The heron that laid the golden egg: metals and metalloids in ibis, darter, cormorant, heron, and egret eggs from the Vaal River catchment, South Africa

Metal pollution issues are afforded the highest priority in developing countries. Only one previous study has addressed metals in African bird eggs. We determined the concentration of metals and metalloids in bird eggs from four sites in the Vaal River catchment (VRC) of South Africa to provide data on the current situation. We analysed 16 pools of 77 heron, ibis, darter, egret, and cormorant eggs for 18 metals and metalloids using ICP-MS. We found high concentrations of gold (Au), uranium (U), thallium (Tl), and platinum (Pt) in Grey Heron eggs from Baberspan. Great white egrets from Bloemhof Dam had high concentrations of mercury (Hg). Multivariate analyses revealed strong associations between Au and U, and between palladium (Pd) and Pt. The toxic reference value (TRV) for Hg was exceeded in seven pools. Selenium exceeded its TRV in one pool; in the same pool, copper (Cu) reached its TRV. Compared with other studies, VRC bird eggs had high concentrations of contaminants. Based on these high concentrations, human health might be at risk as Grey Herons and humans share similar food and are therefore exposed to the same contaminants.

Hydrocortisone as an Intervention for Dexamethasone-Induced Adverse Effects in Pediatric Patients With Acute Lymphoblastic Leukemia: Results of a Double-Blind, Randomized Controlled Trial

PURPOSE

Dexamethasone is a key component in the treatment of pediatric acute lymphoblastic leukemia (ALL), but can induce serious adverse effects. Recent studies have led to the hypothesis that neuropsychological adverse effects may be a result of cortisol depletion of the cerebral mineralocorticoid receptors. We examined whether including a physiologic dose of hydrocortisone in dexamethasone treatment can reduce neuropsychologic and metabolic adverse effects in children with ALL.

PATIENTS AND METHODS

We performed a multicenter, double-blind, randomized controlled trial with a crossover design. Of 116 potentially eligible patients (age 3 to 16 years), 50 were enrolled and were treated with two consecutive courses of dexamethasone in accordance with Dutch Childhood Oncology Group ALL protocols. Patients were randomly assigned to receive either hydrocortisone or placebo in a circadian rhythm (10 mg/m(2)/d) during both dexamethasone courses. Primary outcome measure was parent-reported Strength and Difficulties Questionnaire in Dutch, which assesses psychosocial problems. Other end points included questionnaires, neuropsychological tests, and metabolic parameters.

RESULTS

Of 48 patients who completed both courses, hydrocortisone had no significant effect on outcome; however, a more detailed analysis revealed that in 16 patients who developed clinically relevant psychosocial adverse effects, addition of hydrocortisone substantially reduced their Strength and Difficulties Questionnaire in Dutch scores in the following domains: total difficulties, emotional symptoms, conduct problems, and impact of difficulties. Moreover, in nine patients who developed clinically relevant, sleep-related difficulties, addition of hydrocortisone reduced total sleeping problems and disorders of initiating and maintaining sleep. In contrast, hydrocortisone had no effect on metabolic parameters.

CONCLUSION

Our results suggest that adding a physiologic dose of hydrocortisone to dexamethasone treatment can reduce the occurrence of serious neuropsychological adverse effects and sleep-related difficulties in pediatric patients with ALL.

End-of-Life Decisions in Pediatric Cancer Patients

BACKGROUND

End-of-life decisions (ELDs) have been investigated in several care settings, but rarely in pediatric oncology.

OBJECTIVE

The aims of this study were to characterize the practice of end-of-life decision making in a Dutch academic medical center and to explore pediatric oncologists' perspectives on decision making.

METHODS

Between 2001 and 2010, in a specified period of 2 years, 57 children died of cancer. The attending pediatric oncologists of 48 deceased children were eligible for this study. They were requested to complete a retrospective questionnaire on characteristics of ELDs that may have preceded a child's death. ELDs were defined as decisions concerning administering or forgoing treatment that may unintentionally or intentionally hasten death.

RESULTS

In 31 of 48 cases (65%) one or more ELDs were made. In 20 of 31 cases potentially life-prolonging treatments were discontinued or withheld, and in 22 of 31 cases drugs were administered to alleviate pain or other symptoms in potentially life-shortening dosages. Frequently mentioned considerations for making ELDs were no prospects of improvement (n=21;68%) and unbearable suffering without a curative perspective (n=13;42%). ELDs were discussed with parents in all cases, and with the child in 9 of 31 cases. After the child's death, the pediatric oncologist met the parents in all ELD cases and in 11 of 17 non-ELD cases. Pediatric oncologists were satisfied with care around the child's death in 90% of the ELD cases versus 59% of the non-ELD cases.

CONCLUSIONS

In two-thirds of cases, ELDs preceded the death of a child with cancer. This is the first study providing insights into the characteristics of ELDs from a pediatric oncologist's point of view.

The clinical phenotype of YWHAE-NUTM2B/E positive pediatric clear cell sarcoma of the kidney

Clear cell sarcoma of the kidney (CCSK) although uncommon, is the second most frequent renal malignancy of childhood. Until now, the sole recurrent genetic aberration identified in CCSKs is t(10;17)(q22;p13), which gives rise to a fusion transcript of YWHAE and NUTM2B/E. So far, the clinical relevance of this fusion transcript is unknown. The aim of this descriptive study was to determine the clinical phenotype of t(10;17)(q22;p13) positive CCSKs. Snap-frozen tissues, formalin-fixed paraffin-embedded tissues or RNA previously extracted from CCSK samples throughout European, North-American and Japanese study groups were screened by RT-PCR for the YWHAE-NUTM2B/E transcript. Clinical characteristics, tumor characteristics, and outcome of patients with and without the fusion transcript were studied. The cohort comprised 51 previously published cases to which were added 139 internationally collected CCSK samples. RNA from 57 of these additionally collected cases was of sufficient quality to be successfully screened for the YWHAE-NUTM2B/E transcript. In total, seven of the 108 cases harbored the fusion transcript. Patients with tumors containing the fusion transcript were relatively young (median age 10 months), had associated low median tumor volumes and stage I disease was not observed in these patients. Two of seven patients relapsed and one of seven patients died of disease. Ranges of values were not overtly different between patients with and without the fusion transcript; however, the number of fusion transcript positive cases turned out to be too small to permit reliable statistical analysis. The current study did not identify an explicit clinical phenotype of CCSK cases harboring the YWHAE-NUTM2B/E fusion transcript.

