Review of tests for monitoring doxorubicin-induced cardiomyopathy

Cannabidiol Ameliorates Doxorubicin-Induced Myocardial Injury via Activating Hippo Pathway

Background

Doxorubicin (DOX) is a chemotherapeutic agent widely used for cancer treatment and has non-negligible cardiotoxicity. Some previous studies have reported that cannabidiol (CBD) has cardioprotective effects. In this study, we evaluated the protective effects of CBD against DOX-induced cardiomyocyte injury, and explored the downstream molecular mechanism.

Methods and Materials

GSE193861, containing healthy myocardial tissues and myocardial tissues with DOX-induced injury, was analyzed to screen for the involved proteins and pathways. Molecular docking was performed to identify candidate drugs. After H9c2 cells were treated with DOX and CBD, their viability, oxidative stress, and apoptosis were assessed. After YAP depletion, the role of the Hippo pathway in CBD function was investigated. C57BL/6 mice were treated with DOX to establish an in vivo model, and CBD and verteporfin (VP) were used to treat the mice. Histological analyses and immunofluorescence were used to evaluate myocardial tissue injury, and apoptosis and oxidative stress of the myocardial tissues were also analyzed. Western blotting was used to investigate the regulatory effects of CBD on the Hippo and apoptosis-related pathways.

Results

Bioinformatic analysis suggested that the Hippo pathway was a crucial pathway involved in DOX-induced myocardial injury. Molecular docking showed that CBD targeted multiple regulators of the Hippo pathway. CBD showed cardioprotective effects against DOX-induced myocardial injury both in vitro and in vivo and regulated Hippo pathway activity in cardiomyocytes. After inactivation of the Hippo pathway by YAP knockdown or VP intervention, the protective effects of CBD were reversed.

Conclusion

For the first time, we revealed that CBD is likely to reduce DOX-induced myocardial injury by regulating the Hippo signaling pathway.

Therapy-related Myeloid Neoplasms: Considerations for Patients' Clinical Evaluation

Therapy-related myeloid neoplasms (t-MNs) encompass a specific sub-group of myeloid malignancies arising after exposure to radio/cytotoxic agents for the treatment of unrelated diseases. Such malignancies present unique features, including advanced age, high comorbidities burden, and unfavorable genetic profiles. All these features justify the need for a specific diagnostic work-up and dedicated treatment algorithms. However, as new classification systems recognize the unique clinical characteristics exhibited by t-MN patients, how to assess fitness status in this clinical setting is largely unexplored. Optimizing fitness assessment would be crucial in the management of t-MN patients, considering that factors usually contributing to a worse or better outcome (like age, comorbidities, and treatment history) are patient-specific. In the absence of specific tools for fitness assessment in this peculiar category of AML, the aim of this review is to describe all those factors related to patient, treatment, and disease that allow planning treatments with an optimal risk/benefit ratio.

Clinical implications of chemotherapeutic agent organ toxicity on perioperative care

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

Left ventricle function assessment using gated first-pass 18F-FDG PET: Validation against equilibrium radionuclide angiography

PURPOSE

We appraised the feasibility of left ventricle (LV) function assessment using gated first-pass 18F-FDG PET, and assessed the concordance of the produced measurements with equilibrium radionuclide angiography (ERNA).

MATERIALS AND METHODS

Twenty-four oncologic patients benefited from 99mTc-labeled red-blood-cell ERNA, in planar mode (all patients) and using SPECT (22 patients). All patients underwent gated first-pass 18F-FDG cardiac PET. Gated dynamic PET images were reconstructed over 1 minute during tracer first-pass inside the LV and post-processed using in-house software (TomPool). After re-orientation into cardiac canonical axes and adjustment of the valves plane using a phase image, pseudo-planar PET images obtained by re-projection were automatically segmented using thresholded region growing and gradient-based delineation to produce an LV ejection fraction (EF) estimate. PET images were also post-processed in fully-tomographic mode to produce LV end diastole volume (EDV), end systole volume (ESV), and EF estimates. Concordance was assessed using Lin's concordance (ccc) and Bland-Altman analysis. Reproducibility was assessed using the coefficient of variation (CoV) and intra-class correlation (ICC).

RESULTS

Pseudo-planar PET EF estimates were concordant with planar ERNA (ccc = 0.81, P < .001) with a bias of 0% (95% CI [- 2%; 3%], limits of agreement [- 11%; 12%]). Reproducibility was excellent and similar for both methods (CoV = 2 ± 1% and 3 ± 2%, P = NS; ICC = 0.97 and 0.92, for PET and ERNA, respectively). Measurements obtained in fully-tomographic mode were concordant with SPECT ERNA: ccc = 0.83 and bias = - 3 mL for LV EDV, ccc = 0.92 and bias = 0 mL for LV ESV, ccc = 0.89 and bias = - 1% for LV EF (all P values < .001 for ccc, all biases not significant).

CONCLUSIONS

Gated first-pass 18F-FDG PET might stand as a relevant alternative to ERNA for LV function assessment, enabling a joint evaluation of both therapeutic response and cardiac toxicity in oncologic patients receiving cardiotoxic chemotherapy.

Nuclear cardio-oncology: From its foundation to its future

Cardio-oncology is a growing field focused on the prevention and treatment of cardiovascular disease in oncologic patients. While a major focus of chemotherapy-related cardiac dysfunction has been on left ventricular ejection fraction, oncologic treatment can lead to cardiovascular pathology in a variety of ways. The use of multimodality imaging is essential to the care of these patients, with nuclear cardiology playing an important role. We will review nuclear cardiology's history, its current role, and its promising future in cardio-oncology and the management of these patients.

Cathepsin B Dependent Cleavage Product of Serum Amyloid A1 Identifies Patients with Chemotherapy-Related Cardiotoxicity

Improvements in long-term cancer survival rates have resulted in an increase in the prevalence of chemotherapy-linked cardiac failure, but treatment-induced cardiac injuries may not be detected until long after therapy. Monitoring cardiac function is recommended; however, cardiovascular injury in cancer patients differs from those with primary cardiac dysfunction, which limits the utility of traditional cardiac biomarkers. Here we examined plasma levels of peptides produced by cathepsin B, which is released during chemotherapy-induced cardiac injury. We applied nanotrap fractionation to enrich plasma peptides from cancer patients treated with or without chemotherapy. Peptides associated with chemotherapy-induced cardiotoxicity, but not other cardiac injury, were identified by mass spectrometry, and their dependence on cathepsin B activity was determined using enzyme inhibition experiments. We found that a peptide (SAA-1525) derived from serum amyloid A1 was significantly increased in cardiotoxicity patients, and its production was inhibited when plasma samples were pretreated with cathepsin B specific inhibitors. Plasma SAA-1525 also correlated with other markers of cardiac injury. Analysis of plasma SAA-1525 levels may hold potential as a rapid and minimally invasive method to monitor subclinical injury, thereby allowing timely intervention to mitigate further cardiac damage and avoid more severe clinical presentation.

