In vitro toxicity studies with mitomycins and bleomycin on endothelial cells

Chemotherapy-associated hemorrhagic posterior reversible encephalopathy syndrome (PRES) with considerations for circle of Willis variants on cerebral blood flow and autoregulation: A case report

RATIONALE

Hodgkin lymphoma, a lymphatic system cancer, is treated by chemotherapy, radiation therapy, and hematopoietic stem cell transplantation. Posterior reversible encephalopathy syndrome (PRES) is a rare neurotoxic effect associated with several drugs and systemic conditions. This case study emphasizes the potential risks of intensive chemotherapy regimens and postulates the impact of the circle of Willis variants on the heterogeneity of hemispheric lesions in PRES.

PATIENT CONCERNS

A 42-year-old woman diagnosed with stage IIA nodular sclerosing Hodgkin lymphoma and chronic thrombocytopenia presented after 6 years of initial diagnosis and 4 years post-haploidentical transplant. She underwent planned chemotherapy with ifosfamide, carboplatin, and etoposide.

DIAGNOSES

She developed an alteration in her mental status. A computerized tomography scan and angiogram of the head and neck revealed findings consistent with PRES and a left fetal-type posterior cerebral artery with an aplastic A1 segment of the left anterior cerebral artery. One hour later she was found comatose with clinical sequelae of an uncal herniation.

INTERVENTIONS

Subsequent events led to emergent intubation, and administration of 23.4% hypertonic saline. A repeat computerized tomography scan showed a right intraparenchymal hemorrhage with fluid-fluid levels measuring up to 4.7 cm, bilateral subarachnoid hemorrhage, right uncal herniation, and 15 mm of leftward midline shift. She emergently underwent a right decompressive hemi-craniectomy.

OUTCOMES

An magnetic resonance imaging of the brain demonstrated bilateral cytotoxic edema involving the parieto-occipital lobes. Despite interventions, the patient's neurological condition deteriorated, leading to a declaration of brain death on the 8th day.

LESSONS

This case underscores the importance of recognizing the severe neurological complications, including PRES, associated with chemotherapeutic treatments in Hodgkin lymphoma. PRES may also be exacerbated by coagulopathies such as thrombocytopenia in this case. The circle of Willis variants may influence cerebral blood flow, autoregulation, and other factors of hemodynamics, leading to increased susceptibility to both radiographic lesion burden and the worst clinical outcomes.

Investigation of cancer response to chemotherapy: a hybrid multi-scale mathematical and computational model of the tumor microenvironment

Tumor microenvironment (TME) is a multi-scale biological environment that can control tumor dynamics with many biomechanical and biochemical factors. Investigating the physiology of TME with a heterogeneous structure and abnormal functions not only can achieve a deeper understanding of tumor behavior but also can help develop more efficient anti-cancer strategies. In this work, we develop a hybrid multi-scale mathematical model of TME to simulate the progression of a three-dimensional tumor and elucidate its response to different chemotherapy approaches. The chemotherapy approaches include multiple low dose (MLD) of anti-cancer drug, maximum tolerated dose (MTD) of anti-cancer drug, combination therapy of MLD and anti-angiogenic drug, and combination therapy of MTD and anti-angiogenic drug. The results show that combining anti-angiogenic agent with anti-cancer drug increases the performance of cancer treatment and decreases side effects for normal tissue. Indeed, the vascular normalization caused by anti-angiogenic therapy improves anti-cancer drug delivery for both MLD and MTD approaches. The results show that anti-cancer drug administered in a lower dose than the maximum tolerated dose repetitively over a long period treats cancer with a considerable performance and fewer side effects. We also show that tumor morphology and distribution of cancer cell phenotypes can be considered as the characteristics to distinguish different chemotherapy approaches. This robust model can be applied to predict the behavior of any type of cancer and quantify cancer response to different chemotherapy approaches. The computational results of cancer response to chemotherapy are in good agreement with experimental measurements.