Influence of Cranial Radiotherapy on Outcome in Children With Acute Lymphoblastic Leukemia Treated With Contemporary Therapy

PURPOSE

We sought to determine whether cranial radiotherapy (CRT) is necessary to prevent relapse in any subgroup of children with acute lymphoblastic leukemia (ALL).

PATIENTS AND METHODS

We obtained aggregate data on relapse and survival outcomes for 16,623 patients age 1 to 18 years old with newly diagnosed ALL treated between 1996 and 2007 by 10 cooperative study groups from around the world. The proportion of patients eligible for prophylactic CRT varied from 0% to 33% by trial and was not related to the proportion eligible for allogeneic stem-cell transplantation in first complete remission. Using a random effects model, with CRT as a dichotomous covariate, we performed a single-arm meta-analysis to compare event-free survival and cumulative incidence of isolated or any CNS relapse and isolated bone marrow relapse in high-risk subgroups of patients who either did or did not receive CRT.

RESULTS

Although there was significant heterogeneity in all outcome end points according to trial, CRT was associated with a reduced risk of relapse only in the small subgroup of patients with overt CNS disease at diagnosis, who had a significantly lower risk of isolated CNS relapse (4% with CRT v 17% without CRT; P = .02) and a trend toward lower risk of any CNS relapse (7% with CRT v 17% without CRT; P = .09). However, this group had a relatively high rate of events regardless of whether or not they received CRT (32% [95% CI, 26% to 39%] v 34% [95% CI, 19% to 54%]; P = .8).

CONCLUSION

CRT does not have an impact on the risk of relapse in children with ALL treated on contemporary protocols.

Talking about Death with Children with Incurable Cancer: Perspectives from Parents

OBJECTIVE

To investigate the rationale and consequences associated with a parent's decision to discuss death with a child with incurable cancer.

STUDY DESIGN

We present data from a larger retrospective study involving bereaved parents of a child who died of cancer. Parents were asked whether they had discussed the impending death with their child, whether they reflected on this discussion positively, their reasons for not discussing death with their child, and the manner in which the conversation regarding death occurred. The data were analyzed qualitatively using a framework approach.

RESULTS

Of the 86 parents of 56 children who answered the questions regarding discussing death with their child, 55 parents of 35 children did not discuss the impending death with their child. The following themes were identified: the parents' inability to discuss the impending death; the parents' desire to protect their child; views regarding talking with children; parents' views of child characteristics; the child's unwillingness to discuss the subject; lack of opportunity to talk; and the child's disability. The parents who did discuss death with their child generally used symbolic and/or religious narratives, or they had brief, direct conversations regarding death. The majority of parents felt positive regarding their decision about whether to talk with their child about his/her impending death.

CONCLUSION

Most parents in this study cited several reasons for not discussing death with their child. Our findings highlight the sensitive and complex issues surrounding these conversations, indicating that there may be a role for clinicians in supporting parents.

Aggravated bone density decline following symptomatic osteonecrosis in children with acute lymphoblastic leukemia

Osteonecrosis and decline of bone density are serious side effects during and after treatment of childhood acute lymphoblastic leukemia. It is unknown whether osteonecrosis and low bone density occur together in the same patients, or whether these two osteogenic side-effects can mutually influence each other's development. Bone density and the incidence of symptomatic osteonecrosis were prospectively assessed in a national cohort of 466 patients with acute lymphoblastic leukemia (4-18 years of age) who were treated according to the dexamethasone-based Dutch Child Oncology Group-ALL9 protocol. Bone mineral density of the lumbar spine (BMDLS) (n=466) and of the total body (BMDTB) (n=106) was measured by dual X-ray absorptiometry. Bone density was expressed as age- and gender-matched standard deviation scores. Thirty patients (6.4%) suffered from symptomatic osteonecrosis. At baseline, BMDLS and BMDTB did not differ between patients who did or did not develop osteonecrosis. At cessation of treatment, patients with osteonecrosis had lower mean BMDLS and BMDTB than patients without osteonecrosis (respectively, with osteonecrosis: -2.16 versus without osteonecrosis: -1.21, P<0.01 and with osteonecrosis: -1.73 versus without osteonecrosis: -0.57, P<0.01). Multivariate linear models showed that patients with osteonecrosis had steeper BMDLS and BMDTB declines during follow-up than patients without osteonecrosis (interaction group time, P<0.01 and P<0.01). We conclude that bone density status at the diagnosis of acute lymphoblastic leukemia does not seem to influence the occurrence of symptomatic osteonecrosis. Bone density declines from the time that osteonecrosis is diagnosed; this suggests that the already existing decrease in bone density during acute lymphoblastic leukemia therapy is further aggravated by factors such as restriction of weight-bearing activities and destruction of bone architecture due to osteonecrosis. Osteonecrosis can, therefore, be considered a risk factor for low bone density in children with acute lymphoblastic leukemia.