Anthracycline-Induced Cardiotoxicity

Anthracycline antibiotics are among the most effective and widely used antineoplastic drugs. Their usefulness is limited by a cumulative dose-related cardiotoxicity, whose precise mechanisms are not clear as yet. The principal role is possibly exerted by free oxygen radicals generated by “redox-cycling“ of anthracycline molecule and/or by the formation of anthracycline-ferric ion complexes. The iron catalyzes the hydroxyl radical production via Haber-Weiss reaction. The selective toxicity of ANT against cardiomyocytes results from high accumulation of ANT in cardiac tissue, appreciable production of oxygen radicals by mitochondria and relatively poor antioxidant defense systems. Other additional mechanisms of the anthracycline cardiotoxicity have been proposed - calcium overload, histamine release and impairment in autonomic regulation of heart function. The currently used methods for an early identification of anthracycline cardiotoxicity comprise ECG measurement, biochemical markers, functional measurement and morphologic examination. Among a plenty of studied cardioprotective agents only dexrazoxane (ICRF-187) has been approved for clinical use. Its protective effect likely consists in intracellular chelating of iron. However, in high doses dexrazoxane itself may cause myelotoxicity. This fact encourages investigation of new cardioprotectants with lower toxicity. Orally active iron chelators and flavonoids attract more attention. Modification of dosage schedule and synthesis of new anthracycline analogues may represent alternative approaches to mitigate anthracycline cardiotoxicity while preserving antitumour activity.

[The Role of Endothelial Dysfunction in the Development of Cardiotoxic Action of Cytostatics in Patients with Lymphoproliferative Diseases]

Understanding mechanisms of chemotherapy cardiotoxicity is an important problem due to the lack of clear understanding of its occurrence. Development of endothelial dysfunction is considered to be one of possible ways in implementation of these side effects. The analysis of endothelin-1 and e-selectin levels in 26  patients with lymphoproliferative diseases before and after the completion of the treatment program was been performed. The results of the study showed normal values of E-selectin level and increased level of endothelin-1 in the whole group of patients before treatment. After completion of chemotherapy program, in the whole group, there was a decrease of these two markers. However, values of level of endothelin-1 with vasoconstrictor effect remained high even after the end of therapy. It is imp ortant that at detailed analysis the dynamics of investigated markers in patients of older age group (median age 64 years) was associated with worsening of endothelial dysfunction.

Echocardiographic Assessment for the Detection of Cardiotoxicity Due to Vascular Endothelial Growth Factor Inhibitor Therapy in Metastatic Renal Cell and Colorectal Cancers

BACKGROUND

Cardio-oncology is a recently established discipline that focuses on the management of patients with cancer who are at risk for developing cardiovascular complications as a result of their underlying oncologic treatment. In metastatic colorectal cancer (mCRC) and metastatic renal cell carcinoma (mRCC), vascular endothelial growth factor inhibitor (VEGF-i) therapy is commonly used to improve overall survival. Although these novel anticancer drugs may lead to the development of cardiotoxicity, whether early detection of cardiac dysfunction using serial echocardiography could potentially prevent the development of heart failure in this patient population requires further study. The aim of this study was to investigate the role of two-dimensional speckle-tracking echocardiography in the detection of cardiotoxicity due to VEGF-i therapy in patients with mCRC or mRCC.

METHODS

Patients with mRCC or mCRC were evaluated using serial echocardiography at baseline and 1, 3, and 6 months following VEGF-i treatment.

RESULTS

A total of 40 patients (34 men; mean age, 63 ± 9 years) receiving VEGF-i therapy were prospectively recruited at two academic centers: 26 (65%) were receiving sunitinib, eight (20%) pazopanib, and six (15%) bevacizumab. The following observations were made: (1) 8% of patients developed clinically asymptomatic cancer therapeutics-related cardiac dysfunction; (2) 30% of patients developed clinically significant decreases in global longitudinal strain, a marker for early subclinical cardiac dysfunction; (3) baseline abnormalities in global longitudinal strain may identify a subset of patients at higher risk for developing cancer therapeutics-related cardiac dysfunction; and (4) new or worsening hypertension was the most common adverse cardiovascular event, afflicting nearly one third of the study population.

CONCLUSIONS

Cardiac dysfunction defined by serial changes in myocardial strain assessed using two-dimensional speckle-tracking echocardiography occurs in patients undergoing treatment with VEGF-i for mCRC or mRCC, which may provide an opportunity for preventive interventions.

Cardiotoxicity as indicated by LVEF and troponin T sensitivity following two anthracycline-based regimens in lymphoma: Results from a randomized prospective clinical trial

Anthracycline-induced cardiotoxicity influences treatment selection and may negatively affect clinical outcomes in lymphoma patients. While epirubicin induced cardiotoxicity less often than the same dose of doxorubicin in breast cancer, higher doses of epirubicin are required in lymphoma regimens for equivalent efficacy. Whether a higher dosage of epirubicin also induces cardiotoxicity less often than doxorubicin in lymphoma remains unknown. We therefore administered 6-8 cycles of cyclophosphamide, vincristine and prednisone (CEpOP) +/− rituximab (R) with either epirubicin (CEpOP) or doxorubicin (CHOP) to patients (N=398) with untreated diffuse large B-cell lymphoma (DLBCL) or follicular lymphoma grade 3 (FLG3). Left ventricular ejection fraction (LVEF) and high-sensitivity serum cardiac troponin T (HsTnT) were assessed at baseline and after 4 cycles of treatment. Epirubicin (70 mg/m²/dose) was equivalent to doxorubicin (50 mg/m²/dose) in terms of 3-year progression-free survival. The risk of decreased LVEF was similar between the two regimens. CEpOP+/−R induced HsTnT elevation less often than CHOP+/−R. We conclude that CEpOP+/−R is a more acceptable regimen with short-term efficacy similar to CHOP+/−R in lymphoma patients. Longer follow-up is needed to monitor the risk of cardiac dysfunction and determine whether differences in the induction of elevated HsTnT between epirubicin and doxorubicin justify changes in clinical practice.

