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Background: Asparaginase has played a crucial role in the improvement of survival in children with acute lymphoblastic leukaemia (ALL), which is the commonest cancer among children. Survival rates have steadily increased over decades since the introduction of asparaginase to ALL therapy, and overall survival rates reach 90% with the best contemporary protocols. Currently, polyethylene glycolated native Escherichia coli-derived L-asparaginase (PEG-asparaginase) is the preferred first-line asparaginase preparation. Besides its clinical benefits, PEG-asparaginase is well known for severe toxicities. Agreement on the optimal dose, treatment duration, and frequency of administration has never been reached among clinicians., Objectives: Primary objective To assess the effect of the number of PEG-asparaginase doses on survival and relapse in children and adolescents with ALL. Secondary objectives To assess the association between the number of doses of PEG-asparaginase and asparaginase-associated toxicities (e.g. hypersensitivity, thromboembolism, pancreatitis and osteonecrosis). To undertake a network meta-analysis at dose-level in order to generate rankings of the number of doses of PEG-asparaginase used in the treatment for ALL, according to their benefits (survival and relapse) and harms (toxicity)., Search Methods: We searched CENTRAL, PubMed, Embase, Web of Science databases and three trials registers in November 2021, together with reference checking, citation searching and contact with study authors to identify additional studies., Selection Criteria: We included randomised controlled trials (RCTs) comparing different PEG-asparaginase treatment regimens in children and adolescents (< 18 years of age) with first-line ALL treated with multiagent chemotherapy including PEG-asparaginase., Data Collection and Analysis: Using a standardised data collection form, two review authors independently screened and selected studies, extracted data, assessed risk of bias for each outcome using a standardised tool (RoB 2.0) and assessed the certainty of evidence for each outcome using the GRADE approach. Primary outcomes included overall survival, event-free survival and leukaemic relapse. Secondary outcomes included asparaginase-associated toxicities (hypersensitivity, thromboembolism, pancreatitis, sinusoidal obstruction syndrome and osteonecrosis as well as overall asparaginase-associated toxicity). We conducted the review and performed the analyses in accordance with the guidelines of the Cochrane Handbook for Systematic Reviews of Interventions., Main Results: We included three RCTs in the review, and identified an additional four ongoing studies. We judged outcomes of two RCTs to be at low risk of bias in all the Cochrane risk of bias (RoB 2) domains. We rated the remaining study as having some concerns regarding bias. Due to concerns about imprecision, we rated all outcomes as having low- to moderate-certainty evidence.  One study compared intermittent PEG-asparaginase treatment (eight doses of PEG-asparaginase, 1000 IU/m 2 , intramuscular (IM) administration) versus continuous PEG-asparaginase treatment (15 doses of PEG-asparaginase, 1000 IU/m 2 , IM) in 625 participants with non-high risk ALL aged 1.0 to 17.9 years. We found that treatment with eight doses probably results in little to no difference in event-free survival compared to treatment with 15 doses (RR 1.01, 95% CI 0.97 to 1.06; moderate-certainty evidence). Compared to treatment with 15 doses, treatment with eight doses may result in either no difference or a slight reduction in hypersensitivity (RR 0.64, 95% CI 0.21 to 1.93; low-certainty evidence), thromboembolism (RR 0.55, 95% CI 0.22 to 1.36; low-certainty evidence) or osteonecrosis (RR 0.68, 95% CI 0.35 to 1.32; low-certainty evidence). Furthermore, we found that treatment with eight doses probably reduces pancreatitis (RR 0.31, 95% CI 0.12 to 0.75; moderate-certainty evidence) and asparaginase-associated toxicity (RR 0.53, 95% CI 0.35 to 0.78; moderate-certainty evidence) compared to treatment with 15 doses. One study compared low-risk standard treatment with additional PEG-asparaginase (six doses, 2500 IU/m 2 , IM) versus low-risk standard treatment (two doses, 2500 IU/m 2 , IM) in 1857 participants aged one to nine years old with standard low-risk ALL. We found that, compared to treatment with two doses, treatment with six doses probably results in little to no difference in overall survival (RR 0.99, 95% CI 0.98 to 1.00; moderate-certainty evidence) and event-free survival (RR 1.01, 95% CI 0.99 to 1.04; moderate-certainty evidence), and may result in either no difference or a slight increase in osteonecrosis (RR 1.65, 95% CI 0.91 to 3.00; low-certainty evidence). Furthermore, we found that treatment with six doses probably increases hypersensitivity (RR 12.05, 95% CI 5.27 to 27.58; moderate-certainty evidence), pancreatitis (RR 4.84, 95% CI 2.15 to 10.85; moderate-certainty evidence) and asparaginase-associated toxicity (RR 4.49, 95% CI 3.05 to 6.59; moderate-certainty evidence) compared to treatment with two doses. One trial compared calaspargase (11 doses, 2500 IU/m 2 , intravenous (IV)) versus PEG-asparaginase (16 doses, 2500 IU/m 2 , IV) in 239 participants aged one to 21 years with standard- and high-risk ALL and lymphoblastic lymphoma. We found that treatment with 11 doses of calaspargase probably results in little to no difference in event-free survival compared to treatment with 16 doses of PEG-asparaginase (RR 1.06, 95% CI 0.97 to 1.16; moderate-certainty evidence). However, treatment with 11 doses of calaspargase probably reduces leukaemic relapse compared to treatment with 16 doses of PEG-asparaginase (RR 0.32, 95% CI 0.12 to 0.83; moderate-certainty evidence). Furthermore, we found that treatment with 11 doses of calaspargase results in either no difference or a slight reduction in hypersensitivity (RR 1.17, 95% CI 0.64 to 2.13; low-certainty evidence), pancreatitis (RR 0.85, 95% CI 0.47 to 1.52; low-certainty evidence), thromboembolism (RR 0.83, 95% CI 0.48 to 1.42; low-certainty evidence), osteonecrosis (RR 0.63, 95% CI 0.15 to 2.56; low-certainty evidence) and asparaginase-associated toxicity (RR 1.00, 95% CI 0.71 to 1.40; low-certainty evidence) compared to treatment with 16 doses of PEG-asparaginase., Authors' Conclusions: We were not able to conduct a network meta-analysis, and could not draw clear conclusions because it was not possible to rank the interventions. Overall, we found that different numbers of doses of PEG-asparaginase probably result in little to no difference in event-free survival across all studies. In two studies, we found that a higher number of PEG-asparaginase doses probably increases pancreatitis and asparaginase-associated toxicities., (Copyright © 2023 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.)

