5-Fluorouracil-induced coronary vasospasm

Cardiotoxicity of Fluoropyrimidines: Epidemiology, Mechanisms, Diagnosis, and Management

Cancer is a growing public health problem; it is responsible annually for millions of deaths worldwide. Fluoropyrimidines are highly effective and commonly prescribed anti-neoplastic drugs used in a wide range of chemotherapy regimens against several types of malignancies. 5-fluorouracil and its prodrugs affect neoplastic cells in multiple ways by impairing their proliferation, principally through the inhibition of thymidylate synthase. Fluoropyrimidine-induced cardiotoxicity was described more than 50 years ago, but many details such as incidence, mechanisms, and treatment are unclear and remain disputed. Severe cardiotoxicity is not only life-threatening, but also leads to withdrawal from an optimal chemotherapy regimen and decreases survival rate. Differences in the frequency of cardiotoxicity are explained by different chemotherapy schedules, doses, criteria, and populations. Proposed pathophysiological mechanisms include coronary vasospasm, endothelial damage, oxidative stress, Krebs cycle disturbances, and toxic metabolites. Such varied pathophysiology of the cardiotoxicity phenomenon makes prevention and treatment more difficult. Cardiovascular disturbances, including chest pain, arrhythmias, and myocardial infarction, are among the most common side effects of this class of anti-neoplastic medication. This study aims to summarize the available data on fluoropyrimidine cardiotoxicity with respect to symptoms, incidence, metabolism, pathophysiological mechanism, diagnosis, management, and resistance.

Severe Cardiac Toxicity Induced by Cancer Therapies Requiring Intensive Care Unit Admission

A steadying increase of cancer survivors has been observed as a consequence of more effective therapies. However, chemotherapy regimens are often associated with significant toxicity, and cardiac damage emerges as a prominent clinical issue. Many mechanisms sustain chemotherapy-induced cardiac toxicity: direct myocyte damage, arrhythmia induction, coronary vasospasm, and accelerated atherosclerosis. Anthracyclines are the most studied cardiotoxic drugs and represent a clinical model for cardiac damage induced by chemotherapy. In patients suffering from advanced heart failure (HF) because of chemotherapy-related cardiomyopathy, when refractory to optimal medical therapy, mechanical circulatory support or heart transplantation represents an effective treatment. Here, the main mechanisms of cardiac toxicity induced by cancer therapies are analyzed, with a focus on patients requiring intensive care unit (ICU) admission during the course of the disease because of acute cardiac toxicity, takotsubo syndrome, and acute-on-chronic HF in patients suffering from chemotherapy-induced cardiomyopathy. In a subset of patients, cardiac toxicity can be acute and life-threatening, leading to overt cardiogenic shock. The management of critically ill cancer patients poses a unique challenge and requires a multidisciplinary approach. Moreover, no etiologic therapy is available, and only supportive measures can be implemented.

Do cancer therapies damage the uterus and compromise fertility?

BACKGROUND

As cancer survival rates improve, understanding and preventing the adverse off-target and long-term impacts of cancer treatments, including impacts on fertility, have become increasingly important. Cancer therapy-mediated damage to the ovary and depletion of the primordial follicle reserve are well characterised. However, our knowledge of the full extent of damage to the rest of the female reproductive tract, in particular the uterus, is limited.

OBJECTIVE AND RATIONALE

Improving our understanding of the off-target effects of cancer therapies on the entire female reproductive tract is a critical step towards developing truly effective strategies to protect the fertility of cancer survivors. The objective of this narrative review was to critically evaluate the available literature regarding the capacity for the uterus to sustain a healthy pregnancy following exposure to radiotherapy or chemotherapy.

SEARCH METHODS

The authors performed PubMed (Medline) searches using the following key words: uterus, cancer survivors, radiotherapy, chemotherapy, pregnancy outcome, fertility preservation, infertility. There were no limits placed on time of publication.

