Childhood cancer survival: a report from the United Kingdom Childhood Cancer Study

Cohort profile: the United Kingdom Childhood Cancer Study (UKCCS) - a UK-wide population-based study examining the health of cancer survivors

PURPOSE

The United Kingdom Childhood Cancer Study's (UKCCS's) matched cohort was established to examine the longer term morbidity and mortality of individuals previously diagnosed with cancer before 15 years of age, comparing future healthcare patterns in 5-year cancer survivors to baseline activity seen in age- and sex-matched individuals from the general population.

PARTICIPANTS

Predicated on a national childhood cancer case-control study conducted in the early 1990s (4430 cases, 9753 controls) in England, Scotland and Wales, the case population comprises 3125 cancer survivors (>5 years), and the control population 7156 age- and sex-matched individuals from the general population who did not have cancer as a child. Participants are now being followed up via linkage to national administrative healthcare databases (deaths, cancers and secondary care hospital activity).

FINDINGS TO DATE

Enabling the creation of cohorts with minimal selection bias and loss to follow-up, the original case-control study registered all newly diagnosed cases of childhood cancer and their corresponding controls, regardless of their family's participation. Early findings based on the registered case population found marked survival variations with age and sex across subtypes and differences with deprivation among acute lymphoblastic leukaemia (ALL) survivors. More recently, comparing the health-activity patterns of the case and control populations revealed that survivors of childhood ALL experienced excess outpatient and inpatient activity across their teenage/young adult years. Adding to increased risks of cancer and death and involving most clinical specialties, excesses were not related to routine follow-up monitoring and showed no signs of diminishing over time.

FUTURE PLANS

With annual linkage updates, the UKCCS's maturing population-based matched cohorts provide the foundation for tracking the health of individuals through their lifetime. Comparing the experience of childhood cancer survivors to that of unaffected general-population counterparts, this will include examining subsequent morbidity and mortality, secondary care hospital activity and the impact of deprivation on longer term outcomes.

Childhood Cancer Survival, 2006-2012 Cohorts of Mexican Institute of Social Security Beneficiaries at the Central-South Region of Mexico

Introduction

In Mexico, the main institution of social security is the “Instituto Mexicano del Seguro Social” (IMSS), with more than 60 million enrolled individuals. This study of childhood cancer survival is the first based on complete cohorts of incident cases for the population IMSS- affiliated in the central-south region, which represents 27% of all children IMSS affiliated.

Methods

It is an observational cohort study from 2006 to 2012 to estimate the 5-year observed survival of the minors under 18 years old, identified in the Central-South Region Registry of Children with Cancer. The survival of cases was carried out through the active and passive search. Survival rates were estimated by the Kaplan–Meier (KM) method, the analysis of equality of survival functions was evaluated for some clinical variables.

Results

The study included 2,357 minors; the 5-year observed survival was 56.1% with a time of survival median of 3.4 years, and the overall loss of follow-up was 18.4%. The 5-year survival in cases with a diagnosis of leukemia was 53.5%, while for solid tumors, it was 57.9%. The median time of death was 1 year. The types of cancer with a survival greater than 70% were group V-retinoblastoma (87.2%), IIa-Hodgkin’s lymphoma (86.8%), Xc- gonadal tumors (83.3%), Iid-miscellaneous lymphomas (80%), IVa-nephroblastoma (79.5%), and IIc-Burkitt’s lymphoma (75.4%). Meanwhile, the lowest survival rates were in group VIII-bone tumors (32.3%), III-CNS (central nervous system; 44.1%), and IX-soft tissues (46.8%).

Conclusions

Survival results in the 2006–2012 cohorts show a significant gap in relation to the goal of 60% proposed by the World Health Organization for 2030.

Excess morbidity and mortality among survivors of childhood acute lymphoblastic leukaemia: 25 years of follow-up from the United Kingdom Childhood Cancer Study (UKCCS) population-based matched cohort

OBJECTIVES

To examine morbidity and mortality among teenagers and young adults (TYAs) previously diagnosed with acute lymphoblastic leukaemia (ALL) in childhood, and compare to the general TYA population.

