Cardiac abnormalities 15 years and more after adriamycin therapy in 229 childhood survivors of a solid tumour at the Institut Gustave Roussy

Doxorubicin-induced cardiotoxicity and risk factors

Doxorubicin (DOX) is an anthracycline antibiotic widely used as a chemotherapeutic agent to treat solid tumours and hematologic malignancies. Although useful in the treatment of cancers, the benefit of DOX is limited due to its cardiotoxic effect that is observed in a large number of patients. In the literature, there is evidence that the presence of various factors may increase the risk of developing DOX-induced cardiotoxicity. A better understanding of the role of these different factors in DOX-induced cardiotoxicity may facilitate the choice of the therapeutic approach in cancer patients suffering from various cardiovascular risk factors. In this review, we therefore discuss the latest findings in both preclinical and clinical research suggesting a link between DOX-induced cardiotoxicity and various risk factors including sex, age, ethnicity, diabetes, dyslipidaemia, obesity, hypertension, cardiovascular disease and co-medications.

Dosimetric Comparison of 3D Conformal Radiotherapy (3D-CRT), Intensity-Modulated Radiotherapy (IMRT), and Volumetric-Modulated Arc Therapy (VMAT) in Cardiac-Sparing Whole Lung Irradiation

Introduction Whole lung irradiation (WLI) is used for the treatment of lung metastasis in Wilms tumor and Ewing sarcoma; however, cardiac complications are one of the concerns. We report the dosimetric advantages of WLI using volumetric-modulated arc therapy (VMAT) and present a dosimetric comparison of VMAT with anteroposterior-posteroanterior (AP-PA) and static-field intensity-modulated radiation therapy (IMRT). Additionally, we evaluated the dosimetric impact of respiratory motion and intra-fractional motion during VMAT treatment. Methods Seven patients were recruited in this study. AP-PA, IMRT, one-isocenter (1-IC) VMAT, and 2-IC VMAT were planned on the maximum inspiration and expiration CT, respectively. The prescribed dose was 15 Gy in 10 fractions. To determine the effects of respiratory motion, the CT series was replaced and the dose was evaluated while maintaining the beam information. To determine the effect of patient motion, perturbed dose calculations were performed using a two-IC VMAT. The perturbation doses were calculated by shifting only the IC of the one side beam by 3 mm or 5 mm in the right-to-left (RL) direction. Results The mean heart dose was 1467.0 cGy, 790.0 cGy, 764.2 cGy, and 738.4 cGy for AP-PA, IMRT, 1-IC VMAT, and 2-IC VMAT, respectively. When the expiration CT plan was recalculated with inspiration CT, Dmax increased approximately by 8%. In the 2-IC VMAT plan, the D50%, D98%, and D2% dose differences were within ±2%, even with a 5 mm IC shift. Conclusion We confirmed a significant dosimetric advantage of VMAT over other techniques. 2-IC VMAT should be considered an effective treatment option during irradiation for large target volumes.

Crystal plane-integrated strontium oxide/hexagonal boron nitride nanohybrids for rapid electrochemical sensing of anticancer drugs in human blood serum samples

In this work, the crystal plane of strontium oxide (SrO) nanorods was integrated into hexagonal-boron nitride (h-BN) nanosheets to form 1D-2D (SrO/h-BN) composite were utilized for the electrochemical detection of the chemotherapeutic drug 5-fluorouracil (5-Fu). 5-Fu is a clinically proven and the third most frequently applied chemotherapeutic drug for treating solid tumours, such as colorectal, stomach, cutaneous and breast malignancies. Its overdoses lead to toxic metabolite accumulation that has serious adverse consequences on humans, including neurotoxicity, death and the induction of morbidity. Therefore, to improve the chemotherapy and predict the potential adverse effects of 5-Fu residues in the human body, susceptible and quick analytical methods for detecting 5-Fu in human body fluids (blood serum/plasma and urine) are needed. The effective interaction of the synthesized SrO/h-BN composite shows increased efficiency for the electrochemical detection of 5-Fu with good selectivity. Notably, a simple sonochemical method achieved a synergistic interaction between the (100) plane of SrO and the (002) plane of h-BN. Various analytical and spectroscopic techniques were used to characterize the SrO/h-BN nanocomposite, which provided useful insights into the composition and properties of the composite material. The crystalline, structural and chemical characteristics of the as-synthesized material were characterized by XRD, Raman spectroscopy, HR-TEM, XPS and HR-SEM. Furthermore, the proposed electrode's electrochemical sensing capability was analysed using CV, EIS, DPV and i-t curve methods. Numerous active sites created on a modified electrode enhanced the mass transport and electron transfer rate, thereby increasing the electrochemical activity towards the 5-Fu detection. Consequently, under optimized conditions, the SrO/h-BN/GCE exhibited remarkable selectivity, durability, low detection limit (0.003 μM) and wide linear range (0.02-56 μM) for 5-Fu. Finally, the successful application of this sensor for 5-Fu detection in biological samples was successfully tested with high recovery percentages.

Tenascin-C as a potential marker for immunohistopathology of doxorubicin-induced cardiomyopathy

Aims

Doxorubicin is used in classical chemotherapy for several cancer types. Doxorubicin-induced cardiomyopathy (DOX-CM) is a critical issue among cancer patients. However, differentiating the diagnosis of DOX-CM from that of other cardiomyopathies is difficult. Therefore, in this study, we aimed to determine novel histopathological characteristics to diagnose DOX-CM.

Methods and results

Twelve consecutive patients with DOX-CM who underwent cardiac histopathological examination in two medical centres were included. Twelve patients with dilated cardiomyopathy, who were matched with DOX-CM patients in terms of age, sex, and left ventricular ejection fraction, formed the control group. Another control group comprised five consecutive patients with cancer therapy-related cardiac dysfunction induced by tyrosine kinase inhibitors or vascular endothelial growth factor inhibitors were the controls. The positive area of tenascin-C, number of infiltrating macrophages, and presence of p62- and ubiquitin-positive cardiomyocytes were evaluated. Human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) were used for in vitro investigation. The myocardium exhibited significantly greater tenascin-C-positive area and macrophage number in the DOX-CM group than in the control groups (P < 0.01). The tenascin-C-positive area correlated with the number of both CD68- and CD163-positive cells (r = 0.748 and r = 0.656, respectively). Immunostaining for p62 was positive in 10 (83%) patients with DOX-CM. Furthermore, western blotting analysis revealed significant increase in tenascin-C levels in hiPSC-CMs upon doxorubicin treatment (P < 0.05).

Conclusion

The combined histopathological assessment for tenascin-C, macrophages, and p62/ubiquitin may serve as a novel tool for the diagnosis of DOX-CM. Doxorubicin may directly affect the expression of tenascin-C in the myocardium.

Intermediate Molecular Phenotypes to Identify Genetic Markers of Anthracycline-Induced Cardiotoxicity Risk

Cardiotoxicity due to anthracyclines (CDA) affects cancer patients, but we cannot predict who may suffer from this complication. CDA is a complex trait with a polygenic component that is mainly unidentified. We propose that levels of intermediate molecular phenotypes (IMPs) in the myocardium associated with histopathological damage could explain CDA susceptibility, so variants of genes encoding these IMPs could identify patients susceptible to this complication. Thus, a genetically heterogeneous cohort of mice (n = 165) generated by backcrossing were treated with doxorubicin and docetaxel. We quantified heart fibrosis using an Ariol slide scanner and intramyocardial levels of IMPs using multiplex bead arrays and QPCR. We identified quantitative trait loci linked to IMPs (ipQTLs) and cdaQTLs via linkage analysis. In three cancer patient cohorts, CDA was quantified using echocardiography or Cardiac Magnetic Resonance. CDA behaves as a complex trait in the mouse cohort. IMP levels in the myocardium were associated with CDA. ipQTLs integrated into genetic models with cdaQTLs account for more CDA phenotypic variation than that explained by cda-QTLs alone. Allelic forms of genes encoding IMPs associated with CDA in mice, including AKT1, MAPK14, MAPK8, STAT3, CAS3, and TP53, are genetic determinants of CDA in patients. Two genetic risk scores for pediatric patients (n = 71) and women with breast cancer (n = 420) were generated using machine-learning Least Absolute Shrinkage and Selection Operator (LASSO) regression. Thus, IMPs associated with heart damage identify genetic markers of CDA risk, thereby allowing more personalized patient management.

