Cardiovascular toxicity induced by chemotherapy, targeted agents and radiotherapy: ESMO Clinical Practice Guidelines

Cardiovascular (CV) toxicity is a potential short- or long-term complication of various anticancer therapies. Some drugs, such as anthracyclines or other biological agents, have been implicated in causing potentially irreversible clinically important cardiac dysfunction. Although targeted therapies are considered less toxic and better tolerated by patients compared with classic chemotherapy agents, rare but serious complications have been described, and longer follow-up is needed to determine the exact profile and outcomes of related cardiac side-effects. Some of these side-effects are irreversible, leading to progressive CV disease, and some others induce reversible dysfunction with no long-term cardiac damage to the patient. Assessment of the prevalence, type and severity of cardiac toxicity caused by various cancer treatments is a breakthrough topic for patient management. Guidelines for preventing, monitoring and treating cardiac side-effects are a major medical need. Efforts are needed to promote strategies for cardiac risk prevention, detection and management, avoiding unintended consequences that can impede development, regulatory approval and patient access to novel therapy. These new ESMO Clinical Practice Guidelines are the result of a multidisciplinary cardio-oncology review of current evidence with the ultimate goal of providing strict criteria-based recommendations on CV risk prevention, assessment, monitoring and management during anticancer treatment.

How can we improve our understanding of cardiovascular safety liabilities to develop safer medicines?

Given that cardiovascular safety liabilities remain a major cause of drug attrition during preclinical and clinical development, adverse drug reactions, and post-approval withdrawal of medicines, the Medical Research Council Centre for Drug Safety Science hosted a workshop to discuss current challenges in determining, understanding and addressing 'Cardiovascular Toxicity of Medicines'. This article summarizes the key discussions from the workshop that aimed to address three major questions: (i) what are the key cardiovascular safety liabilities in drug discovery, drug development and clinical practice? (ii) how good are preclinical and clinical strategies for detecting cardiovascular liabilities? and (iii) do we have a mechanistic understanding of these liabilities? It was concluded that in order to understand, address and ultimately reduce cardiovascular safety liabilities of new therapeutic agents there is an urgent need to: • Fully characterize the incidence, prevalence and impact of drug-induced cardiovascular issues at all stages of the drug development process. • Ascertain the predictive value of existing non-clinical models and assays towards the clinical outcome. • Understand the mechanistic basis of cardiovascular liabilities; by addressing areas where it is currently not possible to predict clinical outcome based on preclinical safety data. • Provide scientists in all disciplines with additional skills to enable them to better integrate preclinical and clinical data and to better understand the biological and clinical significance of observed changes. • Develop more appropriate, highly relevant and predictive tools and assays to identify and wherever feasible to eliminate cardiovascular safety liabilities from molecules and wherever appropriate to develop clinically relevant and reliable safety biomarkers.

Phase separation of ligand-activated enhancers licenses cooperative chromosomal enhancer assembly

A crucial feature of differentiated cells is the rapid activation of enhancer-driven transcriptional programs in response to signals. The potential contributions of physicochemical properties of enhancer assembly in signaling events remain poorly understood. Here we report that in human breast cancer cells, the acute 17β-estradiol-dependent activation of functional enhancers requires assembly of an enhancer RNA-dependent ribonucleoprotein (eRNP) complex exhibiting properties of phase-separated condensates. Unexpectedly, while acute ligand-dependent assembly of eRNPs resulted in enhancer activation sensitive to chemical disruption of phase separation, chronically activated enhancers proved resistant to such disruption, with progressive maturation of eRNPs to a more gel-like state. Acute, but not chronic, stimulation resulted in ligand-induced, condensin-dependent changes in spatial chromatin conformation based on homotypic enhancer association, resulting in cooperative enhancer-activation events. Thus, distinct physicochemical properties of eRNP condensates on enhancers serve as determinants of rapid ligand-dependent alterations in chromosomal architecture and cooperative enhancer activation.

