Adverse cardiac effects during induction chemotherapy treatment with cis-platin and 5-fluorouracil

Drug-induced atrial fibrillation. A narrative review of a forgotten adverse effect

Atrial fibrillation (AF) is the most common cardiac arrhythmia and is associated with an increased morbidity and mortality. There is clinical evidence that an increasing number of cardiovascular and non-cardiovascular drugs, mainly anticancer drugs, can induce AF either in patients with or without pre-existing cardiac disorders, but drug-induced AF (DIAF) has not received the attention that it might deserve. In many cases DIAF is asymptomatic and paroxysmal and patients recover sinus rhythm spontaneously, but sometimes, DIAF persists, and it is necessary to perform a cardioversion. Furthermore, DIAF is not mentioned in clinical guidelines on the treatment of AF. The risk of DIAF increases in elderly and in patients treated with polypharmacy and with risk factors and comorbidities that commonly coexist with AF. This is the case of cancer patients. Under these circumstances ascribing causality of DIAF to a given drug often represents a clinical challenge. We review the incidence, the pathophysiological mechanisms, risk factors, clinical relevance, and treatment of DIAF. Because of the limited information presently available, further research is needed to obtain a deeper insight into DIAF. Meanwhile, it is important that clinicians are aware of the problem that DIAF represents, recognize which drugs may cause DIAF, and consider the possibility that a drug may be responsible for a new-onset AF episode.

Impaired microvascular reactivity in patients treated with 5-fluorouracil chemotherapy regimens: Potential role of endothelial dysfunction

Background

5-fluorouracil (5-FU) is the second most common cancer chemotherapy associated with short- and long-term cardiotoxicity. Although the mechanisms mediating these toxicities are not well understood, patients often present with symptoms suggestive of microvascular dysfunction. We tested the hypotheses that patients undergoing cancer treatment with 5-FU based chemotherapy regimens would present with impaired microvascular reactivity and that these findings would be substantiated by decrements in endothelial nitric oxide synthase (eNOS) gene expression in 5-FU treated human coronary artery endothelial cells (HCAEC).

Methods

We first performed a cross-sectional analysis of 30 patients undergoing 5-FU based chemotherapy treatment for cancer (5-FU) and 32 controls (CON) matched for age, sex, body mass index, and prior health history (excluding cancer). Cutaneous microvascular reactivity was evaluated by laser Doppler flowmetry in response to endothelium-dependent (local skin heating; acetylcholine iontophoresis, ACh) and -independent (sodium nitroprusside iontophoresis, SNP) stimuli. In vitro experiments in HCAEC were completed to assess the effects of 5-FU on eNOS gene expression.

Results

5-FU presented with diminished microvascular reactivity following eNOS-dependent local heating compared to CON (P = 0.001). Iontophoresis of the eNOS inhibitor L-NAME failed to alter the heating response in 5-FU (P = 0.95), despite significant reductions in CON (P = 0.03). These findings were corroborated by lower eNOS gene expression in 5-FU treated HCAEC (P < 0.01) compared to control. Peak vasodilation to ACh (P = 0.58) nor SNP (P = 0.39) were different between groups.

Conclusions

The present findings suggest diminished microvascular function along the eNOS-NO vasodilatory pathway in patients with cancer undergoing treatment with 5-FU-based chemotherapy regimens and thus, may provide insight into the underlying mechanisms of 5-FU cardiotoxicity.

Redefining the Incidence and Profile of Fluoropyrimidine-Associated Cardiotoxicity in Cancer Patients: A Systematic Review and Meta-Analysis

Aim: The cardiac toxicity that occurs during administration of anti-tumor agents has attracted increasing concern. Fluoropyrimidines have been used for more than half a century, but their cardiotoxicity has not been well clarified. In this study, we aimed to assess the incidence and profile of fluoropyrimidine-associated cardiotoxicity (FAC) comprehensively based on literature data. Methods: A systematic literature search was performed using PubMed, Embase, Medline, Web of Science, and Cochrane library databases and clinical trials on studies investigating FAC. The main outcome was a pooled incidence of FAC, and the secondary outcome was specific treatment-related cardiac AEs. Random or fixed effects modeling was used for pooled meta-analyses according to the heterogeneity assessment. PROSPERO registration number: (CRD42021282155). Results: A total of 211 studies involving 63,186 patients were included, covering 31 countries or regions in the world. The pooled incidence of FAC, by meta-analytic, was 5.04% for all grades and 1.5% for grade 3 or higher. A total of 0.29% of patients died due to severe cardiotoxicities. More than 38 cardiac AEs were identified, with cardiac ischemia (2.24%) and arrhythmia (1.85%) being the most frequent. We further performed the subgroup analyses and meta-regression to explore the source of heterogeneity, and compare the cardiotoxicity among different study-level characteristics, finding that the incidence of FAC varied significantly among different publication decades, country/regions, and genders. Patients with esophagus cancer had the highest risk of FAC (10.53%), while breast cancer patients had the lowest (3.66%). The treatment attribute, regimen, and dosage were significantly related to FAC. When compared with chemotherapeutic drugs or targeted agents, such a risk was remarkably increased (χ2 = 10.15, p < 0.01; χ2 = 10.77, p < 0.01). The continuous 5-FU infusion for 3–5 consecutive days with a high dosage produced the highest FAC incidence (7.3%) compared with other low-dose administration patterns. Conclusions: Our study provides comprehensive global data on the incidence and profile of FAC. Different cancer types and treatment appear to have varying cardiotoxicities. Combination therapy, high cumulative dose, addition of anthracyclines, and pre-existing heart disease potentially increase the risk of FAC.

The Role of Vasospasm and Microcirculatory Dysfunction in Fluoropyrimidine-Induced Ischemic Heart Disease

Cardiovascular diseases and cancer are the leading cause of morbidity and mortality globally. Cardiotoxicity from chemotherapeutic agents results in substantial morbidity and mortality in cancer survivors and patients with active cancer. Cardiotoxicity induced by 5-fluorouracil (5-FU) has been well established, yet its incidence, mechanisms, and manifestation remain poorly defined. Ischemia secondary to coronary artery vasospasm is thought to be the most frequent cardiotoxic effect of 5-FU. The available evidence of 5-FU-induced epicardial coronary artery spasm and coronary microvascular dysfunction suggests that endothelial dysfunction or primary vascular smooth muscle dysfunction (an endothelial-independent mechanism) are the possible contributing factors to this form of cardiotoxicity. In patients with 5-FU-related coronary artery vasospasm, termination of chemotherapy and administration of nitrates or calcium channel blockers may improve ischemic symptoms. However, there are variable results after administration of nitrates or calcium channel blockers in patients treated with 5-FU presumed to have myocardial ischemia, suggesting mechanisms other than impaired vasodilatory response. Clinicians should investigate whether chest pain and ECG changes can reasonably be attributed to 5-FU-induced cardiotoxicity. More prospective data and clinical randomized trials are required to understand and mitigate potentially adverse outcomes from 5-FU-induced cardiotoxicity.