Changes in hemodynamics, renal blood flow and urine output during continuous renal replacement therapies

Continuous renal replacement therapies (CRRT) affect hemodynamics and urine output. Some theories suggest a reduced renal blood flow as the cause of the decreased urine output, but the exact mechanisms remain unclear. A prospective experimental study was carried out in 32 piglets (2–3 months old) in order to compare the impact of CRRT on hemodynamics, renal perfusion, urine output and renal function in healthy animals and in those with non-oliguric acute kidney injury (AKI). CRRT was started according to our clinical protocol, with an initial blood flow of 20 ml/min, with 10 ml/min increases every minute until a goal flow of 5 ml/kg/min. Heart rate, blood pressure, central venous pressure, cardiac output, renal blood flow and urine output were registered at baseline and during the first 6 h of CRRT. Blood and urine samples were drawn at baseline and after 2 and 6 h of therapy. Blood pressure, cardiac index and urine output significantly decreased after starting CRRT in all piglets. Renal blood flow, however, steadily increased throughout the study. Cisplatin piglets had lower cardiac index, higher vascular resistance, lower renal blood flow and lower urine output than control piglets. Plasma levels of ADH and urine levels of aquaporin-2 were lower, whereas kidney injury biomarkers were higher in the cisplatin group of piglets. According to our findings, a reduced renal blood flow doesn’t seem to be the cause of the decrease in urine output after starting CRRT.

Clinical and Genetic Risk Factors for Adverse Metabolic Outcomes in North American Testicular Cancer Survivors

Background: Testicular cancer survivors (TCS) are at significantly increased risk for cardiovascular disease (CVD), with metabolic syndrome (MetS) an established risk factor. No study has addressed clinical and genetic MetS risk factors in North American TCS. Patients and Methods: TCS were aged <55 years at diagnosis and received first-line chemotherapy. Patients underwent physical examination, and had lipid panels, testosterone, and soluble cell adhesion molecule-1 (sICAM-1) evaluated. A single nucleotide polymorphism in rs523349 (5-α-reductase gene, SRD5A2), recently implicated in MetS risk, was genotyped. Using standard criteria, MetS was defined as ≥3 of the following: hypertension, abdominal obesity, hypertriglyceridemia, decreased high-density lipoprotein (HDL) cholesterol level, and diabetes. Matched controls were derived from the National Health and Nutrition Examination Survey. Results: We evaluated 486 TCS (median age, 38.1 years). TCS had a higher prevalence of hypertension versus controls (43.2% vs 30.7%; P<.001) but were less likely to have decreased HDL levels (23.7% vs 34.8%; P<.001) or abdominal obesity (28.2% vs 40.1%; P<.001). Overall MetS frequency was similar in TCS and controls (21.0% vs 22.4%; P=.59), did not differ by treatment (P=.20), and was not related to rs523349 (P=.61). For other CVD risk factors, TCS were significantly more likely to have elevated low-density lipoprotein (LDL) cholesterol levels (17.7% vs 9.3%; P<.001), total cholesterol levels (26.3% vs 11.1%; P<.001), and body mass index ≥25 kg/m² (75.1% vs 69.1%; P=.04). On multivariate analysis, age at evaluation (P<.001), testosterone level ≤3.0 ng/mL (odds ratio [OR], 2.06; P=.005), and elevated sICAM-1 level (OR_{highest vs lowest quartile}, 3.58; P=.001) were significantly associated with MetS. Conclusions and Recommendations: Metabolic abnormalities in TCS are characterized by hypertension and increased LDL and total cholesterol levels but lower rates of decreased HDL levels and abdominal obesity, signifying possible shifts in fat distribution and fat metabolism. These changes are accompanied by hypogonadism and inflammation. TCS have a high prevalence of CVD risk factors that may not be entirely captured by standard MetS criteria. Cancer treatment-associated MetS requires further characterization.