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.

Impaired aerobic capacity in adolescents and young adults after treatment for cancer or non-malignant haematological disease

PURPOSE

Childhood cancer survivors are at increased risk for cardiovascular disease. Maximal oxygen uptake (VO_2max) is a major determinant of cardiovascular morbidity. The aim of this study was to compare aerobic capacity, measured by cardiopulmonary exercise test (CPET), of adolescents and young adults in remission with that of healthy controls and to identify the predictors of aerobic capacity in this population.

METHOD

This is a controlled cross-sectional study.

RESULTS

A total of 477 subjects (77 in remission and 400 controls), aged from 6 to 25 years, were included, with a mean delay between end of treatment and CPET of 2.9 ± 2.3 years in the remission group. In this group, the mean VO_2max was significantly lower than in controls (37.3 ± 7.6 vs. 43.3 ± 13.1 mL/kg/min, P < 0.01, respectively), without any clinical or echocardiographic evidence of heart failure. The VAT was significantly lower in the remission group (26.9 ± 6.0 mL/kg/min vs. 31.0 ± 9.9 mL/kg/min, P < 0.01, respectively). A lower VO_2max was associated with female sex, older age, higher BMI, radiotherapy, and hematopoietic stem cell transplantation.

CONCLUSION

Impaired aerobic capacity had a higher prevalence in adolescents and young adults in cancer remission. This impairment was primarily related to physical deconditioning and not to heart failure.

TRIAL REGISTRY

NCT04815447.

IMPACT

In childhood cancer survivors, aerobic capacity is five times more impaired than in healthy subjects. This impairment mostly reflects early onset of physical deconditioning. No evidence of heart failure was observed in this population.

Intermediate molecular phenotypes to identify genetic markers of anthracycline-induced cardiotoxicity risk

Cardiotoxicity due to anthracyclines (CDA) affects cancer patients, but we cannot predict who may suffer from this complication. CDA is a complex disease whose polygenic component is mainly unidentified. We propose that levels of intermediate molecular phenotypes in the myocardium associated with histopathological damage could explain CDA susceptibility; so that variants of genes encoding these intermediate molecular phenotypes could identify patients susceptible to this complication. A genetically heterogeneous cohort of mice generated by backcrossing (N = 165) was treated with doxorubicin and docetaxel. Cardiac histopathological damage was measured by fibrosis and cardiomyocyte size by an Ariol slide scanner. We determine intramyocardial levels of intermediate molecular phenotypes of CDA associated with histopathological damage and quantitative trait loci (ipQTLs) linked to them. These ipQTLs seem to contribute to the missing heritability of CDA because they improve the heritability explained by QTL directly linked to CDA (cda-QTLs) through genetic models. Genes encoding these molecular subphenotypes were evaluated as genetic markers of CDA in three cancer patient cohorts (N = 517) whose cardiac damage was quantified by echocardiography or Cardiac Magnetic Resonance. Many SNPs associated with CDA were found using genetic models. LASSO multivariate regression identified two risk score models, one for pediatric cancer patients and the other for women with breast cancer. Molecular intermediate phenotypes associated with heart damage can identify genetic markers of CDA risk, thereby allowing a more personalized patient management. A similar strategy could be applied to identify genetic markers of other complex trait diseases.

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

Survivors of childhood cancer are at risk of anthracycline-induced cardiotoxicity, which might be prevented by dexrazoxane. However, concerns exist about the safety of dexrazoxane, and little guidance is available on its use in children. To facilitate global consensus, a working group within the International Late Effects of Childhood Cancer Guideline Harmonization Group reviewed the existing literature and used evidence-based methodology to develop a guideline for dexrazoxane administration in children with cancer who are expected to receive anthracyclines. Recommendations were made in consideration of evidence supporting the balance of potential benefits and harms, and clinical judgement by the expert panel. Given the dose-dependent risk of anthracycline-induced cardiotoxicity, we concluded that the benefits of dexrazoxane probably outweigh the risk of subsequent neoplasms when the cumulative doxorubicin or equivalent dose is at least 250 mg/m² (moderate recommendation). No recommendation could be formulated for cumulative doxorubicin or equivalent doses of lower than 250 mg/m², due to insufficient evidence to determine whether the risk of cardiotoxicity outweighs the possible risk of subsequent neoplasms. Further research is encouraged to determine the long-term efficacy and safety of dexrazoxane in children with cancer.

Severe Cardiac Toxicity Induced by Cancer Therapies Requiring Intensive Care Unit Admission

A steadying increase of cancer survivors has been observed as a consequence of more effective therapies. However, chemotherapy regimens are often associated with significant toxicity, and cardiac damage emerges as a prominent clinical issue. Many mechanisms sustain chemotherapy-induced cardiac toxicity: direct myocyte damage, arrhythmia induction, coronary vasospasm, and accelerated atherosclerosis. Anthracyclines are the most studied cardiotoxic drugs and represent a clinical model for cardiac damage induced by chemotherapy. In patients suffering from advanced heart failure (HF) because of chemotherapy-related cardiomyopathy, when refractory to optimal medical therapy, mechanical circulatory support or heart transplantation represents an effective treatment. Here, the main mechanisms of cardiac toxicity induced by cancer therapies are analyzed, with a focus on patients requiring intensive care unit (ICU) admission during the course of the disease because of acute cardiac toxicity, takotsubo syndrome, and acute-on-chronic HF in patients suffering from chemotherapy-induced cardiomyopathy. In a subset of patients, cardiac toxicity can be acute and life-threatening, leading to overt cardiogenic shock. The management of critically ill cancer patients poses a unique challenge and requires a multidisciplinary approach. Moreover, no etiologic therapy is available, and only supportive measures can be implemented.

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

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

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

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

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

Asymptomatic systolic dysfunction on contemporary echocardiography in anthracycline-treated long-term childhood cancer survivors: a systematic review

Purpose

Echocardiographic surveillance for asymptomatic left ventricular systolic dysfunction (ALVSD) is advised in childhood cancer survivors (CCS), because of their risk of heart failure after anthracycline treatment. ALVSD can be assessed with different echocardiographic parameters. We systematically reviewed the prevalence and risk factors of late ALVSD, as defined by contemporary and more traditional echocardiographic parameters.

Methods

We searched databases from 2001 to 2020 for studies on ≥ 100 asymptomatic 5-year CCS treated with anthracyclines, with or without radiotherapy involving the heart region. Outcomes of interest were prevalence of ALVSD—measured with volumetric methods (ejection fraction; LVEF), myocardial strain, or linear methods (fractional shortening; FS)—and its risk factors from multivariable analyses.

Results

Eleven included studies represented 3840 CCS. All studies had methodological limitations. An LVEF < 50% was observed in three studies in 1–6% of CCS, and reduced global longitudinal strain (GLS) was reported in three studies in 9–30% of CCS, both after a median follow-up of 9 to 23 years. GLS was abnormal in 20–28% of subjects with normal LVEF. Abnormal FS was reported in six studies in 0.3–30% of CCS, defined with various cut-off values (< 25 to < 30%), at a median follow-up of 10 to 18 years. Across echocardiographic parameters, reported risk factors were cumulative anthracycline dose and radiotherapy involving the heart region, with no ‘safe’ dose for ALVSD.

Conclusions

GLS identifies higher prevalence of ALVSD in anthracycline-treated CCS, than LVEF.

Implications for Cancer Survivors

The diagnostic and prognostic value of GLS should be evaluated within large cohorts.

Protocol registration

PROSPERO CRD42019126588

Supplementary Information

The online version contains supplementary material available at 10.1007/s11764-021-01028-4.

