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Summary: Background: Growth hormone deficiency (GHD) is usually the first and most frequent endocrine problem occurring after cranial radiotherapy (CRT). The aim of this systematic review was to evaluate the existing evidence of the prevalence and risk factors of radiation-induced GHD in childhood cancer survivors. Methods: MEDLINE, EMBASE and CENTRAL were searched for studies reporting on radiation-induced GHD in childhood cancer survivors. Information about study characteristics, prevalence and risk factors was abstracted and the quality of each study was assessed. A meta-regression analysis was performed. Results: The prevalence of radiation-induced GHD was estimated in 33 studies. Most studies had methodological limitations. The prevalence varied considerably between 0% and 90.9%. Selecting only the studies with adequate peak GH cut-off limits (<5μg/L) resulted in 3 studies. In these studies the prevalence ranged from 29.0% to 39.1%, with a pooled prevalence of 35.6%. Higher CRT dose and longer follow-up time have been suggested to be the main risk factors of GHD by studies included in this review. The meta-regression analysis showed that the wide variation in the prevalence of GHD could be explained by differences in maximal CRT dose. Conclusions: GHD is a frequent consequence after CRT in childhood cancer survivors. The prevalence of radiation-induced GHD ranged from 29.0% to 39.1% when selecting only studies with adequate peak GH cut-off limits. Higher CRT dose and longer follow-up time are the main risk factors. More well-designed studies are needed to accurately estimate the prevalence of GHD and to define the exact CRT threshold dose. [Copyright &y& Elsevier]

Abstract: Anthracycline-induced cardiotoxicity after treatment for childhood cancer is a considerable and serious problem. In this review, important insight into the current state of the evidence on the use of different cardioprotective agents, different anthracycline analogues, and different anthracycline infusion durations to reduce or prevent cardiotoxicity in children treated with anthracyclines is provided. It has become clear that, at the present time, there is not enough reliable evidence for many aspects of the prevention of anthracycline-induced cardiotoxicity in children. More high quality research is necessary. Suggestions for future research have been presented. As the results of these new studies become available, it will hopefully be possible to develop evidence-based recommendations for preventing anthracycline-induced cardiotoxicity in children. Until then, we can only advise care providers to carefully monitor the cardiac function of children treated with anthracyclines. With regard to the use of the cardioprotectant dexrazoxane, it might be justified to use dexrazoxane in children if the risk of cardiac damage is expected to be high. However, for each individual patient, care providers should weigh the cardioprotective effect of dexrazoxane against the possible risk of adverse effects including a lower response rate. We recommend its use in the context of well-designed studies. [Copyright &y& Elsevier]

Abstract: The use of anthracyclines is limited by a dose-dependent cardiotoxicity (A-CT). The aim of this study was to gain insight in the currently available guidelines for monitoring cardiotoxicity during anthracycline therapy in children and in the monitoring recommendations currently used in European paediatric oncology trials. An extensive literature search to identify guidelines was performed and one guideline was identified. Twelve protocols including anthracycline therapy were evaluated. With regard to the minimally required diagnostic tests, parameters and definitions of A-CT most protocols roughly followed the guideline. However, both monitoring schedules and recommendations to prevent further cardiac damage in case A-CT was diagnosed varied widely between protocols and only a minority of the protocols followed the recommendations of the guideline. In conclusion, despite an existing guideline, there is a wide variation in the recommendations for monitoring cardiac function during anthracycline therapy in the currently used European paediatric oncology protocols. A possible explanation could be the lack of rigorous evidence on the most optimal way to monitor cardiac function in children treated with anthracyclines. There is a strong need for evidence from clinical research which can support recommendations for monitoring cardiac function during anthracycline therapy for childhood cancer. In the meantime, it is important to uniformise the used cardiac monitoring schedules. [Copyright &y& Elsevier]

Neuroblastoma is predominantly characterised by chromosomal rearrangements. Next to V-Myc Avian Myelocytomatosis Viral Oncogene Neuroblastoma Derived Homolog (MYCN) amplification, chromosome 7 and 17q gains are frequently observed. We identified a neuroblastoma patient with a regional 7q36 gain, encompassing the enhancer of zeste homologue 2 (EZH2) gene. EZH2 is the histone methyltransferase of lysine 27 of histone H3 (H3K27me3) that forms the catalytic subunit of the polycomb repressive complex 2. H3K27me3 is commonly associated with the silencing of genes involved in cellular processes such as cell cycle regulation, cellular differentiation and cancer. High EZH2 expression correlated with poor prognosis and overall survival independent of MYCN amplification status. Unexpectedly, treatment of 3 EZH2-high expressing neuroblastoma cell lines (IMR32, CHP134 and NMB), with EZH2-specific inhibitors (GSK126 and EPZ6438) resulted in only a slight G1 arrest, despite maximum histone methyltransferase activity inhibition. Furthermore, colony formation in cell lines treated with the inhibitors was reduced only at concentrations much higher than necessary for complete inhibition of EZH2 histone methyltransferase activity. Knockdown of the complete protein with three independent shRNAs resulted in a strong apoptotic response and decreased cyclin D1 levels. This apoptotic response could be rescued by overexpressing EZH2ΔSET, a truncated form of wild-type EZH2 lacking the SET transactivation domain necessary for histone methyltransferase activity. Our findings suggest that high EZH2 expression, at least in neuroblastoma, has a survival function independent of its methyltransferase activity. This important finding highlights the need for studies on EZH2 beyond its methyltransferase function and the requirement for compounds that will target EZH2 as a complete protein. [ABSTRACT FROM AUTHOR]