Toxicities Associated with Cisplatin-Based Chemotherapy and Radiotherapy in Long-Term Testicular Cancer Survivors

Testicular cancer has become the paradigm of adult-onset cancer survivorship, due to the young age at diagnosis and 10-year relative survival of 95%. This clinical review presents the current status of various treatment-related complications experienced by long-term testicular cancer survivors (TCS) free of disease for 5 or more years after primary treatment. Cardiovascular disease and second malignant neoplasms represent the most common potentially life-threatening late effects. Other long-term adverse outcomes include neuro- and ototoxicity, pulmonary complications, nephrotoxicity, hypogonadism, infertility, and avascular necrosis. Future research efforts should focus on delineation of the genetic underpinning of these long-term toxicities to understand their biologic basis and etiopathogenetic pathways, with the goal of developing targeted prevention and intervention strategies to optimize risk-based care and minimize chronic morbidities. In the interim, health care providers should advise TCS to adhere to national guidelines for the management of cardiovascular disease risk factors, as well as to adopt behaviors consistent with a healthy lifestyle, including smoking cessation, a balanced diet, and a moderate to vigorous intensity exercise program. TCS should also follow national guidelines for cancer screening as currently applied to the general population.

Chemotherapy-associated Posterior Reversible Encephalopathy Syndrome: A Case Report and Review of the Literature

INTRODUCTION

There are increasing reports of posterior reversible encephalopathy syndrome (PRES) associated with the use of chemotherapeutic agents. Recognition of PRES is crucial given its reversibility with appropriate supportive management. We report a patient presenting with PRES after treatment with Rituximab, Cyclophosphamide, Hydroxydaunorubicin/Adriamycin, Oncovin/Vincristine, Prednisone (R-CHOP) and intrathecal methotrexate. We also perform a systematic review of the literature on chemotherapy-associated PRES.

CASE REPORT

A 72-year-old man with recently diagnosed diffuse large B-cell lymphoma became unresponsive 4 days after initiation of R-CHOP and intrathecal methotrexate. Brain magnetic resonance imaging showed interval development of occipital and temporal fluid attenuation inversion recovery hyperintensities consistent with PRES. The patient's blood pressure was aggressively controlled and he received 5 days of high-dose methylprednisone. He subsequently regained consciousness and his mental status gradually improved. Repeat magnetic resonance imaging showed interval resolution of the bilateral fluid attenuation inversion recovery hyperintensities.

REVIEW SUMMARY

We performed a systematic review of the literature and included a total of 70 unique cases involving chemotherapy-associated PRES. Platinum-containing drugs, Cyclophosphamide, Hydroxydaunorubicin/Adriamycin, Oncovin/Vincristine, Prednisone/R-CHOP regimens, and gemcitabine were the agents most commonly used in patients who developed suspected chemo-associated PRES. Median onset of symptoms occurred 8 days after chemotherapy. Hypertension was the most commonly reported risk factor associated with the development of chemotherapy-associated PRES. In most cases, PRES improved with supportive management alone within 2 weeks.

CONCLUSIONS

Chemotherapy-associated PRES is an increasingly encountered syndrome. Both neurologists and non-neurologists should be familiar with the most commonly implicated agents, symptoms, risk factors, and clinical course of chemotherapy-associated PRES, given its favorable prognosis with appropriate management.

Long-term arterial complications of chemotherapy in patients with cancer

The number of cancer survivors has gradually increased in recent decades. However, the cancer survivors are at risk for conditions related to their initial disease and its treatment, i.e. surgery, systemic treatment or radiotherapy. Cardiovascular complications, such as myocardial infarction, are common side effects of these therapies. Cardiovascular damage can occur during treatment or month to years after the initial treatment, as late effect of the cancer treatment. The pathophysiology of these effects is not yet fully understood, but an important part of the cardiovascular complications are thought to be the result of effects of anticancer agents on the structural and functional properties of the endothelium. Because these conditions can result in a high degree of morbidity and mortality, understanding how to improve the prevention, recognition, and treatment of vascular disease is an important medical priority in the care for cancer survivors. This review will focus on the long-term arterial complications of chemotherapy in cancer survivors. It will summarize the epidemiology and pathophysiology of these complications. Furthermore, important long-term clinical conditions related to these effects will be outlined, including cardiovascular risk management in terms of prevention, evaluation and therapy.

Growth differentiation factor 15 (GDF-15) plasma levels increase during bleomycin- and cisplatin-based treatment of testicular cancer patients and relate to endothelial damage

Introduction

Chemotherapy-related endothelial damage contributes to the early development of cardiovascular morbidity in testicular cancer patients. We aimed to identify relevant mechanisms of and search for candidate biomarkers for this endothelial damage.