Consideration of Sex as a Biological Variable in the Development of Doxorubicin Myotoxicity and the Efficacy of Exercise as a Therapeutic Intervention

Doxorubicin (DOX) is an anthracycline antibiotic used to treat a wide variety of hematological and solid tumor cancers. While DOX is highly effective at reducing tumor burden, its clinical use is limited by the development of adverse effects to both cardiac and skeletal muscle. The detrimental effects of DOX to muscle tissue are associated with the increased incidence of heart failure, dyspnea, exercise intolerance, and reduced quality of life, which have been reported in both patients actively receiving chemotherapy and cancer survivors. A variety of factors elevate the probability of DOX-related morbidity in patients; however, the role of sex as a biological variable to calculate patient risk remains unclear. Uncertainty regarding sexual dimorphism in the presentation of DOX myotoxicity stems from inadequate study design to address this issue. Currently, the majority of clinical data on DOX myotoxicity come from studies where the ratio of males to females is unbalanced, one sex is omitted, and/or the patient cohort include a broad age range. Furthermore, lack of consensus on standard outcome measures, difficulties in long-term evaluation of patient outcomes, and other confounding factors (i.e., cancer type, drug combinations, adjuvant therapies, etc.) preclude a definitive answer as to whether differences exist in the incidence of DOX myotoxicity between sexes. This review summarizes the current clinical and preclinical literature relevant to sex differences in the incidence and severity of DOX myotoxicity, the proposed mechanisms for DOX sexual dimorphism, and the potential for exercise training to serve as an effective therapeutic countermeasure to preserve muscle strength and function in males and females.

A New Proton Therapy Solution Provides Superior Cardiac Sparing Compared With Photon Therapy in Whole Lung Irradiation for Pediatric Tumor Patients

Objective

Whole lung irradiation (WLI) plays a crucial role in local control in pediatric patients with lung metastases and improves patient survival. The intention of this research was to explore the advantage of cardiac sparing between photons and protons during WLI. We also propose a new solution for cardiac sparing with proton techniques.

Methods

Eleven patients with pediatric tumors and pulmonary metastasis treated with 12 Gy WLI (all received volumetric-modulated arc therapy (VMAT)) in our institute between 2010 and 2019 were retrospectively selected. Each patient was replanned with intensity-modulated radiation therapy (IMRT), helical tomotherapy (HT), and two intensity-modulated proton radiotherapy (IMPT) plans (IMPT-1 and IMPT-2). IMPT-1 considered the whole lung as the planning target volume (PTV), utilizing the anteroposterior technique (0/180°). IMPT-2 was a new proton solution that we proposed in this research. This approach considered the unilateral lung as the PTV, and 3 ipsilateral fields were designed for each lung. Then, IMPT-2 was generated by summing two unilateral lung plans. The primary objective was to obtain adequate coverage (95% of the prescription dose to the PTV) while maximally sparing the dose to the heart. The PTV coverage, conformity index (CI), homogeneity index (HI), and dose–volume statistics of the heart and substructures were assessed by means of the averages of each comparison parameter.

Results

All treatment techniques achieved the target volume coverage required by clinical practice. HT yielded the best coverage and homogeneity for the target structure compared with other techniques. The CI from IMRT was excellent. For photon radiation therapy, the HT plan afforded superior dose sparing for the V₅, V₆, V₇, V₈, and D_mean of the heart and D_mean of the right ventricle (RV). IMRT displayed the most notable dose reductions in the V₉, V₁₀, V₁₁, and V₁₂ of the heart and D_mean of the right atrium (RA). The VMAT plan was the least effective on the heart and substructures. However, compared with photon radiation therapy, IMPT-1 did not show an advantage for heart protection. Interestingly, IMPT-2 provided significant superiority in cardiac sparing, including maximum dose sparing for the V₅, V₆, V₇, V₈, V₉ and D_mean of the heart and D_mean of the RA, RV, left atrium (LA) and left ventricle (LV) compared to all other techniques.

Conclusions

Considering the complex anatomical relation between target volumes and organs at risk (OARs), IMPT can provide a dose advantage for organs located outside of the target area rather than within or surrounding the area. It is hoped that advances in proton therapy (PT) plan design will lead to further improvements in radiotherapy approaches and provide the best treatment choice for individual patients.

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

Background

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

Objectives

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

Methods

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

Results

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

Conclusions

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

Improving reproducibility of left ventricular ejection fraction in pediatric oncology patients: less is more

Reproducible measurement of left ventricular (LV) systolic function by echocardiography is important to detect cancer therapy-related cardiac dysfunction (CTRCD). We hypothesized that limiting the number of imaging operators and use of a single vendor would improve reproducibility of these measures. A standard operating procedure (SOP) whereby LV measurements were standardized and a cardio-oncology imaging team (5 sonographers, 6 cardiologists) was established. All pediatric oncology patient echocardiograms were acquired on a single vendor platform. In total, 100 consecutive pre-SOP and 100 post-SOP studies were reviewed. LV end-diastolic dimension (LVEDD), posterior wall thickness (PW), shortening fraction (SF), and ejection fraction by Simpson's biplane (EF) were re-measured by 2 blinded readers, and compared to what was originally reported. Image quality was scored by number of LV segments imaged (grades 1-4). Inter-observer reproducibility pre/post-SOP was assessed with intra-class coefficient (α). Reducing the number of imaging operators improved image quality (Grade ≥ 3: 13% vs. 46%, p < 0.001). Reproducibility of PW and LVEDD marginally improved (PW: 0.78 to 0.82; LVEDD: 0.96 to 0.97), and SF improved significantly (α = 0.65 vs. 0.79, p < 0.001). Pre-SOP reproducibility of LV EF was poor (α = 0.65), but improved significantly post-SOP (α = 0.83, p < 0.001). Reproducibility of LV EF improved with higher image quality score. Limiting imaging operators and vendor platform for pediatric oncology echocardiograms improves image quality and reproducibility of LV EF. Establishing an SOP and a cardio-oncology echocardiography team may improve precision of measurements used to detect CTRCD.

p38δ genetic ablation protects female mice from anthracycline cardiotoxicity

The efficacy of an anthracycline antibiotic doxorubicin (DOX) as a chemotherapeutic agent is limited by dose-dependent cardiotoxicity. DOX is associated with activation of intracellular stress signaling pathways including p38 MAPKs. While previous studies have implicated p38 MAPK signaling in DOX-induced cardiac injury, the roles of the individual p38 isoforms, specifically, of the alternative isoforms p38γ and p38δ, remain uncharacterized. We aimed to determine the potential cardioprotective effects of p38γ and p38δ genetic deletion in mice subjected to acute DOX treatment. Male and female wild-type (WT), p38γ-/-, p38δ-/-, and p38γ-/-δ-/- mice were injected with 30 mg/kg DOX and their survival was tracked for 10 days. During this period, cardiac function was assessed by echocardiography and electrocardiography and fibrosis by Picro Sirius Red staining. Immunoblotting was performed to assess the expression of signaling proteins and markers linked to autophagy. Significantly improved survival was observed in p38δ-/- female mice post-DOX relative to WT females, but not in p38γ-/- or p38γ-/-δ-/- male or female mice. The improved survival in DOX-treated p38δ-/- females was associated with decreased fibrosis, increased cardiac output and LV diameter relative to DOX-treated WT females, and similar to saline-treated controls. Structural and echocardiographic parameters were either unchanged or worsened in all other groups. Increased autophagy, as suggested by increased LC3-II level, and decreased mammalian target of rapamycin activation was also observed in DOX-treated p38δ-/- females. p38δ plays a crucial role in promoting DOX-induced cardiotoxicity in female mice by inhibiting autophagy. Therefore, p38δ targeting could be a potential cardioprotective strategy in anthracycline chemotherapy.NEW & NOTEWORTHY This study for the first time identifies the sex-specific roles of the alternative p38γ and p38δ MAPK isoforms in promoting doxorubicin (DOX) cardiotoxicity. We show that p38δ and p38γ/δ systemic deletion was cardioprotective in female but not in male mice. Cardiac structure and function were preserved in DOX-treated p38δ-/- females and autophagy marker was increased.