Introduction Neuroblastoma (NBL) accounts for 10% of the paediatric malignancies and is responsible for 15% of the paediatric cancer-related deaths. Vanillylmandelic acid (VMA) and homovanillic acid (HVA) are most commonly analysed in urine of NBL patients. However, their diagnostic sensitivity is suboptimal (82%). Therefore, we performed in-depth analysis of the diagnostic sensitivity of a panel of urinary catecholamine metabolites. Patients and methods Retrospective study of a panel of 8 urinary catecholamine metabolites (VMA, HVA, 3-methoxytyramine [3MT], dopamine, epinephrine, metanephrine, norepinephrine and normetanephrine [NMN]) from 301 NBL patients at diagnosis. Special attention was given to subgroups, metaiodobenzylguanidine (MIBG) non-avid tumours and VMA/HVA negative patients. Results Elevated catecholamine metabolites, especially 3MT, correlated with nine out of 12 NBL characteristics such as stage, age, MYCN amplification, loss of heterozygosity for 1p and bone-marrow invasion. The combination of the classical markers VMA and HVA had a diagnostic sensitivity of 84%. NMN was the most sensitive single diagnostic metabolite with overall sensitivity of 89%. When all 8 metabolites were combined, a diagnostic sensitivity of 95% was achieved. Among the VMA and HVA negative patients, were also 29% with stage 4 disease, which usually had elevation of other catecholamine metabolites (93%). Diagnostic sensitivity for patients with MIBG non-avid tumour was improved from 33% (VMA and/or HVA) to 89% by measuring the panel. Conclusions Our study demonstrates that analysis of a urinary catecholamine metabolite panel, comprising 8 metabolites, ensures the highest sensitivity to diagnose NBL patients. [ABSTRACT FROM AUTHOR]

Purpose: Long-term childhood cancer survivors are at high risk of late adverse effects, including stroke. We aimed to determine the cumulative incidence of clinically validated symptomatic stroke (transient ischemic attack [TIA], cerebral infarction, and intracerebral hemorrhage [ICH]) and to quantify dose-effect relationships for cranial radiation therapy (CRT) and supradiaphragmatic radiation therapy (SDRT).Methods and Materials: Our single-center study cohort included 1362 survivors of childhood cancer that were diagnosed between 1966 and 1996. Prescribed CRT and SDRT doses were converted into the equivalent dose in 2-Gy fractions (EQD2). Multivariate Cox regression models were used to analyze the relationship between the EQD2 and stroke.Results: After a median latency time of 24.9 years and at a median age of 31.2 years, 28 survivors had experienced a first stroke: TIA (n=5), infarction (n=13), and ICH (n=10). At an attained age of 45 years, the estimated cumulative incidences, with death as competing risk, among survivors treated with CRT only, SDRT only, both CRT and SDRT, and neither CRT nor SDRT were, respectively, 10.0% (95% confidence interval [CI], 2.5%-17.0%), 5.4% (95% CI, 0%-17.0%), 12.5% (95% CI, 5.5%-18.9%), and 0.1% (95% CI, 0%-0.4%). Radiation at both locations significantly increased the risk of stroke in a dose-dependent manner (hazard ratios: HRCRT 1.02 Gy(-1); 95% CI, 1.01-1.03, and HRSDRT 1.04 Gy(-1); 95% CI, 1.02-1.05).Conclusions: Childhood cancer survivors treated with CRT, SDRT, or both have a high stroke risk. One in 8 survivors treated at both locations will have experienced a symptomatic stroke at an attained age of 45 years. Further research on the pathophysiologic processes involved in stroke in this specific group of patients is needed to enable the development of tailored secondary prevention strategies. [ABSTRACT FROM AUTHOR]

Background Many paediatric brain tumour survivors (PBTS) suffer from neurocognitive impairments. Promising effects of neurofeedback (NF) on neurocognitive functioning have been reported, however research into NF for PBTS has not been conducted. We investigated the effects of NF on neurocognitive functioning in PBTS using a double-blind randomised placebo-controlled trial with a parallel-group design (Pediatric Research on Improving Speed, Memory, and Attention; the PRISMA study). Methods Eligible for inclusion were PBTS with neurocognitive complaints, aged 8–18 years, >2 years post-treatment. They were recruited from five medical centres in the Netherlands. A randomisation table assigned participants to 30 sessions (two per week) of either NF or placebo feedback (PF) (ratio 1:1). Participants, parents, trainers, and researchers handling the data were blinded to group assignment. Participants were assessed pre-, post- and 6 months post-training to determine whether NF training would lead to improved functioning as compared with PF training. Primary outcome measures were attention, processing speed, memory, executive functioning, visuomotor integration, and intelligence. Linear mixed models analyses were used to test differences between NF and PF training over time. Results A total of 82 children were enrolled (mean age 13.9 years, standard deviation = 3.2, 49% males); 80 participants were randomised (NF: n = 40, PF n = 40); 71 participants completed the training (NF: n = 34, PF: n = 37); 68 participants completed training and 6 months post-training assessment (NF: n = 33, PF: n = 35). Similar improvements were found over time for the two treatment groups on the primary outcomes (all p 's > 0.15). Conclusion Results indicated no specific treatment-effects of NF on neurocognitive functioning of PBTS. [ABSTRACT FROM AUTHOR]

