Cardiovascular disease: cause of morbidity and mortality in adult survivors of childhood cancers.

Although important advances have been made in curing childhood cancer in the last several decades, long-term survivors face considerable morbidity and mortality because of late effects from their initial anticancer therapy. By 30 years after treatment, the cumulative mortality from treatment-related medical illness actually exceeds that of mortality from cancer recurrence. Cardiovascular disease, in particular, is a leading threat to the well-being of adult survivors of childhood cancers. Unfortunately, the mechanisms of these late cardiac effects are understudied and poorly understood. This article reviews cardiotoxicity associated with 2 major anticancer regimens used in treating childhood cancer patients: anthracycline treatment and radiation therapy. The known pathophysiology and clinical cardiac risk factors that further predispose these patients to late-onset cardiac events are discussed. Basic and translational research is urgently needed to clarify pathophysiologic mechanisms of late cardiac effects and to develop therapies to improve both long-term survival and quality of life of adults cured of pediatric cancers.

Related papers:

title: Late mortality among 5-year survivors of childhood cancer: a summary from the Childhood Cancer Survivor Study.
abstract: The Childhood Cancer Survivor Study (CCSS) has assembled the largest cohort to date for assessment of late mortality. Vital status and cause of death of all patients eligible for participation in CCSS was determined using the National Death Index and death certificates to characterize the mortality experience of 20,483 survivors, representing 337,334 person-years of observation. A total of 2,821 deaths have occurred as of December 31, 2002. The overall cumulative mortality is 18.1% (95% CI, 17.3 to 18.9) at 30 years from diagnosis. With time, while all-cause mortality rates have been stable, the pattern of late death is changing. Mortality attributable to recurrence or progression of primary disease is decreasing, with increases in rates of mortality attributable to subsequent neoplasms (standardized mortality ratios [SMR], 15.2; 95% CI, 13.9 to 16.6), cardiac death (SMR, 7.0; 95% CI, 5.9 to 8.2), and pulmonary death (SMR, 8.8; 95% CI, 6.8 to 11.2) largely due to treatment-related causes. In addition, the CCSS has identified specific treatment-related risk factors for late mortality. Radiotherapy (relative risk [RR], 2.9; 95% CI, 2.1 to 4.2), alkylating agents (RR, 2.2; 95% CI, 1.6 to 3.0), and epipodophyllotoxins (RR, 2.3; 95% CI, 1.2 to 4.5) increase the risk of death due to subsequent malignancy. Cardiac radiation exposure (RR, 3.3; 95% CI, 2.0 to 5.5) and high dose of anthracycline exposure (RR, 3.1; 95% CI, 1.6 to 5.8) are associated with late cardiac death. By continued longitudinal follow-up of the cohort and expansion of the cohort to include patients diagnosed between 1987 and 1999, the CCSS will remain a primary resource for assessment of late mortality of survivors of childhood cancers.

title: Long-Term Survivors of Childhood Cancers in the United States
abstract: To estimate the number of individuals in the United States diagnosed with cancer as children (ages 0-19 years) as of 2005, with a focus on those surviving for >30 years.  To estimate the national prevalence of survivors of childhood cancers, we used data from the Surveillance Epidemiology and End Results program from 1975 to 2004. Long-term childhood cancer survivors, diagnosed before 1975, were estimated using incidence and survival models extrapolated into years before 1975.  We estimated that there are a total of 328,652 survivors of childhood cancer in the United States as of January 1, 2005, of these, 24% have survived >30 years since diagnosis. The cancer sites with the largest number of survivors are brain (51,650), acute lymphoblastic leukemia (49,271), germ cell tumors (34,169), and Hodgkin lymphoma (31,598). Sites with higher proportions of survivors diagnosed >30 years ago are germ cell (43%), soft tissue (38%), renal (34%), and bone (26%). Historical trends from Connecticut data show major improvements in survival for all of the childhood cancer sites.  The number of survivors of childhood cancers is expected to increase in the future consequent to the lifesaving advances in treatment introduced after 1970, especially for acute lymphoblastic leukemia. Because this population is at increased risk for illness-related morbidity and mortality, appreciating the number of survivors who were treated as children is important both to determining the national cancer burden and planning for the future health care needs of these individuals.

title: Childhood cancer survivorship : improving care and quality of life
abstract: Only more recently has it been realized that the intense effort to care for and cure a child with cancer does not end with survival. Continued surveillance and a variety of interventions may, in many cases, be needed to identify and care for consequences of treatment that can appear early or only after several decades and impair survivorsa (TM) health and quality of life. The more than two-thirds of childhood cancer survivors who experience late effects -- that is, complications, disabilities, or adverse outcomes -- as a result of their disease, its treatment, or both, are the focus of this report which outlines a comprehensive policy agenda that links improved health care delivery and follow-up, investments in education and training for health care providers, and expanded research to improve the long-term outlook for this growing population now exceeding 270,000 Americans.

title: A Model-Based Estimate of Cumulative Excess Mortality in Survivors of Childhood Cancer
abstract: Although childhood cancer survival rates have dramatically increased, survivors face elevated risk for life-threatening late effects, including secondary cancer.



To estimate the cumulative effect of disease- and treatment-related mortality risks on survivor life expectancy.



State-transition model to simulate the lifetime clinical course of childhood cancer survivors.



Childhood Cancer Survivor Study.



Five-year survivors of childhood cancer.



Probabilities of risk for death from the original cancer diagnosis, excess mortality from subsequent cancer and cardiac, pulmonary, external, and other complications, and background mortality (age-specific mortality rates for the general population) were estimated over the lifetime of survivors of childhood cancer.



For a cohort of 5-year survivors aged 15 years who received a diagnosis of cancer at age 10 years, the average lifetime probability was 0.10 for late-recurrence mortality; 0.15 for treatment-related subsequent cancer and death from cardiac, pulmonary, and external causes; and 0.05 for death from other excess risks. Life expectancy for the cohort of persons aged 15 years was 50.6 years, a loss of 10.4 years (17.1%) compared with the general population. Reduction in life expectancy varied by diagnosis, ranging from 4.0 years (6.0%) for kidney tumor survivors to more than 17.8 years (> or =28.0%) for brain and bone tumor survivors, and was sensitive to late-recurrence mortality risk and duration of excess mortality risk.



Estimates are based on data for survivors who received treatment 20 to 40 years ago; patients who received treatment more recently may have more favorable outcomes.



Childhood cancer survivors face considerable mortality during adulthood, with excess risks reducing life expectancy by as much as 28%. Monitoring the health of current survivors and carefully evaluating therapies with known late toxicities in patients with newly diagnosed cancer are needed.

title: Chronic disease in the Childhood Cancer Survivor Study cohort: a review of published findings.
abstract: A primary objective of the Childhood Cancer Survivor Study (CCSS) is to characterize the major chronic health conditions faced by childhood cancer survivors, and to determine the risk factors for those conditions. In order to characterize these conditions, at entry into the study, participants completed questionnaires that documented self-reported chronic illnesses, symptoms, and medications. Over time, follow-up questionnaires (administered approximately every 2 to 3 years) have allowed analysis of changes in symptoms and disease burden. To date, analyses have been completed which describe the profile of chronic disease in the cohort at first entry into the study and for specific subgroups, defined by primary cancer, by specific exposures, and by demographic factors.1,2 Generally, these analyses estimate risk of chronic disease by calculating a risk estimate for self-reported symptoms or conditions. Relative risks for chronic disease or specific conditions are calculated comparing the survivor cohort with the sibling cohort or population norms. In addition, relative risk for an outcome in a subgroup with a specific treatment exposure or demographic characteristic is calculated relative to a comparison group without that specific factor of interest. Cumulative incidence of specific chronic illnesses is estimated in many of the reports, and analyses of chronic illnesses in each of the survivor groups by primary diagnosis are completed (acute lymphoblastic leukemia [ALL],3 acute myeloid leukemia [AML],4 and rhadbdomyosarcoma5) or in progress (neuroblastoma, bone sarcoma, renal tumors, lymphomas, and brain tumors). 
 
This review presents the completed analyses of overall chronic illness in the original cohort and then describes findings by organ system. Specific chronic diseases reported here will include: endocrinologic disorders (including thyroid disease, disorders of growth, weight, and pubertal regulation), osteonecrosis, cardiac disease, pulmonary conditions, and neurosensory/neurologic adverse outcomes. Adverse outcomes in some domains which might be considered chronic illnesses—secondary cancers, emotional and psychological disorders, pain—are not covered herein, but are reviewed separately in other articles within this issue of Journal of Clinical Oncology. For some outcomes, only subsets of the cohort have been analyzed, often because a hypothesis regarding a specific exposure or disease (eg, weight regulation in leukemia survivors or stroke after neck radiation therapy [RT]) has been explored. Analyses in progress, and not included in this report, include risk of renal and urinary disorders, gastrointestinal diseases, and more in depth cohort-wide characterizations of cardiovascular disease. Additional studies to characterize further longitudinal changes in risk as the cohort ages are planned.

title: Late mortality experience in five-year survivors of childhood and adolescent cancer: the Childhood Cancer Survivor Study.
abstract: Survivors of childhood and adolescent cancer are at risk for long-term effects of disease and treatment. The Childhood Cancer Survivor Study assessed overall and cause-specific mortality in a retrospective cohort of 20,227 5-year survivors.



Eligible subjects were individuals diagnosed with cancer (from 1970 to 1986) before the age of 21 who had survived 5 years from diagnosis. Underlying cause of death was obtained from death certificates and other sources and coded and categorized as recurrent disease, sequelae of cancer treatment, or non-cancer-related. Age and sex standardized mortality ratios (SMRs) were calculated using United States population mortality data.



The cohort, including 208,947 person-years of follow-up, demonstrated a 10.8-fold excess in overall mortality (95% confidence interval, 10.3 to 11.3). Risk of death was statistically significantly higher in females (SMR = 18.2), individuals diagnosed with cancer before the age of 5 years (SMR = 14.0), and those with an initial diagnosis of leukemia (SMR = 15.5) or CNS tumor (SMR = 15.7). Recurrence of the original cancer was the leading cause of death among 5-year survivors, accounting for 67% of deaths. Statistically significant excess mortality rates were seen due to subsequent malignancies (SMR = 19.4), along with cardiac (SMR = 8.2), pulmonary (SMR = 9.2), and other causes (SMR = 3.3). Treatment-related associations were present for subsequent cancer mortality (radiation, alkylating agents, epipodophyllotoxins), cardiac mortality (chest irradiation, bleomycin), and other deaths (radiation, anthracyclines). No excess mortality was observed for external causes (SMR = 0.8).



While recurrent disease remains a major contributor to late mortality in 5-year survivors of childhood cancer, significant excesses in mortality risk associated with treatment-related complications exist up to 25 years after the initial cancer diagnosis.

title: Monitoring for Cardiovascular Disease in Survivors of Childhood Cancer: Report From the Cardiovascular Disease Task Force of the Children's Oncology Group
abstract: Curative therapy for childhood cancer has improved significantly in the last 2 decades such that, at present, ∼80% of all children with cancer are likely to survive ≥5 years after diagnosis. Prevention, early diagnosis, and treatment of long-term sequelae of therapy have become increasingly more significant as survival rates continue to improve. Cardiovascular disease is a well-recognized cause of increased late morbidity and mortality among survivors of childhood cancer. The Children's Oncology Group Late Effects Committee and Nursing Discipline and Patient Advocacy Committee have recently developed guidelines for follow-up of long-term survivors of pediatric cancer. A multidisciplinary task force critically reviewed the existing literature to evaluate the evidence for the cardiovascular screening recommended by the Children's Oncology Group guidelines. In this review we outline the clinical manifestations of late cardiovascular toxicities, suggest modalities and frequency of monitoring, and address some of the controversial and unresolved issues regarding cardiovascular disease in childhood cancer survivors.

title: Pediatric cancer survivorship research: experience of the Childhood Cancer Survivor Study.
abstract: The Childhood Cancer Survivor Study (CCSS) is a comprehensive multicenter study designed to quantify and better understand the effects of pediatric cancer and its treatment on later health, including behavioral and sociodemographic outcomes. The CCSS investigators have published more than 100 articles in the scientific literature related to the study. As with any large cohort study, high standards for methodologic approaches are imperative for valid and generalizable results. In this article we describe methodological issues of study design, exposure assessment, outcome validation, and statistical analysis. METHODS for handling missing data, intrafamily correlation, and competing risks analysis are addressed; each with particular relevance to pediatric cancer survivorship research. Our goal in this article is to provide a resource and reference for other researchers working in the area of long-term cancer survivorship.

title: The Childhood Cancer Survivor Study: a National Cancer Institute-supported resource for outcome and intervention research.
abstract: Survival for childhood cancer has increased dramatically over the last 40 years with 5-year survival rates now approaching 80%. For many diagnostic groups, rapid increases in survival began in the 1970s with the broader introduction of multimodality approaches, often including combination chemotherapy with or without radiation therapy. With this increase in rates of survivorship has come the recognition that survivors are at risk for adverse health and quality-of-life outcomes, with risk being influenced by host-, disease-, and treatment-related factors. In 1994, the US National Cancer Institute funded the Childhood Cancer Survivor Study, a multi-institutional research initiative designed to establish a large and extensively characterized cohort of more than 14,000 5-year survivors of childhood and adolescent cancer diagnosed between 1970 and 1986. This ongoing study, which reflects the single most comprehensive body of information ever assembled on childhood and adolescent cancer survivors, provides a dynamic framework and resource to investigate current and future questions about childhood cancer survivors.

title: Clinical cardiotoxicity following anthracycline treatment for childhood cancer: the Pediatric Oncology Group experience.
abstract: To determine the incidence of clinical cardiotoxicity from anthracycline chemotherapy in children with cancer and to identify associated risk factors.



The study population consisted of 6,493 children with cancer who had received anthracycline chemotherapy on Pediatric Oncology Group (POG) protocols from 1974 to 1990. Cardiotoxicity, defined as congestive heart failure not due to other causes, abnormal measurements of cardiac function that prompted discontinuation of therapy, or sudden death from presumed cardiac causes, was determined by a review of protocol records.