OUTCOMES

Overall, there were major limitations to the current available literature, meaning that interpretations should be taken with caution. Despite these drawbacks, data suggest that the uterus may sustain off-target damage, with the extent of damage dependent on the type of cancer treatment and patient age. Specifically, uterine growth is stunted and resistant to hormone replacement therapy in prepubertal girls receiving abdominal, pelvic or whole-body radiotherapy. In contrast, females treated with radiotherapy post-puberty can benefit from hormone replacement therapy, as demonstrated by increased uterine volume and function. No live births have been reported in women previously exposed to radiotherapy after transplantation of cryopreserved ovarian tissue, even when menstruation returns. However, this technique has proven to be a successful fertility preservation method for women previously treated with chemotherapy. Obstetricians commonly report that women who maintain sufficient ovarian function can achieve pregnancy naturally following radiotherapy, but they have thin and/or fibrotic myometrium at delivery, compromising safe delivery and subsequent pregnancy. Furthermore, women exposed to either radiotherapy or chemotherapy have a higher prevalence of preterm birth and low birth weight infants, even in those with normal ovarian function or when oocyte donation is utilised. The mechanisms of potential uterine damage are poorly understood. While the myometrium, vasculature and endometrial progenitor cells are possibly targets, further studies are clearly required and well-controlled animal models could provide the best avenue for these types of future investigations.

WIDER IMPLICATIONS

Female cancer survivors experience greater rates of early pregnancy loss and complications, suggesting that cancer therapy-induced damage to the uterus contributes to infertility. Despite clinical reports dating back to 1989, we highlight a surprising lack of detail in the literature regarding the precise nature and extent of off-target damage inflicted to the uterus in response to cancer therapies. Young women requiring cancer treatment, and the clinicians treating them, must be equipped with accurate information to aid informed decision-making regarding cancer treatment regimens as well as the development and use of effective fertility preservation measures. As the current literature on the impacts of cancer treatments is limited, we hope that our narrative review on this subject will stimulate more research in this important field.

Acute reversible left ventricular systolic dysfunction associated with 5-fluorouracil therapy: a rare and increasingly recognised cardiotoxicity of a commonly used drug

5-Fluorouracil (5-FU) is the third most common chemotherapeutic agent for treating solid cancers and the second most common to cause cardiotoxicity. We present a rare case of acute reversible severe left ventricular systolic dysfunction associated with 5-FU. A 54-year-old woman with a history of stage IV gastric cancer presented with features of transient ischaemic attack after receiving the first dose of FLOT (5-FU, leucovorin, oxaliplatin and docetaxel). During the diagnostic workup, it was found that her ejection fraction was severely reduced to 15% with features of global hypokinesis, which later improved back to 65% within 13 days. These cases challenge our current understanding of the underlying mechanisms of this cardiotoxicity. Additionally, even though the patient did not experience any cardiac symptoms, it is important to monitor these patients closely as they are at high risk for fatal complications like arrhythmia and thrombus formation.

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.

Neoadjuvant Chemotherapy with Continuous Infusion of Cisplatin and Fluorouracil in Stage II-IV, M0 Squamous Cell Carcinoma of the Head and Neck

Aims and Background

The aim of the study was to assess the activity and the toxicity of cisplatin (DDP) and fluorouracil (FU) administered by continuous infusion as neoadjuvant chemotherapy for patients with stage II-IV, MO squamous cell carcinoma of the head and neck.

Methods

Thirty previously untreated patients were submitted to chemotherapy with DDP (20 mg/m2) and FU (1000 mg/m2), both in continuous infusion for 5 days, repeated every 21 days, for a maximum of 5 cycles. Following completion of chemotherapy, the patients underwent radiotherapy; in some patients surgery was performed immediately after chemotherapy. All patients were monitored for response, time to failure, survival, treatment-related events and toxicity.