Introduction The clinical importance of the detection of neuroblastoma messenger RNA (mRNA) in bone marrow (BM) of localised neuroblastoma patients at diagnosis remains unclear. In this prospective multicentre study, BM samples of a large cohort, were studied using real-time quantitative polymerase chain reaction (qPCR). Methods BM samples at diagnosis from 160 patients with localised neuroblastoma were prospectively collected at Dutch and German centres between 2009 and 2013. qPCR was performed using five neuroblastoma specific markers. The association with other biological factors and the prognostic impact of BM positivity and clinical response was assessed. Results In 58 out of 160 patients neuroblastoma mRNA was detected in BM. In 47 of the 58 positive samples only one marker was found positive. BM positivity was significantly associated with MYCN amplification (p = 0.02) and deletion of chromosome 1p (p = 0.04). In total 31 patients had an event, of which only five patients had progression to stage IV. BM positivity was not associated with an unfavourable outcome. However, the detection of more than one marker was associated with an unfavourable outcome (systemic or local relapse) (event free survival 48% versus 85%; p = 0.03) in the whole cohort and in the observation group. Conclusions BM positivity was associated with unfavourable biological factors and might represent more aggressive tumours. Patients with qPCR positive BM should not be upstaged, because of very few systemic events in the cohort. However, for patients with more than one marker positive a more careful follow-up is advisable. These results need to be verified in a very large cohort of localised patients. [ABSTRACT FROM AUTHOR]

Background The prevention of central venous catheter (CVC) associated bloodstream infections (CABSIs) in paediatric oncology patients is essential. Ethanol locks can eliminate pathogens colonising CVCs and microbial resistance is rare. Aim of this study was to determine whether two hour 70% ethanol locks can reduce CABSI in paediatric oncology patients. Methods We conducted a randomised, double blind, multi-centre trial in paediatric oncology patients (1–18 years) with newly inserted CVCs. Patients were randomly assigned to receive two hour ethanol locks (1.5 or 3 ml 70%) or heparin locks (1.5 or 3 ml 100 IU/ml), whenever it was needed to use the CVC, maximum frequency once weekly. Primary outcomes were time to CABSI or death due to CABSI. Results We recruited 307 patients (ethanol, n = 153; heparin, n = 154). In the ethanol group, 16/153 (10%) patients developed a CABSI versus 29/154 (19%) in the heparin group. The incidence of CABSI was 0.77/1000 and 1.46/1000 catheter days respectively ( p = 0.039). The number-needed-to-treat was 13. No patients died of CABSI. In particular, Gram-positive CABSIs were reduced (ethanol, n = 8; heparin, n = 21; p = 0.012). Fewer CVCs were removed because of CABSI in the ethanol group ( p = 0.077). The ethanol lock patients experienced significantly more transient symptoms compared to the heparin lock patients (maximum grade 2) (nausea, p = 0.030; taste alteration, p < 0.001; dizziness, p = 0.001; blushing, p < 0.001), no suspected unexpected serious adverse reactions (SUSAR) occurred. Conclusions This is the first randomised controlled trial to show that ethanol locks can prevent CABSI in paediatric oncology patients, in particular CABSI caused by Gram-positive bacteria. Implementation of ethanol locks in clinical practice should be considered. [ABSTRACT FROM AUTHOR]

Purpose To determine the prevalence of valvular abnormalities after radiation therapy involving the heart region and/or treatment with anthracyclines and to identify associated risk factors in a large cohort of 5-year childhood cancer survivors (CCS). Methods and Materials The study cohort consisted of all 626 eligible 5-year CCS diagnosed with childhood cancer in the Emma Children's Hospital/Academic Medical Center between 1966 and 1996 and treated with radiation therapy involving the heart region and/or anthracyclines. We determined the presence of valvular abnormalities according to echocardiograms. Physical radiation dose was converted into the equivalent dose in 2-Gy fractions (EQD 2 ). Using multivariable logistic regression analyses, we examined the associations between cancer treatment and valvular abnormalities. Results We identified 225 mainly mild echocardiographic valvular abnormalities in 169 of 545 CCS (31%) with a cardiac assessment (median follow-up time, 14.9 years [range, 5.1-36.8 years]; median attained age 22.0 years [range, 7.0-49.7 years]). Twenty-four CCS (4.4%) had 31 moderate or higher-graded abnormalities. Most common abnormalities were tricuspid valve disorders (n=119; 21.8%) and mitral valve disorders (n=73; 13.4%). The risk of valvular abnormalities was associated with increasing radiation dose (using EQD 2 ) involving the heart region (odds ratio 1.33 per 10 Gy) and the presence of congenital heart disease (odds ratio 3.43). We found no statistically significant evidence that anthracyclines increase the risk. Conclusions Almost one-third of CCS treated with potentially cardiotoxic therapy had 1 or more asymptomatic, mostly mild valvular abnormalities after a median follow-up of nearly 15 years. The most important risk factors are higher EQD 2 to the heart region and congenital heart disease. Studies with longer follow-up are necessary to investigate the clinical course of asymptomatic valvular abnormalities in CCS. [ABSTRACT FROM AUTHOR]

