Monitoring left ventricular function in adults receiving anthracycline-containing chemotherapy

Gender Differences in Oxidative Stress in Relation to Cancer Susceptibility and Survival

Genetic, developmental, biochemical, and environmental variables interact intricately to produce sex differences. The significance of sex differences in cancer susceptibility is being clarified by numerous studies. Epidemiological research and cancer registries have revealed over the past few years that there are definite sex variations in cancer incidence, progression, and survival. However, oxidative stress and mitochondrial dysfunction also have a significant impact on the response to treatment of neoplastic diseases. Young women may be more protected from cancer than men because most of the proteins implicated in the regulation of redox state and mitochondrial function are under the control of sexual hormones. In this review, we describe how sexual hormones control the activity of antioxidant enzymes and mitochondria, as well as how they affect several neoplastic diseases. The molecular pathways that underlie the gender-related discrepancies in cancer that have been identified may be better understood, which may lead to more effective precision medicine and vital information on treatment options for both males and females with neoplastic illnesses.

The role of the Tei index in assessing for cardiotoxicity from anthracycline chemotherapy: a systematic review

Background

Anthracycline agents are known to be effective in treating tumors and hematological malignancies. Although these agents improve survival, their use is associated with cardiotoxic effects, which most commonly manifests as left ventricular systolic dysfunction (LVSD). As such, guidelines recommend the periodic assessment of left ventricular ejection fraction (LVEF). However, as diastolic dysfunction likely proceeds systolic impairment in this setting, the role of Tei index may offer additional benefit in detecting subclinical LVSD.

Methods

We conducted a systematic review to investigate the evidence for the use of Tei index in assessing subclinical cardiotoxicity in patients receiving anticancer agents. A search of Medline and EMBASE was performed and relevant studies were reviewed and narratively synthesized.

Results

A total of 13 studies were included with a total of 800 patients (mean age range 46–62 years, percentage of male participants ranged from 0–86.9%). An increase in Tei index was observed in 11 studies, which suggested a decline in cardiac function following chemotherapy. Out of these, six studies indicated that the Tei index is a useful parameter in predicting cardiotoxic LVSD. Furthermore, five studies indicated Tei index to be superior to LVEF in detecting subclinical cardiotoxicity.

Conclusions

Though there are some studies that suggest that Tei index may be a useful indicator in assessing subclinical anthracycline-related cardiotoxicity, the findings are inconsistent and so more studies are needed before the evaluation of Tei index is performed routinely in patients receiving chemotherapy.

Extrahepatic cytochrome P450 epoxygenases: pathophysiology and clinical significance in human gastrointestinal cancers

Cytochrome P450 (CYP) epoxygenases, a multi-gene superfamily of heme-containing enzymes, are commonly known to metabolize endogenous arachidonic acid (AA) to epoxyeicosatrienoic acids (EETs). The role of CYPs is mostly studied in liver drugs metabolism, cardiac pathophysiology, and hypertension fields. Particularly, the biological functions of these enzymes have increasingly attracted a growing interest in cancer biology. Most published studies on CYPs in cancer have been limited to their role as drug metabolizing systems. The activity of these enzymes may affect drug pharmacokinetics and bioavailability as well as exogenous compounds turnover. Some CYP isoforms are selectively highly expressed in tumors, suggesting a potential mechanistic role in promoting resistance to chemotherapy. Majority of drugs elicit their effects in extrahepatic tissues whereby their metabolism can significantly determine treatment outcome. Nonetheless, the role of extrahepatic CYPs is not fully understood and targeting these enzymes as effective anti-cancer therapies are yet to be developed. This review article summarizes an up-to-date body of information from published studies on CYP enzymes expression levels and pathophysiological functions in human normal and malignant gastrointestinal (GI) tract tissues. Specifically, we reviewed and discussed the current research initiatives by emphasizing on the clinical significance and the pathological implication of CYPs in GI malignancies of esophagus, stomach, and colon.