Objective: The diagnosis of cancer in a child is a profoundly stressful experience. The impact on parents' somatic health, including lifestyle-related diseases, however, is unresolved. This paper assesses parents' risk of hospitalization with somatic disease after a child's cancer diagnosis., Methods: We conducted a nationwide population- and register-based study with parents of all children under age 20 diagnosed with cancer in Denmark between 1998 and 2013 and parents of cancer-free children, matched (1:10) on child's age and family type. We estimated HR with 95% CI in Cox proportional hazard models for 13 major International Classification of Diseases-10 disease groups, selected stress- and lifestyle-related disease-groups, and investigated moderation by time since diagnosis, parental sex, and cancer type., Results: Among n = 7797 parents of children with cancer compared with n = 74,388 parents of cancer-free children (51% mothers, mean age 42), we found no overall pattern of increased risk for 13 broad disease groups. We found increases in digestive system diseases (HR 1.06, 95% CI 1.01-1.12), genitourinary system diseases (HR 1.08, 95% CI 1.02-1.14), and neoplasms (HR 1.20, 95% CI 1.13-1.27), the latter attributable mostly to increased rates of tobacco-related cancers and mothers' diet-related cancers., Conclusions: This is the first attempt to document the impact of childhood cancer on parents' somatic health. With the exception of increased risk for neoplasms, likely due to shared genetic or lifestyle factors, our findings offer the reassuring message, that the burden of caring for a child with cancer does not in general increase parents' risk for somatic diseases., (© 2022 John Wiley & Sons Ltd.)

6-mercaptopurine (6-MP) is widely used in the treatment of acute lymphoblastic leukemia (ALL), and its cytotoxicity is primarily mediated by thioguanine nucleotide (TGN) metabolites. A recent genomewide association study has identified germline polymorphisms (e.g., rs72846714) in the NT5C2 gene associated with 6-MP metabolism in patients with ALL. However, the full spectrum of genetic variation in NT5C2 is unclear and its impact on 6-MP drug activation has not been comprehensively examined. To this end, we performed targeted sequencing of NT5C2 in 588 children with ALL and identified 121 single nucleotide polymorphisms nominally associated with erythrocyte TGN during 6-MP treatment (P < 0.05). Of these, 61 variants were validated in a replication cohort of 372 children with ALL. After considering linkage disequilibrium and multivariate analysis, we confirmed two clusters of variants, represented by rs72846714 and rs58700372, that independently affected 6-MP metabolism. Functional studies showed that rs58700372 directly altered the activity of an intronic enhancer, with the variant allele linked to higher transcription activity and reduced 6-MP metabolism (lower TGN). By contrast, rs72846714 was not located in a regulatory element and instead its association signal was explained by linkage disequilibrium with a proximal functional variant rs12256506 that activated NT5C2 transcription in-cis. Our results indicated that NT5C2 germline variation significantly contributes to interpatient variability in thiopurine drug disposition., (© 2020 The Authors. Clinical Pharmacology & Therapeutics © 2020 American Society for Clinical Pharmacology and Therapeutics.)