Abstract: Recently protocols have been devised for the culturing of cell lines from fresh tumours under serum-free conditions in defined neural stem cell medium. These cells, frequently called tumour initiating cells (TICs) closely retained characteristics of the tumours of origin. We report the isolation of eight newly-derived neuroblastoma TICs from six primary neuroblastoma tumours and two bone marrow metastases. The primary tumours from which these TICs were generated have previously been fully typed by whole genome sequencing (WGS). Array comparative genomic hybridisation (aCGH) analysis showed that TIC lines retained essential characteristics of the primary tumours and exhibited typical neuroblastoma chromosomal aberrations such as MYCN amplification, gain of chromosome 17q and deletion of 1p36. Protein analysis showed expression for neuroblastoma markers MYCN, NCAM, CHGA, DBH and TH while haematopoietic markers CD19 and CD11b were absent. We analysed the growth characteristics and confirmed tumour-forming potential using sphere-forming assays, subcutaneous and orthotopic injection of these cells into immune-compromised mice. Affymetrix mRNA expression profiling of TIC line xenografts showed an expression pattern more closely mimicking primary tumours compared to xenografts from classical cell lines. This establishes that these neuroblastoma TICs cultured under serum-free conditions are relevant and useful neuroblastoma tumour models. [Copyright &y& Elsevier]

Abstract: Background: Identification of tumour predisposition syndromes in patients who have cancer in childhood is paramount for optimal care. A screening instrument that can help to identify such patients will facilitate physicians caring for children with cancer. The complete screening instrument should consist of a standardised series of pictures and a screening form for manifestations not visible in the pictures. Here we describe the development of such a screening form based on an international two-stage Delphi process and an initial validation of the complete instrument. Patients and methods: We identified manifestations that may contribute to the diagnosis of a tumour predisposition syndrome through the Winter–Baraitser Dysmorphology Database and the textbook “Gorlin’s Syndromes of the Head and Neck”. In a two-round Delphi process, eight international content-experts scored the contribution of each of these manifestations. We performed a clinical validation of the instrument in a selected cohort of 10 paediatric cancer patients from another centre. Results: In total, 49 manifestations were found to contribute to the diagnosis of a tumour predisposition syndrome and were included in the screening form. The pilot validation study showed that patients suspected of having a tumour predisposition syndrome were recognised. Excellent correlation for indications of patient’s referral between the screening instrument and the reference standard (personal evaluation by an experienced clinical geneticist) was found. Conclusions: The Delphi process performed by international specialists with a function as opinion leaders in their field of expertise, has led to a screening instrument for childhood cancer patients. Patients who may have a tumour predisposition syndrome and thus have an indication to be referred for further genetic analysis, can be identified using the screening instrument. [Copyright &y& Elsevier]

Purpose: To evaluate the prevalence and severity of clinical adverse events (AEs) and treatment-related risk factors in childhood cancer survivors treated with cranial radiation therapy (CRT), with the aim of assessing dose-effect relationships. Methods and Materials: The retrospective study cohort consisted of 1362 Dutch childhood cancer survivors, of whom 285 were treated with CRT delivered as brain irradiation (BI), as part of craniospinal irradiation (CSI), and as total body irradiation (TBI). Individual CRT doses were converted into the equivalent dose in 2-Gy fractions (EQD2). Survivors had received their diagnoses between 1966 and 1996 and survived at least 5 years after diagnosis. A complete inventory of Common Terminology Criteria for Adverse Events grade 3.0 AEs was available from our hospital-based late-effect follow-up program. We used multivariable logistic and Cox regression analyses to examine the EQD2 in relation to the prevalence and severity of AEs, correcting for sex, age at diagnosis, follow-up time, and the treatment-related risk factors surgery and chemotherapy. Results: There was a high prevalence of AEs in the CRT group; over 80% of survivors had more than 1 AE, and almost half had at least 5 AEs, both representing significant increases in number of AEs compared with survivors not treated with CRT. Additionally, the proportion of severe, life-threatening, or disabling AEs was significantly higher in the CRT group. The most frequent AEs were alopecia and cognitive, endocrine, metabolic, and neurologic events. Using the EQD2, we found significant dose-effect relationships for these and other AEs. Conclusion: Our results confirm that CRT increases the prevalence and severity of AEs in childhood cancer survivors. Furthermore, analyzing dose-effect relationships with the cumulative EQD2 instead of total physical dose connects the knowledge from radiation therapy and radiobiology with the clinical experience. [Copyright &y& Elsevier]