5-Fluorouracil, capecitabine and vasospasm: a scoping review of pathogenesis, management options and future research considerations

BACKGROUND

5-Fluorouracil (5-FU) is a widely used chemotherapeutic agent that can cause cardiotoxicity manifesting, among others, as chest pain. Capecitabine is an oral prodrug of 5-FU, with reported preferential activation in malignant cells that may also cause cardiotoxic reactions. Standard treatment of 5-FU and capecitabine induced chest pain with vasodilators is mostly effective, but there are several cases of patients unresponsive to these agents.

METHODS

We performed a PubMed search on 31st May 2020. We used a three keyword search strategy using Boolean search operators. More specifically, we included fluorouracil or 5-FU or capecitabine and chest pain or angina and mechanism or treatment or management. We included primary reports of clinical and non-clinical data, as well as systematic reviews. Narrative reviews, expert opinions, letters to the editor and other forms of non-primary literature were excluded.

RESULTS

Our search yielded a total of 1595 reports. Of these, 1460 were narrative reviews or irrelevant to the topic and were excluded. A total of 135 reports were used for our review. We used 81 reports for data extraction, which included 13 clinical trials, 4 retrospective reports, 61 case reports, and 3 systematic reviews.

CONCLUSION

We report the incidence and predisposing factors, the value of available diagnostic procedures, and standard medical and invasive treatments. We also speculate on the potential benefit of arginine as a promising option both in prevention as well as treatment of 5-FU-induced chest pain. Finally, gaps of evidence are identified and proposals are made in terms of future research.

Drug-Induced Atrial Fibrillation / Atrial Flutter

Drug-induced atrial fibrillation / flutter (DIAF) is a serious and potentially life-threatening complication of pharmacotherapy. Purpose of the work: systematization and analysis of scientific literature data on drugs, the use of which can cause the development of DIAF, as well as on epidemiology, pathophysiological mechanisms, risk factors, clinical picture, diagnosis and differential diagnosis, treatment and prevention of DIAF. Analysis of the literature has shown that many groups of drugs can cause the development of DIAF, with a greater frequency while taking anticancer drugs, drugs for the treatment of the cardiovascular, bronchopulmonary and central nervous systems. The mechanisms and main risk factors for the development of DIAF have not been finally established and are known only for certain drugs, therefore, this section requires further study. The main symptoms of DIAF are due to the severity of tachycardia and their influence on the parameters of central hemodynamics. For diagnosis, it is necessary to conduct an electrocardiogram (ECG) and Holter monitoring of an ECG and echocardiography. Differential diagnosis should be made with AF, which may be caused by other causes, as well as other rhythm and conduction disturbances. Successful treatment of DIAF is based on the principle of rapid recognition and immediate discontinuation of drugs (if possible), the use of which potentially caused the development of adverse drug reactions (ADR). The choice of management strategy: heart rate control or rhythm control, as well as the method of achievement (medication or non-medication), depends on the specific clinical situation. For the prevention of DIAF, it is necessary to instruct patients about possible symptoms and recommend self-monitoring of the pulse. It is important for practitioners to be wary of the risk of DIAF due to the variety of drugs that can potentially cause this ADR.

Adjuvant Treatment with 5-Fluorouracil and Oxaliplatin Does Not Influence Cardiac Function, Neurovascular Control, and Physical Capacity in Patients with Colon Cancer

BACKGROUND

Adjuvant chemotherapy with 5-fluorouracil (5-FU) and oxaliplatin increases recurrence-free and overall survival in patients with colon adenocarcinoma. It is known that these drugs have been associated with cardio- and neurotoxicity. We investigated the effects of 5-FU ± oxaliplatin on cardiac function, vascular responses, neurovascular control, and physical capacity in patients with colon cancer.

METHODS

Twenty-nine patients with prior colectomy for stage II-III adenocarcinoma and clinical indication for adjuvant chemotherapy were allocated to receive 5-FU (n = 12) or 5-FU + oxaliplatin (n = 17), according to the oncologist's decision. All the analyses were performed just before and after the end of chemotherapy. Cardiac function was assessed by echocardiography and speckle tracking, and cardiac autonomic control was assessed by heart rate variability (HRV). Vascular endothelial function was assessed by flow-mediated dilation (FMD). Muscle sympathetic nerve activity (MSNA) was directly recorded by microneurography technique, and muscle blood flow by venous occlusion plethysmography. Physical capacity was evaluated by cardiopulmonary exercise test.

RESULTS

Chemotherapy (pooled data) did not significantly change left ventricular ejection fraction (58 ± 1 vs. 55 ± 2%, p = .14), longitudinal strain (-18 ± 1 vs. -18 ± 1%, p = .66), and HRV. Likewise, chemotherapy did not significantly change FMD, muscle blood flow, and MSNA (33 ± 2 vs. 32 ± 1 bursts/min, p = .31). Physical capacity was not significantly changed in both groups. Similar findings were observed when the patients were subdivided in 5-FU and 5-FU + oxaliplatin treatment groups. 5-FU and 5-FU + oxaliplatin did not significantly change cardiac function, HRV, vascular responses, MSNA, and physical capacity.

CONCLUSION

This study provides evidence that adjuvant treatment with 5-FU ± oxaliplatin is well tolerated and does not promote changes compatible with long-term cardiotoxicity.

IMPLICATIONS FOR PRACTICE

Adjuvant chemotherapy with 5-fluorouracil (5-FU) and oxaliplatin increases recurrence-free and overall survival in patients with colon adenocarcinoma; however, these drugs have been associated with cardio- and neurotoxicity. This study investigated the effects of these drugs on cardiac function, vascular responses, neurovascular control, and physical capacity in patients with colon cancer. It was found that 5-FU and oxaliplatin did not significantly change cardiac function, cardiac autonomic control, vascular endothelial function, muscle sympathetic nerve activity, and physical capacity. This study provides evidence that adjuvant treatment with 5-FU ± oxaliplatin is well tolerated and does not promote changes compatible with long-term cardiotoxicity.

Anticancer Therapy-Induced Atrial Fibrillation: Electrophysiology and Related Mechanisms

Some well-established immunotherapy, radiotherapy, postoperation, anticancer drugs such as anthracyclines, antimetabolites, human epidermal growth factor receptor 2 blockers, tyrosine kinase inhibitors, alkylating agents, checkpoint inhibitors, and angiogenesis inhibitors, are significantly linked to cardiotoxicity. Cardiotoxicity is a common complication of several cancer treatments. Some studies observed complications of cardiac arrhythmia associated with the treatment of cancer, including atrial fibrillation (AF), supraventricular arrhythmias, and cardiac repolarization abnormalities. AF increases the risk of cardiovascular morbidity and mortality; it is associated with an almost doubled risk of mortality and a nearly 5-fold increase in the risk of stroke. The occurrence of AF is also usually researched in patients with advanced cancer and those undergoing active cancer treatments. During cancer treatments, the incidence rate of AF affects the prognosis of tumor treatment and challenges the treatment strategy. The present article is mainly focused on the cardiotoxicity of cancer treatments. In our review, we discuss these anticancer therapies and how they induce AF and consequently provide information on the precaution of AF during cancer treatment.