Methods

Human micro-vascular endothelial cells (HMEC-1) were exposed to bleomycin or cisplatin with untreated samples as control. 18k cDNA microarrays were used. Gene expression differences were analysed at single gene level and in gene sets clustered in biological pathways and validated by qRT-PCR. Protein levels of a candidate biomarker were measured in testicular cancer patient plasma before, during and after bleomycin-etoposide-cisplatin chemotherapy, and related to endothelial damage biomarkers (von Willebrand Factor (vWF), high-sensitivity C-Reactive Protein (hsCRP)).

Results

Microarray data identified several genes with highly differential expression; e.g. Growth Differentiation Factor 15 (GDF-15), Activating Transcription Factor 3 (ATF3) and Amphiregulin (AREG). Pathway analysis revealed strong associations with ‘p53’ and ‘Diabetes Mellitus’ gene sets. Based on known function, we measured GDF-15 protein levels in 41 testicular patients during clinical follow-up. Pre-chemotherapy GDF-15 levels equalled controls. Throughout chemotherapy GDF-15, vWF and hsCRP levels increased, and were correlated at different time-points.

Conclusion

An unbiased approach in a preclinical model revealed genes related to chemotherapy-induced endothelial damage, like GDF-15. The increases in plasma GDF-15 levels in testicular cancer patients during chemotherapy and its association with vWF and hsCRP suggest that GDF-15 is a potentially useful biomarker related to endothelial damage.

In vivo MRI Follow-up of Murine Tumors Treated by Electrochemotherapy and other Electroporation-based Treatments

In vivo cell electropermeabilization can be used alone or in combination with a hydrophilic, nonpermeant cytotoxic drug such as bleomycin (electrochemotherapy) to efficiently treat tumors. We used magnetic resonance imaging to detect rapid structural modifications in tumors treated by electroporation-based methods. Water diffusion coefficient (ADC), transverse relaxation time (T2) and tumor volume of fibrosarcomas xenografted on syngenic mice were measured upon 3 groups of 6 treated mice within the 48 hrs following ECT done with a normal (BE) or a high dose of bleomycin (HBE), and after irreversible electroporation (IRE), and in three control groups. As expected, the tumor volume increased in the control groups at 48 hrs (p < 0.05) and the values of ADC and T2 did not varied significantly in the control groups except for ADC decrease and T2 increase observed between 3 hrs and 24 hrs (p < 0.03) in the group that received bleomycin only. Tumor volumes decreased significantly at 24 hrs in the IRE and HBE groups. The mean tumor ADC increased significantly at 24 hrs (+17.6%, p < 0.03) in the BE group, probably reflecting apoptosis, while in the HBE group the mean tumor ADC increased earlier, at 10 hrs (+19%, p < 0.03) because of the speed of the pseudoapopototic process. In the IRE group, the mean tumor ADC decreased significantly at 1 hrs (p < 0.05) and 3 hrs (p < 0.03), and T2 decreased (p < 0.03), both probably reflecting cell swelling induced by the vascular lock. Thus ADC and T2 changes in the treated tumors correlated with previous histological observations on the same tumor models. Noteworthy, ADC allowed the visualization of early and rapid changes in the treated tumors, when tumor volume monitoring was not yet able to detect any effect of the treatments.

Nanospheres encapsulating anti-leishmanial drugs for their specific macrophage targeting, reduced toxicity, and deliberate intracellular release

The current work focuses on the study of polymeric, biodegradable nanoparticles (NPs) for the encapsulation of doxorubicin and mitomycin C (anti-leishmanial drugs), and their efficient delivery to macrophages, the parasite's home. The biodegradable polymer methoxypoly-(ethylene glycol)-b-poly (lactic acid) (MPEG-PLA) was used to prepare polymeric NPs encapsulating doxorubicin and mitomycin C. The morphology, mean diameter, and surface area of spherical NPs were determined by transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), and BET surface area analysis. X-ray diffraction was performed to validate drug encapsulation. An in vitro release profile of the drugs suggested a fairly slow release. These polymeric NPs were efficiently capable of releasing drug inside macrophages at a slower pace than the free drug, which was monitored by epi-fluorescence microscopy. Encapsulation of doxorubicin and mitomycin C into NPs also decreases cellular toxicity in mouse macrophages (J774.1A).

