Strategies to prevent anthracycline-related congestive heart failure in survivors of childhood cancer

Acute and early-onset cardiotoxicity in children and adolescents with cancer: a systematic review

BACKGROUND

Cardiotoxicity is among the most important adverse effects of childhood cancer treatment. Anthracyclines, mitoxantrone and radiotherapy involving the heart are its main causes. Subclinical cardiac dysfunction may over time progress to clinical heart failure. The majority of previous studies have focused on late-onset cardiotoxicity. In this systematic review, we discuss the prevalence and risk factors for acute and early-onset cardiotoxicity in children and adolescents with cancer treated with anthracyclines, mitoxantrone or radiotherapy involving the heart.

METHODS

A literature search was performed within PubMed and reference lists of relevant studies. Studies were eligible if they reported on cardiotoxicity measured by clinical, echocardiographic and biochemical parameters routinely used in clinical practice during or within one year after the start of cancer treatment in ≥ 25 children and adolescents with cancer. Information about study population, treatment, outcomes of diagnostic tests used for cardiotoxicity assessment and risk factors was extracted and risk of bias was assessed.

RESULTS

Our PubMed search yielded 3649 unique publications, 44 of which fulfilled the inclusion criteria. One additional study was identified by scanning the reference lists of relevant studies. In these 45 studies, acute and early-onset cardiotoxicity was studied in 7797 children and adolescents. Definitions of acute and early-onset cardiotoxicity prove to be highly heterogeneous. Prevalence rates varied for different cardiotoxicity definitions: systolic dysfunction (0.0-56.4%), diastolic dysfunction (30.0-100%), combinations of echocardiography and/or clinical parameters (0.0-38.1%), clinical symptoms (0.0-25.5%) and biomarker levels (0.0-37.5%). Shortening fraction and ejection fraction significantly decreased during treatment. Cumulative anthracycline dose proves to be an important risk factor.

CONCLUSIONS

Various definitions have been used to describe acute and early-onset cardiotoxicity due to childhood cancer treatment, complicating the establishment of its exact prevalence. Our findings underscore the importance of uniform international guidelines for the monitoring of cardiac function during and shortly after childhood cancer treatment.

Cardio-Oncology in Childhood: State of the Art

PURPOSE OF REVIEW

Cardio-oncology is an increasingly important field of cardiology that focuses on the detection, monitoring, and treatment of cardiovascular disease (CVD) occurring during and after oncological treatments. The survival rate for childhood cancer patients has dramatically increased thanks to new treatment protocols and cardiovascular (CV) sequelae represent the third most frequent cause of mortality in surviving patients. This study aims to provide a complete and updated review of all the main aspects of cardio-oncology in childhood and to highlight the critical issues.

RECENT FINDINGS

The problem of CV complications in childhood cancer survivors raises the need to make an early diagnosis of cardiotoxicity by the new imaging and laboratory techniques in order to intervene promptly and to implement pharmacological strategies and lifestyle changes to reduce or even to prevent cardiac injury. Furthermore, a stratification of CV risk, also including new predisposing factors such as the presence of some genetic mutations, is of paramount importance before undertaking oncological treatments. Besides, a systematic and personalized planning of long-term follow-up is fundamental to ensure a transition from pediatric to adult hospital and to avoid missed or late diagnosis of cardiomyopathy. We reviewed the main risk factors for cardiotoxicity in children, both traditional and emerging ones: the mechanisms of toxicity of both old and new antineoplastic therapies, the techniques for detecting cardiac damage, and the current evidence regarding pharmacological cardioprotection. At the end, we focused our attention on the existing guidelines and strategies about the long-term follow-up of childhood cancer survivors.