Background: The risk of venous thromboembolism is increased in adults and enhanced by asparaginase-based chemotherapy, and venous thromboembolism introduces a secondary risk of treatment delay and premature discontinuation of key anti-leukaemic agents, potentially compromising survival. Yet, the trade-off between benefits and harms of primary thromboprophylaxis in adults with acute lymphoblastic leukaemia (ALL) treated according to asparaginase-based regimens is uncertain.  OBJECTIVES: The primary objectives were to assess the benefits and harms of primary thromboprophylaxis for first-time symptomatic venous thromboembolism in adults with ALL receiving asparaginase-based therapy compared with placebo or no thromboprophylaxis. The secondary objectives were to compare the benefits and harms of different groups of primary systemic thromboprophylaxis by stratifying the main results per type of drug (heparins, vitamin K antagonists, synthetic pentasaccharides, parenteral direct thrombin inhibitors, direct oral anticoagulants, and blood-derived products for antithrombin substitution)., Search Methods: We conducted a comprehensive literature search on 02 June 2020, with no language restrictions, including (1) electronic searches of Pubmed/MEDLINE; Embase/Ovid; Scopus/Elsevier; Web of Science Core Collection/Clarivate Analytics; and Cochrane Central Register of Controlled Trials (CENTRAL) and (2) handsearches of (i) reference lists of identified studies and related reviews; (ii) clinical trials registries (ClinicalTrials.gov registry; the International Standard Randomized Controlled Trial Number (ISRCTN) registry; the World Health Organisation's International Clinical Trials Registry Platform (ICTRP); and pharmaceutical manufacturers of asparaginase including Servier, Takeda, Jazz Pharmaceuticals, Ohara Pharmaceuticals, and Kyowa Pharmaceuticals), and (iii) conference proceedings (from the annual meetings of the American Society of Hematology (ASH); the European Haematology Association (EHA); the American Society of Clinical Oncology (ASCO); and the International Society on Thrombosis and Haemostasis (ISTH)). We conducted all searches from 1970 (the time of introduction of asparaginase in ALL treatment). We contacted the authors of relevant studies to identify any unpublished material, missing data, or information regarding ongoing studies., Selection Criteria: Randomised controlled trials (RCTs); including quasi-randomised, controlled clinical, cross-over, and cluster-randomised trial designs) comparing any parenteral/oral preemptive anticoagulant or mechanical intervention with placebo or no thromboprophylaxis, or comparing two different pre-emptive anticoagulant interventions in adults aged at least 18 years with ALL treated according to asparaginase-based chemotherapy regimens. For the description of harms, non-randomised observational studies with a control group were eligible for inclusion.  DATA COLLECTION AND ANALYSIS: Using a standardised data collection form, two review authors independently screened and selected studies, extracted data, assessed risk of bias for each outcome using standardised tools (RoB 2.0 tool for RCTs and ROBINS-I tool for non-randomised studies) and the certainty of evidence for each outcome using the GRADE approach. Primary outcomes included first-time symptomatic venous thromboembolism, all-cause mortality, and major bleeding. Secondary outcomes included asymptomatic venous thromboembolism, venous thromboembolism-related mortality, adverse events (i.e. clinically relevant non-major bleeding and heparin-induced thrombocytopenia for trials using heparins), and quality of life. Analyses were performed according to the guidelines of the Cochrane Handbook for Systematic Reviews of Interventions. For non-randomised studies, we evaluated all studies (including studies judged to be at critical risk of bias in at least one of the ROBINS-I domains) in a sensitivity analysis exploring confounding.  MAIN RESULTS: We identified 23 non-randomised studies that met the inclusion criteria of this review, of which 10 studies provided no outcome data for adults with ALL. We included the remaining 13 studies in the 'Risk of bias' assessment, in which we identified invalid control group definition in two studies and judged outcomes of nine studies to be at critical risk of bias in at least one of the ROBINS-I domains and outcomes of two studies at serious risk of bias. We did not assess the benefits of thromboprophylaxis, as no RCTs were included. In the main descriptive analysis of harms, we included two retrospective non-randomised studies with outcomes judged to be at serious risk of bias. One study evaluated antithrombin concentrates compared to no antithrombin concentrates. We are uncertain whether antithrombin concentrates have an effect on all-cause mortality (risk ratio (RR) 0.55, 95% confidence interval (CI) 0.26 to 1.19 (intention-to-treat analysis); one study, 40 participants; very low certainty of evidence). We are uncertain whether antithrombin concentrates have an effect on venous thromboembolism-related mortality (RR 0.10, 95% CI 0.01 to 1.94 (intention-to-treat analysis); one study, 40 participants; very low certainty of evidence). We do not know whether antithrombin concentrates have an effect on major bleeding, clinically relevant non-major bleeding, and quality of life in adults with ALL treated with asparaginase-based chemotherapy, as data were insufficient. The remaining study (224 participants) evaluated prophylaxis with low-molecular-weight heparin versus no prophylaxis. However, this study reported insufficient data regarding harms including all-cause mortality, major bleeding, venous thromboembolism-related mortality, clinically relevant non-major bleeding, heparin-induced thrombocytopenia, and quality of life. In the sensitivity analysis of harms, exploring the effect of confounding, we also included nine non-randomised studies with outcomes judged to be at critical risk of bias primarily due to uncontrolled confounding. Three studies (179 participants) evaluated the effect of antithrombin concentrates and six studies (1224 participants) evaluated the effect of prophylaxis with different types of heparins. When analysing all-cause mortality; venous thromboembolism-related mortality; and major bleeding (studies of heparin only) including all studies with extractable outcomes for each comparison (antithrombin and low-molecular-weight heparin), we observed small study sizes; few events; wide CIs crossing the line of no effect; and substantial heterogeneity by visual inspection of the forest plots. Although the observed heterogeneity could arise through the inclusion of a small number of studies with differences in participants; interventions; and outcome assessments, the likelihood that bias due to uncontrolled confounding was the cause of heterogeneity is inevitable. Subgroup analyses were not possible due to insufficient data.  AUTHORS' CONCLUSIONS: We do not know from the currently available evidence, if thromboprophylaxis used for adults with ALL treated according to asparaginase-based regimens is associated with clinically appreciable benefits and acceptable harms. The existing research on this question is solely of non-randomised design, seriously to critically confounded, and underpowered with substantial imprecision. Any estimates of effect based on the existing insufficient evidence is very uncertain and is likely to change with future research., (Copyright © 2020 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.)