Cardiotoxicity was confirmed in 106 patients (1.6%): 58 had congestive heart failure, 43 had changes in measures of cardiac function that prompted the discontinuation of therapy, and five died suddenly from presumed cardiac causes. In a multivariate analysis, factors that contributed to the relative risk (RR) of toxicity were a cumulative anthracycline dose > or = 550 mg/m2 of body-surface area (RR = 5.2), maximal dose > or = 50 mg/m2 (RR = 2.8), female sex (RR = 1.9), black race (RR = 1.7), presence of trisomy 21 (RR = 3.4), and exposure to amsacrine (RR = 2.6). Cardiotoxicity within 1 year after the completion of anthracycline treatment (early cardiotoxicity) represented 89.5% of all cases.



Early clinical cardiotoxicity in children treated with anthracycline is rare. A high maximal dose, or cumulative dose of anthracycline, female sex, black race, presence of trisomy 21, and treatment with amsacrine increase the risk for anthracycline-associated cardiotoxicity.

title: Chronic progressive cardiac dysfunction years after doxorubicin therapy for childhood acute lymphoblastic leukemia.
abstract: Cross-sectional studies show that cardiac abnormalities are common in long-term survivors of doxorubicin-treated childhood malignancies. Longitudinal data, however, are rare.



Serial echocardiograms (N = 499) were obtained from 115 doxorubicin-treated long-term survivors of childhood acute lymphoblastic leukemia (median age at diagnosis, 4.8 years; median follow-up after completion of doxorubicin, 11.8 years). Results were expressed as z scores to indicate the number of standard deviations (SDs) above (+) or below (-) the normal predicted value. Median individual and cumulative doxorubicin doses were 30 mg/m2 per dose and 352 mg/m2, respectively.



Left ventricular fractional shortening was significantly reduced after doxorubicin therapy, and the reduction was related to cumulative dose. z scores for fractional shortening transiently improved before falling to -2.76 more than 12 years after diagnosis. Reduced fractional shortening was related to impaired contractility and increasing afterload, consequences of a progressive reduction of ventricular mass, and wall thickness relative to body-surface area. Left ventricular contractility fell significantly over time and was depressed at last follow-up in patients receiving more than 300 mg/m2 of doxorubicin. Systolic and diastolic blood pressures were below normal more than 9 years after diagnosis. Even patients receiving lower cumulative doxorubicin doses experienced reduced mass and dimension. Fractional shortening and dimension at the end of therapy predicted these parameters 11.8 years later.



Cardiac abnormalities were persistent and progressive after doxorubicin therapy. Inadequate ventricular mass with chronic afterload excess was associated with progressive contractile deficit and possibly reduced cardiac output and restrictive cardiomyopathy. The deficits were worst after highest cumulative doses of doxorubicin, but appeared even after low doses.

title: Cardiovascular complications of cancer therapy: incidence, pathogenesis, diagnosis, and management.
abstract: Cancer treatment today employs a combination of chemotherapy, radiotherapy, and surgery to prolong life and provide cure. However, many of these treatments can cause cardiovascular complications such as heart failure, myocardial ischemia/infarction, hypertension, thromboembolism, and arrhythmias. In this article we review the incidence of cardiotoxicity caused by commonly used chemotherapeutic agents as well as discuss the pathogenesis, diagnosis, management, and prevention of these cardiovascular side effects. Cardiotoxicity related to anticancer treatment is important to recognize as it may have a significant impact on the overall prognosis and survival of cancer patients, and it is likely to remain a significant challenge for both cardiologists and oncologists in the future due to an increasing aging population of patients with cancer and the introduction of many new cancer therapies.

title: Pathology of late-onset anthracycline cardiomyopathy.
abstract: Anthracyclines are known to have acute cardiotoxicity. Anthracycline-induced dilated cardiomyopathy may have late onset and present years after administration of the drug. Several studies have described the clinical findings in patients with late-onset cardiomyopathy, including electrocardiography, exercise testing, echocardiography, and histological findings in endomyocardial biopsies; however, there is little information on the pathological changes that are found in explanted or autopsy hearts.



We reviewed the medical records and microscopic slides of heart tissue from one patient who had an autopsy and from nine patients who had cardiac transplants between 2001 and 2008. Heart weights were compared to historic controls (heart weights normalized for the patient's heights). Hematoxylin and eosin (H&E)-stained slides were semiquantitated for evidence of necrosis, myocytolysis, interstitial fibrosis, replacement fibrosis, and the presence of inflammation.



The average heart weight ranged from 231 to 470 g (mean=317 ± 65 g, median=303 g). Review of the histological sections revealed no evidence of significant necrosis or myocytolysis. Interstitial fibrosis was identified in all 10 patients, with six patients showing multifocal fibrosis, three patients showing diffuse fibrosis, and only one patient showing focal fibrosis. Replacement fibrosis was identified in six patients, with two patients displaying multifocal and four patients displaying focal replacement fibrosis.



Late-onset cardiomyopathy is a serious consequence of anthracycline therapy resulting in death or the need for cardiac transplantation in some patients. Unlike most other forms of dilated cardiomyopathy, the major pathological changes appear to be interstitial and/or replacement fibrosis without significant cardiac hypertrophy.

title: Molecular and cellular mechanisms of anthracycline cardiotoxicity
abstract: The molecular and cellular mechanisms that cause cumulative dose-dependent anthracycline-cardiotoxicity remain controversial and incompletely understood. Studies examining the effects of anthracyclines in cardiac myocytes in vitro have demonstrated several forms of cellular injury. Cell death in response to anthracyclines can be observed by one of several mechanisms including apoptosis and necrosis. Cell death by apoptosis can be inhibited by dexrazoxane, the iron chelator that is known to prevent clinical development of heart failure at high cumulative anthracycline exposure. Together with clinical evidence for myocyte death after anthracycline exposure, in the form of elevations in serum troponin, make myocyte cell death a probable mechanism for anthracycline-induced cardiac injury. Other mechanisms of myocyte injury include the development of cellular ‘sarcopenia’ characterized by disruption of normal sarcomere structure. Anthracyclines suppress expression of several cardiac transcription factors, and this may play a role in the development of myocyte death as well as sarcopenia. Degradation of the giant myofilament protein titin may represent an important proximal step that leads to accelerated myofilament degradation. Titin is an entropic spring element in the sarcomere that regulates length-dependent calcium sensitivity. Thus titin degradation may lead to impaired diastolic as well as systolic dysfunction, as well as potentiate the effect of suppression of transcription of sarcomere proteins. An interesting interaction has been noted clinically between anthracyclines and newer cancer therapies that target the erbB2 receptor tyrosine kinase. Studies of erbB2 function in viro suggest that signaling through erbB2 by the growth factor neuregulin may regulate cardiac myocyte sarcomere turnover, as well as myocyte-myocyte/myocyte-matrix force coupling. A combination of further in vitro studies, with more careful monitoring of cardiac function after exposure to these cancer therapies, may help to understand to what extent these mechanisms are at work during clinical exposure of the heart to these important pharmaceuticals.

title: Anthracycline cardiotoxicity: from bench to bedside.
abstract: Anthracyclines remain among the most widely prescribed and effective anticancer agents. Unfortunately, life-threatening cardiotoxicity continues to compromise their usefulness. Despite more than four decades of investigation, the pathogenic mechanisms responsible for anthracycline cardiotoxicity have not been completely elucidated. In addition, new drugs and combination therapies often exacerbate the toxicity. The First International Workshop on Anthracycline Cardiotoxicity, held in fall 2006, in Como, Italy, focused on the state-of-the-art knowledge and discussed the research needed to address the cardiotoxicity of these drugs. Here, we incorporate these discussions into the framework of a broader review of preclinical and clinical issues.

title: Anthracycline associated cardiotoxicity in survivors of childhood cancer
abstract: The development of effective antineoplastic therapies for childhood cancer is a great success in modern medicine. Five year survival rates of children diagnosed with cancer in the USA and Western Europe in excess of 70% make long term survivors of childhood cancer a steadily increasing population. Although there is much to celebrate, new challenges lie ahead in treating the systemic sequelae of chemotherapy.1 Results from the Childhood Cancer Survivor Study (CCSS) showed that 30 years after treatment, the cumulative incidence of chronic health conditions in long term survivors reaches 73%, with a cumulative incidence of 42% for severe, disabling, or life threatening conditions or death.2 Severe conditions, that are significantly more common in childhood cancer survivors than in their siblings, include: major joint replacement (relative risk (RR) 54.0), congestive heart failure (RR 15.1), second malignant neoplasm (RR 14.8), severe cognitive dysfunction (RR 10.5), coronary artery disease (RR 10.4), cerebrovascular accident (RR 9.3), and renal failure (RR 8.9).2 Previous CCSS results found that patients who had survived at least 5 years after diagnosis had 10.8-fold increased rates of all cause mortality.3 The standardised mortality ratio for cardiac causes was 8.2 times higher than expected and the cumulative probability of cardiac death increased 15–25 years after cancer diagnosis. A similar study in a large Nordic cohort documented a standardised mortality ratio of 5.8 for cardiac death and elevated rates of sudden, presumed arrhythmic, 

Chief among adverse late effects is the cardiovascular toxicity of anthracyclines.5–11 Unfortunately, despite well documented dose related toxicity, the superior disease-free survival rates of regimens including anthracyclines leave limited viable treatment alternatives and the majority of long term paediatric cancer survivors in the Pediatric Oncology Group received an anthracycline during treatment.12

### Mechanism of cardiotoxicity

Several cytotoxic biochemical changes follow anthracycline exposure in …

title: Cardiovascular complications of cancer therapy: diagnosis, pathogenesis, and management.
abstract: The cardiotoxicity of anticancer agents can lead to significant complications that can affect patients being treated for various malignancies. The severity of such toxicity depends on many factors such as the molecular site of action, the immediate and cumulative dose, the method of administration, the presence of any underlying cardiac condition, and the demographics of the patient. Moreover, toxicity can be affected by current or previous treatment with other antineoplastic agents. Cardiotoxic effects can occur immediately during administration of the drug, or they may not manifest themselves until months or years after the patient has been treated. In this article we review commonly used chemotherapy agents, including several recently approved medications, for their propensity to cause cardiotoxicity. Further research will be required to more accurately predict which patients are at risk for developing cardiotoxicity. In addition, management plans, as well as strategies to reduce cardiotoxicity, need to be developed.

title: Epidemiology of anthracycline cardiotoxicity in children and adults.
abstract: Anthracyclines, potent cytotoxic agents used to treat a broad spectrum of malignancies, are limited in their use by an attendant risk of cardiotoxicity. Malignancies affect all age ranges, and anthracyclines are used in all age ranges, thereby exposing a broad population of patients to the development of heart disease. For some treated patients, anthracyclines affect cardiac muscle, resulting in cardiomyopathy. The type and degree of cardiomyopathy, as well as when during or after treatment the condition occurs, are dependent on what risk factors are present. Age is a major risk factor. Children and adults may develop restrictive and dilated cardiomyopathy. The length of subsequent survival and amount of subsequent somatic growth may influence late anthracycline-associated cardiac outcome. Early cardiotoxicity, occurring during or within 1 year of completion of treatment, is the largest risk factor for the development of late cardiotoxicity, which occurs beyond a year of completion of treatment. Risk factors, which appear to be specific for early cardiotoxicity in children, include black race, trisomy 21, and the use of amsacrine therapy after anthracycline therapy. More cardiotoxic effects are seen in survivors of childhood cancer, the longer from completion of treatment a patient is followed. Cumulative as well as peak anthracycline doses affect adults and children alike, and cardiotoxicity occurs early and late. In adults, left ventricular contractility is affected by anthracyclines. Children may manifest impairment of left ventricular contractility and increased afterload due to thinning of left ventricular walls. Patients with an early presentation of depressed left ventricular contractility are likely to show progression of cardiac disease with time. In addition, female gender appears to affect early and late cardiotoxicity in both adults and children, although this risk factor has been described predominantly in the survivors of childhood cancer. Thus, although anthracycline chemotherapy has improved overall survivorship of patients with cancer, there is a significant risk of cardiotoxicity associated with this class of drugs.

title: Iron signaling and oxidant damage
abstract: In this brief essay we discuss the interrelationship between the cellular signaling effects induced by extracellular and intracellular ROS and nitric oxide in the context of doxorubicin (DOX) toxicity.

title: Adriamycin-induced interference with cardiac mitochondrial calcium homeostasis
abstract: Adriamycin (doxorubicin) is a potent and broad-spectrum antineoplastic agent, the clinical utility of which is limited by the development of a cumulative and irreversible cardiomyopathy. Although the drug affects numerous structures in different cell types, the mitochondrion appears to a principal subcellular target for the development of cardiomyopathy. This review describes evidence demonstrating that adriamycin redox cycles on complex I of the mitochondrial electron transport chain to liberate highly reactive free radical species of molecular oxygen. The primary effect of adriamycin on mitochondrial performance is the interference with oxidative phosphorylation and inhibition of ATP synthesis. Free radicals liberated from adriamycin redox cycling are thought to be responsible for many of the secondary effects of adriamycin, including lipid peroxidation, the oxidation of both proteins and DNA, and the depletion of glutathione and pyridine nucleotide reducing equivalents in the cell. It is this altered redox status that is believed to cause assorted changes in intracellular regulation, including the induction of the mitochondrial permeability transition and complete loss of mitochondrial integrity and function. Associated with this is the interference with mitochondrial-mediated cell calcium signaling, which is implicated as essential to the capacity of mitochondria to participate in bioenergetic regulation in response to external signals reflecting changes in metabolic demand. If taken to an extreme, this loss of mitochondrial plasticity may manifest in the liberation of signals mediating either oncotic or necrotic cell death, further perpetuating the cardiac failure associated with adriamycin-induced mitochondrial cardiomyopathy.