[Fluoropyrimidines cardiac toxicity: 5-fluorouracil, capecitabine, compound S-1 and trifluridine/tipiracil]

The incidence of cardiac toxicity of 5-flurorouracil (5-FU) IV and capecitabine varies from 1.2 to 18%. The physiopathology of this toxicity is still under study, various hypotheses are mentioned. In the absence of identified prophylactic treatment, reintroduction of this cytotoxic is at risk. A discussion between oncologists and cardiologists is essential to estimate the balance between benefit and risk and the careful reintroduction of treatment. An alternative compound might be raltitrexed which is currently the treatment recommended in case of intolerance to fluoropyrimidines. The compound S-1 does not have any cardiac toxicity. Of a total of 2910 patients in phase II or III studies, no grade III or IV cardiovascular events were reported. However, the treatment is not reimbursed in France and therefore not available. The trifluridine/tipiracil, for which approval from French authorities was obtained in November 2016 for patients with metastatic colorectal cancer in progress despite standard treatment lines, does not appear to have cardiac toxicity according to studies published to date. The pivotal phase III study (RECOURSE), that led to this marketing authorization, was performed in 800 patients with metastatic colorectal cancer refractory and only one patient (less than 1% of patients) treated with trifluridine/tipiracil presented an episode of cardiac ischemia. Thus, trifluridine/tipiracil, which is well tolerated, could be an alternative to raltitrexed for patients with cardiovascular history contraindicating or discouraging the use of fluoropyrimidines.

5-fluorouracil and cardiotoxicity: a review

Fluoropyrimidines such as 5-fluorouracil (5-FU) form the foundation of a wide variety of chemotherapy regimens. 5-FU is in fact the third most commonly used chemotherapeutic agent in the treatment of solid malignancies across the world. As with all chemotherapy, balancing the potential benefits of therapy against the risks of drug-related toxicity is crucial when clinicians and patients make shared decisions about treatment. 5-FU is the second most common chemotherapeutic drug associated with cardiotoxicity after anthracyclines, which can manifest as chest pain, acute coronary syndrome/myocardial infarction or death. Nevertheless a widespread appreciation of 5-FU-related cardiotoxicity and its implications is lacking amongst clinicians. In this review, we outline the incidence, possible risk factors, and likely pathophysiological mechanisms that may account for 5-FU-related cardiotoxicity and also highlight potential management strategies for this poorly understood clinical entity.

Cardiotoxicity of 5-fluorouracil and capecitabine in Chinese patients: a prospective study

Background

5-Fluorouracil (5-FU) and capecitabine-associated cardiotoxicity ranging from asymptomatic electrocardiography (ECG) abnormalities to severe myocardial infarction has been reported in a number of studies, but such cardiotoxicity in Chinese patients with malignant diseases has not been investigated to date. In the present study, we aimed to prospectively evaluate the incidence rates and clinical manifestations of 5-FU- and capecitabine-associated cardiotoxicity in cancer patients recruited from multiple centers in China.

Methods

Among the 527 patients who completed the study, 196 received 5-FU-based chemotherapy and 331 received capecitabine-based chemotherapy as either first-line or adjuvant therapy. Adverse events were reported during the treatment and up to 28 days of follow-up. Outcome measures included ECG, myocardial enzymes, cardiac troponin, brain natriuretic peptide and echocardiography. Univariate analysis and logistic regression were performed for subgroup analysis and identification of significant independent variables that are associated with cardiotoxicity of both agents.

Results

In total, 161 of 527 patients (30.6%) experienced cardiotoxicity. The incidence rate of cardiotoxicity was 33.8% (112/331) in the capecitabine group, which was significantly higher than the rate of 25% (49/196) in the 5-FU group (P = 0.0042). 110/527 patients (20.9%) suffered arrhythmia, 105/527 (19.9%) developed ischemic changes, while only 20/527 patients (3.8%) presented heart failure and 6/527 patients (1.1%) had myocardial infarction. Pre-existing cardiac disease, hypertension, capecitabine-based chemotherapy and duration of treatment were identified as significant risk factors associated with cardiotoxicity. The odds ratio were 15.7 (prior history of cardiac disease versus no history), 1.86 (capecitabine versus 5-FU), 1.06 (5–8 versus 1–4 chemotherapy cycles) and 1.58 (hypertension versus no hypertension), respectively.

Conclusions

Cardiotoxicity induced by fluoropyrimidines in the Chinese population may be underestimated in clinical practice. Close monitoring of patients is recommended, especially for those patients at high risk for cardiotoxicity. Possible risk factors are duration of treatment, capecitabine-based chemotherapy, pre-existing cardiac diseases and hypertension.

Trial registration This study was initiated on January 22, 2014 and has been retrospectively registered with the registration number ChiCTR1800015434

Cardiovascular Disease and Breast Cancer: Where These Entities Intersect: A Scientific Statement From the American Heart Association

Cardiovascular disease (CVD) remains the leading cause of mortality in women, yet many people perceive breast cancer to be the number one threat to women's health. CVD and breast cancer have several overlapping risk factors, such as obesity and smoking. Additionally, current breast cancer treatments can have a negative impact on cardiovascular health (eg, left ventricular dysfunction, accelerated CVD), and for women with pre-existing CVD, this might influence cancer treatment decisions by both the patient and the provider. Improvements in early detection and treatment of breast cancer have led to an increasing number of breast cancer survivors who are at risk of long-term cardiac complications from cancer treatments. For older women, CVD poses a greater mortality threat than breast cancer itself. This is the first scientific statement from the American Heart Association on CVD and breast cancer. This document will provide a comprehensive overview of the prevalence of these diseases, shared risk factors, the cardiotoxic effects of therapy, and the prevention and treatment of CVD in breast cancer patients.

Cisplatin-induced sudden cardiac death with hemodynamic collapse: a severe adverse drug reaction: Case report

RATIONALE

Cisplatin is responsible for a significant percentage of adverse drug reactions (ADRs) in oncology setting. A great proportion of cisplatin-induced severe adverse events are difficult to foresee, and giving premedication does not always prevent the occurrence of such events.

PATIENT CONCERNS

A 53-year-old woman with progressive T4 N0 M0 stage IV pleural mesothelioma experienced cardiac arrest with hemodynamic collapse after cisplatin and pemetrexed chemotherapy administration.

DIAGNOSES

Progressive pleural T4 N0 M0 stage IV mesothelioma of the right lung, primary arterial hypertension, and cardiac arrest with hemodynamic collapse.

INTERVENTIONS

The cisplatin and pemetrexed chemotherapy was administered intravenously for progressive pleural T4 N0 M0 stage IV mesothelioma of the right lung. During infusion of cisplatin the patient developed cardiac arrest, and cardiopulmonary resuscitation was initiated.

OUTCOMES

The patient was treated in intensive care unit and recovered successfully. Further chemotherapy with cisplatin and pemetrexed was withheld due to this severe adverse reaction to cisplatin.

LESSONS

Cisplatin therapy should be thoroughly monitored including electrolyte, especially magnesium levels. Absence of previous ADRs to cisplatin and premedication should not give false sense of security.