Objective: As survival rates increase, growing numbers of childhood acute lymphoblastic leukemia (ALL) survivors are at risk for somatic and psychosocial late effects. Adolescent and young adult (AYA) survivors represent a distinct and vulnerable group. This study aimed to explore how AYA survivors of childhood ALL experience everyday life after cancer while adjusting to the potential impact of prior disease and treatment., Methods: Semi-structured interviews were performed with survivors aged 15-22 years. Criterion-based homogenous purposive sampling was used to identify similarities within the group. Data were analyzed using an inductive, thematic approach., Results: Data saturation occurred after 18 interviews. Identified themes included the post-chemo body, negotiating identities, and disruption. More than 80% reported physical or cognitive late effects, but survivors adapted to these and had a positive view on own health. However, a co-existing experience of frailty persisted. Social disruption during treatment had a negative impact on social relations even years following cure. Identity issues revolved around the paradox of seeking recognition for their cancer-related experiences, while also wanting to be treated like everyone else. Some participants aged 18-22 years experienced delayed reactions and a new, but unmet, need to process the past., Conclusions: AYA survivors of childhood ALL adapt well to their new life situations, but many experience ongoing cancer-related disruptions and experience not being fully understood. We suggest exploration and verbalization of these issues alongside somatic follow-up around the age of 16-18 years to support the AYA survivors during their transition into adulthood., (© 2020 John Wiley & Sons Ltd.)