title: Anthracycline-induced cardiotoxicity: overview of studies examining the roles of oxidative stress and free cellular iron.
abstract: The risk of cardiotoxicity is the most serious drawback to the clinical usefulness of anthracycline antineoplastic antibiotics, which include doxorubicin (adriamycin), daunorubicin or epirubicin. Nevertheless, these compounds remain among the most widely used anticancer drugs. The molecular pathogenesis of anthracycline cardiotoxicity remains highly controversial, although the oxidative stress-based hypothesis involving intramyocardial production of reactive oxygen species (ROS) has gained the widest acceptance. Anthracyclines may promote the formation of ROS through redox cycling of their aglycones as well as their anthracycline-iron complexes. This proposed mechanism has become particularly popular in light of the high cardioprotective efficacy of dexrazoxane (ICRF-187). The mechanism of action of this drug has been attributed to its hydrolytic transformation into the iron-chelating metabolite ADR-925, which may act by displacing iron from anthracycline-iron complexes or by chelating free or loosely bound cellular iron, thus preventing site-specific iron-catalyzed ROS damage. However, during the last decade, calls for the critical reassessment of this "ROS and iron" hypothesis have emerged. Numerous antioxidants, although efficient in cellular or acute animal experiments, have failed to alleviate anthracycline cardiotoxicity in clinically relevant chronic animal models or clinical trials. In addition, studies with chelators that are stronger and more selective for iron than ADR-925 have also yielded negative or, at best, mixed outcomes. Hence, several lines of evidence suggest that mechanisms other than the traditionally emphasized "ROS and iron" hypothesis are involved in anthracycline-induced cardiotoxicity and that these alternative mechanisms may be better bases for designing approaches to achieve efficient and safe cardioprotection.

title: Preclinical animal models of cardiac protection from anthracycline-induced cardiotoxicity.
abstract: The chronic cardiotoxic effects of anthracyclines were initially detected in clinical trials with daunorubicin and doxorubicin. The clinical importance of anthracycline-induced chronic cardiotoxicity has led to the development of several animal models of this syndrome. Animal species examined in detail as models of this cardiac toxicity include the rabbit, the normotensive and spontaneously hypertensive rat, the mouse, the pig, and the dog. The advantages and disadvantages of these animal models differ according to species: small animals can be used for comparative investigations of anthracycline analogues and/or protectors, which may be available only in limited amounts, while large animals can be used for studies in which evaluation of cardiac function are to be made. Among the various animals examined, the spontaneously hypertensive rat and the beagle dog are considered the most suitable small and large animal models, respectively, because of the reproducibility of the lesions induced by anthracyclines in the two species. A variety of pharmacologic agents has been tested for cardioprotective activity. The most successful of these agents are those that function as antioxidants, because they either scavenge reactive oxygen species or prevent their formation. The most clinically useful of these agents is ICRF-187 (dexrazoxane), which has been found to be cardioprotective in all animal models.

title: Antioxidants and cancer therapy: a systematic review.
abstract: Many patients with cancer take antioxidant nutritional supplements during cancer treatment to alleviate treatment toxicities and to improve long-term outcomes, but little is known about the efficacy and safety of antioxidant use during cancer treatment. We reviewed English-language manuscripts published in the biomedical literature, reporting the results of observational studies of antioxidant status and cancer outcomes and of intervention trials of antioxidants among patients receiving chemotherapy with or without radiation for various malignancies.



We searched the Medline database and the bibliographies of the retrieved manuscripts, reviews, and books on antioxidants and cancer. The retrieved studies are grouped by study design, malignancy, and end points.



More than 100 citations were retrieved; 52 met our criteria, 31 were observational studies, and 21 were intervention trials. The studies varied in study design, timing of observation/intervention, intervention protocol, malignancy, and anticancer regimen.



These inconsistencies preclude a definitive conclusion as to the effect of chemotherapy on antioxidant status in patients undergoing anticancer therapy. However, our review suggests that total antioxidant status (measured by total radical antioxidant parameter) declines during cancer treatment. Adequately powered trials or observational studies among patients with a specific cancer diagnosis receiving a specific treatment regimen are needed to address patients' and physicians' concerns regarding these associations.

title: Myocardial infarction, viral infection, and the cytoskeleton final common pathways of a common disease?
abstract: Myocardial infarction (MI) is a major cause of morbidity and mortality in adults worldwide and is believed to result from an acute coronary syndrome in most affected individuals ([1][1]). In subjects with MI caused by acute coronary syndrome, the coronary obstruction leads to ischemia, and the

title: Dystrophin‐deficiency increases the susceptibility to doxorubicin‐induced cardiotoxicity
abstract: The clinical use of doxorubicin (DOX) and other anthracyclines is limited by a dosage‐dependent cardiotoxicity, which can lead to cardiomyopathy. The role of the individual genetic makeup in this disorder is poorly understood. Alterations in genes encoding cardiac cytoskeleton or sarcolemma proteins may increase the susceptibility to doxorubicin‐related cardiotoxicity.

title: Use of chemotherapy plus a monoclonal antibody against HER2 for metastatic breast cancer that overexpresses HER2.
abstract: The HER2 gene, which encodes the growth factor receptor HER2, is amplified and HER2 is overexpressed in 25 to 30 percent of breast cancers, increasing the aggressiveness of the tumor.



We evaluated the efficacy and safety of trastuzumab, a recombinant monoclonal antibody against HER2, in women with metastatic breast cancer that overexpressed HER2. We randomly assigned 234 patients to receive standard chemotherapy alone and 235 patients to receive standard chemotherapy plus trastuzumab. Patients who had not previously received adjuvant (postoperative) therapy with an anthracycline were treated with doxorubicin (or epirubicin in the case of 36 women) and cyclophosphamide alone (138 women) or with trastuzumab (143 women). Patients who had previously received adjuvant anthracycline were treated with paclitaxel alone (96 women) or paclitaxel with trastuzumab (92 women).



The addition of trastuzumab to chemotherapy was associated with a longer time to disease progression (median, 7.4 vs. 4.6 months; P<0.001), a higher rate of objective response (50 percent vs. 32 percent, P<0.001), a longer duration of response (median, 9.1 vs. 6.1 months; P<0.001), a lower rate of death at 1 year (22 percent vs. 33 percent, P=0.008), longer survival (median survival, 25.1 vs. 20.3 months; P=0.01), and a 20 percent reduction in the risk of death. The most important adverse event was cardiac dysfunction of New York Heart Association class III or IV, which occurred in 27 percent of the group given an anthracycline, cyclophosphamide, and trastuzumab; 8 percent of the group given an anthracycline and cyclophosphamide alone; 13 percent of the group given paclitaxel and trastuzumab; and 1 percent of the group given paclitaxel alone. Although the cardiotoxicity was potentially severe and, in some cases, life-threatening, the symptoms generally improved with standard medical management.



Trastuzumab increases the clinical benefit of first-line chemotherapy in metastatic breast cancer that overexpresses HER2.

title: The vulnerability of the heart as a pluricellular paracrine organ: lessons from unexpected triggers of heart failure in targeted ErbB2 anticancer therapy.
abstract: In this review, we address clinical aspects and mechanisms of ventricular dysfunction induced by anticancer drugs targeted to the ErbB2 receptor. ErbB2 antagonists prolong survival in cancer, but also interfere with homeostatic processes in the heart. ErbB2 is a coreceptor for ErbB4, which is activated by neuregulin-1. This epidermal growth factor-like growth factor is released from endothelial cells in the endocardium and in the myocardial microcirculation, hence contributing to intercellular crosstalk in the ventricle. We look at the physiological aspects of neuregulin-1/ErbB signaling in the ventricle, and review its (mal)adaptive responses in chronic heart failure. We also compare structural aspects of ErbB receptor activation in cancer and cardiac cells, and analyze the mode of action of current ErbB2 antagonists. This allows us to predict how these drugs interfere with paracrine processes in the ventricle. Differences in the mode of action of individual ErbB2 antagonists affect their impact on the function of the ventricle, considered to be "on-target" or "off-target." Establishing the relation between the cardiac side effects of ErbB2 antagonists and their impact on paracrine ventricular control mechanisms may direct the design of a next generation of ErbB2 inhibitors. For cardiologists, there are lessons to be learned from the unexpected side effects of ErbB2-targeted cancer therapy. The vulnerability of the heart as a pluricellular paracrine system appears greater than anticipated and intercellular crosstalk an essential component of its functional and structural integrity.

title: Trastuzumab-associated cardiac adverse effects in the herceptin adjuvant trial.
abstract: The purpose of this analysis was to investigate trastuzumab-associated cardiac adverse effects in breast cancer patients after completion of (neo)adjuvant chemotherapy with or without radiotherapy.



The Herceptin Adjuvant (HERA) trial is a three-group, multicenter, open-label randomized trial that compared 1 or 2 years of trastuzumab given once every 3 weeks with observation in patients with HER-2-positive breast cancer. Only patients who after completion of (neo)adjuvant chemotherapy with or without radiotherapy had normal left ventricular ejection fraction (LVEF > or = 55%) were eligible. A repeat LVEF assessment was performed in case of cardiac dysfunction.



Data were available for 1,693 patients randomly assigned to 1 year trastuzumab and 1,693 patients randomly assigned to observation. The incidence of trastuzumab discontinuation due to cardiac disorders was low (4.3%). The incidence of cardiac end points was higher in the trastuzumab group compared with observation (severe congestive heart failure [CHF], 0.60% v 0.00%; symptomatic CHF, 2.15% v 0.12%; confirmed significant LVEF drops, 3.04% v 0.53%). Most patients with cardiac dysfunction recovered in fewer than 6 months. Patients with trastuzumab-associated cardiac dysfunction were treated with higher cumulative doses of doxorubicin (287 mg/m(2) v 257 mg/m(2)) or epirubicin (480 mg/m(2) v 422 mg/m(2)) and had a lower screening LVEF and a higher body mass index.



Given the clear benefit in disease-free survival, the low incidence of cardiac adverse events, and the suggestion that cardiac dysfunction might be reversible, adjuvant trastuzumab should be considered for treatment of breast cancer patients who fulfill the HERA trial eligibility criteria.

title: Mechanisms of Cardiac Dysfunction Associated With Tyrosine Kinase Inhibitor Cancer Therapeutics
abstract: Treatment of patients with cancer has changed radically over the last several years with the advent of “targeted therapeutics.” Whereas traditional chemotherapy was directed at all rapidly dividing cells, whether cancerous or not, today’s anticancer drugs are increasingly tailored to the specific genetics of each cancer. This targeted approach, predominantly via inhibition of tyrosine kinase activity, has markedly improved the management of cancers including chronic myeloid leukemia (CML), breast cancer, gastrointestinal stromal tumor (GIST), renal cell carcinoma (RCC), and colon carcinoma.1–5

Inhibitors of tyrosine kinases are of 2 classes: monoclonal antibodies (mAbs), typically targeting growth factor receptor tyrosine kinases, and small molecules, referred to as tyrosine kinase inhibitors (TKIs), targeting both receptor and nonreceptor tyrosine kinases. The goal of targeted therapy is to improve antitumor activity with fewer toxic side effects than traditional anticancer therapies; given the initial success of this approach, the number of targeted therapy drugs entering into development in the last 5 years has increased dramatically.6,7 However, several recent studies have revealed unanticipated side effects of targeted therapy, including left ventricular (LV) dysfunction and heart failure, the primary manifestations of cardiotoxicity we will be examining here.5,8,9

Herein, we will examine the potential risk of LV dysfunction of targeted therapy and the molecular mechanisms that underlie that risk. We will review the importance of tyrosine kinase signaling pathways both for oncogenesis and for the survival of normal cardiomyocytes. To understand basic mechanisms of cardiomyopathy of TKIs, it is critical to understand 2 general classes of toxicity. The first is “on-target” toxicity, wherein the tyrosine kinase target regulating cancer cell survival and/or proliferation (and therefore a good target in cancer therapy) also serves an important role in normal cardiomyocyte survival, and thus inhibition leads to myocardial dysfunction. “Off-target” toxicity occurs when a TKI leads to toxicity …

title: Cardiotoxicity associated with tyrosine kinase inhibitor sunitinib
abstract: Sunitinib, a multitargeted tyrosine-kinase inhibitor, which is approved by both US and European Commission regulatory agencies for clinical use, extends survival of patients with metastatic renal-cell carcinoma and gastrointestinal stromal tumours, but concerns have arisen about its cardiac safety. We therefore assessed the cardiovascular risk associated with sunitinib in patients with metastatic gastrointestinal stromal tumours.



We retrospectively reviewed all cardiovascular events in 75 patients with imatinib-resistant, metastatic, gastrointestinal stromal tumours who had been enrolled in a phase I/II trial investigating the efficacy of sunitinib. The composite cardiovascular endpoint was cardiac death, myocardial infarction, and congestive heart failure. We also examined sunitinib's effects on left ventricular ejection fraction (LVEF) and blood pressure. We investigated potential mechanisms of sunitinib-associated cardiac effects by studies in isolated rat cardiomyocytes and in mice.



Eight of 75 (11%) patients given repeating cycles of sunitinib in the phase I/II trial had a cardiovascular event, with congestive heart failure recorded in six of 75 (8%). Ten of 36 (28%) patients treated at the approved sunitinib dose had absolute LVEF reductions in ejection fraction (EF) of at least 10%, and seven of 36 (19%) had LVEF reductions of 15 EF% or more. Sunitinib induced increases in mean systolic and diastolic blood pressure, and 35 of 75 (47%) individuals developed hypertension (>150/100 mm Hg). Congestive heart failure and left ventricular dysfunction generally responded to sunitinib being withheld and institution of medical management. Sunitinib caused mitochondrial injury and cardiomyocyte apoptosis in mice and in cultured rat cardiomyocytes.



Left ventricular dysfunction might be due, in part, to direct cardiomyocyte toxicity, exacerbated by hypertension. Patients treated with sunitinib should be closely monitored for hypertension and LVEF reduction, especially those with a history of coronary artery disease or cardiac risk factors.

title: Doxorubicin cardiotoxicity in African Americans.
abstract: The African-American race was examined as a risk factor for cardiotoxicity from doxorubicin-based therapy for cancer.