Abstract: Background: Childhood cancer survivors (CCS) are a growing group of young individuals with a high risk of morbidity and mortality. We evaluated the prevalence and risk factors of hepatic late adverse effects, defined as elevated liver enzymes, in a large cohort of CCS. Methods: The cohort consisted of all five-year CCS treated in the EKZ/AMC between 1966 and 2003, without hepatitis virus infection and history of veno-occlusive disease (VOD). Liver enzyme tests included serum levels of alanine aminotransferase (ALT) for hepatocellular injury and gamma-glutamyltransferase (γGT) for biliary tract injury. We performed multivariable linear and logistic regression analyses. Results: The study population consisted of 1404 of 1795 eligible CCS, of whom 1362 performed liver enzyme tests at a median follow-up of 12years after diagnosis. In total, 118 (8.7%) of 1362 CCS had hepatic late adverse effects defined as ALT or γGT above the upper limit of normal. Abnormal ALT and γGT levels were found in 5.8% and 5.3%, respectively. In multivariable regression analyses treatment with radiotherapy involving the liver, higher body mass index, higher alcohol intake and longer follow-up time were significantly associated with elevated ALT and γGT levels; older age at diagnosis was only significantly associated with elevated γGT levels (all p <0.05). Conclusion: One in twelve CCS showed signs of hepatic late adverse effects after a median follow-up of 12years. Several risk factors have been identified. Future studies should focus on the course of long-term liver related outcomes and on the influence of radiotherapy and chemotherapy dose. [Copyright &y& Elsevier]

Abstract: Genomic aberrations of key regulators of the apoptotic pathway have hardly been identified in neuroblastoma. We detected high BCL2 mRNA and protein levels in the majority of neuroblastoma tumours by Affymetrix expression profiling and Tissue Micro Array analysis. This BCL2 mRNA expression is strongly elevated compared to normal tissues and other malignancies. Most neuroblastoma cell lines lack this high BCL2 expression. Only two neuroblastoma cell lines (KCNR and SJNB12) show BCL2 expression levels representative for neuroblastoma tumours. To validate BCL2 as a therapeutic target in neuroblastoma we employed lentivirally mediated shRNA. Silencing of BCL2 in KCNR and SJNB12 resulted in massive apoptosis, while cell lines with low BCL2 expression were insensitive. Identical results were obtained by treatment of the neuroblastoma cell lines with the small molecule BCL2 inhibitor ABT263, which is currently being clinically evaluated. Combination assays of ABT263 with most classical cytostatics showed strong synergistic responses. Subcutaneous xenografts of a neuroblastoma cell line with high BCL2 expression in NMRI nu/nu mice showed a strong response to ABT263. These findings establish BCL2 as a promising drug target in neuroblastoma and warrant further evaluation of ABT263 and other BCL2 inhibiting drugs. [Copyright &y& Elsevier]

Abstract: The efficacy and mechanism of action of cisplatin and gemcitabine were investigated in a panel of neuroblastoma cell lines and multicellular tumor spheroids. In neuroblastoma spheroids, the combination of cisplatin and gemcitabine induced a complete cytostasis at clinical relevant concentrations. A synergistic effect was observed when cells were coincubated with both drugs or preincubated with gemcitabine first. These administration sequences resulted in NASS cells in decreased ERCC1 and XPA expression, two key proteins of the NER DNA repair system, and increased platinum adduct formation in DNA. Most of these phenomena were not observed in SJNB8 cells which might explain the lack of synergy between cisplatin and gemcitabine in SJNB8 cells. Our results showed favorable interactions between cisplatin and gemcitabine in 4 out of 5 cell lines. Therefore, we feel that inclusion of gemcitabine into cisplatin-containing regiments might be a promising new strategy for the treatment of neuroblastoma. [Copyright &y& Elsevier]

Abstract: The BIRC5 (Survivin) gene is located at chromosome 17q in the region that is frequently gained in high risk neuroblastoma. BIRC5 is strongly over expressed in neuroblastoma tumour samples, which correlates to a poor prognosis. We recently validated BIRC5 as a potential therapeutic target by showing that targeted knock down with shRNA’s triggers an apoptotic response through mitotic catastrophe. We now tested YM155, a novel small molecule selective BIRC5 suppressant that is currently in phase I/II clinical trials. Drug response curves showed IC50 values in the low nM range (median: 35nM, range: 0.5–>10,000nM) in a panel of 23 neuroblastoma cell lines and four TIC-lines, which resulted from an apoptotic response. Nine out of 23 cell lines were relatively resistant to YM155 with IC50 values >200nM, although in the same cells shRNA mediated knock down of BIRC5 caused massive apoptosis. Analysis of differentially expressed genes between five most sensitive and five most resistant cell lines using Affymetrix mRNA expression data revealed ABCB1 (MDR1) as the most predictive gene for resistance to YM155. Inhibition of the multi-drug resistance pump ABCB1 with cyclosporine or knockdown with shRNA prior to treatment with YM155 demonstrated that cell lines with ABCB1 expression became 27–695 times more sensitive to YM155 treatment. We conclude that most neuroblastoma cell lines are sensitive to YM155 in the low nM range and that resistant cells can be sensitised by ABCB1 inhibitors. Therefore YM155 is a promising novel compound for treatment of neuroblastoma with low ABCB1 expression. [Copyright &y& Elsevier]