Background: The toxic effect of chemotherapy on the gastrointestinal tract may lead to mucositis and is associated with the pathogenesis of other treatment-related complications. We hypothesized that nutrition supplementation with bovine colostrum, rich in bioactive factors, would ameliorate gastrointestinal toxicity and reduce the incidence of fever and infectious complications during induction treatment for childhood acute lymphoblastic leukemia (ALL)., Methods: Children with newly diagnosed ALL were included in a 2-center, randomized, double-blind, placebo-controlled clinical trial. Patients were randomized to receive a daily colostrum or placebo supplement during 4 weeks of induction treatment. Data on fever, bacteremia, need for antibiotics, and mucosal toxicity were prospectively collected. (Trial registration: www.clinicaltrials.gov NCT01766804)., Results: Sixty-two patients were included. No differences were found for the primary outcome (number of days with fever). No difference was observed for neutropenic fever, intravenous antibiotics, or incidence of bacteremia. Peak severity of oral mucositis was significantly reduced by colostrum (7/29 patients, 24% mild; 6/29, 21% moderate; 1/29, 3% severe) compared with placebo (12/31, 39% mild; 1/31, 3% moderate; 7/31, 23% severe) (P = 0.02). Among patients receiving at least 1 dose of supplement (colostrum: n = 22; placebo: n = 30), the peak weekly self-reported oral mucositis score was overall significantly less severe in the colostrum group (P = 0.009)., Conclusion: The use of prophylactic bovine colostrum showed no effect on fever, infectious morbidity, or inflammatory responses. Nevertheless, these data may suggest protective effects on the oral mucosa during induction therapy in childhood ALL, encouraging additional studies confirming these findings., (© 2019 American Society for Parenteral and Enteral Nutrition.)

Introduction: Children with cancer experience reduced physical fitness and compromised social relationships during and following intensive treatment. This may negatively impact their quality of life. As part of the RESPECT study, we explored the motivations for participation in a physical activity programme during treatment., Methods: Thirteen semi-structured interviews were conducted with seven boys and six girls, diagnosed with paediatric cancer in 2013 and treated with chemotherapy (age 8-16 years; time from diagnosis to interview 6-16 months). Interviews were conducted in the children's homes., Results: The qualitative analysis showed that children's motivations for engaging in the physical activity programme during intensive medical treatment were primarily influenced by (a) opportunity for physical activity with a classmate; (b) participation in group physical activity sessions; (c) support from significant others; and (d) improvement of physical well-being. Main barriers included (a) poor physical well-being; (b) compliance with medical procedures and being treated in protective isolation; and (c) limited physical activity facilities., Conclusion: Despite barriers, it is possible to motivate and engage children with cancer in physical activity during intensive treatment in a paediatric oncology ward. Physical exercise and activity should be recommended and promoted from diagnosis throughout the treatment period and should include psychosocial and professional support., (© 2019 John Wiley & Sons Ltd.)

Thiopurine methyltransferase (TPMT) activity exhibits a monogenic codominant inheritance and catabolizes thiopurines. TPMT variant alleles are associated with low enzyme activity and pronounced pharmacologic effects of thiopurines. Loss-of-function alleles in the NUDT15 gene are common in Asians and Hispanics and reduce the degradation of active thiopurine nucleotide metabolites, also predisposing to myelosuppression. We provide recommendations for adjusting starting doses of azathioprine, mercaptopurine, and thioguanine based on TPMT and NUDT15 genotypes (updates on www.cpicpgx.org)., (© 2018 The Authors Clinical Pharmacology & Therapeutics © 2018 American Society for Clinical Pharmacology and Therapeutics.)

With an impending introduction of genome sequencing into paediatric oncology to facilitate personalised medicine, this study examines parent perspectives on participating in whole genome sequencing (WGS) research in the difficult weeks following diagnosis. As an embedded part of Sequencing Tumor and Germline DNA-Implications and National Guidelines (STAGING), a project aiming to implement WGS of all newly diagnosed paediatric cancer patients in Denmark, a parent perspective study was conducted by a clinical geneticist and anthropologist to document pragmatic, social and ethical dilemmas. Following genetic counselling, systematic debriefings were held and the anthropologist carried out in-depth parent interviews (N = 30 parents to 15 patients). Parents were approached about STAGING 2-28 days after diagnosis. The majority of interviewed parents reported that an early approach had been feasible for them, a few found it too early. Participation was explained in terms of altruism and a desire to learn more about why their child had developed cancer. A number of parents openly disagreed about the amount of information they wanted reported back. Enrolment in WGS research around the time of diagnosis is feasible, however, flexibility from researchers is essential. Notwithstanding high participation rates and a tendency to choose full disclosure, caution as regards the consequences of participating in WGS research is warranted., (© 2018 John Wiley & Sons Ltd.)