DESIGN

National population-based sex-matched and age-matched case-control study converted into a matched cohort, with follow-up linkage to administrative healthcare databases.

SETTING

The study population comprised all children (0-14 years) registered for primary care with the National Health Service (NHS) in England 1992-1996.

PARTICIPANTS

1082 5-year survivors of ALL diagnosed<15 years of age (1992-1996) and 2018 unaffected individuals; followed up to 15 March 2020.

MAIN OUTCOME MEASURES

Associations with hospital activity, cancer and mortality were assessed using incidence rate ratios (IRR) and differences.

RESULTS

Mortality in the 5-year ALL survivor cohort was 20 times higher than in the comparison cohort (rate ratio 21.3, 95% CI 11.2 to 45.6), and cancer incidence 10 times higher (IRR 9.9 95% CI 4.1 to 29.1). Hospital activity was increased for many clinical specialties, the strongest associations being for endocrinology; outpatient IRR 36.7, 95% CI 17.3 to 93.4 and inpatient 19.7, 95% CI 7.9 to 63.2 for males, and 11.0, 95% CI 6.2 to 21.1 and 6.2 95% CI 3.1 to 13.5, respectively, for females. Notable excesses were also evident for cardiology, neurology, ophthalmology, respiratory medicine and general medicine. Males were also more likely to attend gastroenterology; ear, nose and throat; urology; and dermatology, while females were more likely to be seen in plastic surgery and less likely in midwifery.

CONCLUSIONS

Adding to excess risks of death and cancer, survivors of childhood ALL experience excess outpatient and inpatient activity across their TYA years, which is not related to routine follow-up monitoring. Involving most clinical specialties, associations are striking, showing no signs of diminishing over time. Recognising that all survivors are potentially at risk of late treatment-associated effects, our findings underscore the need to take prior ALL diagnosis into account when interpreting seemingly unrelated symptoms later in life.

IKZF1 Rs4132601 Polymorphism and Susceptibility to Acute Lymphocytic Leukemia in Children: A Meta-analysis

BACKGROUND

Many studies have shown that IKAROS family zinc finger 1 (IKZF1) rs4132601 polymorphism is strongly linked to acute lymphoblastic leukemia (ALL) in children, but their conclusions have been inconsistent.

OBJECTIVE

This meta-analysis is set out to investigate the association between IKZF1 rs4132601 polymorphism and its susceptibility to childhood ALL.

DATA AND METHODS

On the basis of inclusion criteria, PubMed, EMBASE, Web of Science, CNKI, China Wanfang, VIP, and other databases were searched from the time of the establishment of the library database to December 2019 for all case-control studies. Stata 15.0 was applied for meta-analysis to calculate the combined odds ratio (OR) value and 95% confidence interval (CI) of each genotype at IKZF1 rs4132601. Subgroup analysis done by ethnicity, sensitivity analysis, and publication bias assessment was further performed.

RESULTS

Nine pieces of literature was included in this meta-analysis, including 2281 children with ALL and 2923 controls. There were significant differences in the allelic model (T vs. G: combined OR=0.75, 95% CI: 0.68-0.82, P<0.05) in both Asian and Caucasian children. In addition to this, there were statistically significant differences in the dominant, homozygous and heterozygous genetic model in both Asian and Caucasian children. The difference was significant in the recessive genetic model (TT vs. TG+GG: combined OR=0.75, 95% CI: 0.67-0.84) in Caucasian children, but not in Asian children (combined OR=0.85, 95% CI: 0.70-1.04, P>0.05).

CONCLUSION

There is a strong correlation between IKZF1 rs4132601 polymorphism and ALL in children. Compared with the G allele, T alleles can lower the risk of childhood ALL, and TT, TT+TG and TG genotypes can also reduce the risk of ALL in children.

A ten-year study of Retinoblastoma in Uganda: An approach to improving outcome with limited resources

BACKGROUND

Survival of children with cancer in resource-limited regions is very poor compared to better-resourced regions. Retinoblastoma (RB) is a childhood cancer that is commonly reported in many regions of Africa. RB may be safely and effectively treated by non-specialists, which could facilitate more widespread availability of treatment in under-resourced areas.