Abstract: To enhance the efficacy of fenretinide (4HPR)-induced reactive oxygen species (ROS) in neuroblastoma, 4HPR was combined with buthionine sulfoximine (BSO), an inhibitor of glutathione (GSH) synthesis, in neuroblastoma cell lines and spheroids, the latter being a three-dimensional tumor model. 4HPR exposure (2.5–10μM, 24h) resulted in ROS induction (114–633%) and increased GSH levels (68–120%). A GSH depletion of 80% of basal levels was observed in the presence of BSO (25–100μM, 24h). The 4HPR–BSO combination resulted in slightly increased ROS levels (1.1- to 1.3-fold) accompanied by an increase in cytotoxicity (110–150%) compared to 4HPR treatment alone. A correlation was observed between the ROS-inducing capacity of each cell line and the increase in cytotoxicity induced by 4HPR–BSO compared to 4HPR. No significant correlation between baseline antioxidant levels and sensitivity to 4HPR or BSO was observed. In spheroids, 4HPR–BSO induced a strong synergistic growth retardation and induction of apoptosis. Our data show that BSO increased the cytotoxic effects of 4HPR in neuroblastoma monolayers and spheroids in ROS-producing cell lines. This indicates that the 4HPR–BSO combination might be a promising new strategy in the treatment of neuroblastoma. [Copyright &y& Elsevier]

Purpose: To evaluate the prevalence and severity of adverse events (AEs) and treatment-related risk factors in long-term Wilms'' tumor (WT) survivors, with special attention to radiotherapy. Methods and Materials: The single-center study cohort consisted of 185 WT survivors treated between 1966 and 1996, who survived at least 5 years after diagnosis. All survivors were invited to a late-effects clinic for medical assessment of AEs. AEs were graded for severity in a standardized manner. Detailed radiotherapy data enabled us to calculate the equivalent dose in 2 Gy fractions (EQD2) to compare radiation doses in a uniform way. Risk factors were evaluated with multivariate logistic regression analysis. Results: Medical follow-up was complete for 98% of survivors (median follow-up, 18.9 years; median attained age, 22.9 years); 123 survivors had 462 AEs, of which 392 had Grade 1 or 2 events. Radiotherapy to flank/abdomen increased the risk of any AE (OR, 1.08 Gy−1 [CI, 1.04–1.13]). Furthermore, radiotherapy to flank/abdomen was associated with orthopedic events (OR, 1.09 Gy−1 [CI, 1.05–1.13]) and second tumors (OR, 1.11 Gy−1 [CI, 1.03–1.19]). Chest irradiation increased the risk of pulmonary events (OR, 1.14 Gy−1 [CI, 1.06–1.21]). Both flank/abdominal and chest irradiation were associated with cardiovascular events (OR, 1.05 Gy−1 [CI, 1.00–1.10], OR, 1.06 Gy−1 [CI, 1.01–1.12]) and tissue hypoplasia (OR, 1.17 Gy−1 [CI, 1.10–1.24], OR 1.10 Gy−1 [CI, 1.03–1.18]). Conclusion: The majority of AEs, overall as well as in irradiated survivors, were mild to moderate. Nevertheless, the large amount of AEs emphasizes the importance of follow-up programs for WT survivors. [Copyright &y& Elsevier]

Introduction: In developing countries, patients with a Wilms’ tumour often present late with a high degree of malnutrition and large tumours. We investigated whether this affects vincristine pharmacokinetics. Methods: Patients newly diagnosed with Wilms’ tumour in Malawi and the UK were included. We documented anthropometric parameters, nutritional status and tumour size. Vincristine (1.50mg/m2) was administered as part of the standard chemotherapy regimen. Vincristine plasma concentrations were measured at several time points by liquid chromatography–mass spectrometry. Vincristine pharmacokinetic parameters (clearance and area under the curve) were calculated by non-compartmental analysis. Results: Eleven Malawian and 8 UK patients were included. Mean Z-score of (corrected) weight for height was significantly lower in the Malawian patients than in the UK patients (−2.3 versus 0.42, p <0.0001). Mean tumour weight at diagnosis was significantly larger in Malawian patients (2.8kg versus 0.7kg, p =0.007). Mean vincristine logClearance was lower in Malawian as compared to UK patients (2.2 versus 2.6ml/min, p =0.001). Mean logAUC values were higher in Malawian than in UK patients (3.8 versus 3.5μg/mlmin, p =0.003). This difference is reflected in the, on average, 1.98-fold larger vincristine AUC values for Malawian patients. The difference in AUC values was statistically significantly explained by nutritional status (p =0.043). Conclusion: Malnourished patients in Malawi exhibited lower vincristine clearance rates and thus higher AUC values than a comparable patient population with a better nutritional status in the UK. In malnourished patients, dose reductions may need to be considered to prevent an increased incidence and severity of toxicity. [Copyright &y& Elsevier]