T-cell brain infiltration and immature antigen-presenting cells in transgenic models of Alzheimer's disease-like cerebral amyloidosis

Cerebral beta-amyloidosis, one of the pathological hallmarks of Alzheimer's disease (AD), elicits a well-characterised, microglia-mediated local innate immune response. In contrast, it is not clear whether cells of the adaptive immune system, in particular T-cells, react to cerebral amyloidosis in AD. Even though parenchymal T-cells have been described in post-mortem brains of AD patients, it is not known whether infiltrating T-cells are specifically recruited to the extracellular deposits of beta-amyloid, and whether they are locally activated into proliferating, effector cells upon interaction with antigen-presenting cells (APCs). To address these issues we have analysed by confocal microscopy and flow-cytometry the localisation and activation status of both T-cells and APCs in transgenic (tg) mice models of AD-like cerebral amyloidosis. Increased numbers of infiltrating T-cells were found in amyloid-burdened brain regions of tg mice, with concomitant up-regulation of endothelial adhesion molecules ICAM-1 and VCAM-1, compared to non-tg littermates. The infiltrating T-cells in tg brains did not co-localise with amyloid plaques, produced less interferon-gamma than those in controls and did not proliferate locally. Bona-fide dendritic cells were virtually absent from the brain parenchyma of both non-tg and tg mice, and APCs from tg brains showed an immature phenotype, with accumulation of MHC-II in intracellular compartments. These results indicate that cerebral amyloidosis promotes T-cell infiltration but interferes with local antigen presentation and T-cell activation. The inability of the brain immune surveillance to orchestrate a protective immune response to amyloid-beta peptide might contribute to the accumulation of amyloid in the progression of the disease.

Ligand-dependent enhancer activation regulated by topoisomerase-I activity

The discovery that enhancers are regulated transcription units, encoding eRNAs, has raised new questions about the mechanisms of their activation. Here, we report an unexpected molecular mechanism that underlies ligand-dependent enhancer activation, based on DNA nicking to relieve torsional stress from eRNA synthesis. Using dihydrotestosterone (DHT)-induced binding of androgen receptor (AR) to prostate cancer cell enhancers as a model, we show rapid recruitment, within minutes, of DNA topoisomerase I (TOP1) to a large cohort of AR-regulated enhancers. Furthermore, we show that the DNA nicking activity of TOP1 is a prerequisite for robust eRNA synthesis and enhancer activation and is kinetically accompanied by the recruitment of ATR and the MRN complex, followed by additional components of DNA damage repair machinery to the AR-regulated enhancers. Together, our studies reveal a linkage between eRNA synthesis and ligand-dependent TOP1-mediated nicking-a strategy exerting quantitative effects on eRNA expression in regulating AR-bound enhancer-dependent transcriptional programs.

Pooled analysis of cardiac safety in patients with cancer treated with pertuzumab

BACKGROUND

Pertuzumab, a human epidermal growth factor receptor (HER) 2 dimerization inhibitor, has demonstrated promising efficacy in combination with trastuzumab in patients with metastatic breast cancer. As HER signaling pathways are not only involved in oncogenesis, but also in myocardial homeostasis, an analysis of cardiac safety data was undertaken in a large group of patients treated with pertuzumab.

PATIENTS AND METHODS

A complete database of patients treated with full-dose pertuzumab was used to describe the incidence of asymptomatic left ventricular systolic dysfunction (LVSD) and symptomatic heart failure (HF).

RESULTS

Information for 598 unique patients was available for the current analysis. Of the patients treated with pertuzumab alone (n = 331) or pertuzumab in combination with a non-anthracycline-containing cytotoxic (n = 175) or trastuzumab (n = 93), 23 (6.9%), 6 (3.4%), and 6 (6.5%), respectively, developed asymptomatic LVSD and 1 (0.3%), 2 (1.1%), and 1 (1.1%), respectively, displayed symptomatic HF. None of the 15 patients receiving both pertuzumab and erlotinib demonstrated LVSD.

CONCLUSIONS

Patients treated with pertuzumab experienced relatively low levels of asymptomatic LVSD or symptomatic HF. There was no notable increase in cardiac side-effects when pertuzumab was given in combination with other anticancer agents.

Validation of a new automatic system for biplane quantitative coronary arteriography

In a collaboration between the University of Texas (software) and the University of Zürich (hardware) a compact, automatic system for biplane quantitative coronary arteriography was developed. The system is based on a 35 mm film projector, a slow-scan CCD-camera (image digitizing) and a computer workstation (Apollo DN 3000, image storage and processing). A new calibration procedure based on two fixed reference points in the center of the image intensifier was used (isocenter technique). Contour detection of coronary arteries was carried out in biplane projection using a geometric-densitometric edge-detection algorithm. The proximal and distal luminal areas, as well as the minimal luminal area of the stenotic vessel segment were determined. Accuracy and precision were determined from precision drilled holes in a plexiglas cube which were filled with 50%, 75% and 100% contrast medium. The diameter of the holes ranged from 0.5 to 5.0 mm. The mean difference and the standard deviation of the differences between the true and the measured diameters were 0.12 +/- 0.14 mm for plane A and 0.26 +/- 0.17 mm for plane B, respectively. After a second order correction the mean difference amounted to 0.02 +/- 0.09 mm for plane A and 0.02 +/- 0.12 mm for plane B, respectively. Intra- and interobserver variability were evaluated in 5 patients (age 60 +/- 10 years) with coronary artery disease using 16 normal and 5 stenotic vessel segments (cross-sectional area ranging from 0.8 to 8.7 mm2). Two independent observers analyzed the same vessel segment twice. Intraobserver variability expressed as the standard error of estimate in percent of the mean angiographic vessel area (SEE) amounted to 2.1% for observer 1 and 4.4% for observer 2, respectively. Interobserver variability expressed as SEE was 4.1% for measurement 1 and 3.6% for measurement 2, respectively.