A comparison of cardiomyocyte cytotoxic mechanisms for 5-fluorouracil and its pro-drug capecitabine

1. 5-Fluorouracil (5-FU) and its prodrug capecitabine are key chemotherapeutic agents in the treatment of many gastrointestinal tract adenocarcinomas. In addition to their beneficial antitumor effects, they also possess undesired cardiac toxicity. In the present study, we investigated the cytotoxic mechanisms of 5-FU and capecitabine in freshly isolated rat cardiomyocytes. 2. 5-FU and capecitabine cytotoxicities were associated with reactive oxygen species (ROS) formation, lipid peroxidation and rapid glutathione depletion. Increased intracellular ROS could target mitochondria, and our findings confirmed that the cardiomyocytes mitochondrial membrane potential (ΔΨm) was rapidly decreased by 5-FU and capecitabine. Mitochondrial dysfunction subsequently initiates downstream events that trigger caspase-3 activation, and our results showed that 5-FU and capecitabine activated caspase-3 which leads to apoptosis or necrosis. However, 5-FU acted much more powerful than capecitabine at inducing several cytotoxicity markers in heart cardiomyocytes. In addition, 5-FU but not capecitabine caused lysosomal membrane leakiness when it was incubated with cardiomyocytes. All cytotoxicity markers were prevented by antioxidants, ROS scavengers, mitochondrial permeability transition (MPT) pore sealing agents and lysosomotropic agents. 3. Our findings showed that the cytotoxic action of 5-FU and capecitabine on cardiomyocytes are mediated by oxidative stress and subsequent mitochondrial dysfunction which causes caspase-3 activation and cell death.

Cytotoxic activity of Alpinia murdochii Ridl.: A mountain ginger species from Peninsular Malaysia

Background:

Alpinia murdochii (Zingiberaceae) is a wild ginger species restricted to mountain areas of Peninsular Malaysia. Due to rapid development and deforestation activities, this species is becoming rare. This is the first report of the cytotoxic activity of A. murdochii.

Objective:

The present study aimed to investigate the cytotoxic effect of leaves and rhizomes of A. murdochii against selected human cancer cell lines by using in vitro cytotoxicity assay.

Materials and Methods:

The leaves and rhizomes of A. murdochii were extracted in hexane, dichloromethane (CH₂Cl₂), and methanol (MeOH) prior to cytotoxic activity assessment against selected human cancer cell lines, namely MCF7 (hormone dependent breast carcinoma cell line), HT29 (colon carcinoma cell line), and SKOV-3 (ovarian cancer cell line) by using in vitro neutral red cytotoxicity assay.

Results:

The hexane and CH₂Cl₂ extracts of both leaves and rhizomes exhibited remarkable cytotoxic effect against SKOV-3 cells with the IC₅₀ values in the range of 5.2-16.7 μg/ml.

Conclusion:

Based on the preliminary data obtained in the present study, the leaves and rhizomes of A. murdochii may be viable therapeutic or preventive candidates for the treatment of ovarian cancer.

A mechanistic study on the cardiotoxicity of 5-fluorouracil in vitro and clinical and occupational perspectives

Fluoropyrimidines are key agents for the treatment of gastrointestinal tract adenocarcinomas. The possible cardiotoxic effects in patients and occupationally exposed workers are multifactorial and remain a puzzle to solve for investigators. In the present study, we study what cell death pathways and what doses can determine direct cardiotoxic effects of 5-fluorouracil (5-FU) and doxorubicin (DOXO) on rat cardiocytes (H9c2) and a human colon adenocarcinoma (HT-29) cell line, already reported to be sensitive to 5-FU. We have found that 5-FU induced 50% growth inhibition (IC:50) at 72 h with concentrations of 400 μM and 4 μM on H9c2 and HT-29, respectively. Moreover, we have found that the addition of Levofolinic Acid (LF) to 5-FU potentiated the growth inhibition induced by 5-FU. The growth inhibition induced by 5-FU alone or in combination with LF in cardiocytes was paralleled by an increase of thiobarbituric acid-reactive species (Tbars) and end products of nitric oxide (NO) suggesting the increase of the oxidative stress status in cardiocytes. Interestingly, these effects were strongly potentiated by the addition of LF, a biochemical modulator of 5-FU activity. Our data suggest that agents such as 5-FU different from anthracyclines, conventionally related to the induction of cardiotoxic effects, can also induce cardiocyte damage paralleled by oxidative stress. The strategies based upon the use of scavengers could be used in order to prevent this effect.

Cardiotoxicity in cancer patients treated with 5-fluorouracil or capecitabine: a systematic review of incidence, manifestations and predisposing factors

PURPOSE

To systematically review the incidence, manifestations and predisposing factors for cardiovascular toxicity in cancer patients treated with systemic 5-fluorouracil or capecitabine.

DESIGN

We searched PubMed, EMBASE and Web of science for studies with ≥ 20 cancer patients evaluating cardiovascular toxicity of 5-fluorouracil and capecitabine. We hand searched the reference lists of all included studies. Study selection and assessment of risk of bias were performed by two authors independently.

RESULTS

We identified 30 eligible studies (1 meta-analyses of 4 RCTs, 18 prospective and 11 retrospective). Symptomatic cardiotoxicity occurred in 0-20% of the patients treated with 5-fluorouracil and in 3-35% with capecitabine. The most common symptom was chest pain (0-18.6%) followed by palpitations (0-23.1%), dyspnoea (0-7.6%) and hypotension (0-6%). Severe clinical events such as myocardial infarction, cardiogenic shock and cardiac arrest occurred in 0-2%. Mortality rates ranged from 0 to 8%. Asymptomatic cardiac influence was demonstrated on ECG, in NT-proBNP measurements and with ultrasonic cyclic variation of integrated backscatter. Predisposing factors were mostly tested in univariate analyses. Preexisting cardiac disease was a risk factor in some studies, but there were divergent results. There was some evidence for increased cardiotoxicity during continuous infusion schedules and with concomitant cisplatin treatment. The effects of previous or current chest-radiotherapy were ambiguous.

CONCLUSION

Larger studies suggest an incidence of symptomatic cardiotoxicity of 1.2-4.3% during fluorouracil treatment, however subclinical cardiac influence are common. Possible risk factors are cardiac co-morbidity, continuous infusion schedules and concomitant cisplatin treatment, but existing evidence are of insufficient quality.

Drug-induced atrial fibrillation

INTRODUCTION

Atrial fibrillation (AF) is the most common arrhythmia and an important cause of hospitalization, morbidity, and mortality. A myriad of drugs can induce AF. However, drug-induced AF (DIAF) receives little attention. Thus, this review is an attempt to attract the attention on this adverse effect.

AREAS COVERED

Published reports of drug-induced AF (DIAF) are reviewed in this paper, from January 1974 to December 2011, using the PubMed/Medline database and lateral references.

EXPERT OPINION

In most cases, DIAF is paroxysmal and terminates spontaneously, but sometimes AF persists and it is necessary to perform a cardioversion to restore sinus rhythm and avoid progression to persistent AF. Because of the short duration of DIAF, in addition to physicians/patients not being knowledgeable about this side effect, the real incidence and clinical consequences of DIAF are presently unknown. DIAF is an increasing problem, as some widely prescribed drugs can present this adverse effect. The risk is expected to increase in the elderly and in patients with comorbidities. It is important that physicians understand the significance of DIAF, to increase the collaboration between cardiac and non-cardiac professionals, and to educate patients to make them aware of this adverse side effect.