Retrospective survey of the Howard University Hospital cancer registry during 1997-2001 identified 100 evaluable patients out of 120 African Americans who underwent doxorubicin-based combination chemotherapy (65% women, 35% men, median age 46 years, range 32-84 years). The fraction of patients who developed post-treatment cardiotoxicity, defined as congestive heart failure or a left-ventricular ejection fraction less than 45%, was compared with that from a retrospective study of 399 patients of unknown age and racial distribution. Cases were stratified by cumulative dose of doxorubicin. Statistical significance of the difference in incidence of cardiotoxicity was tested by chi-square analysis.



Patients received multiple doses of doxorubicin (range 264 to 580 mg/m2 with median of 374) with the final echocardiographic assessment at a median of 1.3 years. Howard oncologists frequently used a 48-hour infusion rather than the conventional rapid bolus to reduce the cardiotoxicity of doxorubicin. The fraction with cardiotoxicity in our study versus Lefrak's review at four ranges of doxorubicin was 25% versus 18% at 551-600 mg/m2, 10% versus 4% at 501-550 mg/m2, 4% versus 1% at 451-500 mg/m2, and 0% versus <1% at <450 mg/m2. Seventy-two percent of the patients having depressed ejection fraction and/or heart failure were women. African Americans had a higher rate of cardiotoxicity after doxorubicin (7/100 cases) than that of Lefrak's (10/399) study population and were statistically significant at p<0.027 with an odds ratio of 2.93.



We have shown for the first time that African Americans at our institution appear to suffer cardiotoxicity from doxorubicin three times more frequently than the previously noted study population. To better clarify this observation, a larger study in a multiracial setting is needed.

title: Juvenile Exposure to Anthracyclines Impairs Cardiac Progenitor Cell Function and Vascularization Resulting in Greater Susceptibility to Stress-Induced Myocardial Injury in Adult Mice
abstract: The anthracycline doxorubicin is an effective chemotherapeutic agent used to treat pediatric cancers but is associated with cardiotoxicity that can manifest many years after the initial exposure. To date, very little is known about the mechanism of this late-onset cardiotoxicity.  To understand this problem, we developed a pediatric model of late-onset doxorubicin-induced cardiotoxicity in which juvenile mice were exposed to doxorubicin, using a cumulative dose that did not induce acute cardiotoxicity. These mice developed normally and had no obvious cardiac abnormalities as adults. However, evaluation of the vasculature revealed that juvenile doxorubicin exposure impaired vascular development, resulting in abnormal vascular architecture in the hearts with less branching and decreased capillary density. Both physiological and pathological stress induced late-onset cardiotoxicity in the adult doxorubicin-treated mice. Moreover, adult mice subjected to myocardial infarction developed rapid heart failure, which correlated with a failure to increase capillary density in the injured area. Progenitor cells participate in regeneration and blood vessel formation after a myocardial infarction, but doxorubicin-treated mice had fewer progenitor cells in the infarct border zone. Interestingly, doxorubicin treatment reduced proliferation and differentiation of the progenitor cells into cells of cardiac lineages.  Our data suggest that anthracycline treatment impairs vascular development as well as progenitor cell function in the young heart, resulting in an adult heart that is more susceptible to stress.

title: Late cardiac effects of doxorubicin therapy for acute lymphoblastic leukemia in childhood.
abstract: Cardiotoxicity is a recognized complication of doxorubicin therapy, but the long-term effects of doxorubicin are not well documented. We therefore assessed the cardiac status of 115 children who had been treated for acute lymphoblastic leukemia with doxorubicin 1 to 15 years earlier in whom the disease was in continuous remission.



Eighteen patients received one dose of doxorubicin (45 mg per square meter of body-surface area), and 97 received multiple doses totaling 228 to 550 mg per square meter (median, 360). The median interval between the end of treatment and the cardiac evaluation was 6.4 years. Our evaluation consisted of a history, 24-hour ambulatory electrocardiographic recording, exercise testing, and echocardiography.



Fifty-seven percent of the patients had abnormalities of left ventricular afterload (measured as end-systolic wall stress) or contractility (measured as the stress-velocity index). The cumulative dose of doxorubicin was the most significant predictor of abnormal cardiac function (P less than 0.002). Seventeen percent of patients who received one dose of doxorubicin had slightly elevated age-adjusted afterload, and none had decreased contractility. In contrast, 65 percent of patients who received at least 228 mg of doxorubicin per square meter had increased afterload (59 percent of patients), decreased contractility (23 percent), or both. Increased afterload was due to reduced ventricular wall thickness, not to hypertension or ventricular dilatation. In multivariate analyses restricted to patients who received at least 228 mg of doxorubicin per square meter, the only significant predictive factors were a higher cumulative dose (P = 0.01), which predicted decreased contractility, and an age of less than four years at treatment (P = 0.003), which predicted increased afterload. Afterload increased progressively in 24 of 34 patients evaluated serially (71 percent). Reported symptoms correlated poorly with indexes of exercise tolerance or ventricular function. Eleven patients had congestive heart failure within one year of treatment with doxorubicin; five of them had recurrent heart failure 3.7 to 10.3 years after completing doxorubicin treatment, and two required heart transplantation. No patient had late heart failure as a new event.



Doxorubicin therapy in childhood impairs myocardial growth in a dose-related fashion and results in a progressive increase in left ventricular afterload sometimes accompanied by reduced contractility. We hypothesize that the loss of myocytes during doxorubicin therapy in childhood might result in inadequate left ventricular mass and clinically important heart disease in later years.

title: Pharmacogenetics of target genes across doxorubicin disposition pathway: a review.
abstract: Increased understanding of the molecular mechanisms of tumor heterogeneity combined with rapid advances in the field of pharmacogenetics and pharmacogenomics have fuelled studies on individualizing anticancer therapy. Doxorubicin (Adriamycin), is an anthracycline glycoside antibiotic originally produced by Streptomyces peucetius var. caesius, and is widely used either as a single agent or in combination with other chemotherapeutic regimens for curative, adjuvant, and palliative treatment in cancer patients. The pharmacogenetics of doxorubicin has not been well characterized. The polygenic influence of functional candidate gene variants across doxorubicin biochemical pathway is hypothesized to contribute to its heterogeneity in disposition, influencing the efficacy of treatment and occurrence of adverse effects like cardiomyopathy in patients undergoing doxorubicin based adjuvant and neo-adjuvant chemotherapy. The pharmacogenetics of Asian population differs from that of other ethnic groups, particularly from Caucasian and African populations, and indicates an important role of ethnicity in determining predictive end points during chemotherapy and in individualizing treatment. This review comprehensively examines the pharmacogenetics of the regulatory nuclear receptor Pregnane-X Receptor (PXR), influx (SLC22A16) and efflux drug transporters (ABCB1, ABCG2, ABCC5, ABCB5 and RLIP76) and drug metabolizing enzymes (CBR1, CBR3) across the biochemical pathway of doxorubicin in Asian breast cancer patients receiving doxorubicin based adjuvant chemotherapy. The influence of functional genetic variants on the inter-individual variability in pharmacokinetics of doxorubicin and its major metabolite are also discussed. The incorporation of non-genetic factors and subsequent validation of these findings in different patient and population groups will be valuable in tailoring doxorubicin dosage regimens to an individual to maximize therapeutic efficacy and minimize adverse reactions, leading to improved clinical outcomes.

title: Genetic polymorphisms in the carbonyl reductase 3 gene CBR3 and the NAD(P)H:quinone oxidoreductase 1 gene NQO1 in patients who developed anthracycline‐related congestive heart failure after childhood cancer
abstract: Exposure to anthracyclines as part of cancer therapy has been associated with the development of congestive heart failure (CHF). The potential role of genetic risk factors in anthracycline‐related CHF remains to be defined. Thus, in this study, the authors examined whether common polymorphisms in candidate genes involved in the pharmacodynamics of anthracyclines (in particular, the nicotinamide adenine dinucleotide phosphate:quinone oxidoreductase 1 gene NQO1 and the carbonyl reductase 3 gene CBR3) had an impact on the risk of anthracycline‐related CHF.

title: NAD(P)H Oxidase and Multidrug Resistance Protein Genetic Polymorphisms Are Associated With Doxorubicin-Induced Cardiotoxicity
abstract: A significant number of patients treated with anthracyclines develop cardiotoxicity (anthracycline-induced cardiotoxicity [ACT]), mainly presenting as arrhythmias (acute ACT) or congestive heart failure (chronic ACT). There are no data on pharmacogenomic predictors of ACT.  We genotyped participants of the German non-Hodgkin lymphoma study (NHL-B) who were followed up for the development of heart failure for a median of >3 years. Single-nucleotide polymorphisms (SNPs) were selected from 82 genes with conceivable relevance to ACT. Of 1697 patients, 55 developed acute and 54 developed chronic ACT (cumulative incidence of either form, 3.2%). We detected 5 significant associations with polymorphisms of the NAD(P)H oxidase and doxorubicin efflux transporters. Chronic ACT was associated with a variant of the NAD(P)H oxidase subunit NCF4 (rs1883112, −212A→G; symbols with right-pointing arrows, as edited?‘ odds ratio [OR], 2.5; 95% CI, 1.3 to 5.0). Acute ACT was associated with the His72Tyr polymorphism in the p22phox subunit (rs4673; OR, 2.0; 95% CI, 1.0 to 3.9) and with the variant 7508T→A (rs13058338; OR, 2.6; 95% CI, 1.3 to 5.1) of the RAC2 subunit of the same enzyme. In agreement with these results, mice deficient in NAD(P)H oxidase activity, unlike wild-type mice, were resistant to chronic doxorubicin treatment. In addition, acute ACT was associated with the Gly671Val variant of the doxorubicin efflux transporter multidrug resistance protein 1 (MRP1) (OR, 3.6; 95% CI, 1.6 to 8.4) and with the Val1188Glu-Cys1515Tyr (rs8187694-rs8187710) haplotype of the functionally similar MRP2 (OR, 2.3; 95% CI, 1.0 to 5.4). Polymorphisms in adrenergic receptors previously demonstrated to be predictive of heart failure were not associated with ACT.  Genetic variants in doxorubicin transport and free radical metabolism may modulate the individual risk to develop ACT.

title: Genotyping the risk of anthracycline-induced cardiotoxicity
abstract: Anthracyclines belong to the most successful antineoplastic drugs, but they are cardiotoxic, which may result in congestive heart failure (CHF). The CHF risk increases with the cumulative anthracycline dose, but it seems also to be modified by individual factors. A role of the individual genetic background is consistent with the altered sensitivity to anthracyclines observed in many transgenic and knockout mouse strains. First clinical data obtained in humans suggest the existence of predisposing variants in genes involved in the oxidative stress, and in the metabolism and transport of anthracyclines. These data will have to be verified in further clinical trials before any attempts of their application in the individual cardiotoxicity prediction can be undertaken. In the meantime, anthracycline-induced cardiotoxicity can be best reduced by application of liposomal anthracycline formulations or by a co-medication with the cardioprotective iron chelator dexrazoxane.

title: Long-term prospective follow-up study of cardiac function after cardiotoxic therapy for malignancy in children.
abstract: To evaluate cardiac function by means of conventional and three-dimensional echocardiography (3DE) and measurement of natriuretic peptides in children and adolescents previously treated for childhood malignancy using individual follow-up data and matched control children as reference criteria.



Thirty-nine survivors of childhood malignancy were examined in 1994 and 1998. The mean time from the diagnosis was 8.6 (3.9 to 16.8) years and between cardiac evaluations was 4.1 (3.3 to 5.1) years. Patients were divided into two groups according to therapies given (group I (n = 30): no cardiac irradiation, median cumulative anthracycline dose 210 mg/m2; group II (n = 9): irradiation in the cardiac region, median cumulative anthracycline dose 180 mg/m2).



Fractional shortening (FS) in 1994 was higher than in 1998 (32.5 +/- 4.3 vs. 30.3% +/- 3.3%, P =.009). 33% of patients in group I and 56% in group II in 1994 and 30% of patients in group I and 67% in group II in 1998 had N-terminal of the propeptide-atrial natriuretic peptide (NT-proANP) levels exceeding the 90th percentile of controls. In 1998, both groups (I and II) had lower ejection fraction (EF) measured by 3DE than their matched controls (52.9 +/- 5.2 vs. 58.8% +/- 3.1%, P <.001 and 50.0 +/- 6.6 vs. 60.8% +/- 3.2%, P =.024, respectively). Left atrial maximum volumes/body surface area were smaller in the patients than in controls. B-Type natriuretic peptide values did not differ significantly in either group.



Left ventricular contractility decreases slowly even years after cardiotoxic cancer therapy in children. 3DE and NT-proANP measurements are effective methods to evaluate the cardiac function in these patients.

title: Myocardial dysfunction late after low-dose anthracycline treatment in asymptomatic pediatric patients.
abstract: The occurrence of chronic anthracycline cardiotoxicity leading to heart failure and even death is a major concern in the treatment of childhood malignancies. Currently, most treatment protocols use reduced anthracycline doses compared with historical exposure. The long-term effect of these reduced doses on myocardial function has not been well studied.



We examined 56 asymptomatic patients. They all had been treated with anthracyclines at a cumulative dose less than 300 mg/m2 5.2 (range: 2.0-15.2) years before the current evaluation. In all patients, standard two-dimensional, Doppler echocardiographic measurements, end-systolic wall stress calculation, and color Doppler myocardial imaging data were obtained. From the color Doppler myocardial imaging data, peak systolic myocardial velocities, peak systolic strain rate, and peak systolic strain [symbol: see text] were computed. The myocardial acceleration during isovolumetric contraction was measured at the basal left ventricular (LV) lateral and right ventricular free wall. Data were compared with 32 age-matched normal controls.



In asymptomatic patients previously exposed to low-dose anthracycline treatment, several changes in cardiac function were noted: 1. LV diastolic function was abnormal with a prolonged isovolumetric relaxation time and abnormal pulmonary venous flow patterns. 2. End-systolic wall stress was increased. 3. LV annular motion was reduced. 4. Systolic myocardial deformation was reduced with a significant decrease in both radial and longitudinal peak systolic strain rate and [symbol: see text].