Cardiovascular Toxicity Related to Cancer Treatment: A Pragmatic Approach to the American and European Cardio-Oncology Guidelines

The considerable progress made in the field of cancer treatment has led to a dramatic improvement in the prognosis of patients with cancer. However, toxicities resulting from these treatments represent a cost that can be harmful to short- and long-term outcomes. Adverse events affecting the cardiovascular system are one of the greatest challenges in the overall management of patients with cancer, as they can compromise the success of the optimal treatment against the tumor. Such adverse events are associated not only with older chemotherapy drugs such as anthracyclines but also with many targeted therapies and immunotherapies. Recognizing this concern, several American and European governing societies in oncology and cardiology have published guidelines on the cardiovascular monitoring of patients receiving potentially cardiotoxic cancer therapies, as well as on the management of cardiovascular toxicities. However, the low level of evidence supporting these guidelines has led to numerous discrepancies, leaving clinicians without a consensus strategy to apply. A cardio-oncology expert panel from the French Working Group of Cardio-Oncology has undertaken an ambitious effort to analyze and harmonize the most recent American and European guidelines to propose roadmaps and decision algorithms that would be easy for clinicians to use in their daily practice. In this statement, the experts addressed the cardiovascular monitoring strategies for the cancer drugs associated with the highest risk of cardiovascular toxicities, as well as the management of such toxicities.

Estrogen but not testosterone preserves myofilament function from doxorubicin-induced cardiotoxicity by reducing oxidative modifications

Here, we aimed to explore sex differences and the impact of sex hormones on cardiac contractile properties in doxorubicin (DOX)-induced cardiotoxicity. Male and female Sprague-Dawley rats were subjected to sham surgery or gonadectomy and then treated or untreated with DOX (2 mg/kg) every other week for 10 wk. Estrogen preserved maximum active tension (T_max) with DOX exposure, whereas progesterone and testosterone did not. The effects of sex hormones and DOX correlated with both altered myosin heavy chain isoform expression and myofilament protein oxidation, suggesting both as possible mechanisms. However, acute treatment with oxidative stress (H₂O₂) or a reducing agent (DTT) indicated that the effects on T_max were mediated by reversible myofilament oxidative modifications and not only changes in myosin heavy chain isoforms. There were also sex differences in the DOX impact on myofilament Ca²⁺ sensitivity. DOX increased Ca²⁺ sensitivity in male rats only in the absence of testosterone and in female rats only in the presence of estrogen. Conversely, DOX decreased Ca²⁺ sensitivity in female rats in the absence of estrogen. In most instances, this mechanism was through altered phosphorylation of troponin I at Ser²³/Ser²⁴. However, there was an additional DOX-induced, estrogen-dependent, irreversible (by DTT) mechanism that altered Ca²⁺ sensitivity. Our data demonstrate sex differences in cardiac contractile responses to chronic DOX treatment. We conclude that estrogen protects against chronic DOX treatment in the heart, preserving myofilament function. NEW & NOTEWORTHY We identified sex differences in cardiotoxic effects of chronic doxorubicin (DOX) exposure on myofilament function. Estrogen, but not testosterone, decreases DOX-induced oxidative modifications on myofilaments to preserve maximum active tension. In rats, DOX exposure increased Ca²⁺ sensitivity in the presence of estrogen but decreased Ca²⁺ sensitivity in the absence of estrogen. In male rats, the DOX-induced shift in Ca²⁺ sensitivity involved troponin I phosphorylation; in female rats, this was through an estrogen-dependent mechanism.

Arterial Stiffness Use for Early Monitoring of Cardiovascular Adverse Events due to Anthracycline Chemotherapy in Breast Cancer Patients. A Pilot Study

BACKGROUND

Chemotherapy with doxorubicin and cyclophosphamide, although efficient for treating breast cancer, is associated with cardiovascular complications. Recent studies seek to identify methods that can early detect cardiological and vascular changes as a strategy to decrease the incidence of cardiovascular comorbidities.

OBJECTIVE

To evaluate the role of arterial stiffness measurement in the monitoring of doxorubicin and cyclophosphamide-induced cardiotoxicity in breast cancer patients.

METHODS

Prospective longitudinal study in 24 breast cancer patients undergoing treatment with doxorubicin and cyclophosphamide. Patients underwent an indirect evaluation of arterial stiffness through non-invasive measurement of hemodynamic parameters such as pulse wave velocity with the Mobil-O-Graph® 24H PWA device at three different times of the chemotherapy treatment (pre-chemotherapy, after the first and the fourth cycle). The left ventricular ejection fraction was also evaluated by Doppler echocardiography (pre-chemotherapy and after the fourth chemotherapy cycle). Data were considered significant when p ≤ 0.05.

RESULTS

Patients had a mean age of 52.33 ± 8.85 years and body mass index of 31 ± 5.87 kg/m2. There was no significant difference between the hemodynamic parameters evaluated by the oscillometric method or in the left ventricular ejection fraction in the different evaluated periods.

CONCLUSION

Evaluations of arterial stiffness by oscillometry and measurement of left ventricular ejection fraction by Doppler echocardiography showed equivalence in the values found, suggesting that the evaluation method of arterial stiffness studied could be used as a marker for cardiovascular adverse events associated with doxorrubicin-based chemotherapy drugs.