Recurrent deletions of IKZF1 in pediatric acute myeloid leukemia

IKAROS family zinc finger 1/IKZF1 is a transcription factor important in lymphoid differentiation, and a known tumor suppressor in acute lymphoid leukemia. Recent studies suggest that IKZF1 is also involved in myeloid differentiation. To investigate whether IKZF1 deletions also play a role in pediatric acute myeloid leukemia, we screened a panel of pediatric acute myeloid leukemia samples for deletions of the IKZF1 locus using multiplex ligation-dependent probe amplification and for mutations using direct sequencing. Three patients were identified with a single amino acid variant without change of IKZF1 length. No frame-shift mutations were found. Out of 11 patients with an IKZF1 deletion, 8 samples revealed a complete loss of chromosome 7, and 3 cases a focal deletion of 0.1-0.9Mb. These deletions included the complete IKZF1 gene (n=2) or exons 1-4 (n=1), all leading to a loss of IKZF1 function. Interestingly, differentially expressed genes in monosomy 7 cases (n=8) when compared to non-deleted samples (n=247) significantly correlated with gene expression changes in focal IKZF1-deleted cases (n=3). Genes with increased expression included genes involved in myeloid cell self-renewal and cell cycle, and a significant portion of GATA target genes and GATA factors. Together, these results suggest that loss of IKZF1 is recurrent in pediatric acute myeloid leukemia and might be a determinant of oncogenesis in acute myeloid leukemia with monosomy 7.

Childhood Acute Lymphoblastic Leukemia: Progress Through Collaboration

PURPOSE

To review the impact of collaborative studies on advances in the biology and treatment of acute lymphoblastic leukemia (ALL) in children and adolescents.

METHODS

A review of English literature on childhood ALL focusing on collaborative studies was performed. The resulting article was reviewed and revised by the committee chairs of the major ALL study groups.

RESULTS

With long-term survival rates for ALL approaching 90% and the advent of high-resolution genome-wide analyses, several international study groups or consortia were established to conduct collaborative research to further improve outcome. As a result, treatment strategies have been improved for several subtypes of ALL, such as infant, MLL-rearranged, Philadelphia chromosome-positive, and Philadelphia chromosome-like ALL. Many recurrent genetic abnormalities that respond to tyrosine kinase inhibitors and multiple genetic determinants of drug resistance and toxicities have been identified to help develop targeted therapy. Several genetic polymorphisms have been recognized that show susceptibility to developing ALL and that help explain the racial/ethnic differences in the incidence of ALL.

CONCLUSION

The information gained from collaborative studies has helped decipher the heterogeneity of ALL to help improve personalized treatment, which will further advance the current high cure rate and the quality of life for children and adolescents with ALL.

Abstract 1624: Methotrexate resistance in relation to treatment outcome in childhood acute lymphoblastic leukemia

Methotrexate (MTX) is an essential component of contemporary ALL treatment regimens. This antifolate eradicates leukemic cells by disrupting de novo biosynthesis of nucleotides, leading to inhibition of DNA replication and consequent cell death. Over the past decades, MTX-containing chemotherapy has proven to be crucial in achieving curation in ALL. However, drug resistance continues to be a major obstacle to curative ALL treatment. A number of alterations in MTX metabolism, resulting in impaired accumulation of this antifolate in cancer cells, have been identified as determinants of MTX resistance. However, it remains unclear which of these molecular mechanisms have clinical relevance. Therefore, the current study aimed at determining the relation between MTX resistance and long-term clinical outcome of ALL.

Towards this end, we collected the available clinical data of 235 childhood ALL patients, including clinical data with a follow-up time of 10 years. For these patients, samples obtained at the time of diagnosis were also characterized with respect to MTX resistance. This included determination of MTX polyglutamate levels in leukemic cells, mRNA expression of enzymes involved in (anti)folate metabolism and transport (i.e. FPGS, FPGH, DHFR, TS and RFC); MTX sensitivity was determined by the thymidylate synthase inhibition assay (TSIA) and in vitro FPGS activity assay was performed.

High levels of long-chain MTX polyglutamates was strongly associated with favorable long-term event-free survival (EFS, p = 0.029) and overall survival (OS, p = 0.008) of ALL patients (10-year EFS 81% and OS 91%, compared to EFS 58% and OS 64% in patients with low levels of this active metabolite). Similar relations were observed for the total accumulation of MTX polyglutamates and FPGS activity, which were associated with overall survival (p = 0.018 and p = 0.039, respectively). In the multivariate Cox regression model, including clinical variables, the level of long chain MTX polyglutamates showed a trend towards an association with event-free survival (p = 0.073) but not with overall survival (p = 0.465). In addition, we assessed the association between MTX resistance-related variables and the treatment outcome in patients with different cytogenetic alterations. High MTX sensitivity was associated with hyperdiploid ALL (P&lt;0.001), which was also associated with increased MTX accumulation (p = 0.03) and elevated RFC expression (p = 0.049). Moreover, cells characterized by TEL-AML1 fusion displayed elevated MTX resistance (p = 0.023) compared to samples devoid of this aberration, while MLL-rearrangements were associated with low accumulation of cellular MTX polyglutamates (p = 0.012). These findings emphasize the central role which MTX lays in ALL treatment thereby highlighting the necessity for further exploration of the molecular mechanisms underlying MTX resistance in ALL patients.

Financial support by Kika (Children cancer-free)

Citation Format: Anna Wojtuszkiewicz, Godefridus J. Peters, Nicole L. van Woerden, Boas Dubbelman, Gabrielle Escherich, Kjeld Schmiegelow, Edwin Sonneveld, Rob Pieters, Peter M. van de Ven, Gerrit Jansen, Yehuda G. Assaraf, Gertjan J L Kaspers, Jacqueline Cloos. Methotrexate resistance in relation to treatment outcome in childhood acute lymphoblastic leukemia. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1624. doi:10.1158/1538-7445.AM2015-1624

The potential of clofarabine in MLL-rearranged infant acute lymphoblastic leukaemia