Changes in systolic and diastolic function are noted in asymptomatic patients with normal ejection fraction late after low-dose anthracycline treatment. This confirms that subclinical LV dysfunction is present in patients after low-dose anthracycline treatment during childhood. The long-term significance of these findings warrants further follow-up.

title: Topoisomerase IIbeta mediated DNA double-strand breaks: implications in doxorubicin cardiotoxicity and prevention by dexrazoxane.
abstract: Doxorubicin is among the most effective and widely used anticancer drugs in the clinic. However, cardiotoxicity is one of the life-threatening side effects of doxorubicin-based therapy. Dexrazoxane (Zinecard, also known as ICRF-187) has been used in the clinic as a cardioprotectant against doxorubicin cardiotoxicity. The molecular basis for doxorubicin cardiotoxicity and the cardioprotective effect of dexrazoxane, however, is not fully understood. In the present study, we showed that dexrazoxane specifically abolished the DNA damage signal gamma-H2AX induced by doxorubicin, but not camptothecin or hydrogen peroxide, in H9C2 cardiomyocytes. Doxorubicin-induced DNA damage was also specifically abolished by the proteasome inhibitors bortezomib and MG132 and much reduced in top2beta(-/-) mouse embryonic fibroblasts (MEF) compared with TOP2beta(+/+) MEFs, suggesting the involvement of proteasome and DNA topoisomerase IIbeta (Top2beta). Furthermore, in addition to antagonizing Top2 cleavage complex formation, dexrazoxane also induced rapid degradation of Top2beta, which paralleled the reduction of doxorubicin-induced DNA damage. Together, our results suggest that dexrazoxane antagonizes doxorubicin-induced DNA damage through its interference with Top2beta, which could implicate Top2beta in doxorubicin cardiotoxicity. The specific involvement of proteasome and Top2beta in doxorubicin-induced DNA damage is consistent with a model in which proteasomal processing of doxorubicin-induced Top2beta-DNA covalent complexes exposes the Top2beta-concealed DNA double-strand breaks.

title: The effect of dexrazoxane on myocardial injury in doxorubicin-treated children with acute lymphoblastic leukemia.
abstract: Doxorubicin chemotherapy is very effective in children with acute lymphoblastic leukemia (ALL) but also injures myocardial cells. Dexrazoxane, a free-radical scavenger, may protect the heart from doxorubicin-associated damage.



To determine whether dexrazoxane decreases doxorubicin-associated injury of cardiomyocytes, we randomly assigned 101 children with ALL to receive doxorubicin alone (30 mg per square meter of body-surface area every three weeks for 10 doses) and 105 to receive dexrazoxane (300 mg per square meter) followed immediately by doxorubicin. Serial measurements of serum cardiac troponin T were obtained in 76 of 101 patients in the doxorubicin group and 82 of 105 patients in the group given dexrazoxane and doxorubicin. A total of 2377 serum samples (mean, 15.1 samples per patient) were obtained before, during, and after treatment with doxorubicin. Troponin T levels were evaluated in a blinded fashion to determine whether they were elevated (>0.01 ng per milliliter)--the primary end point--or extremely elevated (>0.025 ng per milliliter).



Elevations of troponin T occurred in 35 percent of the patients (55 of 158). Patients treated with doxorubicin alone were more likely than those who received dexrazoxane and doxorubicin to have elevated troponin T levels (50 percent vs. 21 percent, P<0.001) and extremely elevated troponin T levels (32 percent vs. 10 percent, P<0.001). The median follow-up was 2.7 years. The rate of event-free survival at 2.5 years was 83 percent in both groups (P=0.87 by the log-rank test).



Dexrazoxane prevents or reduces cardiac injury, as reflected by elevations in troponin T, that is associated with the use of doxorubicin for childhood ALL without compromising the antileukemic efficacy of doxorubicin. Longer follow-up will be necessary to determine the influence of dexrazoxane on echocardiographic findings at four years and on event-free survival.

title: Cardiotoxicity after childhood cancer: beginning with the end in mind.
abstract: Worldwide, more than 28 million people live with cancer. This number could triple by 2030. With the increasing number of patients with cancer and improvements in cancer management that continue to reduce cancer death rates, the number of cancer survivors is projected to increase rapidly, in particular, those afflicted during childhood. In children and adolescents, the survival rate has jumped from fewer than 50% in the mid-1970s to 80% today. The growing population of childhood survivors is notable for its vulnerability to adverse health outcomes, many of which may not become clinically apparent until years after the completion of therapy. Despite surviving their initial cancer, childhood cancer survivors continue to face considerable premature mortality as adults. The excess risk of dying from other causes that contributes most to loss of life expectancy is the increased incidence of chronic conditions among survivors of childhood cancer. We need to monitor the health of these survivors and to minimize the use of therapies with late toxicities in newly diagnosed patients. Survivors also experience a higher prevalence of chronic conditions, with as many as two thirds of childhood cancer survivors reporting at least one chronic condition and one fourth reporting a severe, disabling, or life-threatening condition. Survivors of childhood cancer are 5 to 10 times more likely than their healthy siblings to experience heart disease. The incidence of these conditions increases with time, so the full extent of disease- and treatment-related late effects has yet to be realized. Survivors of childhood cancer are a new, large, emerging population at risk for acquired premature symptomatic cardiovascular disease. The report by Tukenova et al 1 provides important information on late excess cardiovascular mortality in childhood cancer survivors and on the factors associated with this mortality. Their report adds new information about late cardiac effects in childhood cancer survivors by specifically using carefully calculated radiation doses to the heart as a factor to assess overall mortality and cardiovascular mortality. Importantly, this study also evaluated the potential classes of medications for their association with cardiovascular mortality. This article not only validates previous studies of overall cardiac mortality, 2-7 it also provides new data on cumulative anthracycline dose, cumulative radiation dose, and the contribution of other agents. Although the dose-dependent risk of congestive heart failure and related deaths associated with anthracyclines among childhood cancer survivors is established, and although radiation exposure to the heart has also been associated with increased risk of cardiovascular disease, this article’s evaluation of the association between the dose of radiation and the dose of anthracyclines on cardiovascular mortality in the same cohort is important. Studies have generally looked only at radiation as a dichotomous variable, although others have looked at treat

title: Prevention of High-Dose Chemotherapy-Induced Cardiotoxicity in High-Risk Patients by Angiotensin-Converting Enzyme Inhibition
abstract: An increase in troponin I soon after high-dose chemotherapy (HDC) is a strong predictor of poor cardiological outcome in cancer patients. This finding has important clinical implications and provides a rationale for the development of prophylactic strategies for preventing cardiotoxicity. Angiotensin-converting enzyme inhibitors slow the progression of left ventricular dysfunction in different clinical settings, but their role in the prevention of cardiotoxicity has never been investigated.  Of the 473 cancer patients evaluated, 114 (72 women; mean age, 45±12 years) who showed a troponin I increase soon after HDC were randomized to receive (angiotensin-converting enzyme inhibitor group; 20 mg/d; n=56) or not to receive (control subjects; n=58) enalapril. Treatment was started 1 month after HDC and continued for 1 year. Cardiological evaluation was performed at baseline and at 1, 3, 6, and 12 months after HDC. The primary end point was an absolute decrease >10 percent units in left ventricular ejection fraction, with a decline below the normal limit value. A significant reduction in left ventricular ejection fraction and an increase in end-diastolic and end-systolic volumes were observed only in untreated patients. According to the Kaplan-Meier analysis, the incidence of the primary end point was significantly higher in control subjects than in the angiotensin-converting enzyme inhibitor group (43% versus 0%; P<0.001).  In high-risk, HDC-treated patients, defined by an increased troponin I value, early treatment with enalapril seems to prevent the development of late cardiotoxicity.

title: Long-term enalapril therapy for left ventricular dysfunction in doxorubicin-treated survivors of childhood cancer.
abstract: A common late effect of doxorubicin therapy for childhood cancer is reduced left-ventricular (LV) wall thickness resulting in elevated LV afterload and depressed LV function. Many children are given angiotensin-converting enzyme inhibitors, which have been studied primarily in adults. We document the long-term effects of angiotensin-converting enzyme inhibitors in doxorubicin-treated survivors of childhood cancer.



In this retrospective study, we reviewed records of 18 children who had regular echocardiographic examinations during enalapril therapy (mean age at cancer diagnosis, 8 years; mean time between completion of doxorubicin therapy and start of enalapril, 7 years; median follow-up since the start of enalapril, 10 years).



Over the first 6 years of enalapril therapy, there was progressive improvement toward normal values in LV dimension, afterload, fractional shortening, and mass, but all these parameters deteriorated between 6 and 10 years. LV wall thickness deteriorated throughout the study period, as did LV contractility and systolic blood pressure. Diastolic blood pressure fell slightly. By 6 years on enalapril, all six patients who had had congestive heart failure at the start of enalapril therapy had either died or undergone cardiac transplantation, compared with three of the 12 asymptomatic patients.



In doxorubicin-treated long-term survivors of childhood cancer, enalapril-induced improvement in LV structure and function is transient. The primary defect, which is LV wall thinning, continues to deteriorate, and thus the short-term improvement was mostly related to lowered diastolic blood pressure.

title: Long-term survival and competing causes of death in patients with early-stage Hodgkin's disease treated at age 50 or younger.
abstract: To analyze the long-term survival and the pattern and timing of excess mortality in patients with early-stage Hodgkin's disease.



Between 1969 and 1997, 1,080 patients age 50 or younger were treated for clinical stage IA to IIB Hodgkin's disease. Overall survival was determined, and prognostic factors were assessed. Relative risk and absolute excess risk (AR) of mortality were calculated for the entire cohort and by prognostic groups (on the basis of B symptoms, mediastinal status, and number of sites, modified from the European Organization for Research and Treatment of Cancer).



The median follow-up was 12 years. The 15- and 20-year Kaplan-Meier survival estimates were 84% and 78%, respectively. Cox proportional hazards models showed that number of involved sites (P =.006), mediastinal status (P =.02), and histology (P =.02) were independent predictors of death from all causes. The AR of mortality in patients with a favorable prognosis increased over time, whereas for those with an unfavorable prognosis, the AR peaked in the first 5 years, predominantly from Hodgkin's disease. The relative risk of mortality from all causes, causes other than Hodgkin's disease, second tumors, and cardiac disease remained significantly elevated more than 20 years after treatment.



Patients treated for early-stage Hodgkin's disease have a sustained excess mortality risk despite good control of the disease. Treatment reduction efforts in patients with early-stage, favorable-prognosis disease should continue, but for patients with an unfavorable prognosis, modified treatment may not be advisable. The excess mortality noted beyond two decades underscores the importance of long-term follow-up care in patients treated for Hodgkin's disease.

title: Predictors of late cardiovascular complications in survivors of hematopoietic cell transplantation.
abstract: Long-term survival after hematopoietic cell transplantation (HCT) is now an expected outcome. The growing population of survivors is at risk of developing treatment-related complications, including cardiovascular disease (CVD). A nested case-controlled design was used to identify clinical and treatment-related risk factors for development of late (1+ years after HCT) CVD. Cases were identified from a cohort of 1+-year survivors who underwent transplantation at City of Hope between 1977 and 2006. Controls (HCT survivors without CVD) were matched on age, year of HCT, type of HCT, and duration of follow-up. Sixty-three patients with late CVD were identified, 44 (69.8%) with a coronary artery event and 19 (30.2%) with a cerebrovascular event. Median age at HCT was 49.0 years. Median age at onset of late CVD was 54.0 years; 66.7% of the affected patients had undergone autologous HCT. Multivariate logistic regression analysis showed that the presence of multiple cardiovascular risk factors (2 or more of the following: obesity, dyslipidemia, hypertension, and diabetes) after HCT was associated with a 5.2-fold increased risk of late CVD (P < .01), and that pre-HCT chest radiation exposure was associated with a 9.5-fold greater risk of coronary artery disease (P = .03). Pre-HCT exposure to chest radiation and the presence of comorbidities were primarily responsible for the risk associated with late CVD after HCT. These data form the basis for developing predictive models for identifying high-risk individuals for targeted surveillance and aggressive management of comorbidities.

title: Clinically significant cardiac disease in patients with Hodgkin lymphoma treated with mediastinal irradiation.
abstract: This study assessed the cumulative incidence of clinically significant cardiac disease in 1279 Hodgkin lymphoma patients treated with mediastinal irradiation and quantified the standard incidence ratios (SIRs) and absolute excess risks of cardiac procedures compared with a normal matched population. Cox regression analysis was used to explore factors associated with cardiac complications. Poisson regression analysis of SIRs was used to estimate the excess risk of cardiac interventions from mediastinal irradiation. After a median follow-up of 14.7 years, 187 patients experienced 636 cardiac events and 89 patients required a cardiac procedure. 5-, 10-, 15-, and 20-year cumulative incidence rates of cardiac events were 2.2%, 4.5%, 9.6%, and 16%. SIRs for cardiac procedures were increased for coronary artery bypass graft (3.19), percutaneous intervention (1.55), implantable cardioverter defibrillator or pacemaker placement (1.9), valve surgery (9.19), and pericardial surgery (12.91). Absolute excess risks were 18.2, 19.3, 9.4, 14.1, and 4.7 per 10 000 person-years, respectively. Older age at diagnosis and male sex were predictors for cardiac events. However, younger age at diagnosis was associated with excess risk specifically from radiation therapy compared with the general population. These results may help guideline development for both the types and timing of cardiac surveillance in survivors of Hodgkin lymphoma.

title: Cardiac function, perfusion, and morbidity in irradiated long-term survivors of Hodgkin's disease.
abstract: The incidence of cardiotoxicity and clinical cardiac events following mantle irradiation (RT) in patients with Hodgkin's disease using modern techniques is controversial. The use of quantitative, prognostically validated noninvasive tests to assess systolic and diastolic cardiac function and regional myocardial blood flow may reveal preclinical abnormalities associated with subsequent clinical events of myocardial infarction, cardiac death, or angina. The goals of this study are to determine, through noninvasive measures, the presence and time course of alterations in cardiac systolic and diastolic function and of relative myocardial blood flow in long-term survivors of Hodgkin's disease, and assess their correlation with subsequent clinical cardiac end points.