Cancer cell spheroids for screening of chemotherapeutics and drug-delivery systems

Over the last few decades, the most popular platform to perform high-throughput screening for viable anti-neoplastic compounds has been monolayer cell culture. However, cells in monolayer culture lose many of their in vivo characteristics. As a result, this platform provides a limited predictive value in determining the clinical outcome of the compounds of interest. Using a technique known as 3D spheroid culture, may be the answer to this conundrum. Spheroids have been shown to mimic the tissue-like properties of tumors necessary for the proper evaluation of compounds. In this review, production of cancer cell spheroids, utilization of these spheroids in understanding various therapeutic mechanisms and the potential for their use in high-throughput screening of drugs and drug-delivery systems are discussed in detail.

Biomarkers for Presymptomatic Doxorubicin-Induced Cardiotoxicity in Breast Cancer Patients

Cardiotoxicity of doxorubicin (DOX) remains an important health concern. DOX cardiotoxicity is cumulative-dose-dependent and begins with the first dose of chemotherapy. No biomarker for presymptomatic detection of DOX cardiotoxicity has been validated. Our hypothesis is that peripheral blood cells (PBC) gene expression induced by the early doses of DOX-based chemotherapy could identify potential biomarkers for presymptomatic cardiotoxicity in cancer patients. PBC gene expression of 33 breast cancer patients was conducted before and after the first cycle of DOX-based chemotherapy. Cardiac function was evaluated before the start of chemotherapy and at its completion. Differentially expressed genes (DEG) of patients who developed DOX-associated cardiotoxicity after the completion of chemotherapy were compared with DEG of patients who did not. Ingenuity database was used for functional analysis of DEG. Sixty-sevens DEG (P<0.05) were identified in PBC of patients with DOX-cardiotoxicity. Most of DEG encode proteins secreted by activated neutrophils. The functional analysis of the DEG showed enrichment for immune- and inflammatory response. This is the first study to identify the PBC transcriptome signature associated with a single dose of DOX-based chemotherapy in cancer patients. We have shown that PBC transcriptome signature associated with one dose of DOX chemotherapy in breast cancer can predict later impairment of cardiac function. This finding may be of value in identifying patients at high or low risk for the development of DOX cardiotoxicity during the initial doses of chemotherapy and thus to avoid the accumulating toxic effects from the subsequent doses during treatment.

Luteinizing hormone-releasing hormone targeted poly(methyl vinyl ether maleic acid) nanoparticles for doxorubicin delivery to MCF-7 breast cancer cells

The purpose of this study was to design a targeted anti-cancer drug delivery system for breast cancer. Therefore, doxorubicin (DOX) loaded poly(methyl vinyl ether maleic acid) nanoparticles (NPs) were prepared by ionic cross-linking method using Zn(2+) ions. To optimise the effect of DOX/polymer ratio, Zn/polymer ratio, and stirrer rate a full factorial design was used and their effects on particle size, zeta potential, loading efficiency (LE, %), and release efficiency in 72 h (RE72, %) were studied. Targeted NPs were prepared by chemical coating of tiptorelin/polyallylamin conjugate on the surface of NPs by using 1-ethyl-3-(3-dimethylaminopropyl) carboiimid HCl as cross-linking agent. Conjugation efficiency was measured by Bradford assay. Conjugated triptorelin and targeted NPs were studied by Fourier-transform infrared spectroscopy (FTIR). The cytotoxicity of DOX loaded in targeted NPs and non-targeted ones were studied on MCF-7 cells which overexpress luteinizing hormone-releasing hormone (LHRH) receptors and SKOV3 cells as negative LHRH receptors using Thiazolyl blue tetrazolium bromide assay. The best results obtained from NPs prepared by DOX/polymer ratio of 5%, Zn/polymer ratio of 50%, and stirrer rate of 960 rpm. FTIR spectrum confirmed successful conjugation of triptorelin to NPs. The conjugation efficiency was about 70%. The targeted NPs showed significantly less IC50 for MCF-7 cells compared to free DOX and non-targeted NPs.

Recent advances of cocktail chemotherapy by combination drug delivery systems

Combination chemotherapy is widely exploited for enhanced cancer treatment in the clinic. However, the traditional cocktail administration of combination regimens often suffers from varying pharmacokinetics among different drugs. The emergence of nanotechnology offers an unparalleled opportunity for developing advanced combination drug delivery strategies with the ability to encapsulate various drugs simultaneously and unify the pharmacokinetics of each drug. This review surveys the most recent advances in combination delivery of multiple small molecule chemotherapeutics using nanocarriers. The mechanisms underlying combination chemotherapy, including the synergistic, additive and potentiation effects, are also discussed with typical examples. We further highlight the sequential and site-specific co-delivery strategies, which provide new guidelines for development of programmable combination drug delivery systems. Clinical outlook and challenges are also discussed in the end.

Doxorubicin induced heart failure: Phenotype and molecular mechanisms

Long term survival of childhood cancers is now more than 70%. Anthracyclines, including doxorubicin, are some of the most efficacious anticancer drugs available. However, its use as a chemotherapeutic agent is severely hindered by its dose-limiting toxicities. Most notably observed is cardiotoxicity, but other organ systems are also degraded by doxorubicin use. Despite the years of its use and the amount of information written about this drug, an understanding of its cellular mechanisms is not fully appreciated. The mechanisms by which doxorubicin induces cytotoxicity in target cancer cells have given insight about how the drug damages cardiomyocytes. The major mechanisms of doxorubicin actions are thought to be as an oxidant generator and as an inhibitor of topoisomerase 2. However, other signaling pathways are also invoked with significant consequences for the cardiomyocyte. Further the interaction between oxidant generation and topoisomerase function has only recently been appreciated and the consequences of this interaction are still not fully understood. The unfortunate consequences of doxorubicin within cardiomyocytes have promoted the search for new drugs and methods that can prevent or reverse the damage caused to the heart after treatment in cancer patients. Alternative protocols have lessened the impact on newly diagnosed cancer patients. However the years of doxorubicin use have generated a need for monitoring the onset of cardiotoxicity as well as understanding its potential long-term consequences. Although a fairly clear understanding of the short-term pathologic mechanisms of doxorubicin actions has been achieved, the long-term mechanisms of doxorubicin induced heart failure remain to be carefully delineated.

[Comorbidity of cardiovascular diseases and cancers: Problems in the diagnosis of cardiotoxic effects of chemo- and radiation therapy]

Cardiovascular diseases (CVD) and cancers are the leaders in their prevalence and the major causes of death in economically developed countries, determining their high sociomedical significance in society. Improvement of methods for the early diagnosis and treatment of cancers has contributed to increases in relapse-free survival and life expectancy in these patients. At the same time, the new problems have emerged particularly in the development of various cardiovascular events/diseases when treating cancer, which may predict worse prognosis in patients and be an independent cause of death. To search for new markers of cardiotoxicity at early stages and to develop effective methods for the prevention and personalized treatment of cancer and CVD are the problems that can be solved only by joint efforts of cardiologists and oncologists.