MLL-rearranged acute lymphoblastic leukaemia (ALL) in infants is the most difficult-to-treat type of childhood ALL, displaying a chemotherapy-resistant phenotype, and unique histone modifications, gene expression signatures and DNA methylation patterns. MLL-rearranged infant ALL responds remarkably well to nucleoside analogue drugs in vitro, such as cytarabine and cladribine, and to the demethylating agents decitabine and zebularine as measured by cytotoxicity assays. These observations led to the inclusion of cytarabine into the treatment regimens currently used for infants with ALL. However, survival chances for infants with MLL-rearranged ALL do still not exceed 30-40%. Here we explored the in vitro potential of the novel nucleoside analogue clofarabine for MLL-rearranged infant ALL. Therefore we used both cell line models as well as primary patient cells. Compared with other nucleoside analogues, clofarabine effectively targeted primary MLL-rearranged infant ALL cells at the lowest concentrations, with median LC50 values of ∼25 nM. Interestingly, clofarabine displayed synergistic cytotoxic effects in combination with cytarabine. Furthermore, at concentrations of 5-10nM clofarabine induced demethylation of the promoter region of the tumour suppressor gene FHIT (Fragile Histidine Triad), a gene typically hypermethylated in MLL-rearranged ALL. Demethylation of the FHIT promoter region was accompanied by subtle re-expression of this gene both at the mRNA and protein level. We conclude that clofarabine is an interesting candidate for further studies in MLL-rearranged ALL in infants.

Methotrexate resistance in relation to treatment outcome in childhood acute lymphoblastic leukemia

Background

Methotrexate (MTX) eradicates leukemic cells by disrupting de novo nucleotide biosynthesis and DNA replication, resulting in cell death. Since its introduction in 1947, MTX-containing chemotherapeutic regimens have proven instrumental in achieving curative effects in acute lymphoblastic leukemia (ALL). However, drug resistance phenomena pose major obstacles to efficacious ALL chemotherapy. Moreover, clinically relevant molecular mechanisms underlying chemoresistance remain largely obscure. Several alterations in MTX metabolism, leading to impaired accumulation of this cytotoxic agent in tumor cells, have been classified as determinants of MTX resistance. However, the relation between MTX resistance and long-term clinical outcome of ALL has not been shown previously.

Methods

We have collected clinical data for 235 childhood ALL patients, for whom samples taken at the time of diagnosis were also broadly characterized with respect to MTX resistance. This included measurement of concentrations of MTX polyglutamates in leukemic cells, mRNA expression of enzymes involved in MTX metabolism (FPGS, FPGH, RFC, DHFR, and TS), MTX sensitivity as determined by the TS inhibition assay, and FPGS activity.

Results

Herein we demonstrate that higher accumulation of long-chain polyglutamates of MTX is strongly associated with better overall (10-year OS: 90.6 vs 64.1 %, P = 0.008) and event-free survival (10-year EFS: 81.2 vs 57.6 %, P = 0.029) of ALL patients. In addition, we assessed both the association of several MTX resistance-related parameters determined in vitro with treatment outcome as well as clinical characteristics of pediatric ALL patients treated with MTX-containing combination chemotherapy. High MTX sensitivity was associated with DNA hyperdiploid ALL (P < 0.001), which was linked with increased MTX accumulation (P = 0.03) and elevated reduced folate carrier (RFC) expression (P = 0.049) in this subset of ALL patients. TEL-AML1 fusion was associated with increased MTX resistance (P = 0.023). Moreover, a low accumulation of MTX polyglutamates was observed in MLL-rearranged and TEL-AML1 rearranged ALL (P < 0.05).

Conclusions

These findings emphasize the central role of MTX in ALL treatment thereby expanding our understanding of the molecular basis of clinical differences in treatment response between ALL individuals. In particular, the identification of patients that are potentially resistant to MTX at diagnosis may allow for tailoring novel treatment strategies to individual leukemia patients.

Electronic supplementary material

The online version of this article (doi:10.1186/s13045-015-0158-9) contains supplementary material, which is available to authorized users.

MLL fusion-driven activation of CDK6 potentiates proliferation in MLL-rearranged infant ALL

Acute lymphoblastic leukemia in infants (< 1 year-of-age) is characterized by a high incidence of MLL rearrangements. Recently, direct targets of the MLL fusion protein have been identified. However, functional validation of the identified targets remained unacknowledged. In this study, we identify CDK6 as a direct target of the MLL fusion protein and an important player in the proliferation advantage of MLL-rearranged leukemia. CDK6 mRNA was significantly higher expressed in MLL-rearranged infant ALL patients compared with MLL wild-type ALL patients (P < 0.001). Decrease of MLL-AF4 and MLL-ENL fusion mRNA expression by siRNAs resulted in downregulation of CDK6, affirming a direct relationship between the presence of the MLL fusion and CDK6 expression. Knockdown of CDK6 itself significantly inhibited proliferation in the MLL-AF4-positive cell line SEM, whereas knockdown of the highly homologous gene CDK4 had virtually no effect on the cell cycle. Furthermore, we show in vitro sensitivity of MLL-rearranged leukemia cell lines to the CDK4/6-inhibitor PD0332991, inducing a remarkable G 1 arrest, and downregulation of its downstream targets pRB1 and EZH2. We therefore conclude that CDK6 is indeed a direct target of MLL fusion proteins, playing an important role in the proliferation advantage of MLL-rearranged ALL cells.

NALP3 inflammasome upregulation and CASP1 cleavage of the glucocorticoid receptor cause glucocorticoid resistance in leukemia cells

Glucocorticoids are universally used in the treatment of acute lymphoblastic leukemia (ALL), and leukemia cell resistant to glucocorticoids confers a poor prognosis. To elucidate mechanisms of glucocorticoid resistance, we determined the sensitivity to prednisolone of primary leukemia cells from 444 newly diagnosed ALL patients, revealing significantly higher expression of caspase 1 (CASP1) and its activator NLRP3 in glucocorticoid resistant leukemia cells, due to significantly lower somatic methylation of CASP1 and NLRP3 promoters. Over-expression of CASP1 resulted in cleavage of the glucocorticoid receptor, diminished glucocorticoid-induced transcriptional response and increased glucocorticoid resistance. Knockdown or inhibition of CASP1 significantly increased glucocorticoid receptor levels and mitigated glucocorticoid resistance in CASP1 overexpressing ALL. Our findings establish a new mechanism by which the NLRP3/CASP1 inflammasome modulates cellular levels of the glucocorticoid receptor and diminishes cell sensitivity to glucocorticoids. The broad impact on glucocorticoid transcriptional response suggests this mechanism could also modify glucocorticoid effects in other diseases.