Equilibrium radionuclide angiocardiography (ERNA) was used to assess left ventricular (LV) systolic and diastolic function by measuring LV ejection fraction (LVEF) and peak filling rate (PFR), respectively, in patients without known ischemic heart disease who received RT. Electrocardiography was performed to assess electrical cardiac function under conditions of rest and either exercise or dipyridamole vasodilator stress. Quantitative rest/stress myocardial perfusion imaging with thallium-201 and/or Tc-99m sestamibi was used to assess myocardial perfusion. Patients at least 1.0 year after RT were eligible if they were <50 years old at RT, had no known cardiac disease, and remained free of clinical recurrence of Hodgkin's disease. Fifty patients, ages 10.2-46.1 years (mean 26.0 +/- 8.6) at RT, were tested 1.1 to 29.1 years (mean 9.1 +/- 7.5) after RT. Seventeen of these patients were tested two times separated by 1.1 to 8.1 years. The mean central cardiac RT dose was 35.1 +/- 7.8 Gy (range 18.5-47.5) in daily 15-2.0 Gy fractions. Twelve patients were concomitantly irradiated to the left ventricle, usually through partial transmission left lung shields (mean 17.0 +/- 2.2 Gy, range 14.3-21.3).



No patients had signs or symptoms of cardiac disease at the time of evaluation. The mean LVEF at the time of initial testing was 59.6 +/- 6.2% (n = 50; range 42-73%; normal > or =50%), and the mean peak filling rate (PFR) was 3.46 +/- 0.88 end diastolic volumes per second (EDV/s) (range 1.5-5.4 EDV/s; normal > or =2.54 EDV/s). The 12 patients also treated to the left ventricle had a normal mean ejection fraction that was lower (56.6 +/- 5.0%) than that of the other 38 patients (LVEF = 60.6 +/- 6.3%, p = 0.051) when initially evaluated. Average PFR was similar in the two groups. For the 15 patients who had repeat tests, changes in LVEF were generally modest in individual patients, and there was no change in the group mean. For all patients, no significant association was found between cardiac function indices and age at RT, dose, or interval from RT to testing. Myocardial perfusion scintigraphy demonstrated mild ischemia in one or more segments in two patients, and borderline normal perfusion in three patients. Rest and stress ECG testing demonstrated mild repolarization abnormalities in three, and one patient was abnormal at rest and had nondiagnostic changes with stress.



Patients irradiated to the heart incidental to the treatment of Hodgkin's disease using modern techniques have generally normal measures of left ventricular function and myocardial perfusion. Modest differences in the normal left ventricular ejection fraction observed may be attributable to the cardiac volume irradiated. Some patients may manifest improved cardiac function as time from RT elapses, while a significant deterioration of ejection fraction was not observed and reduction in diastolic peak filling rate is uncommon. The previously reported increased risk of cardiac death may relate to use of older techniques of RT employing higher doses and lack of cardiac shielding, and uncontrolled patient selection with additional behaviors and cardiac risk factors.

title: Valvular dysfunction and carotid, subclavian, and coronary artery disease in survivors of hodgkin lymphoma treated with radiation therapy.
abstract: The majority of patients with Hodgkin lymphoma are young and highly curable. This necessitates concern for prevention, diagnosis, and optimal management of potential treatment-related complications.



To identify and quantify the incidence of and factors contributing to long-term cardiac and vascular complications after radiation therapy for Hodgkin lymphoma.



Retrospective study comparing patients treated from 1962 to 1998 at a university-based referral center with a matched general population.



Four hundred fifteen consecutive patients who fulfilled the inclusion criteria of a minimum 2-year follow-up (median, 11.2 years) and whose radiation fields included the heart or carotid or subclavian arteries.



Multivariable analyses of potential risk factors and observed-to-expected ratios for cardiac valve surgery, coronary artery bypass graft surgery, percutaneous coronary intervention, or both based on Surveillance, Epidemiology, and End Results (SEER) and National Hospital Discharge Survey (NHDS) data.



Forty-two patients (10.4%) developed coronary artery disease at a median of 9 years after treatment, 30 patients (7.4%) developed carotid and/or subclavian artery disease at a median of 17 years after treatment, and 25 patients (6.2%) developed clinically significant valvular dysfunction at a median of 22 years. The most common valve lesion was aortic stenosis, which occurred in 14 valves. The observed-to-expected ratio for valve surgery was 8.42 (95% confidence interval [CI], 3.20-13.65) and the observed-to-expected ratio for coronary artery bypass graft surgery or percutaneous coronary intervention was 1.63 (95% CI, 0.98-2.28). At least 1 cardiac risk factor was present in all patients who developed coronary artery disease. The only treatment-related factor associated with the development of coronary artery disease was utilization of a radiation technique that resulted in a higher total dose to a portion of the heart (relative risk, 7.8; 95% CI, 1.1-53.2; P =.04). No specific treatment-related factor was associated with carotid or subclavian artery disease or valvular dysfunction. Freedom from any cardiovascular morbidity was 88% at 15 years and 84% at 20 years.



Among patients treated with radiation therapy for Hodgkin lymphoma, there are statistically higher than expected rates of valve surgery and coronary revascularization procedures over the next 10 to 20 years. Coronary vascular disease is associated with higher radiation doses and traditional coronary heart disease risk factors. Noncoronary vascular disease and clinically important valvular dysfunction are less well understood complications at 15 to 20 years after radiation, requiring surveillance and further study.

title: Cardiac risk after mediastinal irradiation for Hodgkin's disease.
abstract: To evaluate the risk of cardiac lesions after conventionally fractionated irradiation (Rt) of the mediastine with or without chemotherapy (Ct) in patients with Hodgkin's disease (HD) and to relate them to known cardiovascular risk factors.



Between 1964 and 1992, 352 (total group) patients with HD were treated with curative intention using Rt with or without Ct including the mediastine and had a follow-up of at least 1 year. More than 96% of the patients had a complete follow-up. One hundred forty-four patients (64% of the living patients, heart study group) have regular follow-up in our department and had a special heart examination including rest and exercise ECG, echocardiography and myocardial perfusion scintigraphy (112 patients). Doses per fraction in the anterior heart region were between 1.3 and 2.1 Gy. Total doses were between 30.0 and 42.0 Gy in 93% of cases. The mean length of follow-up was 11.2 years (range 1.0-31.5 years). Other cardiovascular risk factors evaluated were body mass index, blood pressure, smoking history, diabetes mellitus, hypercholesterolemia and history of coronary artery disease before Rt.



In the total group, the risk of fatal cardiac ischemic events and/or of sudden unexpected death was significantly higher than expected with a relative risk of 4.2 for myocardial infarction and 6.7 for myocardial infarction or sudden death. In female patients and in patients without other cardiovascular risk factors, the risk of fatal or non-fatal ischemic cardiac events was not significantly different from the expected value. In the subgroup with no cardiovascular risk factors and treatment without Ct, there was no ischemic or other major cardiac event. Echocardiography showed valvular thickenings in a large amount of the patients (the cumulative risk after 30-year follow-up was above 60%) but mostly without hemodynamic disturbance. In patients without hypertension and without coronary artery disease, findings of perfusion scintigraphy and echocardiographic evaluation of systolic and diastolic function were normal. Treatment with Ct was not a significant risk factor for cardiac events but the number of patients whose treatment included adriamycin and with a follow-up exceeding 10 years is to low for a definitive evaluation.



In patients without the usual cardiovascular risk factors (smoking, hypertension, obesity, hypercholesterolemia, diabetes mellitus) the risk of serious cardiac lesions after conventionally fractionated irradiation of the mediastinum with an intermediate total dose between 30 and 40 Gy is low. Also the cardiac risk of the combination of this irradiation with Ct including adriamycin with a total dose between 200 and 300 mg/m2 seems low but further long-term observation is necessary.

title: Ischemic heart disease after mantlefield irradiation for Hodgkin's disease in long-term follow-up.
abstract: In patients with Hodgkin's disease treated by radiotherapy with a moderate total dose and a low (mean) fraction dose to the heart, the risk of ischemic heart disease was investigated during long-term follow-up.



The medical records of 258 patients treated in the period 1965-1980 with radiotherapy alone as the primary treatment were reviewed. The median follow-up was 14.2 years (range 0.7-26.2). The mean total dose and fraction dose to the heart were 37.2 Gy (SD 2.9) and 1.64 Gy (SD 0.09), respectively. The impact on the development of ischemic heart disease of treatment-related parameters, such as the applied (fraction) dose, irradiation technique (one or two fields per day), and chemotherapy in case of a relapse, was investigated. The incidence of ischemic heart disease in this patient population was compared with the expected incidence based on gender, age and calendar period-specific data for the Dutch population.



Thirty-one patients (12%) experienced ischemic heart disease (actuarial risk at 20-25 years: 21.2% (95% C.I. 15-30). Twenty-five of them were hospitalized. When compared with the expected incidence, the relative risk (RR) of hospital admission for ischemic heart disease was 2.7 (95% C.I. 1.7-4.0). There were 12 deaths (4.7%) due to ischemic myocardial or sudden death (actuarial risk at 25 years: 10.2% (95% C.I. 5.3-19), compared to 2.3 cases that were expected to have died from these causes, yielding a standardized mortality ratio (SMR) of 5.3 (95% C.I. 2.7-9.3). Gender (male), pretreatment cardiac medical history and increasing age appeared to be the only significant factors for the development of ischemic heart disease.



Despite the moderate total dose and the low (mean) fraction dose to the heart, the observed incidence of ischemic heart disease is high, especially after long follow-up periods. Treatment related cardiac disease in patients treated for Hodgkin's disease has only been reported for doses above 30 Gy. Although the optimum curative dose is still under debate, some studies recommend a dose as low as 32.5 Gy. The observed high rate of severe heart complications in this study advocates a dose reduction to this level, particularly in the regions where the coronary arteries are located.

title: Late-occurring stroke among long-term survivors of childhood leukemia and brain tumors: a report from the Childhood Cancer Survivor Study.
abstract: This report examines the incidence of and risk factors for strokes that occur in > or = 5-year survivors of childhood leukemia and brain tumors.



The rate of first occurrence of self-reported late-occurring strokes was determined for leukemia survivors (n = 4,828), brain tumor survivors (n = 1,871), and a comparison group of a random sample of cancer survivor siblings (n = 3,846). Relative risks (RRs) and 95% confidence intervals (CIs) of stroke by treatment exposures were examined by multivariate analyses.



Thirty-seven leukemia survivors and 63 brain tumor survivors reported a late-occurring stroke. The rate of late-occurring stroke for leukemia survivors was 57.9 per 100,000 person-years (95% CI, 41.2 to 78.7). The RR of stroke for leukemia survivors compared with the sibling comparison group was 6.4 (95% CI, 3.0 to 13.8; P < .0001). The rate of late-occurring stroke for brain tumor survivors was 267.6 per 100,000 person-years (95% CI, 206.8 to 339.2). The RR of stroke for brain tumor survivors compared with the sibling comparison group was 29.0 (95% CI, 13.8 to 60.6; P < .0001). Mean cranial radiation therapy (CRT) dose of > or = 30 Gy was associated with an increased risk in both leukemia and brain tumor survivors in a dose-dependent fashion, with the highest risk after doses of > or = 50 Gy CRT.



Survivors of childhood leukemia and brain tumors, particularly those with brain tumors treated with CRT at doses of greater than 30 Gy, are at an increased risk of stroke.

title: Stroke as a late treatment effect of Hodgkin's Disease: a report from the Childhood Cancer Survivor Study.
abstract: The objectives of this report are to examine the incidence of and risk factors for stroke among childhood Hodgkin's disease (HD) survivors.



The Childhood Cancer Survivor Study is a multi-institutional cohort study of more than 5-year cancer survivors diagnosed between 1970 and 1986 and a sibling comparison group. Incidence rates of stroke among HD survivors (n = 1,926) and siblings (n = 3,846) were calculated and compared. Cox proportional hazards models were used to estimate the hazard ratios, reported as relative risks (RR), of developing stroke between HD survivors and siblings.



Nine siblings reported a stroke, for an incidence of 8.00 per 100,000 person-years (95% CI, 3.85 to 14.43 per 100,000 person-years). Twenty-four HD survivors reported a stroke. The incidence of late-occurring stroke among HD survivors was 83.6 per 100,000 person-years (95% CI, 54.5 to 121.7 per 100,000 person-years). The RR of stroke among HD survivors was 4.32 (95% CI, 2.01 to 9.29; P = .0002). All 24 survivors received mantle radiation exposure (median dose, 40 Gy). The incidence of late-occurring stroke among HD survivors treated with mantle radiation was 109.8 per 100,000 person-years (95% CI, 70.8 to 161.1 per 100,000 person-years). The RR of late-occurring stroke among HD survivors treated with mantle radiation was 5.62 (95% CI, 2.59 to 12.25; P < .0001).



Survivors of childhood HD are at increased risk of stroke. Mantle radiation exposure is strongly associated with subsequent stroke. Potential mechanisms may include carotid artery disease or cardiac valvular disease.

title: Asymptomatic cardiac disease following mediastinal irradiation.
abstract: This study was designed to evaluate the potential benefit of screening previously irradiated patients with echocardiography.



Mediastinal irradiation is known to cause cardiac disease. However, the prevalence of asymptomatic cardiac disease and the potential for intervention before symptom development are unknown.