Korean Guidelines for Diagnosis and Management of Chronic Heart Failure

The prevalence of heart failure (HF) is skyrocketing worldwide, and is closely associated with serious morbidity and mortality. In particular, HF is one of the main causes for the hospitalization and mortality in elderly individuals. Korea also has these epidemiological problems, and HF is responsible for huge socioeconomic burden. However, there has been no clinical guideline for HF management in Korea. 
The present guideline provides the first set of practical guidelines for the management of HF in Korea and was developed using the guideline adaptation process while including as many data from Korean studies as possible. The scope of the present guideline includes the definition, diagnosis, and treatment of chronic HF with reduced/preserved ejection fraction of various etiologies.

Creatine Supplementation and Doxorubicin-Induced Skeletal Muscle Dysfunction: An Ex Vivo Investigation

Supplementing the diet with creatine (Cr) to manage chemotherapy-induced skeletal muscle weakness and fatigue has potential, but little has been done exploring it as an intervention. This study examined the effects of Cr on skeletal muscle dysfunction induced by the chemotherapy drug doxorubicin (Dox). Soleus and extensor digitorum longus (EDL) from male Sprague-Dawley rats maintained in an organ bath were incubated in Krebs-Henseleit (KH) buffer with or without creatine monohydrate (25 mM) for 30 min. Skeletal muscle was then incubated in KH buffer with or without Dox (24 μM) for an additional 30 min. Baths were then refreshed with KH buffer, and a 100-s fatigue protocol was administered. At baseline (0 s time point), no significant differences in force production were observed in the slow, type I soleus, but the Dox-treated soleus fatigued quicker than the non-Dox-treated soleus; however, pretreatment with Cr extended the time to fatigue in the Dox-treated soleus. In the fast, type II EDL, Dox treatment decreased force production at baseline and increased fatigue, and Cr treatment prior to Dox attenuated this dysfunction. Creatine pretreatment mitigated Dox-induced skeletal muscle dysfunction ex vivo suggesting that Cr may play a role in managing Dox-induced skeletal muscle side effects.

Prevention and Monitoring of Cardiac Dysfunction in Survivors of Adult Cancers: American Society of Clinical Oncology Clinical Practice Guideline

Purpose

Cardiac dysfunction is a serious adverse effect of certain cancer-directed therapies that can interfere with the efficacy of treatment, decrease quality of life, or impact the actual survival of the patient with cancer. The purpose of this effort was to develop recommendations for prevention and monitoring of cardiac dysfunction in survivors of adult-onset cancers.

Methods

Recommendations were developed by an expert panel with multidisciplinary representation using a systematic review (1996 to 2016) of meta-analyses, randomized clinical trials, observational studies, and clinical experience. Study quality was assessed using established methods, per study design. The guideline recommendations were crafted in part using the Guidelines Into Decision Support methodology.

Results

A total of 104 studies met eligibility criteria and compose the evidentiary basis for the recommendations. The strength of the recommendations in these guidelines is based on the quality, amount, and consistency of the evidence and the balance between benefits and harms.

Recommendations

It is important for health care providers to initiate the discussion regarding the potential for cardiac dysfunction in individuals in whom the risk is sufficiently high before beginning therapy. Certain higher risk populations of survivors of cancer may benefit from prevention and screening strategies implemented during cancer-directed therapies. Clinical suspicion for cardiac disease should be high and threshold for cardiac evaluation should be low in any survivor who has received potentially cardiotoxic therapy. For certain higher risk survivors of cancer, routine surveillance with cardiac imaging may be warranted after completion of cancer-directed therapy, so that appropriate interventions can be initiated to halt or even reverse the progression of cardiac dysfunction.

Monitoring of Anthracycline-Induced Cardiotoxicity

Objective:

To review the literature regarding the appropriate monitoring for anthracycline-induced cardiotoxicity.

Data Sources:

A MEDLINE search of the literature was performed (1966–August 2007). Search terms included anthracycline, cardiotoxicity, and monitoring. Additional references were identified through bibliographic reviews.

Data Synthesis:

Anthracycline medications are effective in the treatment of many malignancies but their use is limited by their associated cardiotoxicity. The focus of anthracycline-induced cardiotoxicity prevention has been on monitoring cardiac function during treatment; however, a consensus on the most appropriate way to monitor patients is not available. Most guidelines lack specific details on the appropriate methods of cardiac evaluation and schedule. One guideline that does provide specific recommendations on both the method of evaluation and schedule has been criticized for being too restrictive, costly, and tacking in evidentiary support. The literature is insufficient in evaluation of the predictive value of cardiac function monitoring by echocardiography or radionuclide angiography during anthracycline therapy and the future development of cardiotoxicity, the necessity of baseline cardiac function monitoring, the optimal follow-up cardiac evaluation schedule, and the addition of risk stratification to monitoring schemes.

