors of childhood cancer are at increased risk of cardiotoxicity, suggesting that survivor screening recommendations for assessment of global risk of premature cardiovascular disease should apply to all survivors. Optimal, evidence-based monitoring strategies and multiagent preventative treatments still need to be identified.

An expert opinion on pharmacologic approaches to reducing the cardiotoxicity of childhood acute lymphoblastic leukemia therapies

INTRODUCTION

Acute lymphoblastic leukemia (ALL) is the most common hematologic malignancy in children. Treatment-related cardiac damage is progressive and often difficult to reverse. Strategies to minimize cardiotoxicity during treatment are crucial to prevent severe lasting effects on health and quality of life.

AREAS COVERED

This comprehensive review covers the pathophysiology and various presentations, both clinical and subclinical, of treatment-induced cardiotoxicity and characteristics associated with increased risk of cardiac dysfunction in childhood ALL survivors. Additionally, contemporary prevention strategies such as limiting cumulative anthracycline dose, altering drug administration schedule, the use of anthracycline structural analogs, liposomal encapsulated anthracyclines, cardioprotective agents and nutritional supplements are critically analyzed. Finally, this review covers the management options of chemotherapy-induced damage and other treatment-related cardiotoxicity.

EXPERT OPINION

Higher lifetime cumulative doses of anthracyclines, younger age at diagnosis, longer follow-up, female sex, higher dose rates and cranial irradiation are associated with more severe cardiotoxic effects. Long-term adverse effects of both anthracycline and non-anthracycline chemotherapeutic agents are becoming an increasing focus during treatment of childhood malignancies. There must be a careful balance between achieving remission of childhood ALL while avoiding the development of another often-fatal illness, heart failure.

Cardiotoxicity in childhood cancer survivors: strategies for prevention and management

Advances in cancer treatment have greatly improved survival rates of children with cancer. However, these same chemotherapeutic or radiologic treatments may result in long-term health consequences. Anthracyclines, chemotherapeutic drugs commonly used to treat children with cancer, are known to be cardiotoxic, but the mechanism by which they induce cardiac damage is still not fully understood. A higher cumulative anthracycline dose and a younger age of diagnosis are only a few of the many risk factors that identify the children at increased risk of developing cardiotoxicity. While cardiotoxicity can develop at anytime, starting from treatment initiation and well into adulthood, identifying the best cardioprotective measures to minimize the long-term damage caused by anthracyclines in children is imperative. Dexrazoxane is the only known agent to date, that is associated with less cardiac dysfunction, without reducing the oncologic efficacy of the anthracycline doxorubicin in children. Given the serious long-term health consequences of cancer treatments on survivors of childhood cancers, it is essential to investigate new approaches to improving the safety of cancer treatments.

Combination treatment of flag with non-pegylated liposomal doxorubicin (MYOCET(TM)) in elderly patients with acute myeloid leukemia: a single center experience

The incidence of acute myeloid leukemia (AML) increases with age, but results of intensive chemotherapy in elderly patients are disappointing. Non-pegylated liposomal formulations of doxorubicin (Myocet™) have been developed with the aim of reducing systemic and cardiac toxicity especially in the elderly. We evaluated the efficacy and toxicity profiles of fludarabine, cytarabine and granulocyte colony-stimulating factor (FLAG) regimen given in association with Myocet™ in 35 patients with AML, median age 69 years (range 61-83 years). Nineteen (54.3%) had newly-diagnosed AML, twelve (34.3%) patients had secondary AML (ten with Myelodisplastic Syndrome, two with Primary Myelofibrosis) and 4 (11.4%) patients had had a late relapse (>12 months) of AML. Complete remission (CR) and partial remission (PR) were obtained in twenty-two (63%) and 3 (8.5%) patients, respectively. Seven (20%) patients showed a resistant disease. There were 3 early deaths (8.5%). Six patients (17%) experienced severe cardiovascular toxicity. The median overall survival (OS) was 12 months (range 1-52 months) with a median disease-free survival (DFS) of 20 months (range 1-48 months). One-year and two-year DFS were 78.9% and 26.7%, respectively. This study demonstrates that in elderly patients with AML, FLAG-Myocet combination shows promising efficacy response with acceptable toxicity, enabling most patients to receive further treatments, including transplantation procedures.