Results

All patients were evaluated for response; after chemotherapy the complete response rate was 27% and the partial response rate 33%. Twenty-four patients underwent radiotherapy: the overall response rate was 83% (complete response 79%). After a median follow-up of 34 months, the median survival time was 22 months with a median time to failure of 15 months. Acute vascular accidents were the main and unexpected adverse events, with 2 deaths for pulmonary embolism and 1 for stroke. The response rate to the regimen does not seem to be better than that obtained with the standard combination of cisplatin bolus and fluorouracil continuous infusion. The disadvantage of the regimen is that it causes more discomfort for the patient in that it requires hospitalization.

Conclusions

For this reason, we believe that there are no elements for recommending the schedule as neoadjuvant treatment of patients with squamous cell carcinoma of the head and neck or as an experimental arm in a randomized trial.

Cardiac lesions induced by 5-fluorouracil in the rabbit

Cardiotoxicity is a rare, but well-recognized complication of treatments with the anti-cancer drug 5-fluorouracil (5FU). The underlying mechanism, however, is not fully elucidated. A spasm of the coronary arteries is often considered to be the leading cause of myocardial ischemia and decreased contractility associated with 5FU. As spasm cannot account for all reported adverse cardiac effects, the present study was undertaken to search for alternative mechanisms. Groups of six rabbits were given either a single intravenous dose of 50 mg/kg 5FU or four intravenous doses of 15 mg/kg 5FU at 7-day intervals. A third group served as control. The heart was removed shortly after death or scheduled sacrifice of the animals, to perform macroscopic and microscopic examinations of the heart and to evidence apoptosis by the TUNEL method. Following a single dose of 50 mg/kg 5FU, all animals rapidly developed a massive hemorrhagic myocardial infarct with spasms of the proximal coronary arteries. Repeated infusions of 15 mg/kg 5FU induced left ventricular hypertrophy, foci of myocardial necrosis, thickening of intra-myocardial arterioles, and disseminated apoptosis in myocardial cells of the epicardium, as well as endothelial cells of the distal coronary arteries. These results indicate that a spasm of the coronary arteries is not the only mechanism of 5FU cardiotoxicity, and that apoptosis of myocardial and endothelial cells can result in inflammatory lesions mimicking toxic myocarditis.

Thioredoxin-interacting protein: pathophysiology and emerging pharmacotherapeutics in cardiovascular disease and diabetes

The thioredoxin system, which consists of thioredoxin (Trx), nicotinamide adenine dinucleotide phosphate (NADPH) and thioredoxin reductase (TrxR), has emerged as a major anti-oxidant involved in the maintenance of cellular physiology and survival. Dysregulation in this system has been associated with metabolic, cardiovascular, and malignant disorders. Thioredoxin-interacting protein (TXNIP), also known as vitamin D-upregulated protein or thioredoxin-binding-protein-2, functions as a physiological inhibitor of Trx, and pathological suppression of Trx by TXNIP has been demonstrated in diabetes and cardiovascular diseases. Furthermore, TXNIP effects are partially Trx-independent; these include direct activation of inflammation and inhibition of glucose uptake. Many of the effects of TXNIP are initiated by its dissociation from intra-nuclear binding with Trx or other SH-containing proteins: these effects include its migration to cytoplasm, modulating stress responses in mitochondria and endoplasmic reticulum, and also potentially activating apoptotic pathways. TXNIP also interacts with the nitric oxide (NO) signaling system, with apparent suppression of NO effect. TXNIP production is modulated by redox stress, glucose levels, hypoxia and several inflammatory activators. In recent studies, it has been shown that therapeutic agents including insulin, metformin, angiotensin converting enzyme inhibitors and calcium channel blockers reduce TXNIP expression, although it is uncertain to what extent TXNIP suppression contributes to their clinical efficacy. This review addresses the role of TXNIP in health and in cardiovascular and metabolic disorders. Finally, the potential advantages (and disadvantages) of pharmacological suppression of TXNIP in cardiovascular disease and diabetes are summarized.

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 and oncological treatments

BACKGROUND

Cardiotoxic and other side effects limit the usefulness of treatments for cancer.