Conclusions:

Although guidelines are Inadequate to predict and prevent anthracycline-induced cardiotoxicity, until further research is available, following one of the existing guidelines to monitor for this adverse effect is a practical solution.

Mitoxantrone-Induced Cardiotoxicity in Acute Myeloid Leukemia-A Velocity Vector Imaging Analysis

BACKGROUND

The purpose of this investigation was to: (1) determine incidence and predictors of mitoxantrone-induced early cardiotoxicity and (2) study left ventricular mechanics before and after receiving mitoxantrone.

METHOD AND RESULTS

We retrospectively analyzed 80 subjects diagnosed with acute myeloid leukemia (AML) who underwent chemotherapy with bolus high-dose mitoxantrone. Echocardiographic measurements were taken at baseline and at a median interval of 55 days after receiving mitoxantrone. Thirty-five (44%) of the patients developed clinically defined early cardiotoxicity, 29 (36%) of which developed heart failure. There was a significant decrease in the ejection fraction (EF) not only in the cardiotoxicity group (17.6 ± 14.8%, P < 0.001) but also in the noncardiotoxicity group (5.3 ± 8.4%, P < 0.001). Decrease in global longitudinal strain (GLS) (-3.7 ± 4.5, P < 0.001 vs. -2.4 ± 4.3, P = 0.01) and global circumferential strain (GCS) (-5.6 ± 9, P = 0.003 vs. -5.3 ± 8.7, P < 0.001) was significant in both the cardiotoxicity and noncardiotoxicity group, respectively. A multivariate model including baseline left ventricular end-systolic diameter, baseline pre-E/A ratio, and baseline pre-E/e' ratio was found to be the best-fitted model for prediction of mitoxantrone-induced early clinical cardiotoxicity.

CONCLUSION

High-dose mitoxantrone therapy is associated with an excellent remission rate but with a significantly increased risk of clinical and subclinical early cardiotoxicity and heart failure. Mitoxantrone-induced systolic dysfunction is evident from reduction in EF, increase in Tei index, and significant reduction in GLS and GCS. Baseline impaired ventricular relaxation evident from higher E/e' ratio and lower E/A ratio independently predicts increased risk of mitoxantrone-induced early cardiotoxicity.

Advanced Echocardiographic Techniques in Detection of Cardiotoxicity

OPINION STATEMENT

As advancements are made in cancer treatment, there is an increasing recognition of the cardiotoxic potential of chemotherapies and the need to monitor for the development of cardiac dysfunction in survivors. Echocardiography is the cornerstone of cardiac imaging and provides a feasible and non-invasive method to assess cardiac dysfunction in patients with cancer. In recent years, there has been increasing research in echocardiographic techniques to improve diagnosis of cardiotoxicity, including a more accurate assessment of the left ventricular function and the detection of subclinical disease. These specialized techniques include stress and contrast echocardiography, three-dimensional echocardiography, diastolic dysfunction, tissue Doppler imaging, and strain parameters.

Cancer and cardiovascular disease: the use of novel echocardiography measures to predict subsequent cardiotoxicity in breast cancer treated with anthracyclines and trastuzumab

As the population of breast cancer survivors grows, it has become evident that chemotherapy has significant cardiotoxic side effects. Echocardiography is a noninvasive, cost-effective, and widely available imaging tool that is well positioned to serve as a primary modality for monitoring chemotherapy-induced cardiotoxicity. Although left ventricular ejection fraction is a standard measurement by which to monitor chemotherapy-induced cardiotoxicity, its predictive value in identifying subsequent cardiotoxicity is limited. More sophisticated echocardiography modalities may offer improved sensitivity and specificity for detecting chemotherapy-induced cardiotoxicity. These include tissue Doppler imaging measures, newer techniques based upon two- and three-dimensional strain and torsion analysis, and three-dimensional measures of cardiac size. While these modalities are not all currently part of clinical practice, a body of data supporting their use is steadily building. More research remains to be performed, and noninvasively detecting cancer therapy-induced cardiac dysfunction at the earliest stages is of increasing interest.