The utility of cardiac stress testing for detection of cardiovascular disease in breast cancer survivors: a systematic review

Background

Heart function tests performed with myocardial stress, or “cardiac stress tests”, may be beneficial for detection of cardiovascular disease. Women who have been diagnosed with breast cancer are more likely to develop cardiovascular diseases than the general population, in part due to the direct toxic effects of cancer treatment on the cardiovascular system. The aim of this review was to determine the utility of cardiac stress tests for the detection of cardiovascular disease after cardiotoxic breast cancer treatment.

Design

Systematic review.

Methods

Medline and Embase were searched for studies utilizing heart function tests in breast cancer survivors. Studies utilizing a cardiac stress test and a heart function test performed at rest were included to determine whether stress provided added benefit to identifying cardiac abnormalities that were undetected at rest within each study.

Results

Fourteen studies were identified. Overall, there was a benefit to utilizing stress tests over tests at rest in identifying evidence of cardiovascular disease in five studies, a possible benefit in five studies, and no benefit in four studies. The most common type of stress test was myocardial perfusion imaging, where reversible perfusion defects were detected under stress in individuals who had no defects at rest, in five of seven studies of long-term follow-up. Two studies demonstrated the benefit of stress echocardiography over resting echocardiography for detecting left ventricular dysfunction in anthracycline-treated breast cancer survivors. There was no benefit of stress cardiac magnetic resonance imaging in one study. Two studies showed a potential benefit of stress electrocardiography, whereas three others did not.

Conclusion

The use of cardiac stress with myocardial perfusion imaging and echocardiography may provide added benefit to tests performed at rest for detection of cardiovascular disease in breast cancer survivors, and merits further research.

Evaluation of early subclinical cardiotoxicity of chemotherapy in breast cancer

Objective:

Cardiac effects of chemotherapy are usually recognized after clinical symptom or sign occurrence in patients with breast cancer. In this study, we aimed to determine the potential subclinical cardiotoxic effects of chemotherapy that were given lower dosage than well known cardiac safety dosage limits in patients with breast cancer during early period.

Methods:

Fifty-one patients consecutively enrolled to this prospective cohort study. All patients were diagnosed as breast cancer at oncology hospital in University of Gaziantep. Before chemotherapy, all of the patients underwent to detailed ECG and echocardiography (ECHO) examinations. After 6 months, detailed ECG and ECHO examinations were repeated and compared with baseline values. Statistical analysis was performed using Shapiro-Wilk tests, Student t-test and Spearman correlation test.

Results:

The average age of patients was 51 and one was male. Statistically significant decrease in ejection fraction was found after treatment (62.3%±3.3 and 59.9%±5.9, p=0.002). Evaluation of diastolic parameters; significant increase in the transmitral A flow velocity and significant decrease of E/A ratio were observed on Doppler ECHO analysis (77.4±19.1 cm/sec versus 86±18 cm/sec, p<0.001; 1.01±0.3 versus 0.9±0.2, p=0.03, respectively). On tissue Doppler analysis we observed that significant reduction in the value of E’ and significantly increase E/E’ ratio were present (12.5±3.6 cm/sec versus 10.7±2.9 cm/sec, p=0.001; 6.6±2.9 versus 7.7±3.3, p=0.04, respectively).

Conclusion:

Chemotherapy has detrimental subclinical effect on both of systolic and diastolic function in early six months period despite the prescription of lower dosage of chemotherapy than well-known cardiac safety dosage limits. Tissue Doppler imaging may be more sensitive than ECG, conventional ECHO and Doppler for determining the subclinical cardiac damage.

Are cardiac magnetic resonance imaging and radionuclide ventriculography good options against echocardiography for evaluation of anthracycline induced chronic cardiotoxicity in childhood cancer survivors?

Anthracyclines are widely used for the treatment of solid tumors in pediatric oncology. However, their uses may be limited by progressive chronic cardiotoxicity related to the cumulative dosage. The aims of this study are to compare diagnostic techniques and prepare an algorithm for diagnosis of anthracycline induced chronic cardiotoxicity. The patients were evaluated according to age, sex, time elapsed since the last dose of anthracycline treatment, presence of cardiovascular symptoms, follow-up duration, type of anthracycline, cumulative anthracycline dose, and concomitant mediastinal radiation therapy. Late subclinical cardiotoxicity was detected by history, physical examination, electrocardiography (ECG), Holter monitor, echocardiography (ECHO), radionuclide ventriculography (MUGA), and cardiac magnetic resonance imaging (MRI). Thirty-seven male and 19 female patients with a median age of 11.2 ± 4.6 (range, 3.5-22.0) years were included in the study. Patients were grouped according to cumulative anthracycline doses. Subclinical cardiac dysfunction was detected in 20 patients by at least one of ECHO, MRI or MUGA after anthracycline chemotherapy. We revealed that other than ECHO, MRI and MUGA have high clinical importance for evaluating subclinical late cardiac complications in children treated with anthracyclines.

The utility of serum biomarkers to detect myocardial alterations induced by Imatinib in rats

BACKGROUND

Imatinib (Imb) is a tyrosine kinase inhibitor with cardiotoxic activity (decreases in left ventricular function and congestive heart failure) in patients. Currently, clinical diagnosis of Imb cardiotoxicity relies primarily on evaluation of left ventricular function, Imb also induces cardiac lesions in rats.

AIMS

This study, in rats, sought to determine whether monitoring biochemical markers would be a sensitive means to detect Imb-induced changes in cardiomyocyte morphology.

MATERIALS AND METHODS

Groups of male Sprague-Dawley rats were dosed orally with 50, 100, 200 mg kg(-1) Imb or water daily for 28 days. Tissues and blood samples were collected 24 h after the last dosing. Cardiac biomarkers such as cardiac troponin I (cTnI), cardiac troponin T (cTnT), and fatty acid binding protein 3 (FABP3) were monitored by the Erenna, Elecsys, and Meso Scale immunoassay systems.

RESULTS

Imb caused microscopic myocardial lesions (myofibrillar loss, cytoplasmic vacuolization, and necrosis) at all doses as determined by unbiased histopathology analysis. The severity of the alterations was dose-related with mean lesion scores (based on a scale of 0-3) of 1.2 (50 mg kg(-1)), 2.1 (100 mg kg(-1)) and 2.9 (200 mg kg(-1)). However, the increases in cTnI, cTnT, and FABP3 levels were noted primarily in high-dose Imb treated animals.