Clinical implications of chemotherapeutic agent organ toxicity on perioperative care

Cancer is the second most common cause of death in the United States and is a challenging disease to treat. The treatment options for various cancers include but are not limited to surgery, radiation, and chemotherapy. The mechanism behind chemotherapy is intended to promote cellular damage to cells that are proliferating uncontrollably. Unfortunately for the recipients, most chemotherapeutic agents cannot differentiate between malignant cells and healthy cells and tissues. Thus, chemotherapy-induced toxicities are often observed in once-healthy organs. These effects can be acute and self-limiting or chronic, appearing long after chemotherapy is completed. Cancer survivors can then present for non-cancer related surgeries later in life, due to this toxicity. Furthermore, the administration of chemotherapeutic agents can profoundly impact the anesthetic management of patients who are undergoing surgery. This review discusses how chemotherapy-induced organ toxicity can occur in multiple organ systems and what drugs should be avoided if prior toxicity exists in these organ systems.

Minimizing cardiac toxicity in children with acute myeloid leukemia

Anthracycline chemotherapy remains an integral component of modern pediatric acute myeloid leukemia (AML) regimens and is often delivered at high doses to maximize cancer survival. Unfortunately, high-dose anthracyclines are associated with a significant risk of cardiotoxicity, which may result in early and/or long-term left ventricular systolic dysfunction and heart failure. Moreover, the development of cardiotoxicity during pediatric AML therapy is associated with lower event-free and overall survival, which may be partially attributable to incomplete anthracycline delivery. A combined strategy of primary cardioprotection and close cardiac monitoring can maximize chemotherapy delivery while reducing the toxicity of intensive AML therapy. Primary cardioprotection using dexrazoxane reduces short-term cardiotoxicity without compromising cancer survival. Liposomal anthracycline formulations, which are under active investigation, have the potential to mitigate cardiotoxicity while also improving antitumor efficacy. Primary cardioprotective strategies may reduce but not eliminate the risk of cardiotoxicity; therefore, close cardiac monitoring is also needed. Standard cardiac monitoring consists of serial echocardiographic assessments for left ventricular ejection fraction decline. Global longitudinal strain has prognostic utility in cancer therapy-related cardiotoxicity and may be used as an adjunct assessment. Additional cardioprotective measures should be considered in response to significant cardiotoxicity; these include cardiac remodeling medications to support cardiac recovery and anthracycline dose interruption and/or regimen modifications. However, the withholding of anthracyclines should be limited to avoid compromising cancer survival. A careful approach to cardioprotection during AML therapy is critical to maximize the efficacy of leukemia treatment while minimizing the short- and long-term risks of cardiotoxicity.

The Utility of Advanced Cardiovascular Imaging in Cancer Patients-When, Why, How, and the Latest Developments

Cardio-oncology encompasses the risk stratification, prognostication, identification and management of cancer therapeutics related cardiac dysfunction (CTRCD). Cardiovascular imaging (CVI) plays a significant role in each of these scenarios and has broadened from predominantly quantifying left ventricular function (specifically ejection fraction) to the identification of earlier bio-signatures of CTRCD. Recent data also demonstrate the impact of chemotherapy on the right ventricle, left atrium and pericardium and highlight a possible role for CVI in the identification of CTRCD through tissue characterization and assessment of these cardiac chambers. This review aims to provide a contemporary perspective on the role of multi-modal advanced cardiac imaging in cardio-oncology.