A comparative study on the anti-angiogenic effects of DNA-damaging and cytoskeletal-disrupting agents

The discovery of molecules with anti-angiogenic properties has led to promising new strategies for the treatment of diseases characterized by excessive new vessel growth, such as cancer and haemangioma. We have assessed the effects of DNA-damaging and cytoskeletal-disrupting agents in vitro on several endothelial cell functions. We report that bleomycin, mitomycin C and cytoskeletal-disrupting drugs (2-methoxyestradiol, taxol, vincristine, vinblastine, colchicine, nocodazole, and cytochalasin D) exhibit anti-angiogenic activities of varying potency. Bleomycin and the various cytoskeletal-disrupting drugs inhibited endothelial cell migration, while mitomycin C had a marginal effect. Both DNA-damaging and cytoskeletal-disrupting drugs decreased endothelial cell growth in a dose-dependent manner, and this was accompanied by the induction of apoptosis. The growth inhibitory and apoptotic effects of cytoskeletal-disrupting drugs were the most pronounced. We also show that both classes of drugs inhibited capillary-like tube formation in an assay of in vitro angiogenesis, with cytoskeletal-disrupting agents inhibiting in vitro angiogenesis with greater potency. A targeted approach incorporating several compounds with different mechanisms of action may be useful for the treatment of angiogenesis-dependent diseases such as hemangiomas of infancy.

Cardiovascular risk in long-term survivors of testicular cancer

BACKGROUND

Long-term survivors of testicular cancer (TC) who received cisplatin-based chemotherapy have an increased risk of cardiovascular disease. A cross-sectional study was performed to objectively assess cardiovascular risk, subclinical atherosclerosis, and endothelial function in long-term survivors of TC.

METHODS

Long-term survivors of TC underwent evaluation including determination of body mass index (BMI), Framingham relative risk (RR), brachial artery flow-mediated dilatation (FMD), carotid artery intima-media thickness (IMT), soluble intercellular adhesion molecule-1 (sICAM-1), high sensitivity C-reactive protein (hs-CRP), and flow cytometric analysis of peripheral blood for levels of endothelial progenitor cells (EPCs) and circulating endothelial cells (CECs). TC survivors who received chemotherapy were compared with a chemotherapy naive cohort.

RESULTS

Twenty-four patients received cisplatin-based chemotherapy (CBCT) and 15 were chemotherapy-naive (CN). The CBCT cohort demonstrated more impairment of brachial artery FMD than the CN group (5.6% vs 8.8%; P = .05). The mean sICAM was also found to be higher in the CBCT cohort compared with the CN group (P = .04). No significant differences between the groups were noted with regard to BMI, Framingham RR, carotid IMT, or hs-CRP. In a subset of patients, TC survivors who received chemotherapy had a significantly increased level of CECs compared with CN patients (P = .04). No significant difference in EPC levels was detected.

CONCLUSIONS

Long-term survivors of TC who received chemotherapy demonstrate objective evidence of endothelial injury and dysfunction, a potential mechanism for increased cardiovascular risk.

Bleomycin and the skin

Bleomycin is frequently used as a chemotherapeutic agent to treat various kinds of malignancy. However, the cytotoxic effects of bleomycin cause a number of adverse responses, in particular in the lung and the skin. Bleomycin is used by dermatologists as a treatment for various skin cancers, recalcitrant warts, keloid and hypertrophic scars. This article discusses the use of bleomycin for various skin disorders, as well as the risk factors and cutaneous side-effects resulting from its use.

Acute chemotherapy-induced cardiovascular changes in patients with testicular cancer

PURPOSE

After cisplatin- and bleomycin-containing chemotherapy for testicular cancer, part of the patient population will develop acute or long-term cardiovascular toxicity. It is largely unknown whether standard tests can be used to assess chemotherapy-induced cardiovascular changes.