DISCUSSION AND CONCLUSION

The occurrence of myocardial alterations in animals without consistent changes in cardiac troponin and FABP3 concentrations raises questions regarding the utility of these biomarkers as early indicators of Imb-induced cardiotoxicity. Due to limited numbers of animals the reasons for this discrepancy could not be determined.

Catching broken hearts: pre-clinical detection of doxorubicin and trastuzumab mediated cardiac dysfunction in the breast cancer setting

Although breast cancer is one of the leading causes of death in women worldwide, there is an overall improvement in the survival of this patient population. This is likely due to a combination of early detection through screening and awareness, improved targeted biological therapy, and an overall improvement in disease management. Despite the beneficial effects of the 2 anti-cancer drugs doxorubicin (DOX) and trastuzumab (TRZ) in women with breast cancer, development of cardiotoxicity is a major concern. The occurrence of left ventricular systolic dysfunction is unacceptably high in nearly 1 in 4 women treated with DOX+TRZ in the breast cancer setting. In this review, we explore the use of non-invasive cardiac imaging for the early detection of chemotherapy-mediated cardiotoxicity in women with breast cancer, in the hope of preventing end-stage heart disease in this cancer population.

Biomarkers for the early detection of anthracycline-induced cardiotoxicity: current status

BACKGROUND

Cardiotoxicity is a well-known and potentially serious complication of anticancer therapy. Anthracycline-based chemotherapy represents the greatest risk. Early detection of cardiotoxicity is crucial for applying preventive and supportive therapeutic strategies.

METHODS AND RESULTS

Various methods have been recommended for monitoring of cardiotoxicity. In our conditions, echocardiography and electrocardiography are routinely used. However, this approach shows low sensitivity for the early prediction of cardiomyopathy when the possibilities of appropriate management could still improve the patient's outcome. Recently, biomarkers of cardiac injury have been investigated in the assessment of chemotherapy-induced cardiotoxicity. Cardiospecific biomarkers, such as cardiac troponins, show high diagnostic efficacy in the early subclinical phase of the disease before the clinical onset of cardiomyopathy. Increase in their concentrations correlates with disease severity. As for natriuretic peptides, some studies, including ours, have shown promising results. Definitive evidence of their diagnostic and prognostic role in this context is still lacking and natriuretic peptides have not been routinely used for monitoring of cardiotoxicity in clinical practice. Other perspective biomarkers of cardiotoxicity in oncology are under study, especially heart-type fatty acid-binding protein (H-FABP) and glycogen phosphorylase BB (GPBB). Our studies using GPBB have provided encouraging results. However, the available data are limited and their practical use in this context cannot be recommended until their clinical efficacy is clearly defined.

CONCLUSIONS

This review covers the current status of biomarkers for the early detection of anthracycline-induced cardiotoxicity. The authors present in brief, their own experience with multiple biomarkers in the detection of cardiotoxicity.

Recombinant lipoproteins reinforce cytotoxicity of doxorubicin to hepatocellular carcinoma

Cancer nanotherapeutics are changing the landscape of tumor treatment and used to circumvent limitations of conventional chemotherapy, such as non-specificity and low bioavailability. Reconstituted high density lipoproteins (rHDL) system is one of the most promising targeting delivery systems of chemotherapeutic drugs toward tumors. Here, we developed recombined high-density lipoprotein which can be functionalized to deliver doxorubicin intracellular with a higher efficiency. The cellular viability assay showed that the rHDL/Dox nanovectors had an enhanced efficiency in inhibiting the cell viability of hepatocellular carcinoma cell lines HepG2 and SMMC-7721. FACS and confocal microscopy was used to observe the doxorubicin delivery into cancer cells. Intracellular drug accumulation analysis confirmed that treatment of rHDL/Dox nanovectors resulted in higher intracellular doxorubicin concentration to the levels exceeding that of free drug. On the premise of efficient drug delivery, rHDL/Dox nanovectors have been preliminarily demonstrated effective inducing of cytotoxic effect and cell apoptosis to both of the cell lines in vitro. Tissue distribution experiment showed that rHDL/Dox nanovectors could also deliver doxorubicin to liver effectively. So, we proposed that this lipoprotein-based strategy holds promise for a safer and more efficient delivery of chemotherapeutic agents in the treatment of hepatocellular carcinoma.

Cardiac complications of oncologic therapy

As survival rates continue to increase for patients with childhood and adult malignancies, imaging utilization in these patients will likely increase substantially. It is important to detect disease recurrence and to recognize the potential complications that occur after treatment with oncologic medications and therapeutic radiation. The most common cardiotoxic side effect of the anthracycline drug class is a dose-dependent decline in ejection fraction, which may result in dilated cardiomyopathy. Multiple-uptake gated acquisition (MUGA) scanning plays an important role in diagnosis of this subclinical cardiac dysfunction. Other less common cardiotoxic side effects of chemotherapeutic medications include arrhythmia, myocarditis, coronary artery disease, tamponade, pericarditis, and pericardial effusion. Radiation therapy can also lead to cardiotoxicity when the heart or pericardium is included in the radiation portal. Radiation-induced conditions include pericardial disease, coronary artery disease, valvular disease, and cardiomyopathy. Many of these side effects are asymptomatic until late in the course of the disease. With imaging, these pathologic conditions can often be diagnosed before symptom onset, which may allow early intervention. Radiologists should be familiar with the current knowledge and pathophysiology regarding cardiac complications related to chemotherapy and radiation therapy of malignant neoplasms and the appearances of treatment-related cardiotoxicity that can be found at radiography, nuclear medicine examinations, and cross-sectional imaging. Supplemental material available at http://radiographics.rsna.org/lookup/suppl/doi:10.1148/rg.336125005/-/DC1.

Utilization of cardiac monitoring tests in women with nonmetastatic breast cancer treated with trastuzumab

AIMS

Trastuzumab, one of the best known examples of personalized medicine, requires regular cardiac monitoring because it can cause heart failure. We aimed to assess the utilization of cardiac monitoring in women with nonmetastatic breast cancer receiving trastuzumab-based chemotherapy in routine clinical practice.

PATIENTS & METHODS

The medical records of women continuously enrolled in a large national health insurance plan who were diagnosed with nonmetastatic breast cancer and treated with trastuzumab from 2006 to 2008 were reviewed (n = 109). The primary outcome variables were the use and type of cardiac monitoring testing before and during trastuzumab therapy. An exploratory multivariable logistic regression analysis was performed to identify predictors for receiving cardiac monitoring both at baseline and during trastuzumab treatment.