METHOD

This article is based on pertinent articles that were retrieved by a selective search in PubMed and other databases, and on the guidelines of the European Society of Cardiology, the Association of Scientific Medical Societies in Germany, and the European Society of Medical Oncology.

RESULTS

Prospective studies have shown that some treatments for cancer are cardiotoxic. The heart damage that they cause can manifest itself as arrhythmia, arterial hypertension, thromboembolism, angina pectoris, myocardial infarction, or heart failure. It has been observed that potentially lethal complications can arise as late as 40 years after treatment of the original cancer. The anthracycline drug doxorubicin, given in a dose of 500 mg/m2 of body surface area, has been found to cause cardiac complications in 4-36% of the patients treated with it. Trastuzumab and epirubicin cause dose-limiting cardiac events in 1.7-5% of patients, depending on the dosage. Paclitaxel causes bradycardia, intracardiac conduction block, or arrhythmia in 0.5% of patients. 18% of patients treated with sunitimib or sorafenib have clinical manifestations relating to the heart (angina pectoris, dyspnea). 5-fluorouracil can cause angina pectoris at the beginning of treatment and rarely causes myocardial infarction. Cardiac radiation therapy, a form of treatment practiced in earlier decades, can cause cardiac complications 20 years after the event. The opportunity to prevent cardiac complications of anthracycline drugs with dexrazoxane is decidedly limited, but initial studies have shown that treatment with beta-blockers and ACE inhibitors lessens the likelihood of cardiotoxic side effects. When cardiac complications arise, the generally applicable rules for the treatment of each type of cardiac problem should be followed. The oncological treatment protocol should be adjusted or switched to one that is less damaging to the heart.

CONCLUSION

Treating physicians need to be thoroughly acquainted with the cardiotoxic effects of anti-cancer drugs so that they can diagnose them early on and avoid jeopardizing the overall success of treatment.

Alternative treatment options in colorectal cancer patients with 5-fluorouracil- or capecitabine-induced cardiotoxicity

Most chemotherapy regimens in colorectal cancer treatment are 5-fluorouracil (5-FU)/leucovorin or capecitabine-based. Cardiotoxicity is a less common but potentially lethal complication of 5-FU or capecitabine treatment, and some physicians might be unfamiliar with treatment alternatives. Rechallenging should be avoided because it carries a high risk of recurrence of the cardiac symptoms and prophylactic treatment is not always protective. Possible alternative treatment options to be considered are to replace the oral capecitabine or intravenous 5-FU by a 5-FU bolus regimen, by uracil-tegafur or tegafur/gimeracil/oteracil, both oral fluoropyrimidines combining a 5-FU prodrug with a dihydropyrimidine dehydrogenase (DPD) inhibitor, or by raltitrexed, a thymidilate synthase inhibitor whose metabolism is independent of DPD. Patients with advanced colorectal cancer and fluoropyrimidine-induced cardiotoxicity can be treated with other non-fluoropyrimidine related chemotherapy, either as a single agent, combined, or in combination with biological agents. In this report we discuss the different alternative treatment options.

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.

A case of Takotsubo cardiomyopathy during 5-fluorouracil treatment for rectal adenocarcinoma

A case of acute heart failure due to Takotsubo cardiomyopathy induced by 5-fluorouracil is described. Acute heart failure developed during the administration of 5-fluorouracil (5-FU) and levofolinate calcium in a 62-year-old woman who had underwent a Miles operation for rectal adenocarcinoma. Electrocardiography upon admission showed slight ST elevation in leads V1-3, and follow-up electrocardiography on the third hospital day evealed QT interval prolongation and giant negative T waves in leads II, III, aVF, and V1-6. Echocardiography and myocardial scintigraphy showed left ventricular apical ballooning in the acute phase of heart failure, but left ventricular contraction was normal during the recovery phase. Coronary angiography demonstrated normal coronary arteries, and multi-vessel coronary artery vasospasms including microcirculation disorders could be provoked by intracoronary acetylcholine infusion during, but not before, the intravenous administration of levofolinate calcium and 5-FU. The cause of heart failure in this patient, Takotsubo cardiomyopathy induced by multivessel coronary vasospasm including microcirculation disorders only during 5-FU administration, is notable.