Objectives: Extended hospitalization for school-aged cancer patients increases their risk of social marginalization. School-aged children mature through peer-interaction, but healthcare providers fail to incorporate this in rehabilitation efforts. The RESPECT study offers classmates to cancer patients to become ambassadors during hospital stays. This study explores classmate decision-making patterns about ambassadorship., Methods: An open-ended question was prospectively and consecutively provided to classmates (N = 221) (and parents) of 10 children diagnosed with cancer in 2014 and enrolled in the RESPECT study. Statements were analysed using thematic content analysis., Results: Of 221 classmates, 140 responded (63%). Of these, 81 applied for ambassadorship (median 8/patient), 58 declined, one was undecided. Nine forms were incomplete; leaving 131 in total that revealed 303 statements for analysis. Five major themes emerged: existing friendship (132/303 statements), personal resources (academic, emotional and social) (107/303), attitudes towards the ambassadorship (34/303), hospital environment (18/303) and logistics (12/303). Of the classmates with pre-existing friendships, 77% applied for ambassadorship and 80% with a surplus of personal resources applied. These were predominant predictors for ambassadorship application. Classmate motives were condensed into four archetypes: pre-existing friendship with a surplus of resources (100% applied), non-friend classmates with a surplus of resources (63% applied), pre-existing friendship with limited resources (22% applied) and non-friend classmates with limited resources (0% applied)., Conclusion: Classmates are highly motivated to support patients during serious illness, irrespective of pre-existing friendships. Ambassadors offer a novel in-hospital approach to promote rehabilitation in children with severe/chronic diseases. Results need validation in other settings. Copyright © 2016 John Wiley & Sons, Ltd., (Copyright © 2016 John Wiley & Sons, Ltd.)

Increased survival rates from childhood cancer call for efforts to reintegrate children with cancer back into their academic and social environments. The aims of this study were to: (1) review and analyse the existing literature on school re-entry interventions for children with cancer; and (2) discuss the importance of peer involvement in the treatment. Relevant databases were searched using equivalent search algorithms and six studies were selected that target children with cancer and/or their classmates. Two authors independently reviewed the literature for data extraction. The articles were reviewed using the PRISMA model for reporting reviews. Statistical calculations for the meta-analyses were done using Review Manager 5.2. The meta-analyses showed significant effects of school re-entry programmes in terms of enhancing academic achievement in children with cancer (P = 0.008) and lowering their levels of depression (P = 0.05). Increased knowledge among classmates was associated with less fear and a more positive attitude towards the child with cancer. Due to limited numbers of patients, lack of control groups, and the diversity of intervention strategies used in previous studies, there is a need for intervention programmes exploring the optimal path for the reintegration of children with cancer into the education system and into their peer groups., (© 2014 John Wiley & Sons Ltd.)

Childhood acute lymphoblastic leukaemia is treated with long-term intensive chemotherapy. During the latter part of the treatment, the maintenance therapy, the patients receive oral doses of two cytostatics. The doses are tailored to blood counts measured on a weekly basis, and the treatment is therefore highly dynamic. In 1992-1996, the Nordic Society of Paediatric Haematology and Oncology (NOPHO) conducted a randomised study (NOPHO-ALL-92) to investigate the effect of a new and more sophisticated dynamic treatment strategy. Unexpectedly, the new strategy worsened the outcome for the girls, whereas there were no treatment differences for the boys. There are as yet no general guidelines for optimising the treatment. On basis of the data from this study, our goal is to formulate an alternative dosing strategy. We use recently developed methods proposed by van der Laan et al. to obtain statistical models that may be used in the guidance of how the physicians should assign the doses to the patients to obtain the target of the treatment. We present a possible strategy and discuss the reliability of this strategy. The implementation is complicated, and we touch upon the limitations of the methods in relation to the formulation of alternative dosing strategies for the maintenance therapy., (Copyright © 2011 John Wiley & Sons, Ltd.)

The study aims to describe the experiences of a hospital-based home care programme in the families of children with cancer. Fourteen parents, representing 10 families, were interviewed about their experiences of a hospital-based home care programme during a 4-month period in 2009 at a university hospital in Denmark. Five children participated in all or part of the interview. The interviews were transcribed verbatim and analysed using qualitative content analysis. The findings indicate that hospital-based home care enabled the families to remain intact throughout the course of treatment, as it decreased the strain on the family and the ill child, maintained normality and an ordinary everyday life and fulfilled the need for safety and security. According to family members of children with cancer, hospital-based home care support enhanced their quality of life during the child's cancer trajectory. Our study highlights the importance of providing hospital-based home care with consideration for the family members' need for the sense of security achieved by home care by experienced paediatric oncology nurses and regular contact with the doctor. In future studies, interviews with children and siblings could be an important source of information for planning and delivering care suited to the families' perceived needs., (© 2011 Blackwell Publishing Ltd.)