Reproductive hormone levels and differential mitochondria-related oxidative gene expression as potential mechanisms for gender differences in cardiosensitivity to Doxorubicin in tumor-bearing spontaneously hypertensive rats

PURPOSE

Chemotherapy with doxorubicin (Dox) causes dose-limiting cardiotoxicity. We investigated the role that gender has on cardiosensitivity to Dox treatment by evaluating reproductive hormone levels in male, castrated male (c-male), female and ovariectomized female (o-female) adult spontaneously hypertensive rats (SHRs) and expression of mitochondria-related genes in male and female adult SHRs.

METHODS

SST-2 breast tumor-bearing SHRs were treated with saline, Dox, dexrazoxane (Drz) or both Dox and Drz and monitored for 14 days. Tumor size was used to monitor anticancer activity. Heart weight, cardiac lesion score and serum levels of cardiac troponin T (cTnT) were used to determine cardiotoxicity. Serum estradiol (E2) and testosterone were evaluated using electrochemiluminescence immunoassays. Expression of mitochondria-related genes was profiled in heart by MitoChip array analyses.

RESULTS

Dox significantly reduced tumor volume (±Drz) and increased heart weight in all genders (13-30% vs. control). Higher heart lesion scores were observed in reproductively normal animals (male 2.9, female 2.2) than in hormone-deficient animals (c-male 1.7, o-female 1.9). Lesion score and cTnT inversely correlated with hormone levels. Reduced levels of both sex hormones were observed after Dox treatment. Gene expression analyses of Dox-treated hearts showed significant differential expression of oxidative stress genes in male hearts and apoptotic genes in both male and female hearts.

CONCLUSIONS

Our results demonstrate that adult tumor-bearing male SHRs are more cardiosensitive to Dox than female or hormone-deficient animals. We provide evidence to suggest that reproductive hormones negatively regulate or are inhibited by Dox-induced cardiotoxicity and the selective cytotoxic mechanism likely functions through the greater activation of oxidative stress and apoptosis in male SHRs.

Assessment of cardiac troponin I (cTnI) and tissue velocity imaging (TVI) in 14 dogs with malignant lymphoma undergoing chemotherapy treatment with doxorubicin

Doxorubicin has been shown to be cardiotoxic at high doses but is an efficacious chemotherapeutic agent in the treatment of canine lymphoma. Echocardiographic measurements and serum ultrasensitive cardiac troponin I (cTnI) levels were obtained before and after doxorubicin administration in 14 dogs diagnosed with lymphoma. The aim of this prospective study was to evaluate changes in cTnI concentrations and tissue velocity imaging (TVI) values in dogs with lymphoma undergoing chemotherapy with doxorubicin. A total of 182 cTnI and 1017 TVI measurements were performed. Standard echocardiographic parameters, tissue Doppler indices and cTnI concentrations did not differ at any time point within a 12-week cyclic combination protocol. In conclusion, the use of doxorubicin at standard doses in the treatment of canine lymphoma may not be associated with significant myocardial damage.

[Towards an integrated approach to cardiovascular toxicities related to the treatments of breast cancer]

There is an increasing number of therapeutic options in breast cancer management. While prognosis improves, the cardiac toxicity related to treatments remains a significant issue. This toxicity has several clinical presentations and can be explained by complex and diverse molecular mechanisms. Systemic treatments (anthracyclines, inhibitors of HER2 signaling pathway, hormone therapy, antiangiogenic agents) and radiotherapy have their own cardiac toxicity. However, the toxicities associated with these treatments may potentiate together and the existence of pre-existing cardiovascular risk factors should be taken into account. The assessment of cardiac hazard evolves toward a multifactorial approach. Several possibilities exist to minimize the incidence of cardiac complications. Those include pharmacological and technological innovations, but also a more accurate selection of patients and a growing involvement of practitioners in the field of cardiac toxicity, which is prerequisite for an early management of cardiac events.

Contemporary strategies in the diagnosis and management of heart failure

Heart failure (HF) is an important public health problem, and strategies are needed to improve outcomes and decrease health care resource utilization and costs. Its prevalence has increased as the population ages, and HF continues to be associated with a high mortality rate and frequent need for hospitalization. The total cost of care for patients with HF was $30.7 billion in 2012, and it is estimated to more than double to $69.8 billion by 2030. Given this reality, there has been recent investigation into ways of identifying and preventing HF in patients at risk (stage A HF) and those with cardiac structural and functional abnormalities but no clinical HF symptoms (stage B). For patients who have symptoms of HF (stage C), there has been important research into the most effective ways to decongest patients hospitalized with acute decompensated HF and prevent future hospital readmissions. Successful strategies to treat patients with HF and preserved ejection fraction, which has increased in prevalence, continue to be sought. We are in the midst of a rapid evolution in our ability to care for patients with end-stage HF (stage D) because of the introduction of and improvements in mechanical circulatory support. Left ventricular assist devices used as destination therapy offer an important therapeutic option to patients who do not qualify for heart transplant because of advanced age or excessive comorbidity. This review provides a thorough update on contemporary strategies in the diagnosis and management of HF by stage (A to D) that have emerged during the past several years.

