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

Pediatric Hodgkin's lymphoma: changing concepts and moving points in radiation therapy

The classic treatment of Hodgkin's lymphoma (HL) in children resulted in significant late toxicity in long-term survivors. Late treatment effects included skeletal, cardio- pulmonary, gonadal toxicities, and second malignant tumor (SMN). This has driven pediatric HL groups to adopt treatment strategies using less intense chemotherapy, less alkylating agents, reduced radiation dose and volume, and omission of radiation therapy in selected group of patients. In limited disease, the aim is to maintain a high cure rate with minimal side effects. Patients with advanced-stage HL have a lower outcome, and need treatment intensification. Dose-dense, risk and response-adapted treatment strategies are evolving aiming at improving outcome and reducing toxicity.

Imaging of early modification in cardiomyopathy: the doxorubicin-induced model

Doxorubicin chemotherapy is effective and widely used to treat acute lymphoblastic leukemia. However, its effectiveness is hampered by a wide spectrum of dose-dependent cardiotoxicity including both morphological and functional changes, affecting primarily the myocardium. Non-invasive imaging techniques are used for the diagnosis and monitoring of these cardiotoxic effects. The purpose of this review is to summarize and compare the most common imaging techniques used in early detection and therapeutic monitoring of doxorubicin-induced cardiotoxicity and the suggested mechanisms of such side effects. Imaging techniques using echocardiography including conventional 2D and 3D echocardiography along with MRI sequences including Tagging, Cine, and quantitative MRI in detecting early myocardial damage are also reviewed. As there is a multitude of reported indices and imaging methods to assess particular functional alterations, we limit this review to the most relevant techniques based on their clinical application and their potential to early detection of doxorubicin-induced cardiotoxic effects.

Children's Oncology Group's 2013 blueprint for research: survivorship and outcomes

Improvements in the treatment of childhood cancer have resulted in over 360,000 survivors of childhood cancer in the U.S. There is now a heightened recognition of the need to reduce treatment-related sequelae and optimize the quality of life of children treated for cancer. Survivorship studies conducted in the cooperative group setting have provided us with important information on long-term intellectual function, organ toxicity, reproductive outcomes, second cancers, late mortality, and disparities in outcomes. Ongoing health education initiatives have helped standardize the follow-up care for childhood cancer survivors and facilitate the early transfer of health-related information to patients, families, and healthcare providers.

Anthracycline induced cardiac toxicity in pediatric Ewing sarcoma: a longitudinal study

BACKGROUND

Reports on incidence and factors associated with anthracycline cardiotoxicity in patients with Ewing sarcoma vary and few studies evaluate effect over time. Longitudinal trends in cardiac function and prognostic value of % decline in ejection fraction (EF) during therapy have not been previously described in Ewing sarcoma.

PROCEDURE

A retrospective review of patients age <17 years, diagnosed with Ewing sarcoma during 1978-2006, treated at British Columbia Children's Hospital with anthracycline chemotherapy was undertaken. Echocardiograms performed pre-treatment, worst function during treatment, on therapy completion; worst function during surveillance and the most recent echocardiogram were reviewed. Cardiac toxicity was graded using Common Terminology Criteria for Adverse Events v 3.0 and 4.0.

RESULTS

Among 71 eligible patients, median age at diagnosis 11.1 years, median cumulative dose of anthracycline was 365 mg/m2 . There were 397 echocardiograms with 153 (39%) abnormal. There were 21/71 patients with EF < 50%, 11 with EF < 40% and five cardiac deaths including 2/3 patients post-cardiac transplant. The median time to worst cardiac function was 51 months. Post-therapy completion 16/71 patients with progressive decline in cardiac function were noted. No patient with 10-15% decline in EF during therapy developed cardiotoxicity. Younger age (P = 0.004) and low BMI (P = 0.034) as continuous variables with anthracycline administration by IV push (P = 0.03) were risk factors for cardiotoxicity on univariate analysis but not significant within logistic regression models.

CONCLUSIONS

The high incidence of cardiotoxicity associated with higher administered anthracycline dose, young age, bolus infusion, and EF decline warrants evaluation in a larger cohort.

Higher frequency of genetic variants conferring increased risk for ADRs for commonly used drugs treating cancer, AIDS and tuberculosis in persons of African descent

There is established clinical evidence for differences in drug response, cure rates and survival outcomes between different ethnic populations, but the causes are poorly understood. Differences in frequencies of functional genetic variants in key drug response and metabolism genes may significantly influence drug response differences in different populations. To assess this, we genotyped 1330 individuals of African (n=372) and European (n=958) descent for 4535 single-nucleotide polymorphisms in 350 key drug absorption, distribution, metabolism, elimination and toxicity genes. Important and remarkable differences in the distribution of genetic variants were observed between Africans and Europeans and among the African populations. These could translate into significant differences in drug efficacy and safety profiles, and also in the required dose to achieve the desired therapeutic effect in different populations. Our data points to the need for population-specific genetic variation in personalizing medicine and care.