RESULTS

Monitoring both before and during therapy was less common (62%), although 74% had cardiac monitoring before therapy and 80% had at least one test during therapy. Radionuclide ventriculogram was utilized more often than echocardiography (48 vs 42%). Only the use of anthracycline (odds ratio: 2.39; 95% CI: 1.01-5.71) was significantly associated with use of a cardiac monitoring both at baseline and during trastuzumab treatment.

CONCLUSION

The use of cardiac monitoring testing was variable and opportunities to improve quality and reduce cost are evident. These results have clinical implications for other personalized medicine interventions requiring regular laboratory monitoring.

Prediction of anthracycline cardiotoxicity after chemotherapy by biomarkers kinetic analysis

Anthracyclines are active drugs against breast cancer, but can exert cardiotoxic effects. We analyzed the association between the kinetics of various biomarkers during chemotherapy, and the risk of subsequent cardiac toxicity. 50 patients (49 women) with early breast cancer surgically treated and eligible to anthracycline-based adjuvant chemotherapy were analyzed. The left ventricular ejection fraction (LVEF) together with the plasma concentration of several blood markers was measured at the beginning of anthracycline chemotherapy (t (0)), 5 months (t (1)), 16 months (t (2)), 28 months (t (3)), and 40 months later (t (4)). A single measured LVEF value less than 50% or a clinically overt congestive heart failure (CHF) was considered cardiotoxic effects. We tested whether the kinetics of LVEF and blood biomarkers measured during chemotherapy was predictive of subsequent cardiotoxicity and overall cardiac fitness. The left ventricular ejection fraction measured at the end of treatment as well as the rate of change of hemoglobin concentration during anthracycline-based chemotherapy predicted cardiotoxicity in a 3-year follow-up period. When LVEF at the end of chemotherapy was lower than 53% or hemoglobin blood concentration declined more than 0.33 g/dL/month during chemotherapy, the odds ratio of subsequent cardiotoxicity was 37.3 and 18, respectively. The specificity of these two tests was 93.3% and 80%, whereas the sensitivity was 90.9 and 81.2%, respectively. Testing the rate of change of hemoglobin concentration during anthracycline-based chemotherapy, as well as the left ventricular ejection fraction at the end of treatment, seems a powerful method to assess the effects of anthracyclines on cardiac fitness and identify patients at high risk of CHF. Further validation of these tests on a large cohort of patients and cost-benefit analysis should be encouraged.

Current applications of cardiac troponin T for the diagnosis of myocardial damage

Biochemical markers of myocardial injury play an important role in the diagnosis of cardiovascular diseases. Measurement of cardiac biomarkers is one of the most important diagnostic tests in acute myocardial infarction (AMI), heart failure, and other cardiovascular disorders. Recently, the European Society of Cardiology, the American College of Cardiology Foundation, the American Heart Association, and the World Heart Federation have published a consensus definition of AMI that includes a detailed guideline for the assessment of biochemical markers in suspected disease. The cardiac troponins (cTI and cTnT) were recommended as preferred markers of myocardial necrosis in this setting. Herein, we review cardiac troponin biochemistry, the performance characteristics of cTnT assays, and optimal utilization of troponin in patients with proven or possible cardiovascular disease. We also discuss the use of troponin tests, with emphasis on cTnT, in different clinical situations in which its levels may be elevated.

Effect of cationic side-chains on intracellular delivery and cytotoxicity of pH sensitive polymer-doxorubicin nanocarriers

Fine-tuning the design of polymer-doxorubicin conjugates permits optimization of an efficient nanocarrier to greatly increase intracellular uptake and cytotoxicity. Here, we report synthesis of a family of self-assembled polymer-doxorubicin nanoparticles and an evaluation of the effects of various types of side-chains on intracellular uptake and cytotoxicity of the nanocarriers for lymphoma cells. Monomers with three different cationic side-chains (CA) and pK(a)'s, i.e., a guanidinium group (Ag), an imidazole group (Im), and a tertiary amine group (Dm), were comparatively investigated. The cationic monomer, poly(ethylene glycol) (PEG), and doxorubicin (Dox) were reacted with 1,4-(butanediol) diacrylate (BUDA) to prepare a poly(β-amino ester) (PBAE) polymer via Michael addition. All three polymer-Dox conjugates spontaneously formed nanoparticles (NP) through hydrophobic interactions between doxorubicin in aqueous solution, resulting in NP-Im/Dox, NP-Ag/Dox, and NP-Dm/Dox, with hydrodynamic sizes below 80 nm. Doxorubicin was linked to all 3 types of NPs with a hydrazone bond to assure selective release of doxorubicin only at acidic pH, as it occurs in the tumor microenvironment. Both NP-Im/Dox and NP-Ag/Dox exhibited much higher intracellular uptake by Ramos cells (Burkitt's lymphoma) than NP-Dm/Dox, suggesting that the type of side chain in the NPs determines the extent of intracellular uptake. As a result, NP-Im/Dox and NP-Ag/Dox showed cytotoxicity that was comparable to free Dox in vitro. Our findings suggest that the nature of surface cationic group on nanocarriers may profoundly influence their intracellular trafficking and resulting therapeutic efficacy. Thus, it is a crucial factor to be considered in the design of novel carriers for intracellular drug delivery.

Chemotherapy-induced cardiotoxicity

Anthracycline-based chemotherapeutics have long been recognized as effective agents for treating a wide range of malignancies. However, their use is not without significant adverse cardiotoxic side effects. Strategies for prevention involve limiting free-radical production and subsequent cardiac myocyte damage. Dexrazoxane remains the most widely studied cardioprotective medication. Alternative agents may reduce cardiotoxicity but may still cause significant cardiovascular problems. The role of β-blockers and angiotensin-converting enzyme inhibitors in the treatment of heart failure is well proven. The role of these medications in the prevention and treatment of chemotherapy-induced cardiotoxicity is not well established.