Magnetic Driven Nanocarriers for pH-Responsive Doxorubicin Release in Cancer Therapy

Doxorubicin is one of the most widely used anti-cancer drugs, but side effects and selectivity problems create a demand for alternative drug delivery systems. Herein we describe a hybrid magnetic nanomaterial as a pH-dependent doxorubicin release carrier. This nanocarrier comprises magnetic iron oxide cores with a diameter of 10 nm, enveloped in a hybrid material made of siliceous shells and ĸ-carrageenan. The hybrid shells possess high drug loading capacity and a favorable drug release profile, while the iron oxide cores allows easy manipulation via an external magnetic field. The pH responsiveness was assessed in phosphate buffers at pH levels equivalent to those of blood (pH 7.4) and tumor microenvironment (pH 4.2 and 5). The nanoparticles have a loading capacity of up to 12.3 wt.% and a release profile of 80% in 5 h at acidic pH versus 25% at blood pH. In vitro drug delivery tests on human breast cancer and non-cancer cellular cultures have shown that, compared to the free drug, the loaded nanocarriers have comparable antiproliferative effect but a less intense cytotoxic effect, especially in the non-cancer cell line. The results show a clear potential for these new hybrid nanomaterials as alternative drug carriers for doxorubicin.

Histological evidence for the cardiac safety of high-dose pegylated liposomal doxorubicin in a patient with HIV-associated Kaposi sarcoma: a case report and literature review

Background

Pegylated liposomal doxorubicin plays an important role in the treatment of patients with severe refractory human immunodeficiency virus (HIV)-associated Kaposi sarcoma (KS). High cumulative doses of conventional doxorubicin exceeding 500 mg/m² are known to cause cardiac toxicity. However, the safe cumulative dose of pegylated liposomal doxorubicin is unclear.

Case presentation

A 40-year-old Japanese man with HIV infection presented with pain, edema, and multiple skin nodules on both legs which worsened over several months. He was diagnosed with HIV-associated KS. He received long-term pegylated liposomal doxorubicin combined with antiretroviral therapy for advanced, progressive KS. The cumulative dose of pegylated liposomal doxorubicin reached 980 mg/m². The patient’s left ventricular ejection fraction remained unchanged from baseline during treatment. After he died as a result of cachexia and wasting, caused by recurrent sepsis and advanced KS, an autopsy specimen of his heart revealed little or no evidence of histological cardiac damage. We also conducted a literature review focusing on histological changes of the myocardium in patients treated with a cumulative dose of pegylated liposomal doxorubicin exceeding 500 mg/m².

Conclusions

This case report and literature review suggest that high (> 500 mg/m²) cumulative doses of pegylated liposomal doxorubicin may be used without significant histological/clinical cardiac toxicity in patients with HIV-associated KS.

Major obstacles to doxorubicin therapy: Cardiotoxicity and drug resistance

Background

Doxorubicin is one of the most commonly prescribed and time-tested anticancer drugs. Although being considered as a first line drug in different types of cancers, the two main obstacles to doxorubicin therapy are drug-induced cardiotoxicity and drug resistance.

Method

The study utilizes systemic reviews on publications of previous studies obtained from scholarly journal databases including PubMed, Medline, Ebsco Host, Google Scholar, and Cochrane. The study utilizes secondary information obtained from health organizations using filters and keywords to sustain information relevancy. The study utilizes information retrieved from studies captured in the peer-reviewed journals on “doxorubicin-induced cardiotoxicity” and “doxorubicin resistance.”

Discussion and results

The exact mechanisms of cardiotoxicity are not known; various hypotheses are studied. Doxorubicin can lead to free radical generation in various ways. The commonly proposed underlying mechanisms promoting doxorubicin resistance are the expression of multidrug resistance proteins as well as other causes.

Conclusion

In this review, we have described the major obstacles to doxorubicin therapy, doxorubicin-induced cardiotoxicity as well as the mechanisms of cancer drug resistance and in following the treatment failures.

Effective heart-sparing whole lung irradiation using volumetric modulated arc therapy: a case report

Background

Late cardiovascular disease-related adverse events are one of the most common causes of premature mortality among long-term survivors of childhood cancer. As it is difficult to reduce the heart dose with traditional anteroposterior–posteroanterior field whole lung irradiation for pulmonary metastasis, improved radiation techniques are highly desirable. We report a case treated with whole lung irradiation using volumetric modulated arc therapy.

Case presentation

A 3-year-old Japanese girl with pulmonary metastases of Wilms’ tumor received 12 Gy in 8 fractions of whole lung irradiation using volumetric modulated arc therapy. The treatment was well tolerated, and the course was completed as planned without any toxicity. We found statistically significant reduced volumetric modulated arc therapy irradiation doses to organs at risk relative to those of the standard anteroposterior–posteroanterior field technique. The mean heart dose was 8.5 Gy for volumetric modulated arc therapy and 12.3 Gy for the anteroposterior–posteroanterior field. The doses to liver and thyroid were also more favorable with volumetric modulated arc therapy than with the anteroposterior–posteroanterior field technique. We confirmed the dosimetric advantages of volumetric modulated arc therapy over anteroposterior–posteroanterior field in whole lung irradiation in terms of superior normal organ protection.

Conclusions

Effective heart sparing is possible for whole lung irradiation using volumetric modulated arc therapy. Large-scale studies using standardized procedures should be conducted to validate our results.

Cancer Therapy-Related Cardiac Dysfunction: An Overview for the Clinician

Cancer therapy-related cardiac dysfunction (CTRCD) is one of the most feared and undesirable side effects of chemotherapy, occurring in approximately 10% of the patients. It can be classified as direct (dose-dependent vs dose-independent) or indirect, either case being potentially permanent or reversible. Risk assessment, recognition, and prevention of CTRCD are crucial.

Anthracycline-induced cardiotoxicity in the chemotherapy treatment of breast cancer: Preventive strategies and treatment

Anthracyclines are highly effective chemotherapeutic agents, used for a wide variety of malignancies. Cardiotoxicity is a well-recognized side effect of anthracycline therapy that limits the total amount of drug administered and can cause heart failure in some patients. Most experimental data support oxidative stress as the etiology of anthracycline-induced cardiotoxicity. The objective of this paper was to provide a review of the clinical classification, risk factors, monitoring and prevention of anthracycline-induced cardiotoxicity in patients with breast cancer.

Surviving Cancer without a Broken Heart

Chemotherapy-associated myocardial toxicity is increasingly recognized with the expanding armamentarium of novel chemotherapeutic agents. The onset of cardiotoxicity during cancer therapy represents a major concern and often involves clinical uncertainties and complex therapeutic decisions, reflecting a compromise between potential benefits and harm. Furthermore, the improved cancer survival has led to cardiovascular complications becoming clinically relevant, potentially contributing to premature morbidity and mortality among cancer survivors. Specific higher-risk populations of cancer patients can benefit from prevention and screening measures during the course of cancer therapies. The pathobiology of chemotherapy-induced myocardial dysfunction is complex, and the individual patient risk for heart failure entails a multifactorial interaction between the selected chemotherapeutic regimen, traditional cardiovascular risk factors, and individual susceptibility. Treatment with several specific chemotherapeutic agents, including anthracyclines, proteasome inhibitors, epidermal growth factor receptor inhibitors, vascular endothelial growth factor inhibitors, and immune checkpoint inhibitors imparts increased risk for cardiotoxicity that results from specific therapy-related mechanisms. We review the pathophysiology, risk factors, and imaging considerations as well as patient surveillance, prevention, and treatment approaches to mitigate cardiotoxicity prior, during, and after chemotherapy. The complexity of decision-making in these patients requires viable discussion and partnership between cardiologists and oncologists aiming together to eradicate cancer while preventing cardiotoxic sequelae.