Resveratrol and adipose-derived mesenchymal stem cells are effective in the prevention and treatment of doxorubicin cardiotoxicity in rats

Anthracyclines can cause severe cardiac toxicity leading to heart failure. The aim of this study was to determine the effects of cardioprotective polyphenolic compound resveratrol (RES) and adipose-derived mesenchymal stem cells (ADMSCs) on cardiac tissue of rats treated with doxorubicin (DOX). Forty-two female and three male Wistar-Albino rats were included in the study. The study groups and the control groups were as follows: Group I: DOX; Group II: DOX + RES; Group III: DOX + ADMSCs; Group IV: DOX + RES + ADMSCs; Group V: Sham operation; and Group VI: normal saline. ADMSCs obtained from male rats were defined with stem cell markers [CD11b/c(-), CD45(-), CD90(+), CD44(+), and CD49(+)]. DOX 12 mg/kg intraperitoneally (i.p.) was injected as a single dose in female rats. Resveratrol 100 mg/kg was injected three times i.p. in Groups II and IV. ADMSCs 2 × 10(6) cells/kg/dose were labeled with bromodeoxyuridine (BrdU) and injected i.p. for a total of three times in Groups III and IV. When the study was terminated after 4 weeks, the beating hearts were connected to a Langendorff setup and records were obtained for 30 minutes. Histopathological, immunhistochemical, and immunofluorescent examination with H&E, Troponin I, and BrdU stains were also performed. Also, ADMSCs were demonstrated in the myocardium of transplanted rats. Left ventricle functions and myocardial histology demonstrated significant impairment in DOX only group compared to groups with ADMSCs (P < .05). We suggest that RES and ADMSCs were successful in the prevention and treatment of the doxorubicin cardiomyopathy in rats. The hypothetical mechanisms of regeneration are multiple, including cell differentiation and autocrine/paracrine effects of ADMSCs.

Childhood cancer survivorship: an update on evolving paradigms for understanding pathogenesis and screening for therapy-related late effects

PURPOSE OF REVIEW

Five-year survival for many childhood cancers approaches 80%, and there is a growing number of long-term survivors in the United States. These survivors are at risk for developing adverse health-related complications. We highlight recently published studies that provide new insight into the association between specific therapeutic exposures and late-occurring complications such as second malignant neoplasms, cardiovascular disease, endocrinopathies, and neurocognitive impairment.

RECENT FINDINGS

The incidence for many long-term complications continues to increase with longer follow-up. Investigators have begun to explore the impact of aging and the role of genetic susceptibility as modifiers of risk in diseases wherein there is a clear association between therapeutic exposure and adverse outcome. Increased awareness of the importance of screening has set the stage for assessment of the impact of early detection for reduction of long-term morbidity and mortality among childhood cancer survivors at highest risk for therapy-related complications.

SUMMARY

The long-term health-related burden in childhood cancer survivors is substantial. Recent studies exploring the etiopathogenesis of treatment-related late effects have provided important information that will assist in ongoing efforts to develop personalized cancer care. Efficacious medical interventions are needed to help mitigate treatment-related complications in high-risk survivors.

Clinical cancer advances 2012: annual report on progress against cancer from the american society of clinical oncology

A MESSAGE FROM ASCO'S PRESIDENT

I am delighted to present you with “Clinical Cancer Advances 2012: Annual Report on Progress Against Cancer From the American Society of Clinical Oncology.” The American Society of Clinical Oncology (ASCO) uses this opportunity each year to share the steady progress occurring in our understanding and treatment of cancer. For 2012, we offer again an inspiring perspective on clinical cancer advances over the past year, but with a cautionary note: if current threats to federal funding materialize, future progress in cancer research will be seriously undermined.

Continued progress against cancer. As you read the following pages of this report, I hope you will share my unabashed enthusiasm—and pride—in how far we have come. To appreciate what this progress has meant to the millions of people who receive a cancer diagnosis each year, consider the following: (1) two of three people in the United States live at least 5 years after a cancer diagnosis (up from roughly one of two in the 1970s); (2) the nation's cancer death rate has dropped 18% since the early 1990s, reversing decades of increases; and (3) individuals with cancer are increasingly able to live active, fulfilling lives because of better management of symptoms and treatments with fewer adverse effects.

Importance of clinical cancer trials. These dramatic trends—and the advances highlighted in this report—would have been unthinkable without the engine that drives life-saving cancer treatment: clinical cancer research. Advances in technology and in our knowledge of how patient-specific molecular characteristics of the tumor and its environment fuel the growth of cancer have brought new hope to patients. Clinical trials are the key to translating cutting-edge laboratory discoveries into treatments that extend and improve the lives of those with cancer.