METHODS

A ten-year consecutive series of children with RB treated at Ruharo Eye Centre between December 2009 and November 2019 was prospectively followed up. Chemoreduction followed by surgery is the standard approach to therapy. Costs of therapy and also of travel and food are borne by the program which is unaffordable to most families and necessitates donors. Survival by stage of RB and number of eyes affected was described using Kaplan-Meier plots. Visual acuity was assessed for all children with bilateral disease and the retention of sight during follow-up assessed.

RESULTS

Among 665 children with RB, 18.2 % (121 children) presented with metastatic (Stage 4) RB with only two of these children surviving >24 months. Five-year survival was 60.2 % among all children with RB rising to 93.3 % and 87.2 % for children with unilateral and bilateral Stage 1 disease, respectively. Among 184 children with bilateral disease, 130 (70.7 %) retained some level of sight following primary treatment with 91 of those (49.5 % of all bilateral children) retaining vision up to their death or to the end of follow-up.

CONCLUSION

Many children in Uganda present with advanced RB and curative treatment is not possible in this setting. Children diagnosed and treated early have good prospects of survival. Retention of sight among many bilaterally affected children is achievable, facilitating access to normal education. Therefore, the strategic priorities for improving survival are changing community perceptions so that children with eye problems are brought without delay, and widening access to modern treatment by using genereal health workers with standard drugs, backed by financial, social and peer support.

Influence of plasma methotrexate level and MTHFR genotype in Korean paediatric patients with acute lymphoblastic leukaemia

Whether plasma MTX concentrations and MTHFR C677T and A1298C polymorphisms could be used as a predictor of occurrence of MTX-related toxicities in Korean paediatric patients with acute lymphoblastic leukaemia (ALL) were assessed. HD-MTX related toxicities, MTHFR polymorphisms and MTX plasma concentrations following 337 HD-MTX cycles to 117 children with ALL on maintenance therapy were analyzed. A significantly higher frequency of hyperbilirubinemia (P = 0.0443) and renal toxicity (P = 0.0107) were associated with high MTX concentrations by Fisher's exact test. Moreover, high MTX concentrations at 24 h, 48, and 72 h were significantly associated with increased frequency of vomiting (P < 0.05) and hyperbilirubinemia (P < 0.05) by Mann-Whitney U test. There was a significantly higher frequency of mucositis in patients with the MTHFR 677 TT genotype (P = 0.0273) and a significantly higher frequency of MTX dose reduction in patients with the 677 TT genotype (P = 0.0217), compared to the CC/CT genotype. Independently, plasma MTX concentrations and MTHFR C677T genotype could be useful markers for tailoring MTX dosing and monitoring adverse effects in childhood ALL HD-MTX therapy in Korean patients.

Social Inequalities Along the Childhood Cancer Continuum: An Overview of Evidence and a Conceptual Framework to Identify Underlying Mechanisms and Pathways

Inequalities in health according to social conditions are regarded as unnecessary and unjust. There is a large body of evidence on inequalities in adult cancer, observable throughout the societies on a national level as well as on a global scale. Socioeconomic influences on health matter at all ages including childhood, for which childhood cancer is the leading cause of disease related death in high-income countries (HICs). Substantial differences in the reported incidence of childhood cancers have been observed globally by socioeconomic development of a population. This is reflected in the higher incidence rates reported for HICs, particularly for acute lymphoblastic leukemia, and for cancer in infants (below 1 year), compared to low- and middle-income countries (LMICs). Considerable inequalities between populations and degree of socioeconomic development are also noted for survival from childhood cancer, with substantially lower survival rates seen in most LMICs compared to HICs. With respect to inequalities by socioeconomic position (SEP) within countries, findings of an association between SEP and childhood cancer risk are diverse and limited to studies from HICs. On the contrary, observations on social inequalities in survival within countries are accumulating and indicate that survival inequalities do not only concern resource-poor countries but also high-income populations including European countries. In turn, a childhood cancer diagnosis in itself may have implications on the parents' socioeconomic situation as well as on the later socioeconomic life after having survived the disease. The underlying mechanisms and causal pathways of these empirically demonstrated social inequalities are poorly understood, although it is of significant public health relevance for any actions or strategies to reduce childhood cancer-related inequity. We propose a conceptual framework on potential underlying mechanism and pathways specifically addressing social inequalities in childhood cancer and after childhood cancer to (i) illustrate potential pathways by which social determinants may create health inequities at different points of the childhood cancer continuum; (ii) illustrate potential pathways by which a childhood cancer diagnosis may impact the socioeconomic situation of the concerned family or the later life of a childhood survivor; and (iii) point out how major determinants may relate to each other.