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.

Cardiotoxicity of cancer therapy

Because cancer is a leading cause of mortality in the United States, the number of therapeutic modalities available for the treatment of neoplastic processes has increased. This has resulted in a large number of patients being exposed to a wide variety of cancer therapy. Historically, it has been well recognized that antineoplastic agents may have adverse effects on multiple organs and normal tissues. The most commonly associated toxicities occur in tissues composed of rapidly dividing cells and may spontaneously reverse with minimal long-term toxicity. However, the myocardium consists of cells that have limited regenerative capability, which may render the heart susceptible to permanent or transient adverse effects from chemotherapeutic agents. Such toxicity encompasses a heterogeneous group of disorders, ranging from relatively benign arrhythmias to potentially lethal conditions such as myocardial ischemia/infarction and cardiomyopathy. In some instances, the pathogenesis of these toxic effects has been elucidated, whereas in others the precise etiology remains unknown. We review herein the various syndromes of cardiac toxicity that are reported to be associated with antineoplastic agents and discuss their putative mechanisms and treatment.

Endothelial cell effects of cytotoxics: balance between desired and unwanted effects

Since Folkman defined angiogenesis more than 25 years ago as the most important process in tumour growth and metastasis, specific anti-angiogenic agents have been developed. One obvious route to block this process was until recently overlooked, however. Tumour endothelial cells are different from normal endothelial cells and may respond differently to conventional cytotoxics. Chemotherapeutic-induced vascular toxicity has been observed in various clinical studies and seems to be based on endothelial cell damage as seen in vitro in human umbilical vein endothelial cells (HUVEC) models with protracted low-dose cytostatic exposure. Translated into the clinical setting, such "metronomically" administered chemotherapy could lead to anti-angiogenesis enhancing anti-tumour efficacy of cytostatic drugs. This paper reviews the desired anti-tumour endothelial activity versus the unwanted general vascular toxicity of cytostatic drugs. Several ways to enhance the anti-tumour activity and to circumvent the unwanted vascular toxicity of these "accidental" anti-angiogenic drugs will be discussed.

5-Fluorouracil induces arterial vasocontractions

BACKGROUND

From 2% to 10% of cancer patients treated with 5-fluorouracil (5-FU) will develop symptomatic cardiotoxicity. Nevertheless, the underlying pathophysiology is mostly unknown.

PATIENTS AND METHODS

We investigated the influence of intravenous chemotherapy (CTX) on the diameter of the brachial artery using high resolution ultrasound in patients with malignant tumors, mostly gastrointestinal cancer. Cytostatic drugs included 30 cases with 5-FU and 30 cases with non-5-FU CTX (cis/carboplatin, anthracycline and cyclophosphamide). In addition, plasma levels of big endothelin were assessed prior to and after CTX.

RESULTS

Fifteen of 30 patients (50%) showed a contraction of the brachial artery after the end of 5-FU application (median 11%, range 4.3-18.5), whereas no single contraction was noticed in 30 patients following non-5-FU-based CTX. Vessel tonus generally normalized within 30 min after stopping 5-FU. Five patients positive for 5-FU associated vessel contraction were repeatedly exposed to 5-FU. Vessel contractions reoccurred in 86% (18/21) of these administrations. When patients with 5-FU bolus application were pre-treated with glyceroltrinitrate no contraction of the brachial artery was detected in five out of five occasions. There was a trend towards increased big endothelin plasma levels after 5-FU application (median 1.52 versus 1.99 fmol/ml; P = 0.07), whereas big endothelin levels remained unchanged after non-5-FU CTX (1.83 versus 1.83 fmol/ml; P = 0.99).