Comparing serum levels of cardiac biomarkers in cancer patients receiving chemotherapy and subjects with chronic periodontitis

BACKGROUND

Chronic periodontitis (CP) is a chronic inflammation associated with elevations of several inflammatory and cardiac markers. Studies implicated CP as one of the etiologies in coronary heart disease (CHD). Cardiotoxicity is a major complication of anticancer drugs, including anthracyclines and 5-fluorouracil (5FU). The most severe cardiac complications are heart failure, arrhythmia and coronary heart disease (CHD). In this study, we compared the level of inflammatory factors and cardiac markers between chronic periodontitis patients and cancer patients receiving chemotherapy.

METHODS

108 blood samples of periodontally healthy subjects were obtained on random from Hong Kong Red Cross, and these represented the controlled population. Forty-four patients diagnosed with chronic periodontitis were recruited from the West China Hospital of Stomatology, Sichuan University. They have received scaling and root planning with mean pocket depths of 6.05 mm. Thirty breast cancer patients diagnosed with invasive ductal carcinoma from UNIMED Medical Institute, Hong Kong gave consent to participate in this study. They received 4 cycles of 500mg/m2 5-fluorouracil, 75 mg/m2 epirubicin and 500mg/m2 cyclophosphamide at a 3-week interval between each cycle. Peripheral venous blood from each group was taken for measurement of blood cells, inflammatory marker (P-selectin, high sensitvity C-reactive protein) and cardiac markers (troponin T; troponin I; N-terminal pro brain natriuretic peptide (Nt-proBNP) and Lactate dehydrogenase (LDH).

RESULTS

The lymphocyte count was higher (p < 0.05) in periodontitis patients than the other two groups, and more neutrophils (p < 0.05) were seen in cancer patients receiving chemotherapy. The two test groups demonstrated higher levels (p < 0.01) of inflammatory and cardiac markers than the control group.

CONCLUSIONS

The elevated cardiac markers found in periodontitis patients suggested that they may carry potential risks in developing cardiac lesions. Troponin T, troponin I, pro-BNP, LDH and high sensitvity C-reactive protein may be used as markers to monitor cardiac lesions in chronic inflammatory patients.

Feasibility of tomotherapy to reduce normal lung and cardiac toxicity for distal esophageal cancer compared to three-dimensional radiotherapy

PURPOSE

To compare the effectiveness of tomotherapy and three-dimensional (3D) conformal radiotherapy to spare normal critical structures (spinal cord, lungs, and ventricles) from excessive radiation in patients with distal esophageal cancers.

MATERIALS AND METHODS

A retrospective dosimetric study of nine patients who had advanced gastro-esophageal (GE) junction cancer (7) or thoracic esophageal cancer (2) extending into the distal esophagus. Two plans were created for each of the patients. A three-dimensional plan was constructed with either three (anteroposterior, right posterior oblique, and left posterior oblique) or four (right anterior oblique, left anterior oblique, right posterior oblique, and left posterior oblique) fields. The second plan was for tomotherapy. Doses were 45 Gy to the PTV with an integrated boost of 5 Gy for tomotherapy.

RESULTS

Mean lung dose was respectively 7.4 and 11.8 Gy (p=0.004) for tomotherapy and 3D plans. Corresponding values were 12.4 and 18.3 Gy (p=0.006) for cardiac ventricles. Maximum spinal cord dose was respectively 31.3 and 37.4 Gy (p < 0.007) for tomotherapy and 3D plans. Homogeneity index was two for both groups.

CONCLUSIONS

Compared to 3D conformal radiotherapy, tomotherapy decreased significantly the amount of normal tissue irradiated and may reduce treatment toxicity for possible dose escalation in future prospective studies.

Fluoropyrimidine-associated cardiotoxicity: revisited

BACKGROUND

The syndrome of 5-fluorouracil (5-FU)-associated cardiotoxicity remains poorly defined.

PATIENTS AND METHODS

We performed a literature review (1969 - 2007) and compiled data derived from 377 evaluable cases out of 448 reported cases.

RESULTS

Patient age ranged from 14 to 86 years. Of the patients 65% were 55 years old and the male:female ratio was 1.5:1. The most commonly treated tumors were gastrointestinal (60%), head and neck (22%) and breast (4%). Of the patients 14% had a history of heart disease whereas cardiac risk factors were found in 37%. Mode of administration included: continuous infusion (72%); bolus (22.5%); intermediate infusion (3%); oral (2%); and intraperitoneal (1 patient). The dosages of 5-FU used were < 750 mg/m(2)/day (36%), 751 - 999 (16%), 1,000 (26%), 1,001 - 1,499 (4%) and 1,500 (16%). Of the patients 54% received 5-FU in combination with other chemotherapeutic agents (cisplatin 44%) whereas 51% received 5-FU alone or with leucovorin. Only 4% patients had undergone previous or concomitant radiation therapy to the mediastinum. Of cardiac incidents that happened 69% were seen during or within 72 h of the first cycle of 5-FU. Angina occurred in 45% of patients whereas myocardial infarction was seen in 22%, arrhythmias in 23, acute pulmonary edema in 5, cardiac arrest and pericarditis in 1.4 and heart failure in 2. Electro-cardiographic evidence of ischemia or ST-T changes were recorded in 69% of patients, but abnormal cardiac enzymes were found in only 12%. The cardiac symptoms were reproducible in 47%, including in one patient subsequently treated with 5-FU p.o. Symptoms were also elicited when the same patients were treated with lower doses or different schedules. Of the patients 68% responded to conservative anti-anginal therapy, although prophylactic coronary vasodilators had limited efficacy. Overall, 8% of patients showing cardiotoxicity on 5-FU administration died. Furthermore, 13% reexposed to 5-FU died.

CONCLUSIONS

Our review suggests that 5-FU cardiotoxicity is an infrequent but real phenomenon that is independent of dose and may be related to a continuous infusion schedule. The presence of cardiac risk factors is not predictive. Patients should be observed closely and 5-FU administration discontinued if cardiac symptoms develop. A rechallenge with 5-FU should be reserved only for those patients in whom there is no reasonable alternative therapy and should be performed in the setting of aggressive prophylaxis and close monitoring.

Decreased oxygen transfer capacity of erythrocytes as a cause of 5-fluorouracil related ischemia

Various mechanisms have been proposed to account for chemotherapy related ischemia, but none of them can explain the available clinical data. In order to explore the possibility that the decreased ability of erythrocytes to deliver oxygen to the heart could be responsible for cardiotoxicity, we have performed an ex vivo and in vivo study of the effects of cisplatin/5-FU on erythrocytes, using a variety of biophysical techniques. Combining EPR and microscopy it was concluded that both cardiotoxic 5-FU and non-cardiotoxic cisplatin have similar effects on the erythrocyte membrane, thus eliminating those changes as a potential source of cardiotoxicity. On the contrary, 31P-NMR and polarography showed that the effects of these cytostatics on the intracellular milieu differ significantly. 5-FU provoked a pronounced decrease of the O2 level in blood and affected the metabolism of phosphate compounds, while cisplatin had no such effects. When combined these two drugs showed synergistic effects, which matches the higher frequency of cardiotoxicity of the combination relative to the sole application of 5-FU. Preliminary results acquired on blood of patients receiving cisplatin/5-FU therapy verified observations obtained ex vivo. These results open a possibility of applying NMR in preclinical trials of new drugs in order to predict their ischemic potential.