Involvement of miRNA polymorphism in mucositis development in childhood acute lymphoblastic leukemia treatment

Aim: Mucositis, linked to methotrexate, daunorubicin or cyclophosphamide, is a frequent childhood acute lymphoblastic leukemia (ALL) therapy side effect. miRNAs regulate the expression of pharmacokinetic/pharmacodynamic pathway genes. SNPs in miRNAs could affect their levels or function, and affect their pharmacokinetic/pharmacodynamic pathway target genes. Our aim was to determine the association between miRNA genetic variants targeting mucositis-related genes and mucositis-developing risk. Patients & methods: We analyzed 160 SNPs in 179 Spanish children with B-cell precursor ALL homogeneously treated with LAL/SHOP protocols. Results: We identified three SNPs in miR-4268, miR-4751 and miR-3117 associated with mucositis, diarrhea and vomiting, respectively. Conclusion: The effect of these SNPs on genes related to drug pharmacokinetics/pharmacodynamics could explain mucositis, diarrhea and vomiting development during ALL therapy.

Pharmacoepigenetics in childhood acute lymphoblastic leukemia: involvement of miRNA polymorphisms in hepatotoxicity

AIM

Hepatotoxicity is one of the most common drug-related toxicities during the treatment of childhood acute lymphoblastic leukemia (ALL). Many genes involved in liver-specific signaling pathways are tightly controlled by miRNAs, and miRNA function could be modulated by SNPs. As a consequence, we hypothesized that variants in miRNAs could be associated with drug-induced hepatotoxicity.

METHODS

We analyzed 213 SNPs in 206 miRNAs in a cohort of 179 children with ALL homogeneously treated.

RESULTS

rs2648841 in miR-1208 was the most significant SNP during consolidation phase after false discovery rate correction, probably through an effect on its target genes DHFR, MTR and MTHFR.

CONCLUSION

These results point out the possible involvement of SNPs in miRNAs in toxicity to chemotherapy in children with ALL.

Role of miRNAs in treatment response and toxicity of childhood acute lymphoblastic leukemia

Childhood acute lymphoblastic leukemia survival rates have increased remarkably during last decades due, in part, to intensive treatment protocols. However, therapy resistance and toxicity are still two important barriers to survival. In this context, pharmacoepigenetics arises as a tool to identify new predictive markers, required to guide clinicians on risk stratification and dose individualization. The present study reviews current evidence about miRNA implication on childhood acute lymphoblastic leukemia therapy resistance and toxicity. A total of 12 studies analyzing differential miRNA expression in relation to drug resistance and six studies exploring the association between miRNAs-related SNPs and drug-induced toxicities were identified. We pointed out to miR-125b together with miR-99a and/or miR-100 overexpression as markers of vincristine resistance and rs2114358 in mir-1206 as mucositis marker as the most promising results.

Mir-pharmacogenetics of Vincristine and peripheral neurotoxicity in childhood B-cell acute lymphoblastic leukemia

Vincristine (VCR), an important component of childhood acute lymphoblastic leukemia (ALL) therapy, can cause sensory and motor neurotoxicity. This neurotoxicity could lead to dose reduction or treatment discontinuation, which could in turn reduce survival. In this line, several studies associated peripheral neurotoxicity and polymorphisms in genes involved in pharmacokinetics (PK) and pharmacodynamics (PD) of VCR. Nowadays, it is well known that these genes are regulated by microRNAs (miRNAs) and SNPs in miRNAs could modify their levels or function. Therefore, the aim of this study was to determine whether SNPs in miRNAs could be associated with VCR-induced neurotoxicity. To achieve this aim, we analyzed all the SNPs in miRNAs (minor allele frequency (MAF) ≥ 0.01) which could regulate VCR-related genes in a large cohort of Spanish children with B-cell precursor ALL (B-ALL) homogeneously treated with LAL/SHOP protocols. We identified the A allele of rs12402181 in the seed region of miR-3117-3p, that could affect the binding with ABCC1 and RALBP1 gene, and C allele of rs7896283 in pre-mature sequence of miR-4481, which could be involved in peripheral nerve regeneration, significantly associated with VCR-induced neurotoxicity. These findings point out the possible involvement of two SNPs in miRNA associated with VCR-related neurotoxicity.