CONCLUSIONS

Application of 5-FU is commonly accompanied by arterial vessel contractions, which is likely to represent the first step in 5-FU-induced cardiotoxicity. 5-FU-associated vessel contractions were highly reproducible on re-exposure and were in the case of bolus application completely preventable by glyceroltrinitrate.

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.

Induction chemotherapy followed by simultaneous hyperfractionated radiochemotherapy in advanced head and neck cancer. A pilot study

PURPOSE

To evaluate the feasibility of induction chemotherapy followed by concomitant chemotherapy and hyperfractionated irradiation in locally advanced, inoperable head and neck cancer.

METHODS

A pilot study was undertaken comprising 3 cycles of cisplatinum (100 mg/m2, day 1) and 5-fluorouracil (1000 mg/m2 in continuous intravenous infusion over the first 120 h) followed by bifractionated radiotherapy applied to tumor/involved lymph nodes up to the dose of 74.4 Gy given in 2 fractions of 1.2 Gy daily for 5 days a week combined with concomitant weekly cisplatinum infusion (50 mg/m2).

RESULTS

Six patients were enrolled in the study. All of them completed the protocol therapy. Severe mucositis and myelotoxicity were the most common acute side effects observed in all and in 5 of the patients, respectively. Acute toxicity required interruption of concomitant chemotherapy in 5 cases and in 2 interruption of radiotherapy was necessary. Opioid analgesic parenteral therapy was administered in 4 patients. Three of them had to be hospitalized. One patient experienced cerebral stroke 1 day after the completion of therapy and died 7 days later. Due to high acute toxicity, patient accrual was terminated after 6 patients. At the mean follow-up of 17 months, 4 patients are alive, 3 of them are free of disease and in 1 local progression has been diagnosed.

CONCLUSIONS

High acute toxicity of induction cisplatinum and 5-fluorouracil followed by concomitant cisplatinum and hyperfractionated irradiation calls for less toxic treatment schedules in locally advanced inoperable head and neck cancer.

[Heart pathology of extracardiac origin. VII. Heart and neoplasms]

Cardiac alterations of neoplastic diseases can be due to direct invasion produced by primary cardiac tumors or more frequently secondary to local compression of vascular structures by extracardiac neoplasms, such as superior vena cava syndrome. One of the most important alterations is the cardiotoxicity of anticancer treatments, either chemotherapy drugs or radiotherapy techniques. These treatments cause acute and/or chronic cardiotoxicity that the oncologist and the cardiologist must be aware of. For instance, 4.5% to 7% of patients that have been treated with anthracyclines may suffer cardiac failure in their lifetime. The pathogenesis is still not clear. There is currently a lot of research on cardioprotectors, but nowadays the only one approved by the FDA is dexrazoxane, which is used on breast cancer patients treated with adriamycin.

Raltitrexed (Tomudex): an alternative drug for patients with colorectal cancer and 5-fluorouracil associated cardiotoxicity

Two patients with proven 5-fluorouracil (5-FU)-associated cardiotoxicity were treated with the specific thymidylate synthase inhibitor raltitrexed safely, without evidence of cardiotoxicity. Raltitrexed might be an alternative for patients with advanced colorectal cancer and 5-FU-associated cardiotoxicity. 5-FU cardiotoxicity is not due to the antineoplastic mechanisms via thymidilate synthase.

The influence of 5-fluorouracil and methotrexate on vascular endothelium. An experimental study using endothelial cells in the culture

BACKGROUND

Cardiotoxicity still remains an unexplained toxic manifestation of 5-fluorouracil (5-FU). Clinical and experimental data suggest that endothelium of coronary arteries could be involved in the pathophysiological mechanisms of the syndrome. In order to further explain 5-FU induced cardiotoxicity, we investigated the influence of this drug on endothelial cells (EC) in a cell culture model.