Doxorubicin-induced p53 interferes with mitophagy in cardiac fibroblasts

Anthracyclines are the critical component in a majority of pediatric chemotherapy regimens due to their broad anticancer efficacy. Unfortunately, the vast majority of long-term childhood cancer survivors will develop a chronic health condition caused by their successful treatments and severe cardiac disease is a common life-threatening outcome that is unequivocally linked to previous anthracycline exposure. The intricacies of how anthracyclines such as doxorubicin, damage the heart and initiate a disease process that progresses over multiple decades is not fully understood. One area left largely unstudied is the role of the cardiac fibroblast, a key cell type in cardiac maturation and injury response. In this study, we demonstrate the effect of doxorubicin on cardiac fibroblast function in the presence and absence of the critical DNA damage response protein p53. In wildtype cardiac fibroblasts, doxorubicin-induced damage correlated with decreased proliferation and migration, cell cycle arrest, and a dilated cardiomyopathy gene expression profile. Interestingly, these doxorubicin-induced changes were completely or partially restored in p53-/- cardiac fibroblasts. Moreover, in wildtype cardiac fibroblasts, doxorubicin produced DNA damage and mitochondrial dysfunction, both of which are well-characterized cell stress responses induced by cytotoxic chemotherapy and varied forms of heart injury. A 3-fold increase in p53 (p = 0.004) prevented the completion of mitophagy (p = 0.032) through sequestration of Parkin. Interactions between p53 and Parkin increased in doxorubicin-treated cardiac fibroblasts (p = 0.0003). Finally, Parkin was unable to localize to the mitochondria in wildtype cardiac fibroblasts, but mitochondrial localization was restored in p53-/- cardiac fibroblasts. These findings strongly suggest that cardiac fibroblasts are an important myocardial cell type that merits further study in the context of doxorubicin treatment. A more robust knowledge of the role cardiac fibroblasts play in the development of doxorubicin-induced cardiotoxicity will lead to novel clinical strategies that will improve the quality of life of cancer survivors.

Doxorubicin-Induced Cardiomyopathy in Children

Doxorubicin-induced cardiotoxicity in childhood cancer survivors is a growing problem. The population of patients at risk for cardiovascular disease is steadily increasing, as five-year survival rates for all types of childhood cancers continue to improve. Doxorubicin affects the developing heart differently from the adult heart and in a subset of exposed patients, childhood exposure leads to late, irreversible cardiomyopathy. Notably, the prevalence of late-onset toxicity is increasing in parallel with improved survival. By the year 2020, it is estimated that there will be 500,000 childhood cancer survivors and over 50,000 of them will suffer from doxorubicin-induced cardiotoxicity. The majority of the research to-date, concentrated on childhood cancer survivors, has focused mostly on clinical outcomes through well-designed epidemiological and retrospective cohort studies. Preclinical studies have elucidated many of the cellular mechanisms that elicit acute toxicity in cardiomyocytes. However, more research is needed in the areas of early- and late-onset cardiotoxicity and more importantly improving the scientific understanding of how other cells present in the cardiac milieu are impacted by doxorubicin exposure. The overall goal of this review is to succinctly summarize the major clinical and preclinical studies focused on doxorubicin-induced cardiotoxicity. As the prevalence of patients affected by doxorubicin exposure continues to increase, it is imperative that the major gaps in existing research are identified and subsequently utilized to develop appropriate research priorities for the coming years. Well-designed preclinical research models will enhance our understanding of the pathophysiology of doxorubicin-induced cardiotoxicity and directly lead to better diagnosis, treatment, and prevention. © 2019 American Physiological Society. Compr Physiol 9:905-931, 2019.

Paediatric cardio-oncology: epidemiology, screening, prevention, and treatment

With 5-year survival of children with cancer exceeding 80% in developed countries, premature cardiovascular disease is now a major cause of early morbidity and mortality. In addition to the acute and chronic cardiotoxic effects of anthracyclines, related chemotherapeutics, and radiation, a growing number of new molecular targeted agents may also have detrimental effects on the cardiovascular system. Survivors of childhood cancer also may have earlier development of conventional cardiovascular risk factors such as hypertension, dyslipidaemia, and diabetes, which further increase their risk of serious cardiovascular disease. This review will examine the epidemiology of acute and chronic cardiotoxicity relevant to paediatric cancer patients, including genetic risk factors. We will also provide an overview of current screening recommendations, including the evidence regarding both imaging (e.g. echocardiography and magnetic resonance imaging) and blood-based biomarkers. Various primary and secondary prevention strategies will also be discussed, primarily in relation to anthracycline-related cardiomyopathy. Finally, we review the available evidence related to the management of systolic and diastolic dysfunction in paediatric cancer patients and childhood cancer survivors.