MTHFR polymorphisms in childhood acute lymphoblastic leukemia: influence on methotrexate therapy

Methotrexate (MTX) is an important component in the therapy used to treat childhood acute lymphoblastic leukemia (ALL). Methylenetetrahydrofolate reductase (MTHFR) is a key enzyme for MTX pharmacokinetics. Two single-nucleotide polymorphisms in MTHFR gene, C677T and A1298C, affecting MTHFR activity, have been widely studied as potential markers of MTX toxicity and/or outcome in pediatric ALL. In this review, we show that the majority of published reports do not find association or present opposite effect. Therefore, MTHFR C677T and A1298C polymorphisms do not seem to be good markers of MTX-related toxicity and/or outcome in pediatric ALL. The efforts should be focused on other genes, such as transporter genes or microRNA-related genes.

MTHFR gene polymorphisms and methotrexate toxicity in adult patients with hematological malignancies: a meta-analysis

Background: MTHFR gene polymorphisms has been shown to be associated with methotrexate (MTX) toxicity in adult hematological malignancies; however, the results remain inconclusive. Materials & methods: To examine the role of common MTHFR variants in MTX toxicity prediction, we performed a meta-analysis via identifying relevant studies for quantitative data pooling. Results: Our results showed a significant association between MTHFR C677T polymorphism and increased risk of MTX-induced all-grade (grade 1–4) and severe (grade 3–4) hepatic and gastrointestinal toxicities in Caucasian independent of MTX dosage. MTHFR 677T allele increased risk of severe mucositis and all-grade hematological toxicity. MTHFR A1298C polymorphism was not significantly associated with hepatic and hematological toxicity, whereas perhaps having a protective effect on mucositis and gastrointestinal toxicity. Conclusion: MTHFR C677T polymorphism may be a good predictor for MTX toxicity in adult hematological malignancies.

Sperm cryopreservation in adolescents and young adults with cancer: results of the French national sperm banking network (CECOS)

OBJECTIVE

To determine the feasibility of fertility preservation in adolescent males with cancer.

DESIGN

Large multicenter retrospective study of male patients ≤20 years from 23 centers of a national network of sperm banks over a 34-year period.

SETTING

Sperm banks.

PATIENT(S)

A total of 4,345 boys and young men aged 11 to 20 years.

INTERVENTION(S)

Age, cancer diagnosis, feasibility of sperm banking, and sperm parameters.

MAIN OUTCOME MEASURE(S)

Description of patients, and success of their fertility preservation.

RESULT(S)

We observed a mean yearly increase in referred patients of 9.5% (95% confidence interval, 9.1%-9.8%) between 1973 and 2007. Over the study period, the percentage of younger cancer patients who banked their sperm increased, especially in the 11-14 year age group, rising from 1% in 1986 to 9% in 2006. We found that 4,314 patients attempted to produce a semen sample, 4,004 succeeded, and sperm was banked for 3,616. The mean total sperm count was 61.75 × 10(6) for the 11-14 year age group, and 138.81 × 10(6) for the 18-20 year age group. It was noteworthy that intercenter variations in practices involving young patients seeking to preserve their fertility before cancer therapy were observed within this national network.

CONCLUSION(S)

Our results emphasize the need for decisive changes in public health policy to facilitate the access to reproductive health-care for young cancer patients.