MATERIALS AND METHODS

The influence of 5-FU on EC, with respect to DNA synthesis, cell death and release of prostacyclin by endothelial cells (EC) was studied. For comparison, we tested methotrexate (MTX), an antimetabolite without cardiotoxic properties, in the same way. Human endothelial cell lines (HEC) and bovine endothelial cells (BEC) were incubated with increasing concentrations of 5-FU and MTX for 48 hours. (3H)thymidine incorporation, total cellular protein, loss of (3H)thymidine from prelabelled cells and 6-keto-prostaglandin F1 were measured.

RESULTS

DNA synthesis decreased significantly in both HEC and BEC, and the release of prostacyclin by BEC increased significantly when incubated with 5-FU. This effect was not seen with MTX.

CONCLUSION

The results indicate specific susceptibility of benign EC to 5-FU. Such susceptibility was confirmed by the release of prostacyclin by the BEC, indicating leakage secondary to EC injury.

Clinical cardiotoxicity of 5-fluorouracil

5-Fluorouracil is widely known to be toxic to the hematopoietic and gastrointestinal systems. It also has cardiac toxicity, but this is perceived to be rare. During a 16-month period from January 1990 through April 1991, approximately 910 patients were treated with 5-fluorouracil. Five of these developed life-threatening toxicity consistent with coronary artery spasm for an incidence of .55%. The acute events occurred on the third or fourth day of the 5-day infusion and after the fourth intravenous bolus in the patient on bolus therapy. Each of the patients had ST elevation and ventricular arrhythmias, four had acute myocardial infarction, and two had cardiac arrests. In these cases and those previously reported, cardiac toxicity is consistent with drug- or metabolite-mediated increases in coronary vasomotor tone and spasm, leading to the full spectrum of signs and symptoms of myocardial ischemia in susceptible individuals.

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.

Current research in side effects of high-dose chemotherapy

The toxicities of chemotherapy continue to hamper dose escalation of specific chemotherapeutic agents. The impact of dose intensification upon survival will be assessed as clinical studies continue. Strategies to support chemotherapy dose intensification include BMT, use of CSFs and antiemetic drug combinations. Advances in symptom management will hopefully enhance quality of life for patients, whereas the development of chemoprotectant agents may allow specific organ toxicities to be avoided.

Myocardial ischemia associated with high-dose carmustine infusion

Carmustine (BCNU), a nitrosourea derivative, is an antineoplastic agent used recently for the treatment of human solid tumors and lymphomas in high doses with autologous bone marrow transplantation. Cardiac toxicity related to BCNU has not been described well. Three patients are reported without a history of angina pectoris who had clinical and electrocardiographic evidence of myocardial ischemia during and immediately after BCNU infusion. The incidence, cause, and mechanism of such a side effect are unknown but should be considered in patients receiving high-dose carmustine infusions.

Vascular events in patients receiving high-dose infusional 5-fluorouracil-based chemotherapy: the University of Chicago experience

In a retrospective review, 22 of a total of 244 patients (9%) patients with head and neck or gastrointestinal cancer who were treated with infusional 5-fluorouracil (5-FU)-based chemotherapy regimens experienced thrombotic vascular events. These events occurred concurrently with treatment or several months following the completion of therapy and consisted mainly of cardiac arrhythmias, myocardial infarction, sudden death, and thromboembolism. The temporal relationship of these vascular events to the time of treatment suggests that infusional 5-FU may have been the underlying cause.

5-fluorouracil in the treatment of scleroderma: a randomised, double blind, placebo controlled international collaborative study

A six month controlled study of 5-fluorouracil in the treatment of scleroderma showed a modest benefit in skin scores, Raynaud's phenomenon, and patients' global assessment. Visceral organ and hand function were unaffected. Mild to moderate toxicity was common in the 5-fluorouracil treated patients but usually responded to dose reduction. Two patients receiving 5-fluorouracil died from causes seemingly unrelated to treatment. Significant clinical improvement in scleroderma was not noted in the first six months of treatment with 5-fluorouracil.