Abstract: Mannose-binding lectin (MBL)-deficient children with cancer may benefit from substitution of the innate immune protein MBL during chemotherapy-induced neutropaenia. We determined the safety and pharmacokinetics of MBL substitution in a phase II study in MBL-deficient children. Twelve MBL-deficient children with cancer (aged 0–12 years) received infusions of plasma-derived MBL once, or twice weekly during a chemotherapy-induced neutropaenic episode (range: 1–4 weeks). Four patients participated multiple times. Target levels of 1.0μg/ml were considered therapeutic. In total, 65 MBL infusions were given. No MBL-related adverse reactions were observed, and the observed trough level was 1.06μg/ml (range: 0.66–2.05μg/ml). Pharmacokinetics were not related to age after correction for body weight. The half-life of MBL, for a child of 25kg, was 36.4h (range: 23.7–66.6h). No anti-MBL antibodies were measured 4 weeks after each MBL course. Substitution therapy with MBL-SSI twice weekly was safe and resulted in trough levels considered protective. [Copyright &y& Elsevier]

Abstract: Purpose: To determine the response to radionuclide targeted therapy with I-131-metaiodobenzylguanidine (131I-MIBG) as induction therapy in high-risk neuroblastoma patients. Patients and methods: The protocol dictated at least two cycles of 131I-MIBG with a fixed dose of 7.4 and 3.7 GBq, respectively, followed by surgery, if feasible, or followed by neoadjuvant chemotherapy and surgery. This was followed by consolidation with four courses of chemotherapy myeloablative chemotherapy and autologous stem-cell transplantation (ASCT). Consolidation therapy with 13-cis-retinoic acid was given for 6 months. Results: Of 44 consecutive patients, 41 were evaluable after two courses of 131I-MIBG. The objective response rate at this point was 66%. In 24 patients, 131I-MIBG was continued as pre-operative induction treatment. Seventeen patients required additional chemotherapy before surgery. After pre-operative therapy and surgery, the overall response rate was 73%. Conclusion: First line 131I-MIBG-targeted therapy is a valuable tool in the treatment of MIBG-positive high-risk neuroblastoma patients. [Copyright &y& Elsevier]

Abstract: The c-Myc and MYCN oncogenes strongly induce cell proliferation. Although a limited series of cell cycle genes were found to be induced by the myc transcription factors, it is still unclear how they mediate the proliferative phenotype. We therefore analysed a neuroblastoma cell line with inducible MYCN expression. We found that all members of the minichromosome maintenance complex (MCM2–7) and MCM8 and MCM10 were up-regulated by MYCN. Expression profiling of 110 neuroblastoma tumours revealed that these genes strongly correlated with MYCN expression in vivo. Extensive chromatin immunoprecipitation experiments were performed to investigate whether the MCM genes were primary MYCN targets. MYCN was bound to the proximal promoters of the MCM2 to -8 genes. These data suggest that MYCN stimulates the expression of not only MCM7, which is a well defined MYCN target gene, but also of the complete minichromosome maintenance complex. [Copyright &y& Elsevier]

Abstract: The cumulative incidence of anthracycline-induced clinical heart failure (A-CHF) in a large cohort of 830 children treated with a mean cumulative anthracycline dose of 288mg/m2 (median 280mg/m2; range 15–900mg/m2) with a very long and complete follow-up after the start of anthracycline therapy (mean 8.5 years; median 7.1 years; range 0.01–28.4 years) was 2.5%. A cumulative anthracycline dose of 300mg/m2 or more was the only independent risk factor (relative risk (RR)=8). The estimated risk of A-CHF increased with time to 5.5% at 20 years after the start of anthracycline therapy; 9.8% if treated with 300mg/m2 or more. In conclusion, 1 in every 10 children treated with a cumulative anthracycline dose of 300mg/m2 or more will eventually develop A-CHF. This is an extremely high risk and it reinforces the need of re-evaluating the cumulative anthracycline dose used in different treatment protocols and to define strategies to prevent A-CHF which could be implemented in treatment protocols. [Copyright &y& Elsevier]

Abstract: The cumulative incidence of peripartum anthracycline-induced clinical heart failure (A-CHF) was evaluated in a cohort of 53 childhood cancer survivors who had delivered one or more children. None of them developed peripartum A-CHF (cumulative incidence 0%; 95% confidence interval (CI) 0–5.7%). The mean follow-up time after the first administration of anthracycline therapy was 20.3 years. They received a mean cumulative anthracycline dose of 267mg/m2. It is worth noticing that even 2 patients with A-CHF before pregnancy did not develop peripartum A-CHF. Since there were no cases of peripartum A-CHF in our cohort, it was not possible to evaluate associated risk factors. In conclusion, this study demonstrates a low risk of developing peripartum A-CHF in childhood cancer survivors. However, more cohort studies with adequate power and long-term follow-up are needed to reliably evaluate the cumulative incidence of peripartum anthracycline-induced cardiotoxicity (both clinical and asymptomatic) and associated risk factors. [Copyright &y& Elsevier]