[High risk of cardiac dysfunction after treatment of secondary acute myeloid leukemia following chemotherapy and radiotherapy for breast cancer]

Secondary acute myeloid leukaemia (AML) occurring after breast cancer is a rare long-term complication of the chemo- and/or radiation therapy required to treat breast cancer. The usually recognized curative option of these secondary AML includes courses of anthracycline-based chemotherapy followed by haematopoietic stem cell transplantation (HSCT). Cardiac dysfunction during AML treatment of these patients previously treated with anthracyclines for breast cancer has not been reported to date. We evaluated the evolution of cardiac function in seven patients treated with anthracyclines and/or autologous or allogeneic bone marrow transplantation for secondary AML occurring after breast cancer. All of the patients who received a cumulative anthracycline dose above the cardiac toxicity threshold developed cardiac symptoms during AML chemotherapy courses. Moreover, four of the five transplanted patients developed severe heart failure among which two were fatal. Thus, the risk of severe cardiac dysfunction after treatment of secondary AML following breast cancer must be taken in account as part of the therapeutic strategy of those patients. As discussed here, an accurate evaluation of risk factors, the use of sensitive detection tests and of cardioprotective drugs as well as that of non-cardiotoxic chemotherapy might decrease the occurrence and severity of this life-threatening complication.

Twice daily fludarabine/Ara-C associated to idarubicin, G-CSF and ATRA is an effective salvage regimen in non-promyelocytic acute myeloid leukemia

Preclinical data suggest that all-trans retinoic acid (ATRA) synergizing with granulocyte colony stimulating factor (G-CSF), can improve the effectiveness of chemotherapy in acute myeloid leukemia (AML). Fludarabine 15 mg/m(2) is the minimum dose able to optimize intensification with fludarabine-arabinosylcytosine regimen. In this study 52 patients with relapsed/refractory AML obtained a complete remission (CR) rate of 69.2% after FLAIRG regimen (Fludarabine and arabinosylcytosine twice daily, idarubicin, G-CSF, ATRA). This schedule resulted effective and tolerable enabling 53% of the responding patients to receive transplant procedure. FLAIRG regimen could be proposed as a "bridge" to transplant treatment in this poor risk setting.

Anthracycline-induced cardiotoxicity: course, pathophysiology, prevention and management

Although effective anti-neoplastic agents, anthracyclines are limited by their well recognized and pervasive cardiotoxic effects. The incidence of late progressive cardiovascular disease in long-term survivors of cancer is established and may contribute to heart failure and death. To maximize the benefits of these drugs, a high-risk population has been identified and new strategies have been investigated to minimize toxic effects, including limiting the cumulative dose, controlling the rate of administration and using liposomal preparations and novel anthracycline analogues. Dexrazoxane also shows promise as a cardioprotectant during treatment. This paper reviews these strategies, as well as medications used to manage anthracycline-induced cardiotoxicity, and functional and biochemical means of monitoring cardiotoxicity, including echocardiography, radionuclide scans and biomarker analysis. The treatment of adult cancer survivors who have had anthracycline-related cardiotoxicity has not been systematically studied. Empirically, anthracycline-associated cardiac dysfunction is treated very similarly to other forms of heart failure. These treatments include avoiding additional cardiotoxic regimens, controlling hypertension, lifestyle changes, medications and heart transplantation.

Longitudinal evaluation of early and late anthracycline cardiotoxicity in children with AML

BACKGROUND

Anthracyclines are effective antineoplastic drugs in acute myelogenous leukemia (AML). However, their use is limited by cardiomyopathy, which occurs in children already at cumulative doses of 300 mg/m(2) (given as daunorubicin equivalent).

PROCEDURE

To evaluate anthracycline-associated cardiomyopathy in pediatric AML-patients, the incidence of early and late (>1 year after intensive AML chemotherapy) clinical and subclinical cardiotoxicity was analyzed out of a total of 1,207 patients <18 years treated between 1993 and 2003 in trials AML-BFM93/98: 1,010 protocol patients with de novo AML, 121 with Down syndrome (DS)-AML, and 76 with secondary AML. The cumulative dose of anthracyclines was generally risk-adapted: 300-450 mg/m(2) using 1-4-hr infusions of anthracyclines with the assumed lowest cardiotoxic potential. Eight hundred eighty-five patients (73%) were eligible for the analysis of early and 547 (45%) of late cardiotoxicity (1,399 follow-up data).