But progress is only part of the story. Cancer remains a challenge, with many cancers undetected until their latest stages and others resisting most attempts at treatment. Tragically, cancer still kills more than 500,000 people in the United States every year, and its global burden is growing rapidly.

Bridges to better care. To conquer cancer, we need to build bridges to the future—bridges that will get scientific advances to the patient's bedside quicker, bridges that will enable us to share information and learn what works in real time, and bridges that will improve care for all patients around the world.

At ASCO, we recognize the unique role that oncologists must play. ASCO's “Accelerating Progress Against Cancer: Blueprint for Transforming Clinical and Translational Cancer Research,”1published last year, presents our vision and recommendations to make cancer research and patient care vastly more targeted, more efficient, and more effective. We have also launched a groundbreaking initiative, CancerLinQ, that aims to improve cancer care and speed research by drawing insights from the vast pool of data on patients in real-world settings.

Renewing a national commitment to cancer research. We are on the threshold of major advances in cancer prevention, detection, and treatment—but only if, as a nation, we remain committed to this critical endeavor.

The federally funded cancer research system is currently under threat by larger federal budget concerns. Clearly, Congress faces a complex budget environment, but now is not the time to retreat from our nation's commitment to conquering a disease that affects nearly all of us. Bold action must be taken to ensure that we can take full advantage of today's scientific and technologic opportunities.

Please join me in celebrating our nation's progress against cancer and in recommitting ourselves to supporting cancer research. Millions of lives depend on it.

Sandra M. Swain, MD

President

American Society of Clinical Oncology

Transcriptome profiling of peripheral blood cells identifies potential biomarkers for doxorubicin cardiotoxicity in a rat model

Aims

Doxorubicin (DOX), a widely used anticancer agent, can cause an unpredictable cardiac toxicity which remains a major limitation in cancer chemotherapy. There is a need for noninvasive, sensitive and specific biomarkers which will allow identifying patients at risk for DOX-induced cardiotoxicity to prevent permanent cardiac damage. The aim of this study was to investigate whether the expression of specific genes in the peripheral blood can be used as surrogate marker(s) for DOX-induced cardiotoxicity.

Methods/Results

Rats were treated with a single dose of DOX similar to one single dose that is often administered in humans. The cardiac and peripheral blood mononuclear cells (PBMCs) genome-wide expression profiling were examined using Illumina microarrays. The results showed 4,409 differentially regulated genes (DRG) in the hearts and 4,120 DRG in PBMC. Of these 2411 genes were similarly DRG (SDRG) in both the heart and PBMC. Pathway analysis of the three datasets of DRG using Gene Ontology (GO) enrichment analysis and Ingenuity Pathways Analysis (IPA) showed that most of the genes in these datasets fell into pathways related to oxidative stress response and protein ubiquination. IPA search for potential eligible biomarkers for cardiovascular disease within the SDRG list revealed 188 molecules.

Conclusions

We report the first in-depth comparison of DOX-induced global gene expression profiles of hearts and PBMCs. The high similarity between the gene expression profiles of the heart and PBMC induced by DOX indicates that the PBMC transcriptome may serve as a surrogate marker of DOX-induced cardiotoxicity. Future directions of this research will include analysis of PBMC expression profiles of cancer patients treated with DOX-based chemotherapy to identify the cardiotoxicity risk, predict DOX-treatment response and ultimately to allow individualized anti-cancer therapy.

Unexpected doxorubicin-mediated cardiotoxicity in sisters: possible role of polymorphisms in histamine n-methyl transferase

The anthracycline anticancer agent doxorubicin has long been recognized to induce a dose-limiting cardiotoxicity and may be associated with genes relevant to doxorubicin disposition. Recent reports suggest a role for a number of single nucleotide polymorphisms in anthracycline cardiotoxicity in children. We describe two adult sisters with anthracycline cardiotoxicity that developed after a relatively low dose of doxorubicin. One sister carried the variant genotype for histamine N-ethyl transferase (HNMT, rs17583889) while the other was heterozygous, suggesting a similar role for these genotypes in adults with anthracycline cardiotoxicity. Although this requires further study, these genotypes may be important in the clinical dosing, or use of the liposomal formulation of doxorubicin.

Single-nucleotide polymorphisms in aldo-keto and carbonyl reductase genes are not associated with acute cardiotoxicity after daunorubicin chemotherapy

BACKGROUND

Evidence suggests that interpatient variability in anthracycline metabolic rate may contribute to the cardiotoxicity associated with anthracycline-based chemotherapy. Therefore, polymorphisms in the anthracycline metabolizing enzymes have been proposed as potential biomarkers of anthracycline-induced cardiotoxicity (AIC).