Normalization of abnormal coronary vasomotion by calcium antagonists in patients with hypertension

BACKGROUND

Endothelial dysfunction with a loss of endothelium-dependent vasodilation has been reported in patients with arterial hypertension. The purpose of the present study was to evaluate coronary vasomotor response to dynamic exercise in patients with coronary artery disease with and without arterial hypertension and to determine the effect of calcium antagonists on coronary vasomotion.

METHODS AND RESULTS

Cross-sectional areas of a normal and a stenotic coronary vessel segment were examined in 79 patients with coronary artery disease at rest and during supine bicycle exercise (Ex). Change in luminal area after acute administration of a calcium antagonist (diltiazem or nicardipine), during exercise, and after sublingual nitroglycerin (percent change compared with rest = 100%) was assessed by biplane quantitative coronary arteriography. Patients were divided into two groups: Group 1 (control) consisted of 48 patients without (normotensive subjects, n = 30; hypertensive subjects, n = 18) and group 2 of 31 patients with (normotensive subjects, n = 15; hypertensive subjects, n = 16) pretreatment with a calcium antagonist immediately before exercise. The groups did not differ with regard to clinical characteristics or hemodynamic data measured during exercise. Mean aortic pressure at rest, however, was significantly increased in hypertensive patients compared with normotensive subjects in group 1 (103 mm Hg versus 92 mm Hg, P < .01) and group 2 (110 mm Hg versus 98 mm Hg, P < .025). In group 1, exercise-induced vasomotor response was significantly different between normotensive and hypertensive patients in normal (+20% versus +1%, P < .003) and stenotic vessels (-5% versus -20%, P < .025). However, in group 2 there was coronary vasodilation in normotensive and hypertensive patients for both normal (delta Ex +23% versus +21%, P = NS) and stenotic vessel segments (+24% versus +26%, P = NS).

CONCLUSIONS

Abnormal coronary vasomotion during exercise can be observed in hypertensive patients with reduced vasodilator response in normal arteries and enhanced vasoconstrictor response in stenotic arteries. Calcium antagonists prevent the abnormal response of normal and stenotic coronary arteries to exercise in hypertensive patients and thus may compensate for endothelial dysfunction with reduced vasodilator response to exercise.

Final efficacy and updated safety results of the randomized phase III BEATRICE trial evaluating adjuvant bevacizumab-containing therapy in triple-negative early breast cancer

Background

The purpose of this analysis was to assess the long-term impact of adding bevacizumab to adjuvant chemotherapy for early triple-negative breast cancer (TNBC).

Methods

Patients eligible for the open-label randomized phase III BEATRICE trial had centrally confirmed triple-negative operable primary invasive breast cancer (pT1a-pT3). Investigators selected anthracycline- and/or taxane-based chemotherapy for each patient. After definitive surgery, patients were randomized 1:1 to receive ≥4 cycles of chemotherapy alone or with 1 year of bevacizumab (5 mg/kg/week equivalent). Stratification factors were nodal status, selected chemotherapy, hormone receptor status, and type of surgery. The primary end point was invasive disease-free survival (IDFS; previously reported). Secondary outcome measures included overall survival (OS) and safety.

Results

After 56 months' median follow-up, 293 of 2591 randomized patients had died. There was no statistically significant difference in OS between treatment arms in either the total population (hazard ratio 0.93, 95% confidence interval [CI] 0.74-1.17; P = 0.52) or pre-specified subgroups. The 5-year OS rate was 88% (95% CI 86-90%) in both treatment arms. Updated IDFS results were consistent with the primary IDFS analysis. Five-year IDFS rates were 77% (95% CI 75-79%) with chemotherapy alone versus 80% (95% CI 77-82%) with bevacizumab. From 18 months after first study dose to study end, new grade ≥3 adverse events occurred in 4.6% and 4.5% of patients in the two arms, respectively.