RESULTS

Thirty-eight patients (4.3%), including 3 DS-AML and 1 secondary AML, suffered from early cardiomyopathy. After 5 years, four patients showed temporarily or persistently a reduced shortening fraction, which led to death in one DS-AML patient. Including these 4 patients, late cardiomyopathy was seen in 16 patients (cumulative incidence after 11 years: 5% +/- 1%). Nine patients (2.5 +/- 1%) showed clinical symptoms, five of them had persistent abnormal shortening fraction. Late subclinical cardiomyopathy occurred temporarily in seven patients. Late clinical cardiomyopathy mainly affected patients with a second anthracycline therapy (secondary malignancy) and those with early cardiotoxicity.

CONCLUSION

In spite of a highly intensive and effective treatment, the frequency of anthracycline-associated cardiomyopathy was low in the AML-BFM studies.

Influence of the formulation on the tolerance profile of nanoparticle-bound doxorubicin in healthy rats: Focus on cardio- and testicular toxicity

A toxicological study of doxorubicin bound to poly(butyl cyanoacrylate) or human serum albumin nanoparticles coated with polysorbate 80 was performed in healthy rats. The doxorubicin formulations were injected at a therapeutic dose regimen (3 x 1.5 mg/kg with a 72 h interval), and the animals were followed up for 15 or 30 days. The overall result of this study suggests that the surfactant-coated nanoparticle formulations of doxorubicin have favorable toxicological profiles. Specifically, these formulations display a considerably reduced cardio- and testicular toxicity, as compared to a free drug.

Anthracycline cardiotoxicity in long-term survivors of childhood cancer

Anthracycline chemotherapy is a widely-used and effective treatment for a wide spectrum of childhood cancers. Its use is limited by associated progressive and clinically significant cardiotoxic effects. Onset can be acute, early, or late. While acute onset is rare, long-term survivors have significantly elevated rates of cardiac morbidity and mortality. Major complications include cardiomyopathy, coronary artery disease, and atherosclerosis. Means of prevention and treatment continue to be explored including limiting cumulative anthracycline dose, controlling the rate of administration, and using liposomal preparations and novel anthracycline analogues. Dexrazoxane prior to anthracycline chemotherapy has been shown to significantly lower rates of elevated serum cardiac troponin levels, a marker of myocyte injury, indicating a cardioprotective effect. Pilot studies indicate that exercise interventions may also be beneficial in long-term survivors with cardiac damage. Support and study of this population to decrease the morbidity and morality associated with anthracycline-induced cardiotoxicity is indicated in a time sensitive fashion.

Anthracycline cardiotoxicity

The use of anthracyclines is limited by dose-dependent cardiotoxicity. Three forms of anthracycline cardiotoxicity are described; an immediate pericarditis-myocarditis syndrome, an early onset chronic progressive CHF developing during or shortly after therapy and late-onset cardiotoxicity presenting years following treatment. A number of risk factors have been reported, including; cumulative dose, administration schedule, mediastinal radiotherapy, old and young age, concurrent cardiovascular disease, combination therapy, gender, ethnicity and chromosomal abnormalities. Evaluation of left ventricular ejection fraction has been widely adopted as a means of monitoring and assessing anthracycline-induced cardiotoxicity. Biochemical markers and other techniques, such as endomyocardial biopsy, metaiodobenzylguanidine and indium-111-antimyosin scintigraphy are not routinely used. Methods employed to prevent cardiotoxicity include cumulative dose limitation, alteration of administration schedule, anthracycline analogues, liposomal formulations and the cardioprotective agent, dexrazoxane. With the growing number of paediatric malignancy survivors and the increasing use of anthracyclines in the adjuvant treatment of breast cancer, the cardiotoxicity associated with these agents will remain a formidable issue for physicians. Further work is required to identify patients at increased risk of cardiotoxicity and to develop novel methods of protecting and treating this adverse effect.