Management and treatment of osteonecrosis in children and adolescents with acute lymphoblastic leukemia

There is no consensus regarding how to manage osteonecrosis in pediatric acute lymphoblastic leukemia patients. Therefore, we performed a quality assessment of the literature with the result of a search strategy using the MESH terms osteonecrosis, children, childhood cancer, surgery, bisphosphonates, 6 hydroxymethyl-glutaryl CoA reductase inhibitors, anticoagulants and hyperbaric oxygen, and terms related to these MESH terms. A randomized controlled trial showed that osteonecrosis can be prevented by intermittent, instead of continuous, corticosteroid administration. The studies on interventions after onset of osteonecrosis were of low-quality evidence. Seven pediatric acute lymphoblastic leukemia studies described non-surgical interventions; bisphosphonates (n=5), hyperbaric oxygen therapy (n=1), or prostacyclin analogs (n=1). Safety and efficacy studies are lacking. Five studies focused on surgical interventions; none was of sufficient quality to draw definite conclusions. In conclusion, preventing osteonecrosis is feasible in a proportion of the pediatric acute lymphoblastic leukemia patients by discontinuous, instead of continuous, steroid scheduling. The questions as to how to treat childhood acute lymphoblastic leukemia patients with osteonecrosis cannot be answered as good-quality studies are lacking.

Identification of genes transcriptionally responsive to the loss of MLL fusions in MLL-rearranged acute lymphoblastic leukemia

INTRODUCTION

MLL-rearranged acute lymphoblastic leukemia (ALL) in infants (<1 year) is characterized by high relapse rates and a dismal prognosis. To facilitate the discovery of novel therapeutic targets, we here searched for genes directly influenced by the repression of various MLL fusions.

METHODS

For this, we performed gene expression profiling after siRNA-mediated repression of MLL-AF4, MLL-ENL, and AF4-MLL in MLL-rearranged ALL cell line models. The obtained results were compared with various already established gene signatures including those consisting of known MLL-AF4 target genes, or those associated with primary MLL-rearranged infant ALL samples.

RESULTS

Genes that were down-regulated in response to the repression of MLL-AF4 and MLL-ENL appeared characteristically expressed in primary MLL-rearranged infant ALL samples, and often represented known MLL-AF4 targets genes. Genes that were up-regulated in response to the repression of MLL-AF4 and MLL-ENL often represented genes typically silenced by promoter hypermethylation in MLL-rearranged infant ALL. Genes that were affected in response to the repression of AF4-MLL showed significant enrichment in gene expression profiles associated with AF4-MLL expressing t(4;11)+ infant ALL patient samples.

CONCLUSION

We conclude that the here identified genes readily responsive to the loss of MLL fusion expression potentially represent attractive therapeutic targets and may provide additional insights in MLL-rearranged acute leukemias.

Somatic thrombopoietin (THPO) gene mutations in childhood myeloid leukemias

We report, for the first time, a non-syndromic infant with a reversible myeloproliferative disease that harbors a germline hereditary thrombopoietin (THPO) gene mutation, a condition that is known to induce familial thrombocytosis at increasing age. In order to investigate whether somatic THPO gene mutations play a role in sporadic pediatric myeloproliferative diseases, we performed a mutation screening of a large representative cohort of pediatric acute myeloid leukemia, myeloid leukemia of Down syndrome, and juvenile myelomonocytic leukemia samples and show that gain-of-function THPO mutations are extremely rare in sporadic pediatric myeloproliferative diseases.

Decreased induction morbidity and mortality following modification to induction therapy in infants with acute lymphoblastic leukemia enrolled on AALL0631: a report from the Children's Oncology Group

BACKGROUND

Infants with acute lymphoblastic leukemia (ALL) have a poor prognosis. Intensification of therapy has resulted in fewer relapses but increased early deaths, resulting in failure to improve survival.

PROCEDURE

AALL0631 is a Phase 3 study for infants (<366 days of age) with newly diagnosed ALL. Induction initially (Cohort 1) consisted of 3 weeks of therapy based on COG P9407. Due to excessive early mortality, induction was amended to a less intensive 5 weeks of therapy based on Interfant-99. Additionally, enhanced supportive care guidelines were incorporated with hospitalization during induction until evidence of marrow recovery and recommendations for prevention/treatment of infections (Cohort 2).

RESULTS

Induction mortality was significantly lower for patients in Cohort 2 (2/123, 1.6%) versus Cohort 1 (4/26, 15.4%; P = 0.009). All induction deaths were infection related except one due to progressive disease (Cohort 2). Sterile site infections were lower for patients in Cohort 2 (24/123, 19.5%) versus Cohort 1 (15/26, 57.7%; P = 0.0002), with a significantly lower rate of Gram positive infections during induction for patients in Cohort 2, P = 0.0002. No clinically significant differences in grades 3-5 non-infectious toxicities were observed between the two cohorts. Higher complete response rates were observed at end induction intensification for Cohort 2 (week 9, 94/100, 94%) versus Cohort 1 (week 7, 17/25, 68%; P = 0.0.0012).

CONCLUSION

De-intensification of induction therapy and enhanced supportive care guidelines significantly decreased induction mortality and sterile site infections, without decreasing complete remission rates.