Predicting and Preventing Anthracycline-Related Cardiotoxicity

Anthracyclines (doxorubicin, daunorubicin, epirubicin, and idarubicin) are among the most potent chemotherapeutic agents and have truly revolutionized the management of childhood cancer. They form the backbone of chemotherapy regimens used to treat childhood acute lymphoblastic leukemia, acute myeloid leukemia, Hodgkin lymphoma, Ewing sarcoma, osteosarcoma, and neuroblastoma. More than 50% of children with cancer are treated with anthracyclines. The clinical utility of anthracyclines is compromised by dose-dependent cardiotoxicity, manifesting initially as asymptomatic cardiac dysfunction and evolving irreversibly to congestive heart failure. Childhood cancer survivors are at a five- to 15-fold increased risk for congestive heart failure compared with the general population. Once diagnosed with congestive heart failure, the 5-year survival rate is less than 50%. Prediction models have been developed for childhood cancer survivors (i.e., after exposure to anthracyclines) to identify those at increased risk for cardiotoxicity. Studies are currently under way to test risk-reducing strategies. There remains a critical need to identify patients with childhood cancer at diagnosis (i.e., prior to anthracycline exposure) such that noncardiotoxic therapies can be contemplated.

An initial health economic evaluation of pharmacogenomic testing in patients treated for childhood cancer with anthracyclines

BACKGROUND

Anthracyclines are a class of highly effective chemotherapeutic drugs commonly used to treat cancer patients. Anthracyclines, however, are associated with the development of serious adverse reactions, including anthracycline-induced cardiotoxicity (ACT). It is not possible, within current practice, to accurately individualize treatment to minimize risk.

PROCEDURE

Recently, genetic variants have been associated with the risk of ACT in children. Building on these findings and the related genetic test, a predictive model was developed which classifies pediatric patients by their risk of developing ACT. We assessed the value of this ACT-predictive risk classification in addressing ACT.

RESULTS

With current care, the estimated average lifetime cost of ACT is $8,667 per anthracycline-treated patient and approximately 7% of patients are expected to die from ACT. The projected impact of the information from the new predictive model is a 17% reduction in the risk of mortality from ACT and savings of about 6%: lives saved and lower costs.

CONCLUSION

The newly identified genetic variants associated with the risk of ACT provide information that allows a more reliable prediction of the risk of ACT for a given patient and can be obtained at a very moderate cost, which is expected to lead to meaningful progress in reducing harm and costs associated with ACT.

Long-term Outcomes and Complications in Pediatric Ewing Sarcoma

OBJECTIVES

The objective of this study was to determine treatment outcomes and long-term complications in pediatric patients with Ewing Sarcoma treated at the British Columbia Cancer Agency (BCCA).

METHODS

A retrospective chart review of 101 pediatric patients (<19 y old) with Ewing Sarcoma diagnosed between 1960 and 2005 was performed. The Kaplan-Meier survival analysis and Cox regression multivariate analysis were used to assess prognostic factors for overall survival (OS) and event-free survival (EFS).

RESULTS

The median age at diagnosis was 11 years and the median follow-up for nondeceased patients was 13.5 years. The most common primary tumor locations were lower extremity (33%), pelvis (24%), and thorax (18%). Fifty percent of patients received surgery, 79% radiotherapy and 94% chemotherapy. The 5-year OS and EFS for patients with localized disease was 85% and 73% and for metastatic disease was 27% (P<0.0001) and 28% (P<0.0001), respectively. Metastatic disease was an independent predictor of lower OS (hazard ratio [HR], 9.5; 95% confidence interval [CI],4.7-19.4; P<0.0001) and EFS (HR, 4.9; 95% CI, 2.7-8.8; P<0.0001). Extremity tumor location was an independent predictor for improved OS (HR, 0.4; 95% CI, 0.2-0.9; P=0.03). The majority (77%) of long-term survivors (≥5 y) had long-term complications; the most common were musculoskeletal abnormalities (50%) and cardiac toxicity (28%). The actuarial second neoplasm risk was 5% at 10 years.