Pharmacogenetics of microRNAs and microRNAs biogenesis machinery in pediatric acute lymphoblastic leukemia

Despite the clinical success of acute lymphoblastic leukemia (ALL) therapy, toxicity is frequent. Therefore, it would be useful to identify predictors of adverse effects. In the last years, several studies have investigated the relationship between genetic variation and treatment-related toxicity. However, most of these studies are focused in coding regions. Nowadays, it is known that regions that do not codify proteins, such as microRNAs (miRNAs), may have an important regulatory function. MiRNAs can regulate the expression of genes affecting drug response. In fact, the expression of some of those miRNAs has been associated with drug response. Genetic variations affecting miRNAs can modify their function, which may lead to drug sensitivity. The aim of this study was to detect new toxicity markers in pediatric B-ALL, studying miRNA-related polymorphisms, which can affect miRNA levels and function. We analyzed 118 SNPs in pre-miRNAs and miRNA processing genes in association with toxicity in 152 pediatric B-ALL patients all treated with the same protocol (LAL/SHOP). Among the results found, we detected for the first time an association between rs639174 in DROSHA and vomits that remained statistically significant after FDR correction. DROSHA had been associated with alterations in miRNAs expression, which could affect genes involved in drug transport. This suggests that miRNA-related SNPs could be a useful tool for toxicity prediction in pediatric B-ALL.

Polymorphisms of MTHFR Associated with Higher Relapse/Death Ratio and Delayed Weekly MTX Administration in Pediatric Lymphoid Malignancies

Backgrounds. Outcome of childhood malignancy has been improved mostly due to the advances in diagnostic techniques and treatment strategies. While methotrexate (MTX) related polymorphisms have been under investigation in childhood malignancies, many controversial results have been offered. Objectives. To evaluate associations of polymorphisms related MTX metabolisms and clinical course in childhood lymphoid malignancies. Method. Eighty-two acute lymphoblastic leukemia and 21 non-Hodgkin's lymphoma children were enrolled in this study. Four single nucleotide polymorphisms in 2 genes (MTHFR (rs1801133/c.677C>T/p.Ala222Val and rs1801131/c.1298A>C/p.Glu429Ala) and SLCO1B1 (rs4149056/c.521T>C/p.V174A and rs11045879/c.1865+4846T>C)) were genotyped by Taqman PCR method or direct sequencing. Clinical courses were reviewed retrospectively. Results. No patient who had the AC/CC genotype of rs1801131 (MTHFR) had relapsed or died, in which distribution was statistically different among the AA genotype of rs1801131 (P = 0.004). Polymorphisms of SLCO1B1 (rs11045879 and rs4149056) were not correlated with MTX concentrations, adverse events, or disease outcome. Conclusions. Polymorphisms of MTHFR (rs1801131) could be the plausive candidate for prognostic predictor in childhood lymphoid malignancies.

Intron 3 of the ARID5B gene: a hot spot for acute lymphoblastic leukemia susceptibility

PURPOSE

Single-nucleotide polymorphisms (SNPs) in AT-rich interactive domain 5B (ARID5B) have been associated with risk for pediatric acute lymphoblastic leukemia (ALL). After reviewing previous studies, we realized that the most significant associations were restricted to intron 3, but the mechanism(s) by which those SNPs affect ALL risk remain to be elucidated. Therefore, the aim of this study was to analyze the association between genetic variants of the intron 3 region of ARID5B and the incidence of B-ALL in a Spanish population. We also aimed to find a functional explanation for the association, searching for copy number variations (CNVs), and changes in ARID5B expression associated with the genotypes of the SNPs.

METHODS

We analyzed 10 SNPs in intron 3 of ARID5B in a Spanish population of 219 B-ALL patients and 397 unrelated controls with the Taqman Open Array platform. CNVs were analyzed in 23 patients and 17 controls using the Cytogenetics Whole-genome 2.7 M platform. Expression of ARID5B transcript 1 was quantified by qPCR and related to SNPs genotype in seven ALL cell lines.

RESULTS

Association between intron 3 and B-ALL risk was confirmed for all of the SNPs evaluated in our Spanish population. We could not explain this association by the presence of CNVs. We neither detected changes in the expression of ARID5B isoform associated with the genotype of the SNPs.

CONCLUSIONS

The intron 3 of ARID5B gene was found to be strongly associated with B-ALL risk in the Spanish population examined. However, neither CNVs nor changes in mRNA expression were found to be responsible for this association.