[Cardiotoxicity of chemotherapies]

The spectrum of chemotherapy's cardiac side effect of chemotherapy has expanded with the new combinations of cytotoxic and targeted therapies over the past 10 years. Moreover, cancer therapy administrated to "new" populations, especially elderly patients or patients with cardiovascular disease and/or coronary artery disease history, has increased considerably. According to the American College of Cardiology and American Heart Association (ACC/AHA), patients receiving chemotherapy can be considered in the A group of heart failure. Many cardiovascular adverse effects appear with cancer therapy and suspend treatment purchase, or leading to an alteration of quality of life, and increasing mortality risks. The most clinically evident cardiotoxicity and best known is the anthracyclines adverse effect. Other cytotoxic are associated with a significant risk of cardiovascular complications include alkylating agents such as 5-fluorouracil and paclitaxel. Cardiovascular adverse effects are associated with the use of targeted therapies such as tyrosine kinase inhibitors: trastuzumab, bevacizumab. At the same time, drugs used to hematological malignancies, as acid all-trans-retinoic acid and arsenic trioxide are cardiotoxics. The most serious cardiac complications of cancer therapies is heart congestive failure, mainly due to the use of anthracyclines, cyclophosphamide and trastuzumab, usually at high doses. Myocardial ischemia is mainly caused by interferon and antimetabolites. Other side effects may occur such as hypotension, hypertension, arrhythmias and conduction disturbances, pericarditis, and thromboembolic complications.

Changes in cardiac biomarkers during doxorubicin treatment of pediatric patients with high-risk acute lymphoblastic leukemia: associations with long-term echocardiographic outcomes

PURPOSE

Doxorubicin causes cardiac injury and cardiomyopathy in children with acute lymphoblastic leukemia (ALL). Measuring biomarkers during therapy might help individualize treatment by immediately identifying cardiac injury and cardiomyopathy.

PATIENTS AND METHODS

Children with high-risk ALL were randomly assigned to receive doxorubicin alone (n = 100; 75 analyzed) or doxorubicin with dexrazoxane (n = 105; 81 analyzed). Echocardiograms and serial serum measurements of cardiac troponin T (cTnT; cardiac injury biomarker), N-terminal pro-brain natriuretic peptide (NT-proBNP; cardiomyopathy biomarker), and high-sensitivity C-reactive protein (hsCRP; inflammatory biomarker) were obtained before, during, and after treatment.

RESULTS

cTnT levels were increased in 12% of children in the doxorubicin group and in 13% of the doxorubicin-dexrazoxane group before treatment but in 47% and 13%, respectively, after treatment (P = .005). NT-proBNP levels were increased in 89% of children in the doxorubicin group and in 92% of children in the doxorubicin-dexrazoxane group before treatment but in only 48% and 20%, respectively, after treatment (P = .07). The percentage of children with increased hsCRP levels did not differ between groups at any time. In the first 90 days of treatment, detectable increases in cTnT were associated with abnormally reduced left ventricular (LV) mass and LV end-diastolic posterior wall thickness 4 years later (P < .01); increases in NT-proBNP were related to an abnormal LV thickness-to-dimension ratio, suggesting LV remodeling, 4 years later (P = .01). Increases in hsCRP were not associated with any echocardiographic variables.

CONCLUSION

cTnT and NT-proBNP may hold promise as biomarkers of cardiotoxicity in children with high-risk ALL. Definitive validation studies are required to fully establish their range of clinical utility.

Value of echocardiography and electrocardiography as screening tools prior to Doxorubicin administration

The dose-limiting toxicity of doxorubicin is cardiotoxicosis. The authors of this report hypothesized that by using their institution's adopted guidelines (that involve prescreening echocardiography and electrocardiography), they would detect pre-existing cardiac abnormalities that preclude doxorubicin administration in <10% of dogs. Of 101 dogs, only 6 were excluded from doxorubicin administration based on electrocardiogram abnormalities, with a majority of those arrhythmias classified as ventricular premature contractions. One patient was excluded based on echocardiogram alone due to hypertrophic cardiomyopathy. The incidence of cardiotoxicity in treated dogs was 8% (8/101). Additional pretreatment and ongoing studies are indicated to identify risk factors for cardiotoxicity.

A multifaceted evaluation of imatinib-induced cardiotoxicity in the rat

Cardiotoxicity was an unanticipated side effect elicited by the clinical use of imatinib (Imb). This toxicity has been examined in only a limited number of experimental studies. The present study sought, by a variety of approaches, to identify important characteristics of Imb-induced cardiac alterations. Male spontaneously hypertensive rats (SHRs) received oral doses of 10, 30, or 50 mg/kg Imb or water daily for 10 d. Cardiac lesions, detected at all doses, were characterized by cytoplasmic vacuolization and myofibrillar loss. In a second experiment, cardiac lesions were found in Sprague Dawley (SD) and SHR rats given 50 or 100 mg/kg Imb for 14 d. Mean cardiac lesion scores and serum levels of cardiac troponin I were higher in SHRs than in SD rats. Imb induced myocyte death by necrosis, autophagy, and apoptosis. Dose-related increases in cardiac expression were observed for several genes associated with endoplasmic reticulum stress response, protein folding, and vascular development and remodeling. Imb caused alterations in isolated myocytes (myofibrillar loss, highly disrupted and disorganized sarcomeric α-actinin, apoptosis, and increased lactate dehydrogenase release) at low concentrations (5 mM). The authors conclude that Imb exerts cardiotoxic effects that are manifest through a complex pattern of cellular alterations, the severity of which can be influenced by arterial blood pressure.

Doxorubicin-induced cardiotoxicity in adult Indian patients on chemotherapy

Background:

Doxorubicin-induced cardiotoxicity is widely known to occur at cumulative doses exceeding 450 mg/m². However, very few studies have reported incidence of cardiac dysfunction in patients on chemotherapy with lower cumulative doses. To the best of our knowledge, there is no study carried out so far that has reported the incidence of cardiac dysfunction in adult Indian patients receiving doxorubicin. This study was undertaken to determine the incidence of doxorubicin-induced cardiotoxicity by serial resting echocardiography in patients on chemotherapy and identify risk factors associated with cardiotoxicity.

Materials and Methods:

Patients that were started on doxorubicin-based chemotherapy in the period from January 2000 to June 2001 and had completed at least 300 mg/m² cumulative dose were taken in the study. Electrocardiography, chest X-ray and echocardiography were done at baseline, at 300 mg/m² and at 450 mg/m² cumulative doses of doxorubicin. All patients were evaluated for the presence of the following risk factors: Age>70 years, female sex, preexisting cardiac disease, hypertension, chest wall irradiation, body mass index (BMI)<20 kg/m² , Karnofsky performance status, combination chemotherapy with cyclophosphamide and presence of liver disease. Subclinical cardiac dysfunction was defined as ejection fraction fall greater than 10% on follow-up echocardiography.

Results:

Thirty patients satisfied the criterion for being considered for evaluation. One (3%) patient developed congestive cardiac failure, while 8 (27%) patients developed subclinical cardiac dysfunction. Concomitant use of cyclophosphamide significantly increased the risk of cardiac dysfunction (P = 0.048), while low BMI (<20 kg/m²) and preexisting cardiac disease showed a trend towards increased risk of cardiac dysfunction (P = 0.07 for both).