CONCLUSIONS

Ewing sarcoma patients with localized disease had excellent treatment outcomes at the BCCA. However, the majority of patients had chronic complications from treatment. This study validates the need for long-term follow-up of Ewing Sarcoma survivors for management of late effects.

Circulating microRNAs: Potential Markers of Cardiotoxicity in Children and Young Adults Treated With Anthracycline Chemotherapy

Background

Biomarkers for early detection of anthracycline (AC)‐induced cardiotoxicity may allow cardioprotective intervention before irreversible damage. Circulating microRNAs (miRNAs) are promising biomarkers of cardiovascular disease, however, have not been studied in the setting of AC‐induced cardiotoxicity. This study aimed to identify AC‐induced alterations in plasma miRNA expression in children and correlate expression with markers of cardiac injury.

Methods and Results

Candidate plasma profiling of 24 miRNAs was performed in 33 children before and after a cycle of AC (n=24) or noncardiotoxic chemotherapy (n=9). Relative miRNA changes between the pre‐ and postcycle time points (6, 12, and 24 hours) were determined within each treatment group and compared across groups. Plasma miRNA expression patterns were further explored with respect to AC dose and high‐sensitivity troponin T. Greater chemotherapy‐induced dysregulation was observed in this panel of candidate, cardiac‐related plasma miRNAs in patients receiving anthracyclines compared with those receiving noncardiotoxic chemotherapy (24‐hour MANOVA; P=0.024). Specifically, plasma miRs‐29b and ‐499 were upregulated 6 to 24 hours post‐AC, and their postchemotherapy expression significantly correlated with AC dose. Patients with acute cardiomyocyte injury (high‐sensitivity troponin T increase ≥5 ng/L from baseline) demonstrated higher expression of miR‐29b and miR‐499 post‐AC compared with those without.

Conclusions

In this pilot study, cardiac‐related plasma miRNAs are dysregulated following ACs. Plasma miR‐29b and ‐499 are acutely elevated post‐AC, with dose response relationships observed with anthracycline dose and markers of cardiac injury. Further evaluation of miRNAs may provide mechanistic insight into AC‐induced cardiotoxicity and yield biomarkers to facilitate earlier intervention to mitigate cardiotoxicity.

Lipid and lipoprotein abnormalities in acute lymphoblastic leukemia survivors

Survivors of acute lymphoblastic leukemia (ALL), the most common cancer in children, are at increased risk of developing late cardiometabolic conditions. However, the mechanisms are not fully understood. This study aimed to characterize the plasma lipid profile, Apo distribution, and lipoprotein composition of 80 childhood ALL survivors compared with 22 healthy controls. Our results show that, despite their young age, 50% of the ALL survivors displayed dyslipidemia, characterized by increased plasma triglyceride (TG) and LDL-cholesterol, as well as decreased HDL-cholesterol. ALL survivors exhibited lower plasma Apo A-I and higher Apo B-100 and C-II levels, along with elevated Apo C-II/C-III and B-100/A-I ratios. VLDL fractions of dyslipidemic ALL survivors contained more TG, free cholesterol, and phospholipid moieties, but less protein. Differences in Apo content were found between ALL survivors and controls for all lipoprotein fractions except HDL₃ HDL₂, especially, showed reduced Apo A-I and raised Apo A-II, leading to a depressed Apo A-I/A-II ratio. Analysis of VLDL-Apo Cs disclosed a trend for higher Apo C-III₁ content in dyslipidemic ALL survivors. In conclusion, this thorough investigation demonstrates a high prevalence of dyslipidemia in ALL survivors, while highlighting significant abnormalities in their plasma lipid profile and lipoprotein composition. Special attention must, therefore, be paid to these subjects given the atherosclerotic potency of lipid and lipoprotein disorders.