Preclinical assessment of anthracycline cardiotoxicity in laboratory animals: predictiveness and pitfalls

Doxorubicin is one of the most prescribed anticancer drugs, due to its important activity in hematological malignancies as in solid tumors. However, its important cardiac toxicity still limits its long-term use and prevents from reaching optimal benefits. Numerous ways have been proposed to avoid cardiac toxicity, such as protracted infusions or special formulations, development of less cardiotoxic analogues and of cardioprotectors. There is a need for preclinical models able to screen rapidly these various approaches and to provide rational bases for clinical trials. The first model is the long-term rabbit model. Weanling rabbits given weekly injections of doxorubicin for 4 months developed a cardiomyopathy which was obvious from a clinical (cardiac failure) and from a pathological point of view. This model has been widely used afterwards for the discovery of cardioprotective molecules. Models in other animals such as rats or mice were similarly implemented, also with long-term exposures to the drug, resulting in cardiac failure and severe pathological alterations which could be graded for comparison. Starting from the evidence that the damage caused by anthracyclines on cardiomyocytes was immediate after each injection and that the functional efficiency of the myocardium should be affected by the anthracyclines long before the morphological alterations become detectable, we developed a short-term model studying the cardiac performances of isolated perfused hearts of rats that had been treated within 12 days by repetitive administrations of the molecule(s) to be tested. This model appeared easy to implement and provided the data expected from clinical experience: epirubicin appeared less cardiotoxic than doxorubicin; liposomal formulations appeared less cardiotoxic than free drug formulations; dexrazoxane strongly protected against doxorubicin cardiotoxicity. We were then to show that paclitaxel could potentiate doxorubicin cardiotoxicity, but that docetaxel did not so; or that a high dose of dexrazoxane brought significantly higher protection than a conventional dose. Based upon these various contributions, we can encourage the use of the short-term model of isolated perfused rat heart to screen the preclinical cardiotoxicity of anthracycline molecules, formulations and combinations.

In vitro modeling of the structure–activity determinants of anthracycline cardiotoxicity

Doxorubicin and other anthracyclines rank among the most effective anticancer drugs ever developed. Unfortunately, the clinical use of anthracyclines is limited by a dose-related life-threatening cardiotoxicity. Understanding how anthracyclines induce cardiotoxicity is essential to improve their therapeutic index or to identify analogues that retain activity while also inducing less severe cardiac damage. Here, we briefly review the prevailing hypotheses on anthracycline-induced cardiotoxicity. We also attempt to establish cause-and-effect relations between the structure of a given anthracycline and its cardiotoxicity when administered as a single agent or during the course of multiagent chemotherapies. Finally, we discuss how the hypotheses generated by preclinical models eventually translate into phase I-II clinical trials.

Anthracycline-Induced Cardiotoxicity in Adult Hematologic Malignancies

Anthracyclines are a highly efficacious treatment for adult hematologic malignancies, including acute myeloid leukemia, acute lymphoblastic leukemia, multiple myeloma, Hodgkin's disease, and non-Hodgkin's lymphoma. The consequences of anthracycline-induced cardiotoxicity have obliged hematologists to set empirical dose limits, above which the cardiotoxic risk is deemed unacceptable. However, subclinical (and also clinical) cardiotoxicity occurs below these empirical doses and may begin to induce cardiac damage in an unpredictable and progressive manner after the first dose of treatment. As a result, treatment with anthracyclines may be withdrawn from patients prematurely or substituted with less efficacious alternative therapies. Through discontinuing further use of anthracyclines, relapsed patients previously treated with these agents may consequently be treated with second-line therapy that is less effective and possibly less well tolerated. Anthracycline-induced cardiotoxicity is potentially fatal and can significantly impair patients' quality of life, while also substantially increasing health care costs.

Protecting against anthracycline-induced myocardial damage: a review of the most promising strategies

Over the last 40 years, great progress has been made in treating childhood and adult cancers. However, this progress has come at an unforeseen cost, in the form of emerging long-term effects of anthracycline treatment. A major complication of anthracycline therapy is its adverse cardiovascular effects. If these cardiac complications could be reduced or prevented, higher doses of anthracyclines could potentially be used, thereby further increasing cancer cure rates. Moreover, as the incidence of cardiac toxicity resulting in congestive heart failure or even heart transplantation dropped, the quality and extent of life for cancer survivors would improve. We review the proposed mechanisms of action of anthracyclines and the consequences associated with anthracycline treatment in children and adults. We summarise the most promising current strategies to limit or prevent anthracycline-induced cardiotoxicity, as well as possible strategies to prevent existing cardiomyopathy from worsening.