Parents' Faith and Hope during the Pediatric Palliative Phase and the Association with Long-Term Parental Adjustment

BACKGROUND

The loss of a child is associated with an increased risk for developing psychological problems. However, studies investigating the impact of parents' faith and hope for a cure during the palliative phase on long-term parental psychological functioning are limited.

OBJECTIVE

The study's objective was to explore the role of faith and hope as a source of coping and indicator of long-term parental adjustment.

METHODS

Eighty-nine parents of 57 children who died of cancer completed questionnaires retrospectively, exploring faith, hope, and sources of coping, and measuring parents' current level of grief and depression.

RESULTS

For 19 parents (21%) faith was very important during the palliative phase. The majority of parents remained hopeful for a meaningful time with their child (n=68, 76%); a pain-free death (n=58, 65%); and a cure (n=30, 34%). Their child (n=70, 79%) was parents' main source of coping. Twelve parents (14%) suffered from traumatic grief, and 22 parents (25%) showed symptoms of depression. Parents' faith was not associated with less long-term traumatic grief (OR=0.86, p=0.51) or symptoms of depression (OR=0.95, p=0.74), and parents' hope for a cure was not related to more long-term traumatic grief (OR=1.07, p=0.71) or symptoms of depression (OR=1.12, p=0.47).

CONCLUSIONS

Faith was important for a minority of parents and was not associated with less long-term traumatic grief or symptoms of depression. The majority of parents remained hopeful. Hope for a cure was not associated with more long-term traumatic grief or symptoms of depression.

Bone mineral density after childhood cancer in 346 long-term adult survivors of childhood cancer

SUMMARY

More than 45 % of long-term childhood cancer survivors (CCS) were diagnosed with osteopenia. Our data suggest that greater awareness for osteopenia is warranted in long-term CCS, especially in survivors who are older than 30 years, male, and underweight and were treated with cranial-spinal radiotherapy and/or steroids.

INTRODUCTION

Osteopenia is a potential complication of childhood cancer treatment, but the magnitude of this problem in survivors is unknown. We examined (determinants of) bone mineral density (BMD) status in long-term survivors of adult childhood cancer.

METHODS

This retrospective single-centre cohort study included 346 subjects with the most common types of childhood cancer. Subjects had a median age at diagnosis of 7.0 years (range 0.1-16.8 years), a median age at follow-up of 24.5 years (range 18.0-47.6 years) and a median follow-up time of 16.7 years (range 5.6-39.9 years). Total body BMD (BMDTB) and BMD of the lumbar spine (BMDLS) were measured by dual X-ray absorptiometry. Osteopenia was defined as BMD standardized deviation score (SDS) below -1.

RESULTS

Survivors had a lower BMDTB and BMDLS (mean SDS -0.55; p<0.001 and -0.30; p<0.001, respectively) as compared to healthy peers. Osteopenia (BMDTB and/or BMDLS) was present in 45% of the survivors. Multivariate logistic regression analyses identified age at diagnosis<12 years, age>30 years at follow-up, male gender, underweight at follow-up and treatment with cranial-spinal radiotherapy or prednisone as independent prognostic factors for osteopenia.

CONCLUSIONS

This large cohort of childhood cancer survivors identified osteopenia in 45% of CCS. This indicates that greater awareness is warranted, especially in survivors who are older than 30 years, male, have underweight and were treated with cranial-spinal radiotherapy and/or steroids.

Bone marrow immunophenotyping by flow cytometry in refractory cytopenia of childhood

Refractory cytopenia of childhood is the most common type of childhood myelodysplastic syndrome. Because the majority of children with refractory cytopenia have a normal karyotype and a hypocellular bone marrow, differentiating refractory cytopenia from the immune-mediated bone marrow failure syndrome (very) severe aplastic anemia can be challenging. Flow cytometric immunophenotyping of bone marrow has been shown to be a valuable diagnostic tool in differentiating myelodysplastic syndrome from non-clonal cytopenias in adults. Here, we performed the first comprehensive flow cytometric analysis of immature myeloid, lymphoid cells and erythroid cells, and granulocytes, monocytes, and lymphoid cells in bone marrow obtained from a large prospective cohort of 81 children with refractory cytopenia. Children with refractory cyotopenia had a strongly reduced myeloid compartment, but not as severe as children with aplastic anemia. Furthermore, the number of flow cytometric abnormalities was significantly higher in children with refractory cytopenia than in healthy controls and in children with aplastic anemia, but lower than in advanced myelodysplastic syndrome. We conclude that flow cytometric immunophenotyping could be a relevant addition to histopathology in the diagnosis of refractory cytopenia of childhood. (The multi-center studies EWOG-MDS RC06 and EWOG-MDS 2006 are registered at clinicaltrials.gov identifiers 00499070 and 00662090, respectively).

Genetic and metabolic determinants of methotrexate-induced mucositis in pediatric acute lymphoblastic leukemia

Methotrexate (MTX) is an effective and toxic chemotherapeutic drug in the treatment of pediatric acute lymphoblastic leukemia(ALL). In this prospective study, we aimed to identify metabolic and genetic determinants of MTX toxicity. One hundred and thirty-four Dutch pediatric ALL patients were treated with four high infusions MTX (HD-MTX: 5 g m(-2)) every other week according to the DCOG-ALL-10 protocol. Mucositis (National Cancer Institute grade ⩾ 3) was the most frequent occurring toxicity during the HD-MTX phase (20%) and occurred especially after the first MTX course. Mucositis was not associated with plasma MTX, plasma folate or plasma homocysteine levels. Patients with mucositis had higher erythrocyte folate levels at the start of protocol M than patients without mucositis (median 1.4 vs 1.2 μmol l(-1), P<0.008), this could reflect an increased MTX uptake in mucosal cells of patients with mucositis. From 17 single-nucleotide polymorphisms in the MTX pathway, only patients with the wild-type variant of rs7317112 SNP in the ABCC4 gene had more mucositis (AA (39%) vs AG/GG (15%), P=0.016). We found no evidence that erythrocyte folate levels mediate in the association between the rs7317112 and mucositis.