Conclusion

Final OS results showed no significant benefit from bevacizumab therapy for early TNBC. Late-onset toxicities were rare in both groups. Five-year OS and IDFS rates suggest that the prognosis for patients with TNBC is better than previously thought.

ClinicalTrials.gov

NCT00528567.

Antibodies to the junctional adhesion molecule cause disruption of endothelial cells and do not prevent leukocyte influx into the meninges after viral or bacterial infection

A hallmark of infectious meningitis is the invasion of leukocytes into the subarachnoid space. In experimental meningitis triggered by tumor necrosis factor-alpha and interleukin-1beta, the interaction of leukocytes with endothelial cells and the subsequent migration of the cells through the vessel wall can be inhibited by an antibody to the junctional adhesion molecule (JAM). In contrast to the cytokine-induced meningitis model, anti-JAM antibodies failed to prevent leukocyte influx into the central nervous system after infection of mice with Listeria monocytogenes or lymphocytic choriomeningitis virus. Furthermore, in bacterial meningitis, anti-JAM IgG antibodies, but not Fab fragments, caused disruption of the endothelium. Likewise complement-dependent antibody-mediated cytotoxicity was observed in cultured brain endothelial cells treated with anti-JAM IgG but not with its Fab fragment.

Dendritic cells and differential usage of the MHC class II transactivator promoters in the central nervous system in experimental autoimmune encephalitis

In the normal central nervous system (CNS) expression of MHC class II is minimal, but has been found to be highly up-regulated on microglia cells in experimental autoimmune encephalitis (EAE). Here we used the EAE model to examine the regulation of expression of the class II transactivator (CIITA), which is required for activation of MHC class II genes. EAE was induced in C57BL/6 mice by immunization with myelin oligodendrocyte glycoprotein peptide 35-55. CIITA mRNA form I (specific for dendritic cells) and form IV (IFN-gamma inducible) but not form III (B cell specific) were detected in brain and spinal cord of mice with acute EAE. In unimmunized or mock-immunized mice, none of the three CIITA forms was found to be induced. Dendritic cells (DC) were identified by immunostainings for CD11c in perivascular and meningeal cell infiltrates in EAE spinal cord and brain. Time-course analysis showed (1) the appearance of DC in the CNS shortly before onset of disease, (2) the recruitment of CD11b cells occuring much earlier and (3) the absence of CIITA and MHC class II expression in these CD11b+ cells at preclinical stages.

The value of transvaginal sonography with and without saline instillation in the diagnosis of uterine pathology in pre- and postmenopausal women with abnormal bleeding or suspect sonographic findings

In this prospective study, 139 patients, 83 premenopausal patients with abnormal uterine bleeding and 56 postmenopausal patients either with metrorrhagia (33) or a suspect sonographic finding (23), were examined preoperatively with transvaginal sonography (TVS) and saline contrast hysterosonography (SCHS). The histological results, obtained by hysteroscopy, were compared with the preoperative findings. Uterine pathology (benign polyps, submucous fibroids, endometrial hyperplasia and carcinoma) was found in 74.7% and 76.8% of the pre- and postmenopausal patients, respectively. TVS and SCHS are very sensitive at diagnosing uterine pathology, the latter being more specific and enabling better surgical management and a reduction in unnecessary interventions.

Pluripotency factors functionally premark cell-type-restricted enhancers in ES cells

Enhancers for embryonic stem (ES) cell-expressed genes and lineage-determining factors are characterized by conventional marks of enhancer activation in ES cells1-3, but it remains unclear whether enhancers destined to regulate cell-type-restricted transcription units might also have distinct signatures in ES cells. Here we show that cell-type-restricted enhancers are 'premarked' and activated as transcription units by the binding of one or two ES cell transcription factors, although they do not exhibit traditional enhancer epigenetic marks in ES cells, thus uncovering the initial temporal origins of cell-type-restricted enhancers. This premarking is required for future cell-type-restricted enhancer activity in the differentiated cells, with the strength of the ES cell signature being functionally important for the subsequent robustness of cell-type-restricted enhancer activation. We have experimentally validated this model in macrophage-restricted enhancers and neural precursor cell (NPC)-restricted enhancers using ES cell-derived macrophages or NPCs, edited to contain specific ES cell transcription factor motif deletions. DNA hydroxyl-methylation of enhancers in ES cells, determined by ES cell transcription factors, may serve as a potential molecular memory for subsequent enhancer activation in mature macrophages. These findings suggest that the massive repertoire of cell-type-restricted enhancers are essentially hierarchically and obligatorily premarked by binding of a defining ES cell transcription factor in ES cells, dictating the robustness of enhancer activation in mature cells.