Effect of treatment for paediatric cancers on balance: what do we know? A review of the evidence

This review aims to explore the literature investigating balance outcomes in survivors of childhood cancer. A structured search of five databases resulted in 16 articles included in this review. Nearly all were classified as Level 4 evidence using the updated Oxford Centre for Evidence-Based Medicine Levels of Evidence. Balance abilities have been investigated solely in survivors of acute lymphoblastic leukaemia or central nervous system tumours. The literature tends to support the idea that survivors present with balance difficulties but the results need to be closely scrutinised. Several studies report results using the same experimental group, while other studies use balance outcome measures that have not had their psychometric properties assessed with this population. There are also few studies that evaluate dynamic balance abilities in survivors of paediatric cancers, which may be more influential on functional tasks. Furthermore, very few of the included studies investigate how the found balance deficits affect this population's daily lives, which would be necessary in order to determine if intervention should be geared towards this area. Directions for future research should also include multi-centred, clinically oriented trials to evaluate balance abilities in survivors of childhood cancers compared with healthy control subjects in order to strengthen the literature.

A systematic review and meta-analysis of MTHFR polymorphisms in methotrexate toxicity prediction in pediatric acute lymphoblastic leukemia

Methotrexate (MTX) is an important component of therapy used to treat childhood acute lymphoblastic leukemia (ALL). Two single-nucleotide polymorphisms (SNPs) in the methylenetetrahydrofolate reductase (MTHFR) gene, C677T and A1298C, affect MTHFR activity. A large body of studies has investigated the potential role of MTHFR SNPs in MTX toxicity in pediatric ALL. However, the results are controversial. In this review and meta-analysis, we critically evaluate the relationship between the C677T and A1298C polymorphisms of MTHFR and MTX toxicity in pediatric ALL. The majority of published reports do not find associations between MTHFR polymorphisms and toxicity in pediatric ALL. When associations are reported, often the results are contradictory to each other. The meta-analysis confirms a lack of association. In conclusion, MTHFR, C677T and A1298C polymorphisms do not seem to be good markers of MTX-related toxicity in pediatric ALL.

Population-based survival for childhood cancer patients diagnosed during 2002-2005 in Shanghai, China

BACKGROUND

There have been no population-based studies on cancer survival among children aged 0-14 years in China. In this study, we aimed to characterize the cancer survival among children in Shanghai.

PROCEDURE

Childhood cancer cases registered by the Shanghai Cancer Registry between 2002 and 2005 and enrolled in the Shanghai Childhood Survival Study were included in this study. We used Kaplan-Meier product-limit method for survival analysis and Cox proportional hazards models for investigating the effects of various prognostic factors.

RESULTS

The median follow-up time was 5.4 years (range 0-8.9 years). The 5-year observed survival for all childhood cancers combined was 55.7% (95% CI: 51.7-59.6%). For leukemia, lymphoma, and central nervous system tumors, the three most common types of childhood cancer, 5-year survival rates were 52.2%, 58.8%, and 41.2%, respectively. Higher 5-year survival rates were observed for epithelial cancer (88.9%), malignant renal tumors (86.7%), germ cell and other gonadal tumors (78.4%), and retinoblastoma (75.0%). Cancers with poor prognosis included sympathetic nervous system tumors (57.9%), soft tissue sarcoma (54.1%), bone tumors (52.6%), and liver cancer (33.3%). There were no significant differences between survival rates by gender and age groups. Compared with those reported in the USA and Europe, the survival rates for all cancers combined and the three most common types in Shanghai were lower.

CONCLUSIONS

The survival rate for children aged 0-14 diagnosed with cancer in Shanghai during 2002-2005 was at the medium level. There was a substantial survival difference from childhood cancers between Shanghai and specific developed countries.