Abstract A19: Epigenetic drug combination induces genome-wide demethylation and altered gene expression in neuro-ectodermal tumor-derived cell lines

Background: Epigenetic alterations are inherent to cancer cells, and epigenetic drugs are currently primarily used to treat hematological malignancies. Pediatric neuro-ectodermal tumors originate from neural crest cells and also exhibit epigenetic alterations involving e.g. apoptotic pathways, which suggests that also these tumors may be sensitive to epigenetic drugs. This notion prompted us to assess molecular and functional effects of low dosage epigenetic drugs in neuro-ectodermal tumor-derived cell lines of pediatric origin.

Results: In 17 neuroblastoma (NBL) and 5 peripheral primitive neuro-ectodermal tumor (PNET) cell lines a combination treatment of 5-aza-2′-deoxycytidine (DAC) and Trichostatin A (TSA) at nanomolar dosages was found to reduce proliferation and to induce wide-spread DNA demethylation, accompanied by major changes in gene expression profiles. Approximately half of the genes that were significantly up-regulated upon treatment exhibited a significant demethylation in their promoter regions. In the NBL cell lines, almost every cellular pathway (193/200) investigated showed expression alterations after treatment, especially a marked up-regulation of genes in the p53 pathway. The combination treatment also resulted in up-regulation of known epigenetically regulated genes such as X-chromosomal genes, tissue-specific genes and a limited number of imprinted genes, as well as known tumor suppressor genes and oncogenes.

Conclusions: Nanomolar dosages of epigenetic drugs have a dramatic impact on the genomes of neuro-ectodermal tumor derived cell lines, including alterations in DNA methylation and concomitant alterations in gene expression.

Citation Format: Max M. van Noesel, Floor A M Duijkers, Renee X. de Menezes, Dominique J. P. M. Stumpel, Pieter Admiraal, Rob Pieters, Jules P P Meijerink. Epigenetic drug combination induces genome-wide demethylation and altered gene expression in neuro-ectodermal tumor-derived cell lines. [abstract]. In: Proceedings of the AACR Special Conference on Pediatric Cancer at the Crossroads: Translating Discovery into Improved Outcomes; Nov 3-6, 2013; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2013;74(20 Suppl):Abstract nr A19.

The negative impact of being underweight and weight loss on survival of children with acute lymphoblastic leukemia

Body mass index and change in body mass index during treatment may influence treatment outcome of pediatric patients with acute lymphoblastic leukemia. However, previous studies in pediatric acute lymphoblastic leukemia reported contradictory results. We prospectively collected data on body composition from a cohort of newly diagnosed Dutch pediatric patients with acute lymphoblastic leukemia (n=762, age 2-17 years). Patients were treated from 1997-2004 and the median follow-up was 9 years (range, 0-10). Body mass index at diagnosis was expressed as age- and gender-matched standard deviation scores and on the basis of these scores the patients were categorized as being underweight, of normal weight or overweight. Multivariate analyses showed that patients who were underweight (8%) had a higher risk of relapse [hazard ratio: 1.88, 95% confidence interval (1.13-3.13)], but similar overall survival and event-free survival as patients who had a normal weight or who were overweight. Patients with loss of body mass index during the first 32 weeks of treatment had a similar risk of relapse and event-free survival, but decreased overall survival [hazard ratio: 2.10, 95% confidence interval (1.14-3.87)] compared to patients without a loss of body mass index. In addition, dual X-ray absorptiometry scans were performed in a nested, single-center cohort. Data from these scans revealed that a loss of body mass consisted mainly of a loss of lean body mass, while there was a gain in the percentage of fat. In conclusion, being underweight at diagnosis is a risk factor for relapse, and a decrease in body mass index early during treatment is associated with decreased survival. In addition, loss of body mass during treatment seems to consist mainly of a loss of lean body mass. This study was approved by the Medical Ethical Committee in 1996 (trial number NTR460/SNWLK-ALL-9).

The toxicity of very prolonged courses of PEGasparaginase or Erwinia asparaginase in relation to asparaginase activity, with a special focus on dyslipidemia

We prospectively studied the incidence and clinical course of hypertriglyceridemia and hypercholesterolemia during very prolonged use of asparaginase in relation to levels of asparaginase activity in children with acute lymphoblastic leukemia. We also evaluated the incidence of pancreatitis, thrombosis, hyperammonemia and central neurotoxicity and their association with asparaginase activity levels. Eighty-nine patients were treated according to the Dutch Childhood Oncology Group Acute Lymphoblastic Leukemia 10 medium-risk intensification protocol, which includes 15 doses of PEGasparaginase (2,500 IU/m(2)) over 30 weeks. Erwinia asparaginase (20,000 IU/m(2)) was administered when allergy to or silent inactivation of PEGasparaginase occurred. Triglyceride, cholesterol and ammonia levels increased rapidly in children treated with PEGasparaginase and remained temporarily elevated, but normalized after administration of the last asparaginase dose. Among the patients treated with PEGasparaginase, hypertriglyceridemia and hypercholesterolemia (grade 3/4) were found in 47% and 25%, respectively. The correlation between PEGasparaginase activity levels and triglyceride levels was strongest at week 5 (Spearman correlation coefficient = 0.36, P = 0.005). The triglyceride levels were higher in children ≥ 10 years old than in younger patients (<10 years old) after adjustment for type of asparaginase preparation: median 4.9 mmol/L versus 1.6 mmol/L (P<0.001). In patients receiving Erwinia asparaginase, triglyceride levels increased in the first weeks as well, but no grade 3/4 dyslipidemia was found. Hyperammonemia (grade 3/4) was only found in patients treated with Erwinia asparaginase (9%). Thrombosis occurred in 4.5%, pancreatitis in 7%, and central neurotoxicity in 9% of patients using either of the two agents; these toxicities were not related to levels of asparaginase activity or to triglyceride levels. In conclusion, severe dyslipidemia occurred frequently, but was temporary and was not associated with relevant clinical events and should not, therefore, be considered a reason for modifying asparaginase treatment. Dyslipidemia was the only toxicity related to levels of asparaginase activity.