Thiopurine methyltransferase (TPMT) activity exhibits monogenic co-dominant inheritance, with ethnic differences in the frequency of occurrence of variant alleles. With conventional thiopurine doses, homozygous TPMT-deficient patients (~1 in 178 to 1 in 3,736 individuals with two nonfunctional TPMT alleles) experience severe myelosuppression, 30-60% of individuals who are heterozygotes (~3-14% of the population) show moderate toxicity, and homozygous wild-type individuals (~86-97% of the population) show lower active thioguanine nucleolides and less myelosuppression. We provide dosing recommendations (updates at http://www.pharmgkb.org) for azathioprine, mercaptopurine (MP), and thioguanine based on TPMT genotype.

Background: Hepatotoxicity with elevation of aminotransferase levels is common during combined methotrexate and thiopurine therapy. However, the mechanism of hepatotoxicity induced by these drugs remains obscure. We have investigated the relationship of a rise in aminotransferase levels to erythrocyte levels of methotrexate and its polyglutamates, 6-thioguanine nucleotides, the major cytotoxic metabolites of 6-mercaptopurine, and methylated metabolites of 6-mercaptopurine generated by thiopurine methyltransferase in competition with the formation of 6-thioguanine nucleotides., Method: Weighted means of alanine aminotransferase levels and metabolites of methotrexate and 6-mercaptopurine were calculated from a total of 929 blood samples from 43 patients with acute lymphoblastic leukemia during maintenance therapy with methotrexate and 6-mercaptopurine., Results: Weighted means of aminotransferase levels were significantly related to the average doses of 6-mercaptopurine (r(s) = 0.60, P <.001), erythrocyte levels of methylated metabolites of 6-mercaptopurine (r(s) = 0.63, P <.001), and thiopurine methyltransferase activity (r(s) = 0.32, P =.03). Weighted means of aminotransferase levels were negatively correlated with erythrocyte levels of 6-thioguanine nucleotides and were not related to the average doses of methotrexate or erythrocyte levels of methotrexate and its polyglutamates., Conclusion: It was found that 6-mercaptopurine and its methylated metabolites are correlated with the degree of hepatotoxicity during methotrexate and 6-mercaptopurine maintenance therapy. Further studies are needed to explore whether aminotransferase levels could be used as a surrogate marker for methylated metabolites of 6-mercaptopurine and thus to evaluate 6-mercaptopurine treatment compliance.

Background: In contrast to chemotherapy, previous irradiation of the uterus carries an increased risk of an adverse pregnancy outcome. Conflicting results exist as regards the ability of the uterus to increase in volume following radiotherapy-induced damage. We measured uterine volume in a cohort of childhood cancer survivors, and assessed uterine response to a high-dose estrogen replacement regimen., Methods: Uterine volume was assessed by transvaginal sonography in 100 childhood cancer survivors. Three patients with ovarian failure and severely reduced uterine volume following abdominal or pelvic irradiation were treated with percutaneous estradiol 150 microg/24 h for three cycles, and transvaginal uterine sonography was repeated monthly., Results: Uterine volume was significantly reduced in nulliparous patients who had received direct uterine irradiation (n = 13; median 13 mL, range 1-52 mL) compared with nulliparous patients who had received chemotherapy only (n = 37; 47 mL, 22-88), radiotherapy above the diaphragm (n = 17; 40 mL, 24-61), or radiotherapy below the diaphragm not directly involving the uterus (n = 13; 34 mL, 8-77) (p < 0.02 in all comparisons). Among nulliparous patients a significant correlation was found between age at direct uterine irradiation and uterine volume (r = 0.78, p = 0.002). No significant improvement in uterine volume, endometrial thickness or uterine artery blood flow was observed in three hypogonadal patients in response to high-dose estrogen replacement therapy., Conclusions: Our results indicate that cytotoxic treatment in childhood does not affect adult uterine size. In contrast, uterine irradiation at a young age reduces adult uterine volume. The radiotherapy-induced damage is probably irreversible.