Phase II studies on docetaxel alone every third week, or weekly in combination with gemcitabine in patients with primary locally advanced, metastatic, or recurrent esophageal cancer

BACKGROUND

The purpose of these studies was to compare efficacy and toxicity of docetaxel alone with the combination of gemcitabine and docetaxel for treatment of metastatic esophageal carcinoma.

PATIENTS AND METHODS

These studies enrolled patients with histopathologically verified squamous cell carcinoma or adenocarcinoma of the esophagus or cardia. Between March 1997 and June 1999, 52 patients were enrolled in the initial Phase II study (Study 1). They were scheduled for treatment with docetaxel 100 mg/m2 every third week as a 1-h infusion. The second Phase II study between September 2000 and March 2003 included 65 patients (Study II). They were given docetaxel 30 mg/m2, administered as a 30-min i.v. infusion weekly for four times, followed by 2 weeks of rest, and gemcitabine starting with a dose of 750 mg/m2 (if well-tolerated 1,000 mg/m2) on days 1 and 15, followed by 3 weeks of rest. A new cycle began on day 36. Patients were premedicated with betamethasone 8 mg p.o. on the evening before, and 8 mg i.v. 30-60 min before the docetaxel infusion. Response was confirmed by computed tomography and assessed at 12 and 24 weeks. Toxicity was assessed according to WHO scales.

RESULTS

In study I, 38 out of the 52 enrolled patients were valuable. Two patients experienced complete remission (CR) (5%), 10 patients partial remission (PR) (26%), nine patients stable disease (SD) (24%), and 17 patients showed progressive disease (PD) (45%). Toxicity mainly involved leukopenia, which in some cases required hospitalization and treatment with antibiotics. In Study II, 46 out of the 65 enrolled patients (70%) were assessable. Out of these, three patients (7%) had CR, eight patients (17%) had PR, 10 patients (22%) had SD, and 25 (54%) PD. Overall response was 24% while an additional 22% showed stable disease. Toxicity mainly consisted of leucopenia and pain.

CONCLUSION

Docetaxel as a single agent is active in esophageal cancer, both in treatment naive and in previously treated patients with recurrent disease. The overall response rate was 31%, with a good-safety profile. The addition of gemcitabine is well tolerated, but adds no efficacy. Weekly administration of docetaxel may be less effective. It demonstrates moderate efficacy and the doses used provide an acceptable safety profile.

Severe ventricular dysrhythmias and silent ischemia during infusion of the antimetabolite 5-fluorouracil and cis-platin

The antimetabolite 5-fluorouracil is frequently used in the therapy of various malignancies. Cardiotoxicity has frequently been described during treatment, but there is no common agreement on the need to perform cardiovascular monitoring of patients during 5-fluorouracil administration. We report the case of a young patient with an head-neck cancer on whom a continuous electrocardiogram recording was performed, documenting serious ventricular dysrhythmias in the presence of myocardial ischemia during 5-fluorouracil and cis-platin infusion.

Risk factors and prevention of cardiotoxicity induced by 5-fluorouracil or capecitabine

AIM

5-fluorouracil (5-FU) and its prodrug capecitabine are cardiotoxic. This retrospective study aimed to identify risk factors and to give practical measures to make such chemotherapy feasible if cardiotoxicity occur.

METHOD

Review of cardiotoxicity among 668 patients treated with 5-FU or capecitabine for gastrointestinal cancers.

RESULTS

Cardiotoxicity occurred in 29 cases (4.3%). The number of cases according to cardiotoxicity CTC grades 2-4 for patients with and without pre-existing cardiovascular disease were none, 10, and 2 cases, and 3, 14, and no cases, respectively (P=0.16). In three patients intercurrent decrease of renal clearances to <30, 48 and 71 ml min(-1) led to markedly increased cardiotoxicity. Chemotherapy dose reduction to 70 or 50%, either alone or in addition to antiangina medication prevented cardiotoxicity during subsequent chemotherapy in nine (60%) and three (20%) cases out of 15 assessable patients (P=0.001), respectively. To abolish symptoms of cardiotoxicity, sublingual nitroglycerine was efficient for 15 patients and inefficient for two (P=0.001).

CONCLUSION

Cardiac and renal co-morbidity are risk factors for 5-FU induced cardiotoxicity. In this situation, rechallenge with modified 5-FU-based chemotherapy regimen supported by symptomatic medical treatment is feasible.

[Reversible cardiogenic shock under 5-fluorouracil treatment]

5-fluorouracil, an antimetabolite agent, has been widely used since 1957 for treatment of varied types of cancer such as gastro-intestinal, pancreas, breast, lung, head and neck malignancies. Cardiotoxicity of 5-fluorouracil is rare and was first described in 1975. It can induce severe complications and involve vital prognosis in the short-term. These complications are less known by cardiologists than medical oncologists. The following clinical case represents a potentially serious and rare case of completely reversible cardiogenic shock in a patient with a colo-rectal cancer. A better knowledge of these complications could reduce cases of death by an earlier diagnosis, and a better evaluation of patients with high cardiotoxicity risk.

Ultrasound Tissue Characterization by Integrated Backscatter for Analyzing Fluorouracil Induced Myocardial Damage

BACKGROUND

5-Fluorouracil (5-FU) cardiotoxicity is a well-known clinical phenomenon whose pathophysiology remains controversial. Cyclic variation of integrated backscatter (CVIBS) assesses acoustic properties of myocardium that may reflect both contractility and structural changes. The aim of this study was to evaluate CVIBS alterations in cancer patients under high-dose leucovorin and infusional 5-FU (HDLV5FU) chemotherapy.

METHOD

We prospectively evaluated 37 cancer patients under HDLV5FU treatment. Transthoracic echocardiography and CVIBS were performed at the 0th, 48th hours, and on day 15 of the first cycle. The parasternal long-axis view was preferred to obtain the image of integrated backscatter and mainly two regions of interest--interventricular septum (IVS) and posterior wall (PW)--were used.

RESULTS

Clinical cardiotoxicity was observed in two patients. No significant differences were detected in pre- and posttreatment conventional echocardiography evaluations. However, both the IVS (9.3 +/- 1.0 to 8.1 +/- 1.2 dB, P < 0.001) and PW (9.1 +/- 0.7 to 7.8 +/- 0.9 dB, P < 0.001) CVIBS values significantly decreased in all patients. All values were returned to pretreatment levels (9.2 +/- 0.9 dB in the CVIBS-IVS and 8.9 +/- 0.6 dB in CVIBS-PW, respectively) on day 15 after the treatments.