METHODS

We have previously shown that 13 of the naturally occurring nonsynonymous single-nucleotide polymorphisms (nsSNP) in the aldo-keto reductases (AKR) and carbonyl reductases (CBR) reduce anthracycline metabolic rate in vitro. Here, we test these SNPs individually and jointly for association with daunorubicin-induced cardiotoxicity in patients with acute myeloid leukemia (AML).

RESULTS

Five of the 13 nsSNPs exhibiting an in vitro effect on anthracycline metabolism were detected among the 185 patients with AML. No association was found between the SNPs and daunorubicin-induced cardiotoxicity in either individual or joint effect analyses.

CONCLUSIONS

Despite the shown in vitro effect of nsSNPs in reductase genes on anthracycline metabolic rate, on their own these SNPs do not explain enough variability in cardiotoxicity to be useful markers of this adverse event.

IMPACT

The results of this study provide important information for biomarker studies on side effects of anthracycline chemotherapy.

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

Cardiovascular complications are a leading cause of therapy-related morbidity and mortality in long-term survivors of childhood malignancy. In fact, childhood cancer survivors are at a 15-fold risk of developing CHF compared to age-matched controls. There is a strong dose-dependent association between anthracycline exposure and risk of CHF, and the incidence increases with longer followup. Outcome following diagnosis of CHF is generally poor, with overall survival less than 50% at 5 years. The growing number of childhood cancer survivors makes it imperative that strategies be developed to prevent symptomatic heart disease in this vulnerable population. We present here an overview of the current state of knowledge regarding primary, secondary, and tertiary prevention strategies for childhood cancer survivors at high risk for CHF, drawing on lessons learned from prevention studies in nononcology populations as well as from the more limited experience in cancer survivors.

Cardiotoxicity in childhood cancer survivors: strategies for prevention and management

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

DNA sequence variants in the carbonyl reductase 1 (cbr1) gene in seven breeds of Canis lupus familiaris

The anticancer anthracyclines doxorubicin and daunorubicin are used to treat a variety of cancers in dogs. The therapeutic utility of anthracyclines is limited by cardiotoxicity in some cases. Synthesis of anthracycline alcohol metabolites by carbonyl reductase 1 (CBR1) is crucial for the pathogenesis of cardiotoxicity. We hypothesize that genetic polymorphisms in canine cbr1 contribute to the variable pharmacodynamics of anthracyclines in dogs. DNA sequence variants in canine cbr1 were investigated in DNA samples from dogs of seven breeds. Thirteen SNPs were detected in canine cbr1. A 10-bp deletion in the 5'-untranslated region (5'-UTR) was found in specimens from the Labrador Retriever, Beagle, Siberian Husky, and Boxer breeds. The 5'-UTR also included a polymorphic "hot spot" region immediately downstream of the 10-bp deletion. DNA sequence variants in the "hot spot region" ranged from 1 to 21 bp in length. Bioinformatics searches identified a cluster of three to six potential binding sites for the transcription factor Sp1 in the DNA segment containing both the "hot spot" region and the 10-bp deletion. This information provides a foundation to allow us to investigate whether DNA sequence variants in the 5'-UTR of canine cbr1 impact the pharmacodynamics of anticancer anthracyclines in dogs.

A conserved antioxidant response element (ARE) in the promoter of human carbonyl reductase 3 (CBR3) mediates induction by the master redox switch Nrf2

Carbonyl reductase activity catalyzes the two electron reduction of several endogenous and exogenous carbonyl substrates. Recent data indicate that the expression of human carbonyl reductase 3 (CBR3) is regulated by the master redox switch Nrf2. Nrf2 binds to conserved antioxidant response elements (AREs) in the promoters of target genes. The presence of functional AREs in the CBR3 promoter has not yet been reported. In this study, experiments with reporter constructs showed that the prototypical Nrf2 activator tert-butyl hydroquinone (t-BHQ) induces CBR3 promoter activity in cultures of HepG2 (2.7-fold; p<0.05) and MCF-7 cells (22-fold; p<0.01). Computational searches identified a conserved ARE in the distal CBR3 promoter region ((-2698)ARE). Deletion of this ARE from a 4212-bp CBR3 promoter construct impacted basal promoter activity and induction of promoter activity in response to treatment with t-BHQ. Deletion of (-2698)ARE also impacted the induction of CBR3 promoter activity in cells overexpressing Nrf2. Electrophoretic mobility shift assays (EMSA) demonstrated increased binding of specific protein complexes to (-2698)ARE in nuclear extracts from t-BHQ treated cells. The presence of Nrf2 in the specific nuclear protein-(-2698)ARE complexes was evidenced in EMSA experiments with anti-Nrf2 antibodies. These data suggest that the distal (-2698)ARE mediates the induction of human CBR3 in response to prototypical activators of Nrf2.