Polymorphisms of the SLCO1B1 gene predict methotrexate-related toxicity in childhood acute lymphoblastic leukemia

BACKGROUND

Methotrexate (MTX) is an important component of the therapy for childhood acute lymphoblastic leukemia. Treatment with high-dose MTX often causes toxicity, recommending a dose reduction and/or cessation of treatment. Polymorphisms in genes involved in the MTX metabolism have been associated with toxicity with controversial results. The discrepancies could be due to differences in treatment protocols among studies, small, or non-homogeneous populations or the use of different toxicity criteria. The aim of the present study was to analyze the possible correlation of polymorphisms of genes involved in the MTX metabolism with the toxicity during therapy with the well-established LAL/SHOP protocol.

PROCEDURE

We analyzed 10 polymorphisms in seven genes (MTHFR, TS, SHMT1, RFC1, ABCB1, ABCG2, and SLCO1B1) from the MTX metabolism in 115 Spanish pediatric B-ALL patients, using MTX plasma concentration as an objective and quantifiable marker of toxicity.

RESULTS

We confirmed the suitability of MTX plasma levels as a toxicity marker. We found a statistically significant association between MTX plasma concentration and the SLCO1B1 rs11045879 CC genotype (P = 0.030). The rs4149081 AA genotype, in the same gene, could also be an indicator for high-MTX plasma concentrations. We did not find any significant association in the other genetic polymorphisms analyzed.

CONCLUSIONS

Identification of the rs4149081 and rs11045879 SLCO1B1 polymorphisms in children with ALL could be a useful tool for monitoring patients at risk of low-MTX clearance in order to avoid MTX-related toxicity.

Survival from childhood cancer in northern England, 1968-2005

Background:

Cancer is the second most common cause of death in children in the developed world. The study investigated patterns and trends in survival from childhood cancer in patients from northern England diagnosed 1968–2005.

Methods:

Five-year survival was analysed using Kaplan–Meier estimation for four successive time periods. Cox regression analysis was used to explore associations with age and demographic factors.

Results:

The study included 2958 cases (1659 males and 1299 females). Five-year survival for all cancers improved significantly from 39% in 1968–1977 to 79% in 1998–2005 (P<0.001). Five-year survival for leukaemia increased from 24% to 81% (P<0.001), lymphoma from 46% to 87% (P<0.001), central nervous system tumours from 43% to 73% (P<0.001), bone tumours from 21% to 75% (P<0.001), soft tissue sarcoma from 30% to 58% (P<0.001) and germ cell tumours from 59% to 97% (P<0.001). Survival was worse for cases of acute lymphoblastic leukaemia (P<0.001) and astrocytoma (P<0.001) aged 10–14 years compared with 0–4-year olds.

Conclusion:

There were marked improvements in survival over a 38-year time span. Future work should examine factors that could influence further improvement in survival such as diagnosis delays.

The novel calicheamicin-conjugated CD22 antibody inotuzumab ozogamicin (CMC-544) effectively kills primary pediatric acute lymphoblastic leukemia cells

We investigated whether the newly developed antibody (Ab) -targeted therapy inotuzumab ozogamicin (CMC-544), consisting of a humanized CD22 Ab linked to calicheamicin, is effective in pediatric primary B-cell precursor acute lymphoblastic leukemia (BCP-ALL) cells in vitro, and analyzed which parameters determine its efficacy. CMC-544 induced dose-dependent cell kill in the majority of BCP-ALL cells, although IC(50) values varied substantially (median 4.8 ng/ml, range 0.1-1000 ng/ml at 48 h). The efficacy of CMC-544 was highly dependent on calicheamicin sensitivity and CD22/CMC-544 internalization capacity of BCP-ALL cells, but hardly on basal and renewed CD22 expression. Although CD22 expression was essential for uptake of CMC-544, a repetitive loop of CD22 saturation, CD22/CMC-544 internalization and renewed CD22 expression was not required to achieve intracellular threshold levels of calicheamicin sufficient for efficient CMC-544-induced apoptosis in BCP-ALL cells. This is in contrast to studies with the comparable CD33 immunotoxin gemtuzumab ozogamicin (Mylotarg) in acute myeloid leukemia (AML) patients, in which complete and prolonged CD33 saturation was required for apoptosis induction. These data suggest that CMC-544 treatment may result in higher response rates in ALL compared with response rates obtained in AML with Mylotarg, and that therefore clinical studies in ALL, preferably with multiple low CMC-544 dosages, are warranted.