Feasibility and accuracy of UF/NCI phantoms and Monte Carlo retrospective dosimetry in children treated on National Wilms Tumor Study protocols

PURPOSE

This pilot study was done to determine the feasibility and accuracy of University of Florida/National Cancer Institute (UF/NCI) phantoms and Monte Carlo (MC) retrospective dosimetry and had two aims: (1) to determine the anatomic accuracy of UF/NCI phantoms by comparing 3D organ doses in National Wilms Tumor Study (NWTS) patient-matched UF/NCI phantoms to organ doses in corresponding patient-matched CT scans and (2) to compare infield and out-of-field organ dosimetry using two dosimetry methods-standard radiation therapy (RT) treatment planning systems (TPS) and MC dosimetry in these two anatomic models.

METHODS

Twenty NWTS patient-matched Digital Imaging and Communications in Medicine (DICOM) files of UF/NCI phantoms and CT scans were imported into the Pinnacle RT TPS. The NWTS RT fields (whole abdomen, flank, whole lung, or a combination) and RT doses (10-45 Gy) were reconstructed in both models. Both TPS and MC dose calculations were performed. For aim 1, the mean doses to the heart, kidney, thyroid gland, testes, and ovaries using TPS and MC in both models were statistically compared. For aim 2, the TPS and MC dosimetry for these organs in both models were statistically compared.

RESULTS

For aim 1, there was no significant difference between phantom and CT scan dosimetry for any of the organs using either TPS or MC dosimetry. For aim 2, there was a significant difference between TPS and MC dosimetry for both CT scan and phantoms for all organs. Although the doses for infield organs were similar for both TPS and MC, the doses for near-field and out-of-field organs were consistently higher for 90% to 100% of MC doses; however, the absolute dose difference was small (<1 Gy).

CONCLUSIONS

This pilot study has demonstrated that the patient-matched UF/NCI phantoms together with MC dosimetry is an accurate model for performing retrospective 3D dosimetry in large-scale epidemiology studies such as the NWTS.

Lipid Emulsion Inhibits the Late Apoptosis/Cardiotoxicity Induced by Doxorubicin in Rat Cardiomyoblasts

This study aimed to examine the effect of lipid emulsion on the cardiotoxicity induced by doxorubicin in H9c2 rat cardiomyoblasts and elucidates the associated cellular mechanism. The effects of lipid emulsion on cell viability, Bax, cleaved caspase-8, cleaved capase-3, Bcl-XL, apoptosis, reactive oxygen species (ROS), malondialdehyde, superoxide dismutase (SOD), catalase and mitochondrial membrane potential induced by doxorubicin were examined. Treatment with doxorubicin decreased cell viability, whereas pretreatment with lipid emulsion reduced the effect of doxorubicin by increasing cell viability. Lipid emulsion also suppressed the increased expression of cleaved caspase-3, cleaved caspase-8, and Bax induced by doxorubicin. Moreover, pretreatment with lipid emulsion decreased the increased Bax/Bcl-XL ratio induced by doxorubicin. Doxorubicin-induced late apoptosis was reduced by treatment with lipid emulsion. In addition, pretreatment with lipid emulsion prior to doxorubicin enhanced glycogen synthase kinase-3β phosphorylation. The increased malondialdehyde and ROS levels by doxorubicin were reduced by lipid emulsion pretreatment. Furthermore, lipid emulsion attenuated the reduced SOD and catalase activity and the decreased mitochondrial membrane potential induced by doxorubicin. Taken together, these results suggest that lipid emulsion attenuates doxorubicin-induced late apoptosis, which appears to be associated with the inhibition of oxidative stress induced by doxorubicin.

Heart-sparing volumetric modulated arc therapy for whole lung irradiation

PURPOSE

Whole lung irradiation (WLI) is indicated for subgroups of patients with lung metastases from Wilms' tumor (nephroblastoma). WLI has traditionally been performed with an anterior/posterior field arrangement with poor potential for heart sparing; thus, new techniques are desirable to achieve a lower dose to the heart.

MATERIALS AND METHODS

We utilized volumetric modulated arc therapy (VMAT) for WLI with 18 Gy in a patient with metastatic nephroblastoma. The planning results were compared against a three-dimensional (3D) conformal plan.

RESULTS

VMAT resulted in adequate target volume coverage with the prescribed dose. Mean heart dose was 10.2 Gy. The dose to organs at risk (OAR) was generally more favorable with VMAT when compared with a 3D-conformal radiotherapy plan.

DISCUSSION

WLI with VMAT provides superior sparing of OARs and especially a considerably lower dose to the heart.

Cardiac-Sparing Whole Lung IMRT in Patients With Pediatric Tumors and Lung Metastasis: Final Report of a Prospective Multicenter Clinical Trial

PURPOSE

A prospective clinical trial was conducted for patients undergoing cardiac sparing (CS) whole lung irradiation (WLI) using intensity modulated radiation therapy (IMRT). The 3 trial aims were (1) to demonstrate the feasibility of CS IMRT with real-time central quality control; (2) to determine the dosimetric advantages of WLI using IMRT compared with standard anteroposterior (AP) techniques; and (3) to determine acute tolerance and short-term efficacy after a protocol-mandated minimum 2-year follow-up for all patients.

METHODS AND MATERIALS

All patients underwent a 3-dimensional chest computed tomography scan and a contrast-enhanced 4-dimensional (4D) gated chest computed tomography scan using a standard gating device. The clinical target volume was the entire bilateral 3-dimensional lung volume, and the internal target volume was the 4D minimum intensity projection of both lungs. The internal target volume was expanded by 1 cm to get the planning target volume. All target volumes, cardiac contours, and treatment plans were centrally reviewed before treatment. The different cardiac volumes receiving percentages of prescribed radiation therapy (RT) doses on AP and IMRT WLI plans were estimated and compared.

RESULTS

The target 20 patients were accrued in 2 years. Median RT dose was 15 Gy. Real-time central quality assurance review and plan preapproval were obtained for all patients. WLI using IMRT was feasible in all patients. Compared with standard AP WLI, CS IMRT resulted in a statistically significant reduction in radiation doses to the whole heart, atria, ventricles, and coronaries. One child developed cardiac dysfunction and pulmonary restrictive disease 5.5 years after CS IMRT (15 Gy) and doxorubicin (375 mg/m²). The 2- and 3-year lung metastasis progression-free survival was 65% and 52%, respectively.

CONCLUSIONS

We have demonstrated the feasibility of WLI using CS IMRT and confirmed the previously reported advantages of IMRT, including superior cardiac protection and superior dose coverage of 4D lung volumes. Further studies are required to establish the efficacy and safety of this irradiation technique.

Clinical and preclinical evidence of sex-related differences in anthracycline-induced cardiotoxicity

Anthracyclines are very effective chemotherapeutic agents that are widely used to treat pediatric and adult cancer patients. Unfortunately, the clinical utility of anthracyclines is limited by cardiotoxicity. There are several established risk factors for anthracycline-induced cardiotoxicity (AIC), including total cumulative dose, very young and very old age, concomitant use of other cardiotoxic agents, and concurrent mediastinal radiation. However, the role of sex as a risk factor for AIC is not well defined. In pediatric cancer patients, most studies support the notion that female sex is a significant risk factor for AIC. Conversely, there is anecdotal evidence that female sex protects against AIC in adult cancer patients. The lack of consistency in study designs and the different definitions of cardiotoxicity preclude reaching consensus regarding the role of sex as a risk factor for AIC in both pediatric and adult cancer patients. Therefore, more clinical research using reliable techniques such as cardiac magnetic resonance imaging is needed to determine if there truly are sex differences in AIC. In adult preclinical rodent studies, however, there is unequivocal evidence that female sex confers significant protection against AIC, with a possible protective effect of female sex hormones and/or a detrimental role of the male sex hormones. Although findings of these rodent studies may not perfectly mirror the clinical scenario in adult anthracycline-treated cancer patients, understanding the mechanisms of this significant sexual dimorphism may reveal important cardioprotective mechanisms that can be therapeutically targeted.