We recruited 294 asymptomatic patients (mean age 42 +/- 9 years, 49% men, mean mantle irradiation dose 43 +/- 0.3 Gy) treated with at least 35 Gy to the mediastinum for Hodgkin's disease. After providing written consent, each patient underwent electrocardiography and transthoracic echocardiography. Valvular disease was common and increased with time following irradiation. Patients who had received irradiation more than 20 years before evaluation had significantly more mild or greater aortic regurgitation (60% vs. 4%, p < 0.0001), moderate or greater tricuspid regurgitation (4% vs. 0%, p = 0.06), and aortic stenosis (16% vs. 0%, p = 0.0008) than those who had received irradiation within 10 years. The number needed to screen to detect one candidate for endocarditis prophylaxis was 13 (95% confidence interval [CI] 7 to 44) for patients treated within 10 years and 1.6 (95% CI 1.3 to 1.9) for those treated at least 20 years ago. Compared with the Framingham Heart Study population, mildly reduced left ventricular fractional shortening (<30%) was more common (36% vs. 3%), and age- and gender-adjusted left ventricular mass was lower (90 +/- 27 g/m vs. 117 g/m) in irradiated patients.



There is a high prevalence of asymptomatic heart disease in general, and aortic valvular disease in particular, following mediastinal irradiation. Screening echocardiography should be considered for patients with a history of mediastinal irradiation.

title: Cardiovascular status in long-term survivors of Hodgkin's disease treated with chest radiotherapy.
abstract: Cardiovascular status was assessed in 48 Hodgkin's disease (HD) survivors at a median of 14.3 years (range, 5.9 to 27.5 years) after diagnosis because they may be at increased risk for cardiovascular abnormalities.



Patients completed the Short-Form 36 quality-of-life instrument and were screened by echocardiography, exercise stress testing, and resting and 24-hour ECG.



All patients received mediastinal irradiation (median, 40.0 Gy; range, 27.0 to 51.7 Gy) at a median age of 16.5 years (range, 6.4 to 25.0 years). Four patients received an anthracycline. Although every patient described their health as good or better, and none had symptomatic heart disease at screening, all but one had cardiac abnormalities on screening. Restrictive cardiomyopathy was suggested by reduced average left ventricular (LV) dimension (P < .001) and mass (P < .001), without increased LV wall thickness. Significant valvular defects were present in 42%; 75% had conduction defects. One survivor developed complete heart block shortly after the study visit. Autonomic dysfunction was suggested by a monotonous heart rate in 57%, persistent tachycardia in 31%, and blunted hemodynamic responses to exercise in 27%. Peak oxygen uptake (VO2max) during exercise, a predictor of mortality in heart failure, was significantly reduced (< 20 mL/kg/m2) in 30% of survivors. VO2max was correlated with increasing fatigue, increasing shortness of breath (both, r = -0.35; P =. 02), and decreasing physical component score on the SF-36 (r = 0.554; P = .00017).



A variety of unsuspected, clinically significant cardiovascular abnormalities are common in long-term survivors of HD who are treated at a young age with mediastinal irradiation. We recommend serial, comprehensive cardiac screening of HD survivors who fit this profile.

title: Clinically significant cardiac disease in patients with Hodgkin lymphoma treated with mediastinal irradiation.
abstract: This study assessed the cumulative incidence of clinically significant cardiac disease in 1279 Hodgkin lymphoma patients treated with mediastinal irradiation and quantified the standard incidence ratios (SIRs) and absolute excess risks of cardiac procedures compared with a normal matched population. Cox regression analysis was used to explore factors associated with cardiac complications. Poisson regression analysis of SIRs was used to estimate the excess risk of cardiac interventions from mediastinal irradiation. After a median follow-up of 14.7 years, 187 patients experienced 636 cardiac events and 89 patients required a cardiac procedure. 5-, 10-, 15-, and 20-year cumulative incidence rates of cardiac events were 2.2%, 4.5%, 9.6%, and 16%. SIRs for cardiac procedures were increased for coronary artery bypass graft (3.19), percutaneous intervention (1.55), implantable cardioverter defibrillator or pacemaker placement (1.9), valve surgery (9.19), and pericardial surgery (12.91). Absolute excess risks were 18.2, 19.3, 9.4, 14.1, and 4.7 per 10 000 person-years, respectively. Older age at diagnosis and male sex were predictors for cardiac events. However, younger age at diagnosis was associated with excess risk specifically from radiation therapy compared with the general population. These results may help guideline development for both the types and timing of cardiac surveillance in survivors of Hodgkin lymphoma.

title: Components of the metabolic syndrome in 500 adult long-term survivors of childhood cancer.
abstract: Adult survivors of childhood cancer have been reported to have an increased risk of late sequels. A cluster of abnormalities that contribute to the metabolic syndrome may be expressed at a higher level and therefore result in an increased risk for diabetes mellitus and cardiovascular diseases.



We investigated a single-centre cohort of 500 adult survivors (228 females) of childhood cancer, median age 28 years (range 18-59 years) and median follow-up time 19 years (range 6-49 years). We measured total cholesterol, high-density lipoprotein-cholesterol, systolic and diastolic blood pressure, body mass index and the prevalence of diabetes mellitus. Data from the epidemiological Monitoring van Risicofactoren en Gezondheid in Nederland (MORGEN) study were used to calculate standard deviation scores as normative values.



The criteria of the metabolic syndrome were met in 13% of the total cohort. Acute lymphoblastic leukaemia (ALL) survivors treated with cranial irradiation had an increased risk of developing the metabolic syndrome compared with ALL survivors not treated with cranial irradiation (23% versus 7%, P = 0.011), probably determined by higher prevalence of overweight and hypertension.



Adult survivors of childhood cancer, especially those treated with cranial irradiation, are at increased risk of developing the metabolic syndrome.

title: Radiation therapy impairs endothelium-dependent vasodilation in humans.
abstract: The objective of this study was to test the hypothesis that external-beam radiation induces a chronic impairment of endothelium-dependent vasodilation.



Radiation therapy is used commonly in the treatment of cancer and is associated with an increased incidence of adverse vascular events related to the field of radiation, including stroke and myocardial infarction. As endothelial injury is central to the pathogenesis of vascular diseases, we hypothesized that radiotherapy induces arterial endothelial dysfunction.



Sixteen women with unilateral breast cancer who underwent standard external-beam radiation therapy to the breast and axilla >3 years before enrollment and ten healthy women were studied. Vascular ultrasonography was used to image both the artery exposed to radiation and the contralateral artery. Flow-mediated, endothelium-dependent vasodilation and endothelium-independent vasodilation to nitroglycerin of both axillary arteries were measured.



Endothelium-dependent vasodilation was significantly impaired in the irradiated axillary arteries compared with the contralateral, nonirradiated arteries (-0.4 +/- 0.4% vs. 3.2 +/- 0.8% p < 0.001) and also compared with control subjects' arteries (-0.4 +/- 0.4% vs. 2.5 +/- 0.6%, p < 0.001). In contrast, endothelium-independent vasodilation was greater in the arteries that received radiation compared with the contralateral arteries (3.8 +/- 0.5% vs. 2.0 +/- 0.4%, p < 0.05) and also compared with control arteries (3.8 +/- 0.5% vs. 2.5 +/- 0.4%, p < 0.05).



External beam radiation therapy impairs endothelium-dependent vasodilation of conduit arteries, implicating a decrease in the bioavailability of nitric oxide. These abnormalities may contribute to the development of arterial occlusive disease and associated clinical events.

title: Preferential Impairment of Nitric Oxide–Mediated Endothelium-Dependent Relaxation in Human Cervical Arteries After Irradiation
abstract: Vascular abnormalities are a major cause of postoperative complications in irradiated tissues. Endothelial cell dysfunction characterized by diminished endothelium-dependent relaxation may be involved. We examined the endothelium-dependent relaxation and morphology of the endothelium in irradiated human cervical arteries. Irradiated arteries were taken from the neck region of patients who had radiation therapy. Arteries from patients who did not receive radiation therapy were used as controls. Endothelium-dependent relaxation to acetylcholine and A23187 was impaired in irradiated arteries. Norepinephrine-induced contraction and sodium nitroprusside–induced relaxation were unchanged. In control arteries, Nω-nitro-l-arginine and indomethacin each caused a partial inhibition of endothelium-dependent relaxation. In irradiated arteries, the impaired endothelium-dependent relaxation was unaffected by these agents, but it was abolished by high K+. Acetylcholine produced similar deg...

title: X‐irradiation attenuates relaxant responses in the rabbit ear artery
abstract: 1 The relaxant actions of acetylcholine, substance P and calcitonin gene‐related peptide, and the levels of neuropeptide Y and calcitonin gene‐related peptide were assessed in the rabbit central ear artery 1, 4 and 6 weeks after a single dose of 45 Gy X‐irradiation, a dose similar to that used clinically in intraoperative radiotherapy. 2 Relaxant responses induced by acetylcholine and substance P (both endothelium‐dependent) and calcitonin gene‐related peptide (endothelium‐independent) were reduced, and endogenous neuropeptide Y and calcitonin gene‐related peptide levels were unaffected after X‐irradiation. 3 The mechanism(s) by which a single dose of 45 Gy X‐irradiation may selectively damage relaxant, but not direct, contractile responses of the smooth muscle (as we have shown previously) of the rabbit central ear artery are discussed.

title: Functional and morphological damage of endothelium in rabbit ear artery following irradiation with cobalt60
abstract: The relaxant actions of acetylcholine and A23187 were examined in the rabbit central ear artery at different intervals following exposure to different doses of radiation with a cobalt60 unit. The artery was irradiated with a dose of 10 Gy, 20 Gy and 45 Gy. Radiation caused dose‐ and time‐dependent impairment of the endothelium‐dependent relaxations. The impaired endothelium‐dependent relaxations occurred as early as 1 week postirradiation and persisted throughout the experimental period (10 weeks). The endothelium‐independent response to sodium nitroprusside was well preserved up to 6 weeks after irradiation. The contractile response to noradrenaline was unaltered by irradiation throughout the experimental period, but in contrast to control vessels, an increase in the sensitivity to noradrenaline in the presence of the nitric oxide synthase (NOS) inhibitor NG‐nitro‐L‐arginine was not observed in the irradiated vessels. The impaired endothelium‐dependent relaxations in the irradiated vessels were not improved by pretreatment with the NOS substrate L‐arginine, the cyclo‐oxygenase inhibitor indomethacin or the free radical scavengers superoxide dismutase and catalase. Scanning electron microscopy indicated morphologically intact endothelial cells within the first 4 weeks after irradiation. Western blot analysis showed a significant decrease in the expression of endothelial NOS (eNOS) in the irradiated vessels. These data indicate that endothelial cell function is specifically impaired in the irradiated vessels before morphological endothelial cell damage can be detected. This impairment may be related to diminished eNOS expression.

title: Serial changes in arterial endothelium following ischemia and perfusion.
abstract: The acute and chronic changes produced in canine femoral arteries by ischemia and by perfusion with D10W were examined by light and by scanning electron microscopy. Mild changes of injury characterized by medial and adventitial inflammation and an increase in intimal lining cells occur following 30 minutes of perfusion with return to a normal microscopic appearance within one week. Perfusion for 6 hours produces significant injury to the entire arterial wall, as evidenced by depletion of cells and elastin from the media, replacement with collagen, and eventual fibrosis. The intimal surface is replaced by a layer of spindle cells which appear to originate in the media. The internal elastic membrane is flattened and thrombosis is prominent, particularly in areas where medial fibrosis is severe. Many of the vascular changes produced by perfusion injury may persist for 3 months and some may even by permanent. A period of 6 hours of ischemia also produces similar but less prominent alterations in vascular morphology which return to near-normal appearance within 8 weeks.

title: Chronic health conditions in adult survivors of childhood cancer.
abstract: Only a few small studies have assessed the long-term morbidity that follows the treatment of childhood cancer. We determined the incidence and severity of chronic health conditions in adult survivors.



The Childhood Cancer Survivor Study is a retrospective cohort study that tracks the health status of adults who received a diagnosis of childhood cancer between 1970 and 1986 and compares the results with those of siblings. We calculated the frequencies of chronic conditions in 10,397 survivors and 3034 siblings. A severity score (grades 1 through 4, ranging from mild to life-threatening or disabling) was assigned to each condition. Cox proportional-hazards models were used to estimate hazard ratios, reported as relative risks and 95% confidence intervals (CIs), for a chronic condition.



Survivors and siblings had mean ages of 26.6 years (range, 18.0 to 48.0) and 29.2 years (range, 18.0 to 56.0), respectively, at the time of the study. Among 10,397 survivors, 62.3% had at least one chronic condition; 27.5% had a severe or life-threatening condition (grade 3 or 4). The adjusted relative risk of a chronic condition in a survivor, as compared with siblings, was 3.3 (95% CI, 3.0 to 3.5); for a severe or life-threatening condition, the risk was 8.2 (95% CI, 6.9 to 9.7). Among survivors, the cumulative incidence of a chronic health condition reached 73.4% (95% CI, 69.0 to 77.9) 30 years after the cancer diagnosis, with a cumulative incidence of 42.4% (95% CI, 33.7 to 51.2) for severe, disabling, or life-threatening conditions or death due to a chronic condition.



Survivors of childhood cancer have a high rate of illness owing to chronic health conditions.

title: Cardiac morbidity following modern treatment for Hodgkin lymphoma: Supra-additive cardiotoxicity of doxorubicin and radiation therapy
abstract: Age- and sex-specific estimates of the rate of cardiac morbidity among Hodgkin lymphoma (HL) patients treated with doxorubicin-based chemotherapy and radiation therapy (RT) are scarce. We evaluated the risk of hospital admission for cardiac disease in 615 HL patients, adjusting for age, sex, treatment, cardiac risk factors and competing causes of death. Compared with the general population, the risk of cardiac morbidity was highest among patients treated with both doxorubicin and mediastinal RT (HR = 2.77, p < 0.0001). Mediastinal RT without chemotherapy also significantly increased the risk (HR = 1.82, p = 0.038). For females and males treated with doxorubicin plus mediastinal RT at age 40, the estimated 15-year incidence rate of cardiac hospitalisation were 7.3% and 16.5%, respectively, rates 5–15% higher than expected. These results suggest that the risk of clinically important cardiac toxicity following HL treatment that includes both doxorubicin and mediastinal RT may be greater than that reported in prior studies of patients treated with RT alone.

title: Utility of tissue Doppler and strain rate imaging in the early detection of trastuzumab and anthracycline mediated cardiomyopathy.
abstract: Trastuzumab provides considerable therapeutic benefits in the adjuvant setting of breast cancer. However, its use is limited by an elevated incidence of cardiotoxicity when used in combination with doxorubicin. Although Myocet (liposomal encapsulated doxorubicin) is less cardiotoxic, its cardiac safety profile with trastuzumab is not well known. The aim of this study was to determine if sensitive indices of left ventricular (LV) dysfunction, specifically Doppler tissue imaging (DTI), would be useful for addressing the early detection of trastuzumab and anthracycline-mediated cardiotoxicity.