Anthracycline-induced cardiotoxicity: prospective cohort study from Pakistan

OBJECTIVES

To identify anthracycline-induced acute (within 1 month) and early-onset chronic progressive (within 1 year) cardiotoxicity in children younger than 16 years of age with childhood malignancies at a tertiary care centre of Pakistan.

DESIGN

Prospective cohort study.

SETTING

Aga Khan University, Karachi, Pakistan.

PARTICIPANTS

110 children (aged 1 month-16 years).

INTERVENTION

Anthracycline (doxorubicin and/or daunorubicin).

OUTCOME MEASUREMENTS

All children who received anthracycline as chemotherapy and three echocardiographic evaluations (baseline, 1 month and 1 year) between July 2010 and June 2012 were prospectively analysed for cardiac dysfunction. Statistical analysis including systolic and diastolic functions at baseline, 1 month and 1 year was carried out by repeated measures analysis of variance.

RESULTS

Mean age was 74±44 months and 75 (68.2%) were males. Acute lymphoblastic leukaemia was seen in 70 (64%) patients. Doxorubicin alone was used in 59 (54%) and combination therapy was used in 35 (32%). A cumulative dose of anthracycline <300 mg/m(2) was used in 95 (86%). Fifteen (14%) children developed cardiac dysfunction within a month and 28 (25%) children within a year. Of these 10/15 (66.6%) and 12/28 (43%) had isolated diastolic dysfunction, respectively, while 5/15 (33.3%) and 16/28 (57%) had combined systolic and diastolic dysfunction. Seven (6.4%) patients expired due to severe cardiac dysfunction. Eight of 59 (13.5%) children showed dose-related cardiotoxicity (p=<0.001). Cardiotoxicity was also high when the combination of doxorubicin and daunorubicin was used (p=0.004).

CONCLUSIONS

Incidence of anthracycline-induced cardiotoxicity is high. Long-term follow-up is essential to diagnose its late manifestations.

Early cardiac function monitoring for detection of subclinical Doxorubicin cardiotoxicity in young adult patients with breast cancer

PURPOSE

As doxorubicin cardiotoxicity is considered irreversible, early detection of cardiotoxicity and prevention of overt heart failure is essential. Although there are monitoring guidelines for cardiotoxicity, optimal timing for early detection of subclinical doxorubicin cardiotoxicity is still obscure. The purpose of this study is to determine optimal timing of cardiac monitoring and risk factors for early detection of doxorubicin cardiotoxicity in young adult patients with breast cancer.

METHODS

Medical records of 1,013 breast cancer patients diagnosed from January 2009 to December 2010 is being reviewed and analyzed. Properly monitored patients are defined as patients who underwent transthoracic echocardiography before and after the chemotherapy. The definition of subclinical cardiotoxicity (SC) either decreases left ventricular ejection fraction (LVEF) more than 10% or the LVEF declines under 55% from baseline without heart failure symptoms.

RESULTS

Twenty-nine out of 174 (16.7%) properly monitored young adult female patients (mean age, 52±10 years old) developed SC. The mean interval of cardiac evaluation of SC group was 5.5±3.0 months. Among the risk factors, the history of coronary artery disease, cumulative dose of doxorubicin ≥300 mg/m(2) and use of trastuzumab after doxorubicin therapy were associated with development of SC. At cumulative dose of doxorubicin 244.5 mg/m(2), SC can be predicted (sensitivity, 71.4%; specificity, 70.9%; area under the curve, 0.741; 95% confidence interval, 0.608-0.874; p=0.001).

CONCLUSION

In young adult patients with breast cancer, SC was common at cumulative dose of doxorubicin <300 mg/m(2) and early performance of cardiac monitoring before reaching the conventional critical dose of doxorubicin might be a proper strategy for early detection of SC.

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.

Long-term heart function after adjuvant epirubicin chemotherapy for breast cancer

BACKGROUND

Newer studies raise concern that adjuvant anthracycline treatment for breast cancer (BC) causes long-term heart damage. We aimed to examine whether heart failure or impairment could be demonstrated several years after low-dose epirubicin-based adjuvant treatment.