Effect of intravenous propranolol on coronary vasomotion at rest and during dynamic exercise in patients with coronary artery disease

Coronary vasomotion was studied at rest and during bicycle exercise with biplane quantitative coronary arteriography in 28 patients with coronary artery disease. Patients were divided into two groups; the first 18 patients served as controls (group 1), and the next 10 patients were treated with propranolol 0.1 mg/kg, which was infused intravenously before exercise (group 2). Luminal area of a normal and a stenotic vessel segment was determined at rest, during supine bicycle exercise, and 5 minutes after sublingual administration of 1.6 mg nitroglycerin after exercise. In group 1, the normal vessel showed vasodilation (+16%, p less than 0.001) during exercise, whereas the stenotic vessel segment showed vasoconstriction (-31%, p less than 0.001). After sublingual administration of nitroglycerin, there was coronary vasodilation of both normal (+36%, p less than 0.001 vs. rest) and stenotic (+20%, p less than 0.001) vessel segments. Patients with angina pectoris during supine exercise (n = 10) had significantly (p less than 0.05) more vasoconstriction (-36%) than patients without angina (-23%). In group 2, intravenous administration of propranolol at rest was associated with a decrease in luminal area of both normal (-24%, p less than 0.001) and stenotic (-43%, p less than 0.001) vessel segments; however, during subsequent exercise, both normal (-2%, p = NS vs. rest) and stenotic (-3%, p = NS vs. rest) vessel segments dilated when compared with the measurements after propranolol. Administration of nitroglycerin further increased luminal area of both vessel segments (normal segment, +23%, p less than 0.001; stenotic segment, +46%, p less than 0.001 vs. rest). It is concluded that dynamic exercise in patients with coronary artery disease is associated with coronary vasodilation of the normal and vasoconstriction of the stenotic coronary arteries. Patients with exercise-induced angina had significantly more stenosis vasoconstriction than patients without angina although minimal luminal area at rest was similar. Intravenous administration of propranolol is accompanied by a significant decrease in coronary luminal area of both normal and stenotic vessel segments at rest, which is overridden by dynamic exercise and sublingual nitroglycerin. The reduction in myocardial oxygen consumption and the prevention of exercise-induced stenosis vasoconstriction might explain the beneficial effect of beta-blocker treatment in most patients with coronary artery disease.

Abnormal coronary vasomotion in hypertension: role of coronary artery disease

OBJECTIVES

This study sought to evaluate the effect of dynamic exercise on coronary vasomotion in hypertensive patients in the presence and absence of coronary artery disease.

BACKGROUND

Endothelial dysfunction with abnormal coronary vasodilation in response to acetylcholine has been reported in patients with arterial hypertension.

METHODS

Coronary artery dimensions of a normal and stenotic vessel segment were determined in 64 patients by biplane quantitative coronary arteriography at rest and during supine bicycle exercise. Patients were classified into two groups: 20 patients without evidence of coronary artery disease (10 normotensive, 10 hypertensive [group 1]) and 44 patients with coronary artery disease (26 normotensive, 18 hypertensive [group 2]). Both groups were comparable with regard to clinical characteristics, serum cholesterol levels, body mass index, exercise capacity and hemodynamic data.

RESULTS

Mean aortic pressure was significantly higher in hypertensive than normotensive patients. Exercise-induced vasodilation of the normal vessel segment was similar in normotensive and hypertensive patients without coronary artery disease (group 1), namely, +19% versus +20%. However, in hypertensive patients with coronary artery disease, exercise-induced vasodilation was significantly less in both normal and stenotic vessel segments than in normotensive subjects (+1% vs. +20% for normal [p < 0.003] and -20% vs. -5% for stenotic vessels [p < 0.025]). Administration of 1.6 mg of sublingual nitroglycerin at the end of exercise led to a normalization of the vasodilator response in normotensive as well as hypertensive patients. However, this response became progressively abnormal in group 2 when coronary artery disease was present.

CONCLUSIONS

In the absence of coronary artery disease, the vasomotor response to exercise is normal in both normotensive and hypertensive patients. However, in hypertensive patients with coronary artery disease, an abnormal response of the coronary vessels can be observed, with a reduced vasodilator response to exercise in normal arteries but an enhanced vasoconstrictor response in stenotic arteries. This behavior of the epicardial vessels during exercise suggests the occurrence of endothelial dysfunction (i.e., functional defect) that is not evident in the absence of coronary artery disease. Nitroglycerin reverses impaired coronary vasodilation, but this effect is blunted in the presence of coronary artery disease (i.e., structural defect).