Obesity independently influences gonadal function in very long-term adult male survivors of childhood cancer

OBJECTIVE

Although obesity is associated with gonadal dysfunction in the general population, gonadotoxic treatment might diminish the impact of obesity in childhood cancer survivors (CCS). The aim was to evaluate whether altered body composition is associated with gonadal dysfunction in male CCS, independent of gonadotoxic cancer treatment.

METHODS

Three hundred fifty-one male CCS were included. Median age at diagnosis was 5.9 years (0-17.8) and median age at follow-up 25.6 years (18.0-45.8). Total and non-SHBG-bound testosterone, sex hormone-binding globulin, inhibin B, and follicle-stimulating hormone (FSH) were studied. Potential determinants were BMI, waist circumference, waist-hip ratio, and body composition measures (dual energy X-ray absorptiometry).

RESULTS

Non-SHBG-bound testosterone was significantly decreased in survivors with BMI ≥ 30 kg/m(2) (adjusted mean 9.1 nmol/L vs. 10.2 nmol/L, P = 0.015), high fat percentage (10.0 vs. 11.2, P = 0.004), and high waist circumference (>102 cm) (9.0 vs. 11.0, P = 0.020). Survivors with high fat percentage (≥25%) had significantly lower inhibin B/FSH ratios (inhibin B/FSH ratio: β -34%, P = 0.041).

CONCLUSION

Obesity is associated with gonadal dysfunction in male CCS, independent of the irreversible effect of previous cancer treatment. Randomized controlled trials are required to evaluate whether weight normalization could improve gonadal function, especially in obese survivors with potential other mechanisms than lifestyle causing their obesity.

Determinants of quality of life during induction therapy in pediatric acute lymphoblastic leukemia

PURPOSE

Improvement in survival of pediatric acute lymphoblastic leukemia (ALL) has increased the attention to quality of life (QoL) . QoL is impaired during maintenance treatment, but little is known about QoL during induction therapy. Identification of patients with poor QoL during induction will provide opportunities for early interventions, and may subsequently improve future QoL. This national multi-center study aimed to assess QoL and its determinants during ALL induction treatment.

METHODS

Proxy reports of the Child Health Questionnaire (CHQ) and the PedsQL cancer version were collected. Child, treatment, and parental characteristics were analyzed as potential determinants in a multiple regression model.

RESULTS

One hundred thirty parents of children participated (response rate 82 %), median child age was 5.7 years and 48 % were female. QoL, as measured with the CHQ, was significantly lower than the norm, the effect sizes were large, and the differences were clinically relevant. Physical QoL was more often affected than psychosocial QoL. Regression models could be constructed for 4/ 10 CHQ scales and 6/ 8 PedsQL cancer scales, accounting for 7 to 36 % of the variance in scores. Impaired QoL was most often associated with older children, girls, and time since diagnosis. Also, father respondents seem to have a lower QoL perception compared to mother respondents although this needs to be confirmed in future research.

CONCLUSIONS

Specific counseling for subsets of patients with a higher risk of low QoL during the early phases of therapy is warranted.

Does dexamethasone induce more neuropsychological side effects than prednisone in pediatric acute lymphoblastic leukemia? A systematic review

Steroid-induced neuropsychological side effects impact quality of life in children with acute lymphoblastic leukemia. Dexamethasone induces more metabolic side effects than prednisone. To evaluate whether dexamethasone also leads to more neuropsychological side effects, we reviewed all available literature. Randomized controlled trials with neuropsychological function as the primary or secondary outcome did not show clinically meaningful differences between dexamethasone and prednisone on cognition, mood or behavior.

Parents' experiences of pediatric palliative care and the impact on long-term parental grief

CONTEXT

Approximately 25% of children diagnosed with cancer eventually die. Losing a child puts parents at increased risk for developing psychological problems.

OBJECTIVES

To explore parents' perceptions of the interaction with health care professionals (communication, continuity of care, and parental involvement) and symptom management during the pediatric palliative phase, and to investigate the influence on long-term grief in parents who lost a child to cancer.

METHODS

A total of 89 parents of 57 children who died of cancer between 2000 and 2004 participated in this retrospective cross-sectional study by completing a set of questionnaires measuring grief (Inventory of Traumatic Grief), parents' perceptions of the interaction with health care professionals (communication, continuity of care, and parental involvement), and symptom management during the palliative phase. Care was assessed on a five point Likert scale (1=disagree and 5=agree).

RESULTS

Parents highly rated communication (4.6±0.6), continuity of care (4.3±0.6), and parental involvement (4.6±0.7) during the palliative phase. Parents' most often reported physical and psychological symptoms of their child during the palliative phase were fatigue (75%), pain (74%), anxiety to be alone (52%), and anger (48%). Higher ratings of parents on communication (β=-9.08, P=0.03) and continuity of care (β=-11.74, P=0.01) were associated with lower levels of long-term parental grief. The severity of the child's dyspnea (β=2.96, P=0.05), anxiety to be alone (β=4.52, P<0.01), anxiety about the future (β=5.02, P<0.01), anger (β=4.90, P<0.01), and uncontrolled pain (β=6.60, P<0.01) were associated with higher levels of long-term parental grief. Multivariate models combining the interaction with health care professionals and symptom management showed a significant influence of both aspects on long-term parental grief.

CONCLUSION

Both interaction with health care professionals, especially communication and continuity of care, and symptom management in children dying of cancer are associated with long-term parental grief levels.