Abstract: A systematic literature review was carried out to evaluate best existing evidence on prognostic factors for progression of childhood optic pathway glioma. Databases were searched for relevant articles and articles selected independently by two authors. Information about study design, population, treatment, outcome and prognostic analysis were abstracted and the quality of each article was assessed. A total of 23 articles met the inclusion criteria. Many studies had important methodological limitations, regarding external and internal validity. Eleven studies evaluated possible prognostic factors in a multivariate analysis. Three high-quality studies indicated age<1 year as an independent prognostic factor for a worse progression-free survival. Three studies with multivariate analysis, including one high-quality study, found that children with neurofibromatosis type 1 (NF-1) have a better progression-free survival than those without NF-1. Two studies with multivariate analysis found tumour site to be a prognostic factor, both with some methodological limitations. In conclusion, this systematic review demonstrates that only a few of the prognostic factors proposed have been proven to be clinically relevant. Age<1 year is a clear and independent prognostic factor for progression-free survival. Other prognostic factors, such as NF-1, tumour site and others, are suggested, but are still without solid evidence and need further high-quality studies to be clearly proven. [Copyright &y& Elsevier]

Abstract: Additive to synergistic induction of apoptosis has been reported as a result of sequential incubation of cancer cells with a histone deacetylase inhibitor (HDACi) and gemcitabine (dFdC), a deoxycytidine analogue with proven anti-tumour activity. This study shows that sequential treatment of two neuroblastoma cell lines with BL1521, an HDACi, and dFdC resulted in strong antagonism despite a minor increase of dFdCTP incorporation into the DNA of one cell line. Furthermore, no difference in the deoxycytidine kinase activity was observed in response to BL1521. In conclusion, cancer cells that respond to HDACi with a cell cycle arrest and differentiation may no longer be sensitive to dFdC. [Copyright &y& Elsevier]

Abstract: Purpose. – To evaluate the prevalence of abnormalities of rib development in normal Caucasian children and patients with childhood cancer. Materials And Methods. – Chest radiographs of 881 Caucasian pediatric controls and 906 childhood cancer patients were reviewed, and independently scored by four blinded observers, using strict definitions. Prevalences of 6 major rib anomaly categories in controls were compared to their prevalence in the total group of childhood cancer patients, and the 12 individual larger tumor groups using Chi-square tests. Results. – Values in the control population were generated for the occurrence of six major rib anomaly categories; cervical rib anomalies were present in 6.1% of controls, aplasia of 12th ribs in 6.6%, lumbar ribs in 0.9%, bifurcations in 0.7%, synostosis-bridging in 0.3%, and segmentations were not found. The overall prevalence of total rib anomalies in cases and controls was equal (14.9% and 14.2%, respectively). Cervical rib anomalies were found significantly more often in cases (8.6%) compared to controls (p-value=0.047), three groups accounting for this higher prevalence: 12.1% of acute lymphoblastic leukemia patients (p=0.011), 18.2% of astrocytoma patients (p=0.023), and 14.7% of germ cell tumor patients (p=0.046) had a cervical rib anomaly. Conclusion. – Prevalence figures for the presence and type of rib anomalies in a large group of normal Caucasian children were generated. In childhood cancer patients a significantly higher prevalence of cervical rib anomalies was demonstrated in patients with acute lymphoblastic leukemia, astrocytoma, and germ cell tumors. [Copyright &y& Elsevier]

Neuroblastoma is a childhood cancer arising from the sympathetic nervous system. Disseminated neuroblastoma has a poor prognosis despite intensive multimodality treatment. Histone deacetylases (HDACs) were recently discovered as a potential target for pharmacological gene therapy in cancer. HDACs have an important function in regulating DNA packaging in chromatin, thereby affecting the transcription of genes.In this paper, we tested the efficacy of a newly developed histone deacetylase inhibitor, BL1521, on neuroblastoma in vitro by investigating the changes in: acetylation of histone H3, in situ HDAC activity, p21WAF1/CIP1 and MYCN expression, metabolic activity, proliferation, morphology and the amount of apoptosis present.BL1521 inhibited the in situ HDAC activity of a panel of neuroblastoma cell lines by at least 85%. Western analysis showed an increase of histone H3 acetylation in neuroblastoma cells after incubation with BL1521. Northern analysis showed an increase in the expression of p21WAF1/CIP1 and a decrease in the expression of MYCN in neuroblastoma cells after incubation with BL1521. Proliferation as well as the metabolic activity of neuroblastoma cells decreased significantly in response to treatment with BL1521, regardless of the MYCN status of the cells. BL1521 induced poly-(ADP-ribose) polymerase cleavage in a time- and dose-dependent manner, indicating the induction of apoptosis. Furthermore, when compared to the HDAC inhibitors Trichostatin A and 4-phenylbutyrate, BL1521 has an intermediate efficacy. Our results show that BL1521 is a potent inhibitor of HDAC and that HDACs are an attractive target for selective chemotherapy in neuroblastoma. [Copyright &y& Elsevier]