Anthracycline-Induced Cardiomyopathy in Adults

Anthracyclines are one of the most commonly used antineoplastic agent classes, and a core part of the treatment in breast cancers, hematological malignancies, and sarcomas. Their benefit is decreased by their well-recognized cardiotoxicity. The purpose of this review is to outline the presentation, mechanisms, diagnosis, and treatment of anthracyclines-induced cardiotoxicity. Symptomatic heart failure occurs in 2% to 5% of patients treated with anthrayclines and may be higher in older patients or patients with cardiovascular risk factors. The mechanisms involved in anthracycline-induced cardiotoxicity involve myocyte loss by apoptosis in the presence of a limited regenerative capacity. Once symptomatic, anthracycline-induced cardiotoxicity is associated with markedly decreased survival. Left ventricular ejection fraction (LVEF), mostly determined using echocardiography, is used to monitor patients treated with anthracyclines. As more than 1/3 of patients treated with anthracyclines do not recover their baseline LVEF once it is decreased, more sensitive echocardiographic indices of LV function such as myocardial deformation or biomarkers have been studied in patients monitoring. Cardioprotective treatments such as angiotensin-converting enzyme inhibitors, beta-blockers, iron chelators, statins, and metformin are also the topic of research efforts.

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 %.

Late Mortality After Dexrazoxane Treatment: A Report From the Children's Oncology Group

PURPOSE

Given concerns that dexrazoxane may reduce treatment efficacy, induce second cancers, and thus compromise overall survival among children, we examined long-term overall and cause-specific mortality and disease relapse rates from three randomized clinical trials.

PATIENTS AND METHODS

Children's Oncology Group trials P9404 (T-cell acute lymphoblastic leukemia/lymphoma; n = 537), P9425 (intermediate/high-risk Hodgkin lymphoma; n = 216), and P9426 (low-risk Hodgkin lymphoma; n = 255) were conducted between 1996 and 2001. Each trial randomly assigned patients to doxorubicin with or without dexrazoxane. The dexrazoxane:doxorubicin dose ratio was 10:1, and the cumulative protocol-specified doxorubicin dose was 100 to 360 mg/m(2). Dexrazoxane was given as an intravenous bolus before each doxorubicin dose. Data from all three trials were linked with the National Death Index to determine overall and cause-specific mortality by dexrazoxane status.

RESULTS

Among 1,008 patients (507 received dexrazoxane) with a median follow-up of 12.6 years (range, 0 to 15.5 years), 132 died (67 received dexrazoxane). Overall mortality did not vary by dexrazoxane status (12.8% with dexrazoxane at 10 years v 12.2% without; hazard ratio [HR], 1.03; 95% CI, 0.73 to 1.45). Findings were similar when each trial was examined separately. Dexrazoxane also was not significantly associated with differential causes of death. The original cancer caused 76.5% of all deaths (HR, 0.90; 95% CI, 0.61 to 1.32) followed by second cancers (13.6% of deaths; HR, 1.24; 95% CI, 0.49 to 3.15). Specifically, dexrazoxane was not associated with deaths from acute myeloid leukemia/myelodysplasia or cardiovascular events.

CONCLUSION

Among pediatric patients with leukemia or lymphoma, after extended follow-up, dexrazoxane use did not seem to compromise long-term survival.

Secondary Malignant Neoplasms Following Haematopoietic Stem Cell Transplantation in Childhood

Improving survival rates in children with malignancy have been achieved at the cost of a high frequency of late adverse effects of treatment, especially in intensively treated patients such as those undergoing haematopoietic stem cell transplantation (HSCT), many of whom suffer the high burden of chronic toxicity. Secondary malignant neoplasms (SMNs) are one of the most devastating late effects, cause much morbidity and are the most frequent cause of late (yet still premature) treatment-related mortality. They occur in up to 7% of HSCT recipients by 20 years post-HSCT, and with no evidence yet of a plateau in incidence with longer follow-up. This review describes the epidemiology, pathogenesis, clinical features and risk factors of the three main categories of post-HSCT SMNs. A wide range of solid SMNs has been described, usually occurring 10 years or more post-HSCT, related most often to previous or conditioning radiotherapy. Therapy-related acute myeloid leukaemia/myelodysplasia occurs earlier, typically three to seven years post-HSCT, mainly in recipients of autologous transplant and is related to previous alkylating agent or topoisomerase II inhibitor chemotherapy. Post-transplant lymphoproliferative disorders occur early (usually within two years) post-HSCT, usually presenting as Epstein-Barr virus-related B cell non-Hodgkin lymphoma.