Management of Cancer Therapeutics-Related Cardiac Dysfunction

Improvements in detection and treatment of cancer have resulted in a significant increase in cancer survivors. However, cancer survivorship comes with long-term risk of adverse effects of cancer therapies, including cardiomyopathy, heart failure, arrhythmias, ischemic heart disease, atherosclerosis, thrombosis, and hypertension. There is a renewed interest in understanding the pathophysiology of cancer therapeuticserelated cardiac dysfunction. In recent years, efforts have been directed to the management of cancer therapeuticserelated cardiac dysfunction. This article discusses the pathophysiology and molecular mechanisms that contribute to cancer therapeutics-related cardiac dysfunction and presents an napproach to the evaluation and treatment of these patients.

Cardiac-Sparing Whole Lung Intensity Modulated Radiation Therapy in Children With Wilms Tumor: Final Report on Technique and Abdominal Field Matching to Maximize Normal Tissue Protection

PURPOSE

Cardiac-sparing whole lung intensity modulated radiation therapy (WL IMRT) has been shown to improve cardiac protection and lung volume dose coverage compared with standard anteroposterior techniques. This dosimetry study had 2 aims: To determine the dosimetric advantages of a modified WL IMRT (M-WL IMRT) technique, designed to reduce radiation exposure to the thyroid gland and breast tissues, compared with standard WL IMRT (S-WL IMRT) and to determine the dosimetric advantages of M-WL IMRT and dosimetrically matched abdomen and flank radiation therapy (RT) fields designed to reduce normal tissue exposure compared with standard field matching techniques.

METHODS AND MATERIALS

Computed tomography scans of the chest and abdomen that were obtained during computed tomography simulation of 10 female children were used. For Aim 1, for S-WL IMRT, the planning target volume (PTV) was obtained with a 1-cm expansion of the 4-dimensional lung volume (internal target volume). For M-WL IMRT, the PTV was reduced around the breast and thyroid gland to facilitate thyroid and breast sparing. For Aim 2, standard matching techniques for 3-dimensional anterior/posterior-posterior/anteriorwhole lung and abdominal RT fields were compared with a new dosimetric matching technique for WL IMRT and abdomen and flank fields. For both aims, the dose coverage of the lungs and radiation exposure to normal tissues (heart, thyroid, breasts) were statistically compared.

RESULTS

Compared with S-WL IMRT, the M-WL IMRT technique provided similar lung PTV dose coverage and a significantly superior reduction in mean breast and thyroid doses, without compromising cardiac protection. The M-WL IMRT technique combined with a dosimetrically matched abdomen and flank fields showed significantly superior normal tissue protection compared with standard matched anterior/posterior-posterior/anteriorlung and abdomen and flank RT fields.

CONCLUSIONS

This study has shown that the M-WL IMRT technique can reduce radiation exposure to the thyroid gland and breast tissue without compromising cardiac protection and 4-dimensional lung volume dose coverage. This report also describes a new dosimetric matching technique between WL IMRT and abdomen and flank fields that will improve normal tissue sparing compared with standard techniques.

Late Effects of Therapy in Childhood Acute Lymphoblastic Leukemia Survivors

Over the last 50 years, the survival rates in children with acute lymphoblastic leukemia (ALL) have increased remarkably. The optimal use of antileukemic agents in cooperative group protocols, central nervous system-directed treatment, improvements in supportive care, and recognition of biological, clinical, and treatment response characteristics that predict patients with a higher or a lower risk of treatment failure have improved 5-year event-free survival rates, reaching more than 85%, and 5-year overall survival rates, reaching more than 90%. Consequently, it has become increasingly important to characterize the occurrence of long-term late effects. ALL treatments have been associated with increased risks for adverse outcomes such as late mortality, secondary malignancies, and neurological, cardiac, endocrine, and social/psychological disorders. In recent decades, cooperative groups in Europe and in the United States have provided essential information about the long-term effects of ALL therapy, giving recommendations for screening as well as facilitating new approaches for reducing late-term morbidity and mortality. Current frontline protocols continue to examine ways to lower the intensity and amount of therapy to reduce late effects, whereas survivorship studies attempt to predict such adverse effects precisely and develop targeted prevention and treatment strategies.

Utility of Echocardiography as Screening for Late-onset Anthracycline-induced Cardiotoxicity in Pediatric Cancer Survivors: Observations from the First Decade After End of Therapy

Current screening guidelines are available for anthracycline-induced cardiotoxicity. However, the utility of echocardiogram screening for late-onset anthracycline cardiotoxicity especially in the decade immediately after end of therapy is debatable. A retrospective chart review of patients seen in the Thriving after Cancer Clinic at Rady Children's Hospital January 2006 to December 2013 was performed. Treatment data, echocardiogram results, cardiology referral notes and cardiac medication data were abstracted from anthracycline-exposed survivors. Descriptive and univariate comparative statistics were performed. Of 368 patients (45% female, median 5.3 y old at diagnosis [range 0 to 18.3], median 5.0 y from end of therapy [EOT] [range 0 to 18.2]), a total of 4 patients (10-year cumulative incidence after EOT 1.3%; 95% confidence interval, 0.1%-19.7%) required cardiac medication for late-onset cardiotoxicity (>1 y after EOT). Those requiring medication for late-onset cardiotoxicity were exposed to more anthracyclines than survivors without cardiotoxicity (median, 360 mg/m [range, 300 to 375 mg/m] vs. 182 mg/m [range, 26 to 515 mg/m], P=0.009). None had neck or chest radiation. In this population, medication initiation for late-onset anthracycline cardiotoxicity was limited predominantly to the first 3 years after EOT, with the next >13 years after EOT. These findings add to the growing body of literature assessing current guidelines to inform improvements in screening practices of survivorship providers.

Incidence and outcomes of cancer treatment-related cardiomyopathy among referrals for advanced heart failure

Background

Approximately 2-3% of patients undergoing advanced heart failure therapies such as left ventricular assist devices (LVAD) and orthotropic heart transplantation (OHT) have chemotherapy-related cardiomyopathy, according to analyses of large databases such as United Network for Organ Sharing (UNOS) or Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) registries. While these studies have shown similar survival outcomes post-interventions, these databases by definition exclude patients referred for advanced therapies but do not receive them, and thus there is little data on overall outcomes of such patients. Given the lack of nuance in the diagnoses in large registries and the possibility that many cancer treatment-related cardiomyopathy (CCMP) patients might be misclassified by the generic "non-ischemic" or "dilated" cardiomyopathies, we investigated the incidence and clinical outcomes of CCMP patients among advanced heart failure (HF) referrals at a single high volume institution.

Methods

All referrals from 2013 to 2016 were evaluated for type of cardiomyopathy, with careful chart review. Outcomes such as LVAD, OHT and death were compared between CCMP and other cardiomyopathies.

Results

Of 553 referrals for advanced HF, 19 (3.4%) were for CCMP. There was a higher percentage of patients receiving advanced therapies in the CCMP vs. non-ischemic cardiomyopathy (NICMP) and ischemic cardiomyopathy (ICMP) (42.1% vs 30.2% vs 33.6%, not significant). Of the CCMP patients, 3 had OHT directly, 2 had LVAD followed by OHT, and 3 had LVADs as bridge to candidacy or destination therapy. Fifty-eight percent of the CCMP did not receive LVAD or OHT compared to 69.8% and 66.3 of the NICMP and ICMP, respectively (p = 0.0388). Independent of type of advanced therapy, survival was significantly higher in the CCMP group compared to NICMP and ICMP (93.3% vs 84.8% vs 73.8%, respectively P = 0.0021 for 1 year, 93.3% vs 76.2% vs 58.3%, respectively, P = < 0.0001 for 3 year).