In an acute murine model, wild-type C57Bl/6 mice (n = 60) received one of the following drug regimens: (1) control, (2) doxorubicin, (3) Myocet, (4) trastuzumab, (5) doxorubicin plus trastuzumab, or (6) Myocet plus trastuzumab. DTI-derived peak endocardial systolic velocity, strain rate, and LV ejection fraction were measured serially for 5 days. On day 5, the hearts, lungs, and livers were removed for histopathologic and Western blot analyses.



Mice treated with Myocet plus trastuzumab demonstrated minimal cardiotoxicity compared with those treated with doxorubicin plus trastuzumab. Progressive LV dilatation and LV systolic dysfunction were observed by day 4 of treatment with doxorubicin plus trastuzumab, compared with preserved LV ejection fraction in the remaining groups. DTI parameters decreased within 24 hours in the doxorubicin alone and doxorubicin plus trastuzumab groups and predicted early mortality. The survival rate was only 20% at day 5 of the experiment in the doxorubicin plus trastuzumab group, whereas 100% of mice receiving trastuzumab, Myocet, or Myocet plus trastuzumab survived the 5 days.



DTI can detect early LV dysfunction prior to alterations in conventional echocardiographic indices and predicts early mortality in mice receiving doxorubicin plus trastuzumab.

title: Tissue Doppler imaging predicts left ventricular dysfunction and mortality in a murine model of cardiac injury.
abstract: Currently available non-invasive imaging methods frequently fail to detect alterations in left ventricular (LV) function despite histological evidence of injury. Tissue Doppler imaging (TDI) can detect subtle LV dysfunction. The aim of this study was to investigate whether TDI indices can predict LV systolic dysfunction and mortality following exposure to doxorubicin (DOX) in mice.



TDI-derived peak endocardial systolic velocity (V(ENDO)) and strain rate (SR), as well as M-mode and two-dimensional indices of LV systolic function, were measured serially in mice after receiving DOX as a single dose (20 mg/kg). Haemodynamic measurements were obtained invasively before and at 1, 2, 4, and 5 days after the single DOX dose. Cardiac apoptosis was measured before and at 1 day after DOX. V(ENDO) and SR decreased after 1 and 2 days, respectively, whereas changes in fractional shortening (FS) and LV ejection fraction (LVEF) were not detected before 5 days. The reduction in both V(ENDO) and SR correlated with the decrease in dP/dt(MAX), and the change in V(ENDO) correlated with the early increase in cardiac cell apoptosis. In a subsequent experiment, DOX was administered at 4 mg/kg/week for 5 weeks, and LV function was followed serially for 16 weeks. In this chronic experiment, TDI indices decreased before FS and LVEF, correlated with late LV dysfunction, and predicted DOX-induced mortality.



In a murine model of DOX-induced cardiac injury, TDI detects LV dysfunction prior to alterations in conventional echocardiographic indices and predicts mortality. This study suggests that TDI may be a reliable tool to detect early subtle changes in DOX-induced cardiac dysfunction.

title: Use of myocardial deformation imaging to detect preclinical myocardial dysfunction before conventional measures in patients undergoing breast cancer treatment with trastuzumab.
abstract: Trastuzumab prolongs survival in patients with human epidermal growth factor receptor type 2-positive breast cancer. Sequential left ventricular (LV) ejection fraction (EF) assessment has been mandated to detect myocardial dysfunction because of the risk of heart failure with this treatment. Myocardial deformation imaging is a sensitive means of detecting LV dysfunction, but this technique has not been evaluated in patients treated with trastuzumab. The aim of this study was to investigate whether changes in tissue deformation, assessed by myocardial strain and strain rate (SR), are able to identify LV dysfunction earlier than conventional echocardiographic measures in patients treated with trastuzumab.



Sequential echocardiograms (n = 152) were performed in 35 female patients (51 +/- 8 years) undergoing trastuzumab therapy for human epidermal growth factor receptor type 2-positive breast cancer. Left ventricular EF was measured by 2- and 3-dimensional (2D and 3D) echocardiography, and myocardial deformation was assessed using tissue Doppler imaging and 2D-based (speckle-tracking) strain and SR. Change over time was compared every 3 months between baseline and 12 months.



There was no overall change in 3D-EF, 2D-EF, myocardial E-velocity, or strain. However, there were significant reductions seen in tissue Doppler imaging SR (P < .05), 2D-SR (P < .001), and 2D radial SR (P < .001). A drop > or =1 SD in 2D longitudinal SR was seen in 18 (51%) patients; 13 (37%) had a similar drop in radial SR. Of the 18 patients with reduced longitudinal SR, 3 had a concurrent reduction in EF > or =10%, and another 2 showed a reduction over 20 months follow-up.



Myocardial deformation identifies preclinical myocardial dysfunction earlier than conventional measures in women undergoing treatment with trastuzumab for breast cancer.

title: Strain rate imaging detects early cardiac effects of pegylated liposomal Doxorubicin as adjuvant therapy in elderly patients with breast cancer.
abstract: Cardiac toxicity remains an important side effect of anthracyclines. New drug formulations (eg, pegylated liposomal doxorubicin [PL-DOX]) seem to be a successful strategy for reducing it. Changes in cardiac function induced by early chemotherapy, however, are subtle and difficult to quantitate by conventional imaging methods. Doppler myocardial imaging-based velocity, strain, and strain rate measurements have been shown to sensitively quantify abnormalities in cardiac function in other settings.



We evaluated the feasibility and sensitivity of strain rate imaging compared with conventional echocardiography in detecting cardiac effects of PL-DOX therapy in elderly patients with cancer. In a pilot study, we examined 16 elderly women (age 69.8 +/- 3.1 years) with breast cancer receiving 6 cycles of PL-DOX. Conventional and Doppler myocardial imaging echocardiography were obtained at baseline and after 3 and 6 cycles of treatment. Segmental peak systolic longitudinal and radial velocity, strain, and strain rate were measured.



Left ventricular dimensions, ejection fraction, and systolic myocardial velocity did not change throughout the follow-up. In contrast, a significant reduction in longitudinal and radial strain and strain rate was found after 6 cycles (longitudinal strain -18.8% +/- 2.8% vs -22.7% +/- 2.8%, P < .001 vs baseline and P = .001 vs after 3 cycles; radial strain 32.3% +/- 8.1% vs 50.1% +/- 11.6%, P < .001 vs baseline). Changes in radial function appeared earlier and were more pronounced than in longitudinal direction.



In contrast with conventional echocardiography and myocardial velocity measurements, myocardial deformation parameters allowed detecting subtle changes in longitudinal and radial left ventricular function after 6 cycles of PL-DOX. We suggest that Doppler-based myocardial deformation imaging should be used for cardiac function monitoring during chemotherapy.

title: Reduction of cardiac volume in left-breast treatment fields by respiratory maneuvers: a CT study.
abstract: A previous study of healthy female volunteers suggested that deep inspiratory breath holding can reduce the cardiac volume in the treatment portals for left-breast cancer treatment. The reduction of irradiated cardiac volume may be important considering the reported late cardiac morbidity and mortality and the frequent coexistent use of potentially cardiotoxic chemotherapy in breast cancer patients. In the present study, we evaluated the heart volume in the fields and, thus, the true benefit of this respiratory maneuver in breast cancer patients undergoing CT simulation.



Fifteen patients (median age, 53) were studied. For each patient, CT scans were performed both when the patient breathed normally (quiet respiration) and when the patient held her breath after a deep inspiration. Tangential fields were planned using the same medial, lateral, superior, and inferior borders on skin for the normal breathing and the breath-holding configurations. The cardiac and left-lung volumes within the tangential fields were calculated for both breathing configurations. Multiple scan series were performed for the breath-holding configuration to provide a more accurate delineation of the cardiac tissue and to study the reproducibility of the patient's position between different cycles of deep inspiration.



None of the patients had difficulty holding her breath for 20 s. The cardiac volume in the field was reduced (-86 +/- 24%; p < 0.001) when patients held their breath after a deep inspiration compared to when breathing normally. For 7 patients (47%), deep inspiration moved the heart completely out of the radiation fields. The expansion of the lung tissue due to deep inspiration also increased the absolute lung volume in the tangential fields (183 cm(3) vs 97 cm(3), p < 0.001). However, the fractional volume of the left lung in the field was essentially unchanged. For all but 1 patient, the maximum difference between the external body contours from different breath holding cycles was 5 mm and occurred at the lateral aspect of the breast. At the medial aspect, as indicated by the position of the midline marker, the variations were well within the currently accepted tolerance for patient positioning during tangential treatment.



Deep-inspiration breath holding substantially reduces cardiac volume in the tangential fields for left-sided breast cancer treatment. The variation between patient positions at different cycles of breath holding was found to be reasonably small. Therefore, it appears feasible to reduce cardiac radiation by treating patients with intratreatment minifractions lasting 10-15 s while patients hold their breath.

title: Impact of respiratory maneuvers on cardiac volume within left-breast radiation portals.
abstract: Late cardiac morbidity and mortality have been reported among left-breast cancer survivors treated with radiation therapy. Radiation-induced cardiotoxicity is affected by the volume of myocardium included in the radiation portals. We hypothesize that simple respiratory maneuvers may alter the position of the heart relative to the portals without altering the radiation dose delivered to the breast.



Fourteen healthy female adult volunteers underwent cardiac MRI to determine the cardiac volume included in the typical left-breast radiation field during respiratory maneuvers. Cardiac volume within the radiation portals was assessed from a transverse stack of 14 1-cm-thick contiguous slices covering the entire heart, obtained during breath holding at end-tidal volume (baseline), deep inspiration, and forced expiration. Thirteen subjects (92%) had inclusion of a portion of the heart within the radiation portals at end-tidal volume (median, 20.9 cm3; range, 1.3 to 88.4 cm3). In these subjects, inspiration decreased the cardiac volume included within the radiation portals (median change: -10.7 cm3 [-40.2%], P<.001 versus end-tidal volume), whereas expiration increased the cardiac volume included (median change: 4.0 cm3 [21.5%]; P<.001 versus end-tidal volume).



Inclusion of a portion of the heart in the left-breast radiation field is common. The use of simple inspiratory maneuvers significantly decreases cardiac volume within the radiation portals. Such an approach during delivery of radiation therapy may allow for preservation of radiation dosage to the breast while reducing cardiac involvement and subsequent mortality.

title: Respiratory maneuvers decrease irradiated cardiac volume in patients with left-sided breast cancer.
abstract: Late cardiac morbidity and mortality among left breast cancer survivors treated with radiation therapy is related to cardiac volume included in the radiation portals. To determine if respiratory maneuvers can help decrease cardiac volume included in the radiation portals for left-sided breast cancer, 17 women with breast cancer, who had undergone left breast radiation therapy, underwent cardiac magnetic resonance imaging (MRI). Cardiac volume within the radiation portals was assessed from a transverse stack of eight, 10-mm thick, contiguous slices, covering the entire heart and obtained during breathholding at (1) endtidal volume (ETid) and (2) deep inspiration. Fourteen subjects (93% of those who completed the study) had inclusion of at least a portion of their heart within the radiation portals at ETid (median: 25.9 cm3, range 4.2-119.1 cm3). In all subjects, inspiratory breathholding decreased irradiated cardiac volume [median change: -18.1 cm3 (-49%), p < or = 0.001 vs. ETid]. In 21% of patients, the entire heart could be displaced outside the radiation field with deep inspiration. Age was not correlated with change or percentage change in cardiac volume with respiratory maneuvers. We conclude that in breast cancer patients, deep inspiratory maneuvers significantly decrease irradiated cardiac volume included in the left breast radiation field. Such an approach during delivery of radiation therapy allows preservation of radiation dosage to the breast, while reducing cardiac involvement and possible associated cardiovascular toxicity.

title: Interfractional changes in tumour volume and position during entire radiotherapy courses for lung cancer with respiratory gating and image guidance
abstract: With the purpose of implementing gated radiotherapy for lung cancer patients, this study investigated the interfraction variations in tumour size and internal displacement over entire treatment courses. To explore the potential of image guided radiotherapy (IGRT) the variations were measured using a set-up strategy based on imaging of bony landmarks and compared to a strategy using in room lasers, skin tattoos and cupper landmarks.  During their six week treatment course of 60Gy in 2Gy fractions, ten patients underwent 3 respiratory gated CT scans. The tumours were contoured on each CT scan to evaluate the variations in volumes and position. The lung tumours and the mediastinal tumours were contoured separately. The positional variations were measured as 3D mobility vectors and correlated to matching of the scans using the two different strategies.  The tumour size was significantly reduced from the first to the last CT scan. For the lung tumours the reduction was 19%, p=0.03, and for the mediastinal tumours the reduction was 34%, p=0.0007. The mean 3D mobility vector and the SD for the lung tumours was 0.51cm (±0.21) for matching using bony landmarks and 0.85cm (±0.54) for matching using skin tattoos. For the mediastinal tumours the corresponding vectors and SD's were 0.55cm (±0.19) and 0.72cm (±0.43). The differences between the vectors were significant for the lung tumours p=0.004. The interfractional overlap of lung tumours was 80–87% when matched using bony landmarks and 70–76% when matched using skin tattoos. The overlap of the mediastinal tumours were 60–65% and 41–47%, respectively.  Despite the use of gating the tumours varied considerably, regarding both position and volume. The variations in position were dependent on the set-up strategy. Set-up using IGRT was superior to set-up using skin tattoos.