CONCLUSION

This study suggests that HDLV5FU may cause acute transient alterations in CVIBS values in the absence of clinical symptoms and signs of cardiotoxicity. The clinical value of CVIBS should be further studied in patients receiving 5-FU-based therapy.

Influence of high-dose leucovorin and 5-fluorouracil chemotherapy regimen on P wave duration and dispersion

BACKGROUND

Although 5-fluorouracil (5-FU)-related cardiotoxicity is well known, atrial arrhythmia, as a potentially serious complication has not been studied in detail. The aim of this study was to determine the P max and Pd in the electrocardiograms (ECG) of patients receiving 5-FU treatment.

METHODS

Twenty-five patients (mean age: 62 years) receiving a 5-FU bolus plus continuous infusion with calcium leucovorin over 48 h and with normal pre-treatment cardiac physical examinations, ECG and echocardiography were enrolled. P maximum (P max), P minimum (P min) and P dispersion (Pd) (maximum minus minimum P wave duration) were measured from the 12-lead ECG at the 0th and 48th hour of the first chemotherapy cycle. Echocardiography was also obtained in all patients at the same times.

RESULTS

Clinical cardiotoxicity was observed in two patients. P max and Pd were both significantly longer after 5-FU treatment at the 48th hour (P < 0.001). P min did not change (P > 0.05).

CONCLUSION

Treatment with 5-FU based regimens may increase Pd and prolong the P max in cancer patients. These alterations may be predictive of patients at risk of atrial arrhythmias during 5-FU treatment.

Insuffisances cardiaques d’origine médicamenteuse (en dehors des anthracyclines)

The principal drugs implicated in or disclosing cardiac insufficiency are drawn from a review of the literature and observations by the French national pharmacovigilance database, from 1984 to April 2003. Several pharmacological classes are identified: in addition to antimitotic drugs, such as anthracyclines, many drugs are implicated in cardiac insufficiency, e.g. immunomodulators, anti-inflammatory drugs (including coxibs), antiarrhythmic drugs, anaesthetic drugs, antipsychotic drugs, and antidiabetic drugs (including glitazones). It is usual to classify these drugs according to three categories: (i) drugs likely to cause cardiac insufficiency de novo (such as cyclophosphamide, paclitaxel, mitoxantrone, interferons, interleukin-2 etc.); (ii) drugs likely to worsen preexisting cardiac insufficiency (such as antiarrhythmics, beta-blockers, calcium antagonists, nonsteroidal and steroidal anti-inflammatory drugs, sympathomimetic drugs etc.); and (iii) drugs only occasionally causing cardiac insufficiency. This review shows that this classification is, in fact, artificial. If cardiac toxicity is a constant concern when using antimitotic drugs or some immunomodulator drugs, it is advisable to exercise caution in the use of many other drugs when treating patients with cardiac insufficiency, even if the clinical situation is well controlled. In particular, drug-drug interactions and patient medical history must be taken into account.

Antithrombotic treatment in protection against thrombogenic effects of 5-fluorouracil on vascular endothelium: a scanning microscopy evaluation

Cardiotoxicity is a serious side effect of treatment of malignant diseases with 5-fluorouracil (5-FU). The underlying pathophysiologic mechanism remains unclear but clinical data suggest that the endothelium of coronary arteries may be involved. Experimental studies indicate that the endothelium is especially susceptible to 5-FU and support the hypothesis that a thrombogenic effect of 5-FU, secondary to its direct toxic effect on the endothelium, is one of the pathophysiologic mechanisms behind 5-FU-induced cardiotoxicity. In the present study we evaluate the role of antithrombotic treatment with dalteparin as protection against the thrombogenic effect of 5-FU on the vascular endothelium in a rabbit model. The effects on the vascular endothelium of 5-FU, dalteparin, and the combination of these two substances were evaluated with scanning electron microscopy 1, 3, 7, 14, and 30 days after treatment and compared with a control group. Very severe damage to the endothelium was seen in 5-FU-treated animals, often leading to intima disruption and denudation of underlying structures, with accompanying platelet accumulation and fibrin formation. The most extensive damage was observed on Day 3 after treatment. The cytotoxic effect of 5-FU was partly reversible. The combination of 5-FU and dalteparin gave lower scores on Day 3 because of less evidence of thrombotic events. However, the reversibility of the endothelial damage was poorer in this group, as well as in the group that received dalteparin alone. The findings support the hypothesis that antithrombotic treatment with dalteparin can protect against the thrombogenic effect of 5-FU, secondary to its direct toxic effect on the vascular endothelium. However, the study indicates that dalteparin per se has a toxic effect on the endothelium that is different from that of 5-FU.

Acute reversible cardiomyopathy and thromboembolism after cisplatin and 5-fluorouracil chemotherapy--a case report

Acute development of cardiomyopathy and occlusive thromboembolic events following cisplatin and 5-fluorouracil (5-FU) is rare but frequently lethal. The authors report the successful management of such an event in a 52-year-old man with squamous cell carcinoma of the soft palate. The possible pathophysiological mechanisms are discussed.

Cardiotoxicity of chemotherapeutic agents: incidence, treatment and prevention

Cytostatic antibiotics of the anthracycline class are the best known of the chemotherapeutic agents that cause cardiotoxicity. Alkylating agents such as cyclophosphamide, ifosfamide, cisplatin, carmustine, busulfan, chlormethine and mitomycin have also been associated with cardiotoxicity. Other agents that may induce a cardiac event include paclitaxel, etoposide, teniposide, the vinca alkaloids, fluorouracil, cytarabine, amsacrine, cladribine, asparaginase, tretinoin and pentostatin. Cardiotoxicity is rare with some agents, but may occur in >20% of patients treated with doxorubicin, daunorubicin or fluorouracil. Cardiac events may include mild blood pressure changes, thrombosis, electrocardiographic changes, arrhythmias, myocarditis, pericarditis, myocardial infarction, cardiomyopathy, cardiac failure (left ventricular failure) and congestive heart failure. These may occur during or shortly after treatment, within days or weeks after treatment, or may not be apparent until months, and sometimes years, after completion of chemotherapy. A number of risk factors may predispose a patient to cardiotoxicity. These are: cumulative dose (anthracyclines, mitomycin); total dose administered during a day or a course (cyclophosphamide, ifosfamide, carmustine, fluorouracil, cytarabine); rate of administration (anthracyclines, fluorouracil); schedule of administration (anthracyclines); mediastinal radiation; age; female gender; concurrent administration of cardiotoxic agents; prior anthracycline chemotherapy; history of or pre-existing cardiovascular disorders; and electrolyte imbalances such as hypokalaemia and hypomagnesaemia. The potential for cardiotoxicity should be recognised before therapy is initiated. Patients should be screened for risk factors, and an attempt to modify them should be made. Monitoring for cardiac events and their treatment will usually depend on the signs and symptoms anticipated and exhibited. Patients may be asymptomatic, with the only manifestation being electrocardiographic changes. Continuous cardiac monitoring, baseline and regular electrocardiographic and echocardiographic studies, radionuclide angiography and measurement of serum electrolytes and cardiac enzymes may be considered in patients with risk factors or those with a history of cardiotoxicity. Treatment of most cardiac events induced by chemotherapy is symptomatic. Agents that can be used prophylactically are few, although dexrazoxane, a cardioprotective agent specific for anthracycline chemotherapy, has been approved by the US Food and Drug Administration. Cardiotoxicity can be prevented by screening and modifying risk factors, aggressively monitoring for signs and symptoms as chemotherapy is administered, and continuing follow-up after completion of a course or the entire treatment. Prompt measures such as discontinuation or modification of chemotherapy or use of appropriate drug therapy should be initiated on the basis of changes in monitoring parameters before the patient exhibits signs and symptoms of cardiotoxicity.