Individual prediction of heart failure among childhood cancer survivors

PURPOSE

To create clinically useful models that incorporate readily available demographic and cancer treatment characteristics to predict individual risk of heart failure among 5-year survivors of childhood cancer.

PATIENTS AND METHODS

Survivors in the Childhood Cancer Survivor Study (CCSS) free of significant cardiovascular disease 5 years after cancer diagnosis (n = 13,060) were observed through age 40 years for the development of heart failure (ie, requiring medications or heart transplantation or leading to death). Siblings (n = 4,023) established the baseline population risk. An additional 3,421 survivors from Emma Children's Hospital (Amsterdam, the Netherlands), the National Wilms Tumor Study, and the St Jude Lifetime Cohort Study were used to validate the CCSS prediction models.

RESULTS

Heart failure occurred in 285 CCSS participants. Risk scores based on selected exposures (sex, age at cancer diagnosis, and anthracycline and chest radiotherapy doses) achieved an area under the curve of 0.74 and concordance statistic of 0.76 at or through age 40 years. Validation cohort estimates ranged from 0.68 to 0.82. Risk scores were collapsed to form statistically distinct low-, moderate-, and high-risk groups, corresponding to cumulative incidences of heart failure at age 40 years of 0.5% (95% CI, 0.2% to 0.8%), 2.4% (95% CI, 1.8% to 3.0%), and 11.7% (95% CI, 8.8% to 14.5%), respectively. In comparison, siblings had a cumulative incidence of 0.3% (95% CI, 0.1% to 0.5%).

CONCLUSION

Using information available to clinicians soon after completion of childhood cancer therapy, individual risk for subsequent heart failure can be predicted with reasonable accuracy and discrimination. These validated models provide a framework on which to base future screening strategies and interventions.

Metabolic syndrome and cardiovascular risk among long-term survivors of acute lymphoblastic leukaemia - From the St. Jude Lifetime Cohort

Adult survivors of childhood acute lymphoblastic leukaemia (ALL) have a four-fold excess risk of mortality from cardiovascular disease. This cardiovascular risk has not been fully characterized. ALL survivors [n = 784, median age 31·7 years (18·9-59·1)] in the St. Jude Lifetime Cohort Study underwent evaluation for cardiovascular risk and metabolic syndrome (MetS) according to National Cholesterol Education Program - Adult Treatment Panel III criteria. Comparisons were made to 777 age-, sex-, and race-matched controls from the National Health and Nutrition Examination Survey (NHANES). MetS was identified in 259 survivors (33·6%) and associated with older age in 5-year increments (relative risk [RR] 1·13, 95% confidence interval [CI] 1·06-1·19) and prior cranial radiotherapy (CRT) (with craniospinal radiation: RR 1·88, 95%CI 1·32-2·67; without: RR 1·67, 95%CI 1·26-2·23). Measures of obesity were highly prevalent among female survivors and CRT recipients. Compared to NHANES controls, ALL survivors had a higher risk of MetS (RR 1·43, 95%CI 1·22-1·69), hypertension (RR 2·43, 95%CI 2·06-2·86), low high-density lipoprotein (RR 1·40, 95%CI 1·23-1·59), obesity (RR 1·47, 95%CI 1·29-1·68) and insulin resistance (1·64, 95%CI 1·44-1·86). This large study of clinically evaluated ALL survivors identified a high prevalence of MetS, obesity and cardiovascular risk, particularly in CRT recipients, underscoring the need for screening and aggressive reduction of modifiable risks.