Background: 6-Mercaptopurine (6MP) has been regarded as nonleukemogenic, even though the cytotoxicity of 6MP depends on the incorporation of 6-thioguanine nucleotides (6TGN) into DNA. In hematopoietic cells this pathway competes with S-methylation catalyzed by thiopurine methyltransferase (TPMT). However, methylated 6MP metabolites inhibit purine de novo synthesis and thus may enhance incorporation of 6TGN into DNA. Approximately 10% of white individuals have low TPMT activity as a result of polymorphisms in the TPMT gene. The authors attempted to test the hypothesis that the degree of DNA damage during 6MP therapy might reflect variations in 6MP metabolism and pharmacokinetics., Methods: The authors measured TPMT activity as well as erythrocyte levels of 6TGN (E-6TGN) and methylated 6MP metabolites (E-MeMP) during 6MP therapy in 439 children with acute lymphoblastic leukemia, 5 of whom later developed secondary myelodysplasia or acute myeloid leukemia (sMDS/AML)., Results: The patients who developed sMDS/AML had significantly lower TPMT activity compared with the remaining patients (P = 0.03). The 55 patients with TPMT activity <14 U/mL red blood cells (RBC) (antimode of the bimodal distribution) had a 5-year risk of sMDS/AML of 9 +/- 6% versus 1 +/- 1% for the remaining patients (P = 0.002). Cox regression analysis identified TPMT activity and E-MeMP level as the strongest predictors of risk for sMDS/AML (global P value = 0.02). Patients with low TPMT activity and high E-MeMP levels had the highest risk. All 5 patients with sMDS/AML had E-6TGN and/or E-MeMP levels > the 90% percentiles or had TPMT activity < 14 U/mL RBC., Conclusions: These data demonstrate an increased leukemogenic risk when 6MP is administered with other cytotoxic agents in patients with low TPMT activity, and indicate that not only high 6TGN levels but also high levels of methylated metabolites may lead to DNA damage., (Copyright 1999 American Cancer Society.)

Thiopurine methyltransferase (TPMT) catalyzes the S-methylation of thiopurine drugs. TPMT activity is regulated by a common genetic polymorphism that is associated with large individual variations in thiopurine toxicity and efficacy. We previously cloned the functional gene for human TPMT and reported a common variant allele for low enzyme activity, TPMT*3A, that contains point mutations at cDNA nucleotides 460 and 719. In the present study, we set out to determine the number, types, and frequencies of TPMT variant alleles associated with low enzyme activity in clinical laboratory samples in the United States and to compare those results with data obtained from two different ethnic groups. We identified a total of six different variant alleles for low TPMT activity in the 283 clinical laboratory samples studied. The most common variant was *3A; the second most frequent variant allele, *3C, contained only the nucleotide 719 polymorphism; and four other variant alleles were detected. TPMT*3A also appeared to be the most common variant allele in a Norwegian white population sample, but it was not found in a population sample of Korean children. However, *3C was present in samples from the Korean children, as was novel allele, *6. Characterization of variant alleles for low TPMT enzyme activity will help make it possible to assess the potential clinical utility of deoxyribonucleic acid-based diagnostic tests for determining TPMT genotype.

Insulin-like growth factor-(IGF) II and IGF-I and IGF-II/mannose 6-phosphate receptors were expressed in a thoracopulmonary malignant small round cell tumor (MSRCT) from a 14-year-old boy. Northern analysis showed that the MSRCT expresses multiple IGF-II mRNA of 6.0, 4.8, 4.2, and 2.2 kilobase from promoters P3 and P4 of the human IGF-II gene. Chromatography and radioimmunoassay revealed two forms of IGF-II with molecular masses of 7.5 kilodalton (kDa) and 10 kDa, corresponding to mature IGF-II and IGF-II with a C-terminal extension, in concentrations of 61 and 41 ng/g/tumor tissue, respectively. By a combined reverse transcription-polymerase chain reaction analysis, the authors also show that the MSRCT expresses IGF-I and IGF-II/mannose 6-phosphate receptor mRNA. The plasma concentration of IGF-II was 600 ng/ml and within the normal range of serum IGF-II. IGF binding proteins (IGFBP) of 41.5, 38.5, 34, 30, and 24 kDa were present in serum. Compared with normal plasma from healthy subjects and an age-matched group of boys, the level of the 41.5, 38.5, and 30 kDa IGFBP were approximately 3-fold elevated. The authors conclude that transcription of the IGF-II gene leads to the production of significant amounts of 10 kDa IGF-II and 7.5 kDa IGF-II. IGF-II may stimulate the proliferation of MSRCT by interaction with IGF-I receptors on the cells.