MATERIAL AND METHODS

The study-population was a historical cohort comprising 980 women who were randomized to receive one of two adjuvant regimens for treatment for BC: 7-9 cycles of cyclophosphamide-epirubicin-5-fluorouracil [CEF (600 + 60 + 600 mg/m(2))] or cyclophosphamide-methotrexate-5- fluorouracil [CMF (600 + 40 + 600 mg/m(2))]. We collected information in national registries of death and diagnoses and a sample of 77 survivors was examined with tissue-Doppler imaging (TDI), echocardiography, radionuclide ventriculography and N-terminal-pro-B-type-natriuretic peptide (NT-proBNP), an established marker for heart failure.

RESULTS AND CONCLUSION

Median follow-up was 12 years (39 days-20 years). Fifty-one percent had died. Incidence of CHF was 2.6/1000/year and equal in the treatment groups. In the sample, individuals who had received CEF showed no cardiac impairment when compared to individuals who received CMF. NT-proBNP-levels were within normal limits but higher in the CEF-group than in the CMF-group (confidence limits 105-226%, p = 0.03). Results of our study seem reassuring regarding the long-term risk of cardiotoxicity following low-dose adjuvant epirubicin treatment. However, larger, longitudinal studies are needed to establish the clinical implications.

Rationale for and preliminary results of proton beam therapy for mediastinal lymphoma

PURPOSE

To evaluate the potential of three-dimensional proton beam therapy (3D-PBT) for reducing doses to normal structures in patients with mediastinal lymphomas compared with conventional photon radiation therapy (RT).

METHODS AND MATERIALS

We treated 10 consecutive patients with mediastinal masses from lymphomas with 3D-PBT between July 2007 and February 2009 to 30.6-50.4 cobalt-Gray equivalents (CGE). Of those patients, 7 had primary refractory or recurrent disease, and 8 had Hodgkin lymphoma. Dosimetric endpoints were compared with those from conventional RT plans.

RESULTS

PBT delivered lower mean doses to the lung (6.2 vs. 9.5 Gy), esophagus (9.5 vs. 22.3 Gy), and heart (8.8 vs. 17.7 Gy) but not the breasts (5.9 vs. 6.1 Gy) than did conventional RT. Percentages of lung, esophagus, heart, and coronary artery (particularly the left anterior descending artery) volumes receiving radiation were consistently lower in the 3D-PBT plans over a wide range of radiation doses. Of the 7 patients who had residual disease on positron emission tomography before PBT, 6 (86%) showed a complete metabolic response.

CONCLUSIONS

In patients with mediastinal lymphomas, 3D-PBT produced significantly lower doses to the lung, esophagus, heart, and coronary arteries than did the current conventional RT. These lower doses would be expected to reduce the risk of late toxicities in these major organs.

Reversibility of left ventricular dysfunction resulting from chemotherapy: can this be expected?

Recent advances in cancer management have improved long-term survival. Increased longevity has been accompanied by a rise in the frequency of age-related cardiovascular disease and treatment-related cardiotoxicity. Chemotherapy-related left ventricular dysfunction has historically been considered resistant to conventional therapy and to carry a poorer prognosis than other cardiomyopathies. However, these conclusions were drawn primarily from trials that predate contemporary heart failure therapy and where treatment was often initiated only after the development of symptoms. More recent data suggest that selected forms of chemotherapy-related cardiomyopathy are, to some degree, reversible, but response is dependent on early detection and prompt intervention. This challenges us to develop more sophisticated risk stratification and monitoring strategies that include symptom detection, noninvasive imaging, and carefully applied biomarkers. This paradigm also suggests that a multidisciplinary team of cardiologists and oncologists may provide more comprehensive care to this complex patient population.

Valvular dysfunction and left ventricular changes in Hodgkin's lymphoma survivors. A longitudinal study

Purpose:

Hodgkin's lymphoma survivors (HLSs) have an elevated risk for cardiovascular diseases that appear several years after radiotherapy. This study examined the time-dependent development and evolution of valvular and myocardial function related to treatment with mediastinal radiotherapy and anthracyclines in HLSs.

Patients and methods:

In 1993, echocardiography was performed in 116 HLSs median 10 years (range 6–13 years) after treatment with mediastinal radiotherapy. None of the 116 patients had valvular stenosis in 1993 whereas 36 (31%) had moderate valvular regurgitation. In 2005–2007, 51 of 57 invited patients were included in a second echocardiographic study – median 22 years (range 11–27 years) after treatment. Of these patients, 28 (55%) had also received anthracyclines. The patients were selected on the basis of the presence or absence of moderate valvular regurgitation in 1993.