PATIENTS AND METHODS

In 65 testicular cancer patients (median age, 27 years; range, 18 to 48 years), we measured the following cardiovascular parameters before and within 10 weeks after completion of cisplatin-based chemotherapy: platelet numbers, plasma levels of hemostatic and fibrinolytic factors, 24-hour ambulatory blood pressure, baroreflex sensitivity, intima-media thickness of the common carotid artery, and flow-mediated vasodilation of the brachial artery.

RESULTS

Compared with prechemotherapy values, the intima-media thickness of the carotid artery and plasma von Willebrand factor levels increased significantly after treatment. Platelet numbers and plasma levels of other hemostatic and fibrinolytic factors did not appear to change significantly. Blood pressure decreased significantly, but flow-mediated vasodilation and baroreflex sensitivity did not change.

CONCLUSION

In testicular cancer patients treated with cisplatin-based chemotherapy, we found an increase in plasma von Willebrand factor levels and in the intima-media thickness of the carotid artery. These changes may indicate chemotherapy-induced vascular damage and be of prognostic significance for the development of cardiovascular complications in the long term.

Microalbuminuria, decreased fibrinolysis, and inflammation as early signs of atherosclerosis in long-term survivors of disseminated testicular cancer

Testicular cancer patients have an increased risk for coronary artery disease more than ten years after cisplatin-based chemotherapy. We investigated whether vascular changes, including endothelial dysfunction, are present earlier. Ninety chemotherapy-treated testicular cancer patients (median follow-up of seven years) were compared with 44 patients after orchidectomy only and 47 healthy men. Microalbuminuria was present in 10 (12%) chemotherapy patients, one stage I patient and none of the controls. Chemotherapy patients had higher levels of fibrinogen, C-reactive protein (hs-CRP), von Willebrand factor (vWF), plasminogen activator inhibitor (PAI-1), and tissue-type plasminogen activator (t-PA). Chemotherapy patients with elevated PAI-1 (25/90) showed clustering of cardiovascular risk factors resembling the metabolic syndrome. In conclusion, cured testicular cancer patients showed a high prevalence of microalbuminuria and increased plasma levels of endothelial and inflammatory marker proteins, which might progress to more severe endothelial dysfunction and overt atherosclerosis.

Bleomycin induces IL-8 and ICAM-1 expression in microvascular pulmonary endothelial cells

To investigate the pathomechanisms of bleomycin-induced early inflammation of lung parenchyma which is known to result in pulmonary fibrosis, we examined the in vitro effect of bleomycin (BLM) on primary human pulmonary microvascular endothelial cells (HMVEC-L). After incubation of microvascular endothelial cells with BLM we detected an induced phosphorylation of p38 mitogen-activated protein kinase (p38 MAPK) by immunoblotting. Further, after BLM-exposure an increased concentration of interleukin-8 (IL-8) in culture supernatant and an increased expression of intercellular adhesion molecule-1 (ICAM-1, CD54) on the cell surface have been observed. Real-time PCR revealed up-regulated mRNA expression levels of both, IL-8 and ICAM-1 after treatment with BLM. Finally, pre-treatment with a selective p38 MAPK-inhibitor, SB 203580, potently reduced the BLM-induced up-regulation of IL-8 expression but did not show any effect on expression of ICAM-1. These results demonstrate that BLM induces the expression of pro-inflammatory molecules in the pulmonary microvascular endothelium, which thereby may actively contribute to the development of early inflammation and later fibrosis of the lung. Furthermore, investigating the effect of an inhibitor of p38 MAPK the data indicate the involvement of p38 MAPK-dependent as well as p38 MAPK-independent mechanisms in the effects of BLM on the pulmonary microvasculature.