5-Fluorouracil cardiotoxicity: a critical review

5-Fluorouracil is a commonly administered chemotherapy agent that has infrequently been associated with cardiotoxicity. This review highlights the clinical features of this syndrome as described in reports from the medical literature. Clinical and laboratory evidence supporting proposed underlying mechanisms are reviewed.

Thrombogenicity of intravenous 5-fluorouracil alone or in combination with cisplatin

Acute myocardial infarction was observed in two patients receiving standard intravenous doses of 5-fluorouracil (5-FU)-based chemotherapy. Therefore, the authors prospectively assessed the thrombogenicity of this agent by studying ten patients, six with head and neck cancer and four with gastrointestinal malignancies, receiving 5-FU (1 g/m2/day) as a constant intravenous infusion over a 4-day or 5-day period. The six patients with head and neck cancer also received a single dose of 100 mg/m2 of cisplatin on day 1. Blood samples were obtained preinfusion, 24 hours into the infusion, and postinfusion. Samples were assayed for fibrinopeptide A (FpA) by enzyme-linked immunoassay, for protein C activity (PCa) using a chromogenic substrate (Spectrozyme PCa), and protein C (PCag) and free protein S antigen (PSag) by electroimmunoassay. No patient experienced a thrombotic event. A significant increase was observed in FpA levels during the infusion which returned toward baseline at the conclusion of the infusion. After infusion of 5-FU, the PCa value was significantly lower than the PCag (37 +/- 17 versus 69 +/- 24%; P less than 0.002). No effect on protein S was observed. The changes in the patients receiving 5-FU alone were comparable to those who also received CDDP. The authors conclude that during the infusion of 5-FU, the rise in FpA activation and reduction in PCa as compared to PCag are compatible with activation of coagulation.

Failure of preventing 5-fluorouracil cardiotoxicity by prophylactic treatment with verapamil

The most common cardiotoxic effects of 5-fluorouracil (5-FU) are chest pain and ischemic ECG abnormalities. Coronary vasospasm may be the underlying mechanism. If so, prophylactic treatment with calcium channel blockers might have a beneficial effect. In the present study, prophylaxis with verapamil (120 mg three times daily) was given to 58 patients with esophageal or advanced head and neck carcinoma during induction chemotherapy with cisplatin and continuous infusion with 5-FU. Signs of ischemia appeared in 12% of the patients as compared to 13% in a previously studied compatible group of patients not receiving prophylaxis. The study does not support the hypothesis that prophylactic treatment with verapamil reduces the incidence of ischemia in patients undergoing 5-FU treatment. Verapamil might, however, modify the adverse cardiac effects of 5-FU by preventing supraventricular tachyarrhythmia.

Randomized phase II study of a combination of cisplatin (DDP), 5-fluorouracil (5-FU), and allopurinol (HPP) versus 5-FU in advanced colorectal carcinoma. An EORTC Gastrointestinal Tract Cancer Cooperative Group study

In order to improve the therapeutic index of fluorouracil (5-FU), it has been combined with cisplatin (DDP) as synergistic agent and with allopurinol (HPP) as toxicity modulator. Patients with measurable colorectal carcinoma, previously untreated by chemotherapy, were randomized to receive either 5-FU alone 500 mg/m2 push iv days 1-5 or HPP 3 x 300 mg po, days 1-5, 5-FU 800 mg/m2 push iv, days 3-5 and DDP 50 mg/m2 d6. Treatment was repeated every 4 weeks. Of 104 patients randomized, 82 were evaluable for response and survival. Six partial responses were seen in each treatment group (15%) and the median survival time was 7 months. Hematologic toxicities were comparable in both treatment groups, with a mean nadir white blood cell count of 3500/ vs. 3800/mm3 and a mean nadir platelet count of 148,000/ vs, 203,000/mm3 for HPP-5-FU-DDP and 5-FU, respectively. This study suggests that the addition of both HPP and DDP does not improve the activity of 5-FU.