Results:

The second echocardiographic study demonstrated that 10 out of 27 (37%) patients with only mild or no aortic or mitral regurgitation in 1993 had developed moderate regurgitation in either or both the aortic or mitral valve. Of the 24 patients with moderate (n=23) or severe (n=1) regurgitation in the aortic or mitral valve in 1993, 8 (33%) had progressed to severe regurgitation, developed moderate regurgitation in a previously normal or mild regurgitant valve or had received valvular replacement. In total, of all patients, 20 (39%) had developed mild to severe aortic stenosis and 3 patients had received valvular replacement. In a multiple linear regression the use of anthracyclines predicted left ventricular remodelling between ECHO 1993 and 2005 as demonstrated by increased left ventricular end systolic diameter (β =0.09 (95% CI 0.01–0.17), P=0.04) and reduced thickness of the left ventricular posterior wall (β =−0.18 (95% CI −0.33 to −0.03), P=0.02) and interventricular septum (β =−0.16 (95% CI −0.30 to −0.03), P=0.02).

Conclusion:

Given the progressive nature of valvular dysfunction and left ventricular remodelling 20–30 years after diagnosis, we recommend life-long cardiological follow-up of HLSs treated with mediastinal radiotherapy.

Anandamide Preserves Cardiac Function and Geometry in an Acute Doxorubicin Cardiotoxicity Rat Model

We investigated the use of the endocannabinoid anandamide as a means of cardioprotection against doxorubicin-induced cardiac dysfunction. Male rats received doxorubicin with or without anandamide pretreatment. Cardiac function was assessed in vivo using transthoracic echocardiography and ex vivo using the isolated working heart 5 days posttreatment. Doxorubicin administration without anandamide pretreatment resulted in a decline in fractional shortening (P < .05) and left ventricular wall thickness when compared to controls (P < .05). Ex vivo cardiac function analysis revealed a reduction in left ventricular developed pressure in hearts from animals receiving doxorubicin without anandamide pretreatment when compared to controls (P < .05). Left ventricles from animals receiving anandamide pretreatment before doxorubicin administration did not exhibit depressed fractional shortening, ventricular wall thickness, or developed pressure when compared to controls (P > .05). These results suggest that a potential therapy for doxorubicin-induced cardiotoxicity involves targeting the endogenous cannabinoid system.

Expert opinion on the use of anthracyclines in patients with advanced breast cancer at cardiac risk

Anthracyclines are considered to be among the most active agents for the treatment of breast cancer. However, their use is limited by cumulative, dose-related cardiotoxicity. Such cardiotoxicity results in a permanent loss of cardiac myocytes and a progressive reduction in cardiac function following each subsequent dose of anthracycline. Initially, damage to the heart is subclinical; however, increasingly impaired cardiac function can result in cardiovascular symptoms, with serious cardiac injury resulting in chronic heart failure. Since the early detection and treatment of cardiotoxicity can reduce its clinical effects, it is important that oncologists are aware of these adverse effects and manage them appropriately. This review examines the risk factors for anthracycline-associated cardiotoxicity and offers recommendations on strategies to reduce the cardiotoxicity of anthracyclines in the management of patients with advanced breast cancer.

Exercise preconditioning protects against doxorubicin-induced cardiac dysfunction

The clinical use of the chemotherapeutic drug doxorubicin (DOX) is limited due to a dose-dependent cardiotoxicity. Evidence is mounting that exercise protects against DOX-related cardiac dysfunction, and as such, it may be possible that prior endurance training promotes defense against DOX cardiotoxicity.

PURPOSE

To examine the effects of exercise preconditioning on acute DOX-induced cardiotoxicity, and to determine whether any observed cardioprotection was associated with myosin heavy chain (MHC) isoform alterations.

METHODS

Male Sprague-Dawley rats trained on a motorized treadmill, had access to voluntary running wheels, or remained sedentary for 10 wk prior to being injected with either saline or 10 mg.kg(-1) DOX. Left ventricular function was then assessed in vivo using transthoracic echocardiography and ex vivo using the isolated working heart at 5 and 10 d after injection. Additionally, left ventricular MHC isoform expression was analyzed as a possible mechanism to explain exercise-induced cardioprotection.

RESULTS

DOX treatment promoted significant in vivo and ex vivo cardiac dysfunction at 5 and 10 d after injection in sedentary animals, and this dysfunction was associated with an upregulation of the beta-MHC isoform. Exercise preconditioning protected against DOX-induced cardiac dysfunction at 5 and 10 d after injection by attenuating beta-MHC upregulation.

CONCLUSION

Endurance training prior to DOX treatment protects against acute DOX cardiotoxicity for up to 10 d, and this protection can potentially be explained by a preservation of MHC isoform distribution.