Differential secretion of cytokines and adhesion molecules by HUVEC stimulated with low concentrations of bleomycin

Bleomycin (BLM) is known to induce lung inflammation and subsequent fibrosis. Endothelial cells have been reported to play an important role, producing cytokines and adhesion molecules during the inflammatory process in pulmonary fibrosis. To examine the effects of BLM on endothelial cells, we investigated the expression profiles of various cytokines and adhesion molecules produced by endothelial cells stimulated with BLM. Increased expressions of interleukin-8 and monocyte chemoattractant protein-1 measured as protein as well as mRNA by human umbilical vein endothelial cells (HUVECs) were detected after exposure to BLM. Similarly, increased expressions of E-selectin and intercellular adhesion molecule-3 were detected both at the protein and mRNA levels. Under these conditions, a small but significant decrease of [3H]thymidine uptake was detected. These findings indicate that HUVEC were stimulated to secrete cytokines and express adhesion molecules in the presence of low concentrations of BLM which have a mildly inhibitory effect on cellular proliferation.

The metabolic syndrome in long-term cancer survivors, an important target for secondary preventive measures

With increasing numbers of cancer survivors, attention has been drawn to long-term complications of curative cancer treatment, including a range of metabolic disorders. These metabolic disorders often resemble the components of the so-called metabolic syndrome, or syndrome X, which is an important risk factor for the development of cardiovascular disease. The mechanisms behind the development of metabolic disorders in cancer survivors have not been fully elucidated. However, association studies in the general population have demonstrated correlations between the components of the metabolic syndrome on the one hand and hormonal deficiencies, hypomagnesaemia, and endothelial dysfunction on the other. These latter disorders are regularly reported following curative cancer treatment and could, therefore, be important aetiologic factors in the development of the metabolic syndrome in cancer survivors. This review discusses data on the associations between the metabolic syndrome and treatment-related complications in cancer survivors and possibilities for preventive measures.

Electroporation of human microvascular endothelial cells: evidence for an anti-vascular mechanism of electrochemotherapy

Recent studies have indicated that the antitumour effectiveness of electrochemotherapy, a combination of chemotherapeutic drugs with application of high voltage electric pulses applied to the tumour nodule (electroporation), result in a significant reduction in tumour blood flow and may therefore be mediated by an anti-vascular mechanism. The aim of this study was to evaluate the cytotoxicity of electroporation with bleomycin or cisplatin on cultured human microvascular endothelial cells (HMEC-1). The sensitivity of HMEC-1 cells to a 5 min treatment by electroporation with bleomycin or cisplatin (8 electric pulses, pulse duration 100 micros, frequency 1 Hz, electric field intensity 1400 V x cm(-1)) was compared to the sensitivity of cells treated continuously for 3 days with drugs alone. HMEC-1 cells were moderately sensitive to continuous exposure to cisplatin, but showed greater sensitivity to bleomycin. Combination of a 5 min drug exposure with electric pulses increased cytotoxicity approximately 10-fold for cisplatin and approximately 5000-fold for bleomycin. The electroporation of HMEC-1 cells with bleomycin for a 5 min exposure was approximately 250-fold better than a continuous exposure to the drug alone. The results of this study indicate that the anti-tumour action of electrochemotherapy is likely to be due, in part, to the highly sensitive response of vascular endothelial cells. Further studies are necessary to identify the determinants of endothelial response and its relationship to the anti-vascular action of electrochemotherapy in vivo.

Long-term chemotherapy-related cardiovascular morbidity

As a consequence of the successful use of chemotherapy in the treatment of curable neoplasms such as germ cell tumours and malignant lymphomas, and the increasing application of primary and adjuvant chemotherapy for various tumour types, the number of patients with a prolonged life expectancy after treatment is rising. Attention to long-term side-effects, including cardiovascular toxicity, is therefore of growing importance. In this review we evaluate the literature on long-term cardiovascular toxicity related to chemotherapy in adult patients. Two categories of patient with favourable life expectancy have been reviewed, namely patients cured of metastatic disease by chemotherapy and patients treated with adjuvant chemotherapy. In the first category, the literature on long-term cardiovascular morbidity in survivors of metastatic testicular cancer and lymphomas is discussed, while in the second category this is done for patients treated with adjuvant chemotherapy for breast and colon cancer. As well as the direct toxic effects of chemotherapy on the cardiovascular system, the indirect toxic effects such as chemotherapy-related metabolic changes that may cause cardiovascular morbidity are also discussed.