Conclusions

In a single institution, CCMP accounts for more than 3% of all referrals for advanced HF therapies and almost 8% of NICMP. Contrary to concerns for previous cancer and sequelae of cancer treatment excluding patients for advanced therapies, a higher percentage of CCMP underwent advanced HF therapies and with similar outcomes. This is the first study to show that among patients referred for advanced therapies, CCMP patients do not have inferior outcomes compared to other cardiomyopathies regardless of the selected management strategy.

Current views on anthracycline cardiotoxicity

Anthracyclines are well established and effective anticancer agents used to treat a variety of adult and pediatric cancers. Unfortunately, these drugs are also among the commonest chemotherapeutic agents that have been recognized to cause cardiotoxicity. In the last years, several experimental and clinical investigations provided new information and perspectives on anthracycline-related cardiotoxicity. In particular, molecular mechanisms of cardiotoxicity have been better elucidated, early diagnosis has improved through the use of advanced noninvasive cardiac imaging techniques, and emerging data indicate a genetic predisposition to develop anthracycline-related cardiotoxicity. In this article, we review established and new knowledge about anthracycline cardiotoxicity, with special focus on recent advances in cardiotoxicity diagnosis and genetic profiling.

Statins in anthracycline-induced cardiotoxicity: Rac and Rho, and the heartbreakers

Cancer patients receiving anthracycline-based chemotherapy are at risk to develop life-threatening chronic cardiotoxicity with the pathophysiological mechanism of action not fully understood. Besides the most common hypothesis that anthracycline-induced congestive heart failure (CHF) is mainly caused by generation of reactive oxygen species, recent data point to a critical role of topoisomerase II beta (TOP2B), which is a primary target of anthracycline poisoning, in the pathophysiology of CHF. As the use of the only clinically approved cardioprotectant dexrazoxane has been limited by the FDA in 2011, there is an urgent need for alternative cardioprotective measures. Statins are anti-inflammatory and anti-oxidative drugs that are clinically well established for the prevention of cardiovascular diseases. They exhibit pleiotropic beneficial properties beyond cholesterol-lowering effects that most likely rest on the indirect inhibition of small Ras homologous (Rho) GTPases. The Rho GTPase Rac1 has been shown to be a major factor in the regulation of the pro-oxidative NADPH oxidase as well as in the regulation of type II topoisomerase. Both are discussed to play an important role in the pathophysiology of anthracycline-induced CHF. Therefore, off-label use of statins or novel Rac1 inhibitors might represent a promising pharmacological approach to gain control over chronic cardiotoxicity by interfering with key mechanisms of anthracycline-induced cardiomyocyte cell death.

Tissue Doppler Imaging and Focal, Late-Onset Anthracycline-Induced Cardiovascular Disease in Long Term Survivors of Childhood Cancer: A Research Article

INTRODUCTION

In anthracycline-induced cardiomyopathy, the onset of diastolic dysfunction occurs before systolic dysfunction. Although, conventional echocardiogram is the standard method to assess cardiac function post anthracycline therapy, Tissue Doppler Imaging (TDI) may detect early onset cardiac diastolic dysfunction among anthracycline-recipient survivors of childhood cancers. There are limited data on the use of TDI in assessing anthracycline-associated cardiotoxicity in children.

AIM

To evaluate the role of Tissue Doppler Imaging (TDI) in assessing late-onset cardiotoxicity in survivors of paediatric cancers.

MATERIALS AND METHODS

This was a single site, observational, blinded study of 11 long-term survivors of childhood cancer who had been treated with anthracyclines and 22 age-matched controls. The study group and the control group underwent conventional echo and TDI; operators were blind to study group. Conventional echo measurements were obtained. TDI was used to assess systolic and diastolic parameters at the mid-interventricular septum and lateral and medial annuli of the mitral valve; these parameters included: systolic wave (S'), early diastolic wave (E'), late diastolic wave (A'), Isovolemic Contraction Time (ICT), Isovolemic Relaxation Time (IRT) and Ejection Time (ET). Myocardial Performance Index (MPI) was also calculated.

RESULTS

Conventional echo measurements were similar in both groups. Using TDI, cases had a lower mean E' velocity (9.7 ± 1.7 cm/s vs. 11.4 ± 1.3 cm/s, p=0.004) and a lower E'/A' (1.8 ± 0.5 vs. 2.2 ± 0.4, p=0.022) at the mid-interventricular septum than controls. The mean E' septum velocity in chemotherapy-recipients who also received chest radiotherapy was 8.5±0.5 cm/s in comparison to 10.2±1.7 cm/s in those that did not receive chest radiotherapy but this not achieve statistical significance. We did not find any additional associations between TDI parameters and patients' gender, age of diagnosis, length of follow-up and dose of anthracycline.

CONCLUSION

In long-term survivors of childhood cancer who received anthracyclines, diastolic dysfunction can be detected earlier by using TDI before overt systolic dysfunction. Further large-scale multicenter studies are needed.

Cancer Therapy-Related Cardiac Dysfunction and Heart Failure: Part 1: Definitions, Pathophysiology, Risk Factors, and Imaging

Advances in cancer therapy have resulted in significant improvement in long-term survival for many types of cancer but have also resulted in untoward side effects associated with treatment. One such complication that has become increasingly recognized is the development of cardiomyopathy and heart failure. Whether a previously healthy person from a cardiovascular perspective develops cancer therapy-related cardiac dysfunction or a high-risk cardiovascular patient requires cancer therapy, the team of oncologists and cardiologists must be better equipped with an evidence-based approach to care for these patients across the spectrum. Although the toxicities associated with various cancer therapies are well recognized, limitations to our understanding of the appropriate course of action remain. In this first of a 2-part review, we discuss the epidemiologic, pathophysiologic, risk factors, and imaging aspects of cancer therapy-related cardiac dysfunction and heart failure. In a subsequent second part, we discuss the prevention and treatment aspects, concluding with a section on evidence gap and future directions. We focus on adult patients in all stages of cancer therapy from pretreatment surveillance, to ongoing therapy, and long-term follow-up.

Chemotherapy Agents Alter Plasma Lipids in Breast Cancer Patients and Show Differential Effects on Lipid Metabolism Genes in Liver Cells

Cardiovascular complications have emerged as a major concern for cancer patients. Many chemotherapy agents are cardiotoxic and some appear to also alter lipid profiles, although the mechanism for this is unknown. We studied plasma lipid levels in 12 breast cancer patients throughout their chemotherapy. Patients received either four cycles of doxorubicin and cyclophosphamide followed by weekly paclitaxel or three cycles of epirubicin, cyclophosphamide and 5’-fluorouracil followed by three cycles of docetaxel. Patients demonstrated a significant reduction (0.32 mmol/L) in high density lipoprotein cholesterol (HDL-C) and apolipoprotein A1 (apoA1) levels (0.18 g/L) and an elevation in apolipoprotein B (apoB) levels (0.15 g/L) after treatment. Investigation of the individual chemotherapy agents for their effect on genes involved in lipoprotein metabolism in liver cells showed that doxorubicin decreased ATP binding cassette transporter A1 (ABCA1) via a downregulation of the peroxisomal proliferator activated receptor γ (PPARγ) and liver X receptor α (LXRα) transcription factors. In contrast, ABCA1 levels were not affected by cyclophosphamide or paclitaxel. Likewise, apoA1 levels were reduced by doxorubicin and remained unaffected by cyclophosphamide and paclitaxel. Doxorubicin and paclitaxel both increased apoB protein levels and paclitaxel also decreased low density lipoprotein receptor (LDLR) protein levels. These findings correlate with the observed reduction in HDL-C and apoA1 and increase in apoB levels seen in these patients. The unfavourable lipid profiles produced by some chemotherapy agents may be detrimental in the longer term to cancer patients, especially those already at risk of cardiovascular disease (CVD). This knowledge may be useful in tailoring effective follow-up care plans for cancer survivors.

Cardiac Outcomes in Adult Survivors of Childhood Cancer Exposed to Cardiotoxic Therapy: A Cross-sectional Study

BACKGROUND

Studies of cardiac disease among adult survivors of childhood cancer have generally relied on self-reported or registry-based data.