Severe cardiotoxicity during 5-fluorouracil chemotherapy: a case and literature report

The chemotherapeutic agent 5-fluorouracil (5-FU) is a widely accepted part of many cancer treatment protocols. Its cardiotoxic potential is known, but considered uncommon and usually not life threatening, although some cases of severe cardiotoxicity related to 5-FU have been reported. The pathogenesis of cardiotoxicity caused by 5-FU is not clear. We report a case of sudden onset of severe cardiac failure, without ischemic symptoms or signs, during 5-FU treatment with serious consequences, in a previously healthy 23-year-old patient with squamous cell carcinoma of the tongue. Endomyocardial biopsy showed proliferation of the sarcoplasmic reticulum with marked vacuolization, similar to that found with doxorubicin cardiotoxicity. Because 5-FU cardiotoxicity is unpredictable and can have potentially fatal consequences, it requires, in our opinion, further clarification. With this well-documented case, including an endomyocardial biopsy, we hope to encourage additional efforts to investigate the pathophysiologic mechanisms of 5-FU cardiotoxicity.

Cardiotoxicity of the antiproliferative compound fluorouracil

The antimetabolite fluorouracil (5-FU) is frequently administered for chemotherapy of various malignant neoplasms. The drug is well known for its adverse effects involving bone marrow, skin, mucous membranes, intestinal tract and central nervous system, whereas its cardiotoxicity is less familiar to clinicians. The pathophysiology of fluorouracil-associated cardiac adverse events is controversial and conclusions are based on clinical studies and case reports more than on solid experimental evidence. While clinical and electrocardiographic features suggest myocardial ischaemia as a main aetiological factor, possibly induced by coronary vasospasm, histomorphological and biochemical studies indicate a more direct drug-mediated cytotoxic action. Estimates of the overall incidence of fluorouracil cardiotoxicity have varied widely from 1.2 to 18% of patients. Patients may present with angina-like chest pain, cardiac arrhythmias or myocardial infarction. There is no unequivocally effective prophylaxis or treatment in this syndrome. Once fluorouracil administration is discontinued symptoms are usually reversible, although fatal events have been described. The overall mortality rate has been estimated to be between 2.2 and 13.3%. There is a high risk of relapse when patients are re-exposed to this drug following previous cardiac incidents. From the present data it is concluded that cardiotoxicity is a relevant but underestimated problem in fluorouracil treatment. Since the mechanisms of fluorouracil-associated cardiotoxicity are not yet fully understood, all patients undergoing this chemotherapy have to be carefully evaluated and monitored for cardiac risk factors and complaints. After cardiotoxic events, fluorouracil should definitely be withdrawn and replaced by an alternative antiproliferative regimen.

Palliation of dysphagia in patients with malignant esophageal strictures. Comparison of results of radiotherapy, chemotherapy and esophageal stent treatment

Dysphagia is the earliest and the most common symptom of malignant disease in the esophagus. The palliative effects on dysphagia of radiotherapy (RT) and chemotherapy (CT) were evaluated retrospectively and compared with the effect of the self-expanding stent, evaluated in the prospective study. After completion of treatment, 78 (56%) of 140 patients treated with RT; 31 (49%) of 63 patients treated with CT; and 53 (81%) of 66 patients treated with stent insertion were free from dysphagia. Stent treatment has a good and prompt effect on dysphagia and can be recommended for palliation of patients with malignant esophageal strictures.

Changes of blood viscosity in patients treated with 5-fluorouracil--a link to cardiotoxicity?

Cardiotoxicity is a serious but relatively unknown side-effect of treatment with 5-fluorouracil (5-FU). The underlying mechanism of 5-FU cardiotoxicity has not been defined. The aim of the present study was to determine whether hemorheological factors might in part explain 5-FU cardiotoxicity. Changes of blood and plasma viscosity, fibrinogen and hematocrit were studied in 11 patients treated by 5-FU. The study showed a decrease in blood and plasma viscosity during treatment with 5-FU, probably caused by a decrease of plasma fibrinogen. Reversible cardiotoxic effects were demonstrated in four patients.

Predictive factors of a complete response to and adverse effects of a CDDP-5FU combination as primary therapy for head and neck squamous carcinomas

Retrospective analysis of detailed patient and tumour factors associated with a complete response to combination inductive chemotherapy with CDDP-5FU (96 or 120 hour continuous infusion) was performed using data from 147 patients with a previously untreated squamous cell carcinoma of the oral cavity, oropharynx or pharyngo-larynx following completion of two (29 patients) or three (118 patients) cycles. Adverse reactions to chemotherapy were documented for all 164 patients included in the study. Eight drug-related deaths occurred due to: acute myocardial infarction (five patients), peptic ulcer disease (two patients) and severe neutropenia with sepsis (one patient). Severe non-lethal complications included marrow depletion (14 patients), peptic ulcer (two patients), thrombophlebitis (seven patients), angina pectoris (two patients), stroke (one patient), pulmonary oedema (one patient) and convulsions (one patient). Six patients refused further treatment because of untoward side effects and tumoral progression was observed in three cases. Separate response rates for the primary site and nodes were determined and analysis of respective predictive factors of response was performed. Complete response was obtained in 31 per cent at the primary site versus 18 per cent for the nodes (p < 0.05). The combined (primary site + nodes) overall complete response rate was 22 per cent. Among 11 factors studied (age, sex, performance status, primary site, tumour differentiation, initial resectability, 5FU dosage per cycle, number of cycles, T, N and TN stages), only performance status, N stage, resectability and number of cycles were associated with a combined complete response. Multivariate analysis showed performance status, N stage, TN stage and resectability to be significant predictive factors of a combined complete response.(ABSTRACT TRUNCATED AT 250 WORDS)

The syndrome of 5-fluorouracil cardiotoxicity. An elusive cardiopathy

BACKGROUND

A case of reversible cardiogenic shock linked to 5-fluorouracil (5-FU) was observed. Recognizing the increasing use of 5-FU, the authors tried to map this syndrome.

METHODS

They reviewed 134 additional case reports, retrieved information from literature searches, focused on clinical features, and discussed possible pathophysiologic findings and prevention of this syndrome.

RESULTS

Although angina and electrocardiographic changes were common and reproducible (approximately 90% each), coronary artery disease was found in a few patients. A total of 33 patients had severe left ventricular dysfunction, 28 without evidence of myocardial infarction. The symptoms were responsive to conservative management (90%).

CONCLUSIONS

Cardiac toxicity is a little known complication of 5-FU therapy, with an unknown but significant incidence. It is highly treatable.