Conclusion:

Twenty-seven percent of the patients developed subclinical cardiac dysfunction in the cumulative dose range of 300-450 mg/m² . This entails regular monitoring for cardiac dysfunction by echocardiography during treatment.

Scintigraphic techniques for early detection of cancer treatment-induced cardiotoxicity

New antitumor agents have resulted in significant survival benefits for cancer patients. However, several agents may have serious cardiovascular side effects. Left ventricular ejection fraction measurement by (99m)Tc multigated radionuclide angiography is regarded as the gold standard to measure cardiotoxicity in adult patients. It identifies left ventricular dysfunction with high reproducibility and low interobserver variability. A decrease in left ventricular ejection fraction, however, is a relatively late manifestation of myocardial damage. Nuclear cardiologic techniques that visualize pathophysiologic processes at the tissue level could detect myocardial injury at an earlier stage. These techniques may give the opportunity for timely intervention to prevent further damage and could provide insights into the mechanisms and pathophysiology of cardiotoxicity caused by anticancer agents. This review provides an overview of past, current, and promising newly developed radiopharmaceuticals and describes the role and recent advances of scintigraphic techniques to measure cardiotoxicity. Both first-order functional imaging techniques (visualizing mechanical [pump] function), such as (99m)Tc multigated radionuclide angiography and (99m)Tc gated blood-pool SPECT, and third-order functional imaging techniques (visualizing pathophysiologic and neurophysiologic processes at the tissue level) are discussed. Third-order functional imaging techniques comprise (123)I-metaiodobenzylguanidine scintigraphy, which images the efferent sympathetic nervous innervations; sympathetic neuronal PET, with its wide range of tracers; (111)In-antimyosin, which is a specific marker for myocardial cell injury and necrosis; (99m)Tc-annexin V scintigraphy, which visualizes apoptosis and cell death; fatty-acid-use scintigraphy, which visualizes the storage of free fatty acids in the lipid pool of the cytosol (which can be impaired by cardiotoxic agents); and (111)In-trastuzumab imaging, to study trastuzumab targeting to the myocardium. To define the prognostic importance and clinical value of each of these functional imaging techniques, prospective clinical trials are warranted.

Cardio-oncology/onco-cardiology

An understanding of onco-cardiology or cardio-oncology is critical for the effective care of cancer patients. Virtually all antineoplastic agents are associated with cardiotoxicity, which can be divided into 5 categories: direct cytotoxic effects of chemotherapy and associated cardiac systolic dysfunction, cardiac ischemia, arrhythmias, pericarditis, and chemotherapy-induced repolarization abnormalities. Radiation therapy can also lead to coronary artery disease and fibrotic changes to the valves, pericardium, and myocardium. All patients being considered for chemotherapy, especially those who have prior cardiac history, should undergo detailed cardiovascular evaluation to optimize the treatment. Serial assessment of left ventricular systolic function and cardiac biomarkers might also be considered in selected patient populations. Cardiotoxic effects of chemotherapy might be decreased by the concurrent use of angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, or beta-blockers. Antiplatelet or anticoagulation therapy might be considered in patients with a potential hypercoagulable state associated with chemotherapy or cancer. Open dialogue between both cardiologists and oncologists will be required for optimal patient care.

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.

The delivery of doxorubicin to 3-D multicellular spheroids and tumors in a murine xenograft model using tumor-penetrating triblock polymeric micelles

Doxorubicin (DOX) is an effective chemotherapeutic against a wide range of solid tumors. However, its clinical use is limited by severe side effects such as cardiotoxicity as well as inherent and acquired drug resistance of tumors. DOX encapsulation within self-assembled polymeric micelles has the potential to decrease the systemic distribution of free drug and enhance the drug accumulation in the tumor via the enhanced permeability and retention (EPR). In this study, DOX was encapsulated in micelles composed of poly (ethylene oxide)-poly [(R)-3-hydroxybutyrate]-poly (ethylene oxide) (PEO-PHB-PEO) triblock copolymers. Micelle size, DOX loading and DOX release were characterized. To evaluate DOX activity, micelles were tested in both monolayer cell cultures and three-dimensional (3-D) multicellular spheroids (MCS) that mimic solid tumors. Antitumor activity in vivo was further studied with tumor-bearing mice. The micelles improved the efficiency of Dox penetration in 3-D MCS compared with free DOX. Efficient cell killing by Dox-micelles in both monolayer cells and 3-D MCS was also demonstrated. Finally, DOX-loaded micelles mediate efficient tumor delivery from tail vein injections to tumor-bearing mice with much less toxicity compared with free DOX.

Role of three-dimensional echocardiography in breast cancer: comparison with two-dimensional echocardiography, multiple-gated acquisition scans, and cardiac magnetic resonance imaging

PURPOSE

In patients with breast cancer, the administration of doxorubicin and trastuzumab is associated with an increased risk of cardiotoxicity. Although multiple-gated acquisition (MUGA) scans and two-dimensional transthoracic echocardiography (TTE) are conventional methods for baseline and serial assessment of left ventricular ejection fraction (LVEF) in these patients, little is known about the use of real-time three-dimensional TTE (RT3D TTE) in this clinical setting. The aim of this study was to assess the accuracy of MUGA, 2D TTE, and RT3D TTE for determining LVEF in comparison to cardiac magnetic resonance imaging (CMR).

METHODS

Between 2007 and 2009 inclusive, 50 female patients with human epidermal growth factor receptor 2-positive breast cancer received adjuvant trastuzumab after doxorubicin. Serial MUGA, 2D TTE, RT3D TTE, and CMR were performed at baseline, 6, and 12 months after the initiation of trastuzumab.

RESULTS

A comparison of left ventricular end diastolic volume (LVEDV) demonstrated a modest correlation between 2D TTE and CMR (r = 0.64 at baseline; r = 0.69 at 12 months, respectively). A comparison of LVEDV between RT3D TTE and CMR demonstrated a stronger correlation (r = 0.87 at baseline; r = 0.95 at 12 months, respectively). Although 2D TTE demonstrated a weak correlation with CMR for LVEF assessment (r = 0.31 at baseline, r = 0.42 at 12 months, respectively), both RT3D TTE and MUGA showed a strong correlation when compared with CMR (r = 0.91 at baseline; r = 0.90 at 12 months, respectively).

CONCLUSION

As compared with conventional MUGA, RT3D TTE is a feasible, accurate, and reproducible alternate imaging modality for the serial monitoring of LVEF in patients with breast cancer.