OBJECTIVE

To systematically assess cardiac outcomes among survivors of childhood cancer.

DESIGN

Cross-sectional study.

SETTING

St. Jude Children's Research Hospital.

PATIENTS

1853 adult survivors of childhood cancer, aged 18 years or older, who received cancer-related cardiotoxic therapy at least 10 years earlier.

MEASUREMENTS

Baseline history and physical examination, fasting metabolic and lipid panels, echocardiography, electrocardiography, and 6-minute walk test.

RESULTS

One half of the survivors (52.3%) were men with a median age of 8 years (range, 0 to 24 years) at cancer diagnosis and 31 years (range, 18 to 60 years) at evaluation. Cardiomyopathy was present in 7.4% survivors (newly identified at the time of evaluation in 4.7%), coronary artery disease in 3.8% (newly identified in 2.2%), valvular regurgitation or stenosis in 28.0% (newly identified in 24.8%), and conduction or rhythm abnormalities in 4.4% (newly identified in 1.4%). Nearly all survivors were asymptomatic. The prevalence of cardiac conditions increased with age at evaluation, ranging from 3% to 24% among survivors aged 30 to 39 years to 10% to 37% among those aged 40 years or older. In multivariable analysis, survivors exposed to anthracycline doses of 250 mg/m2 or more had greater odds of cardiomyopathy (odds ratio, 2.7 [95% CI, 1.1 to 6.9]) than those who were not exposed. Survivors exposed to heart radiation also had increased odds of cardiomyopathy (odds ratio, 1.9 [CI, 1.1 to 3.7]) compared with those who were not exposed. Radiation exposure greater than 1500 cGy with any anthracycline exposure conferred the greatest odds for valve findings.

LIMITATIONS

Sixty-one percent of survivors exposed to anthracycline chemotherapy or cardiac-directed radiation participated. A comparison group and longitudinal assessments were not available.

CONCLUSION

Cardiovascular screening identified considerable subclinical disease among adult survivors of childhood cancer.

PRIMARY FUNDING SOURCE

National Cancer Institute, American Lebanese Syrian Associated Charities.

Effect of myocardial dysfunction in cardiac morbidity and all cause mortality in childhood cancer subjects treated with anthracycline therapy

BACKGROUND

Subacute cardiotoxicity, consisting of acute myocyte damage and associated left ventricular dysfunction, occurs early during anthracycline therapy. We investigated the impact of myocardial dysfunction, defined herein by a shortening fraction (SF) < 29 % at any time during or after anthracycline therapy, on late onset cardiomyopathy and all-cause mortality, among childhood cancer survivors exposed to anthracyclines. In addition, we sought to identify subpopulations of subjects at highest risk for cardiomyopathy and death from all causes.

METHODS

Five hundred thirty-one childhood cancer survivors exposed to anthracyclines were enrolled and studied on average 10 (1.4-27.3) years following their initial exposure. The medical records were reviewed to identify known risk factors associated with cardiotoxicity, including cumulative anthracycline dose, length of post-therapy interval, administration of other cardiotoxic medications (vinca alkaloids), previous heart disease, radiation dose to the heart, history of bone marrow transplantation, age at treatment, gender, systolic dysfunction, and history of congestive heart failure during anthracycline therapy.

RESULTS

Ninety subjects (16.9 %) developed SF < 29 % and 71 patients (13.4 %) died on average 10 years after initial exposure (range 1.4-27.3 years). Total cumulative dose (OR 3.27, 95 % CI 1.94, 5.49, p < 0.001) and bone marrow transplantation (OR 2.57, 95 % CI 1.24, 5.30, p = 0.01) were found to be statistically significant risk factors for development of myocardial dysfunction. There was a 3-fold increase in the odds of having a SF < 29 % at any point during or following cancer therapy if a subject underwent bone marrow transplantation or had a total cumulative dose anthracycline therapy ≥ 240 mg/m². The all-cause mortality ratio was almost seven-fold higher (95 % CI, 2.40-fold to 17.81-fold higher) if a subject developed systolic dysfunction, defined by a previous SF < 29 % anytime during or after anthracycline therapy. Nine deaths (12.7 %) were attributed to cardiovascular disease. The risk of dying as a result of cardiac disease also was significantly higher in individuals who had a SF < 29 % at any time during or after therapy.

CONCLUSIONS

This study demonstrates an almost seven-fold increase in all cause mortality in pediatric cancer survivors with a history of anthracycline induced myocardial dysfunction defined as SF < 29 %.

Impact of late radiation effects on cancer survivor children: an integrative review

We aimed to identify the late effects of radiation exposure in pediatric cancer survivors. An integrated literature review was performed in the databases MEDLINE and LILACS and SciELO. Included were articles in Portuguese and English, published over the past 10 years, using the following keywords: “neoplasias/neoplasms” AND “radioterapia/radiotherapy” AND “radiação/radiation”. After analysis, 14 articles - published in nine well-known journals - met the inclusion criteria. The publications were divided into two categories: “Late endocrine effects” and “Late non-endocrine effects”. Considering the increased survival rates in children who had cancer, the impact of late effects of exposure to radiation during radiological examinations for diagnosis and treatment was analyzed. Childhood cancer survivors were exposed to several late effects and should be early and regularly followed up, even when exposed to low radiation doses.

Phase I study of non-pegylated liposomal doxorubicin in children with recurrent/refractory high-grade glioma

PURPOSE

To determine the maximum recommended dose (RD) and pharmacokinetics of Myocet®, a non-pegylated liposomal doxorubicin, in children.

METHODS

Eligible patients were children with refractory high-grade glioma who had received prior chemotherapy and radiotherapy but no anthracyclines. Cohorts of at least three patients each received escalating doses of Myocet® starting at 60 mg/m(2) at 3-week intervals, administered intravenously over 1 h, and then doses were escalated to 75 mg/m(2) corresponding to the adult RD. Periodic blood samples were collected, and plasma doxorubicin and doxorubicinol concentrations were quantified to characterise the pharmacokinetics of Myocet®.

RESULTS

Between October 2010 and January 2013, 13 children aged 6-17 years were treated. In total, 27 courses were administered, at the 60 mg/m(2) dose level in seven patients without dose-limiting toxicity (DLT), and at 75 mg/m(2) in six patients of whom two experienced DLT (grade 4 neutropenia). The most common grade 3-4 toxicities reported for all courses were neutropenia (35 and 38 %, respectively), thrombocytopenia (12 and 4 %, respectively); and grade 3 vomiting, nausea, mucositis, and fever (4 % each). Mean estimates of central volume of distribution at steady state, clearance, and elimination half-life of doxorubicin were 24.8 L, 15 L/h/m(2), and 34.8 h, respectively, with a large interpatient variability.

CONCLUSION

The RD of Myocet® administered every 3 weeks to paediatric patients was 60 mg/m(2). The efficacy of Myocet® in paediatric patients with high-grade glioma remains to be determined and should be studied in Phase II trials.

Recommendations for cardiomyopathy surveillance for survivors of childhood cancer: a report from the International Late Effects of Childhood Cancer Guideline Harmonization Group

Survivors of childhood cancer treated with anthracycline chemotherapy or chest radiation are at an increased risk of developing congestive heart failure. In this population, congestive heart failure is well recognised as a progressive disorder, with a variable period of asymptomatic cardiomyopathy that precedes signs and symptoms. As a result, several clinical practice guidelines have been developed independently to help with detection and treatment of asymptomatic cardiomyopathy. These guidelines differ with regards to definitions of at-risk populations, surveillance modality and frequency, and recommendations for interventions. Differences between these guidelines could hinder the effective implementation of these recommendations. We report on the results of an international collaboration to harmonise existing cardiomyopathy surveillance recommendations using an evidence-based approach that relied on standardised definitions for outcomes of interest and transparent presentation of the quality of the evidence. The resultant recommendations were graded according to the quality of the evidence and the potential benefit gained from early detection and intervention.