Childhood leukemia and lymphoma: time trends and factors affecting survival in five Southern and Eastern European Cancer Registries

Real-World Outcomes of Adolescents and Young Adults with Diffuse Large B-Cell Lymphoma: A Multicenter Retrospective Cohort Study

Purpose: Patients with diffuse large B-cell lymphoma (DLBCL) are typically treated with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP). However, a standard of care for managing adolescents and young adults (AYAs) with DLBCL is lacking. We examine treatment approaches and outcomes of this population. Methods: We included 90 AYAs (15-39 years) diagnosed with DLBCL between 2008 and 2018 in three tertiary centers in Peru. Overall response rates (ORR) were available for all patients. Overall survival (OS) and progression-free survival (PFS) rates were estimated using the Kaplan-Meier method. Results: The median age at diagnosis was 33 years, 57% were males, 57% had good performance status (Lansky/Karnofsky ≥90), and 61% were diagnosed with early-stage disease (Ann Arbor stages I-II). R-CHOP (n = 69, 77%) was the most frequently used first-line regimen, with an ORR of 91%. With a median follow-up of 83 months, the 5-year OS and PFS among all patients were 79% and 67%, respectively. Among the patients who received R-CHOP, the 5-year OS and PFS were 77% and 66%, respectively. Of the 29 (32%) patients with relapsed/refractory (R/R) disease, 83% received second-line treatment and only 14% underwent consolidation therapy with autologous transplantation. The 3-year OS for R/R DLBCL was 36%. Conclusion: Our data show that AYAs with DLBCL who received conventional therapy had comparable outcomes to those observed in studies conducted among the adult population. However, the prognosis for AYAs with R/R disease was dismal, indicating the unmet need for developing and increasing access to novel treatment modalities in AYAs.

Incidence and time trends of childhood hematological neoplasms: a 36-year population-based study in the southern European context, 1983-2018

BACKGROUND

Hematological neoplasms (HNs) are the first and most common childhood cancers globally. Currently, there is a lack of updated population-based data on the incidence of these cancers in the Spanish pediatric population. This study aimed to describe the incidence and incidence trends of HNs in children (0-14 years) in Spain using data from the Spanish Network of Cancer Registries and to compare the results with other southern European countries.

METHODS

Data were extracted from 15 Spanish population-based cancer registries between 1983 and 2018. Cases were coded according to the International Classification of Diseases for Oncology, third edition, first revision, and grouped according to the International Classification of Childhood Cancer, third edition. Crude rates (CRs), age-specific rates, and age-standardized incidence rates using the 2013 European population (ASRE) were calculated and expressed as cases per 1,000,000 child-years. Incidence trends and annual percentage changes (APCs) were estimated.

RESULTS

A total of 4,747 HNs were recorded (59.5% boys). Age distribution [n (%)] was as follows: <1 year, 266 (5.6%); 1-4 years, 1,726 (36.4%); 5-9 years, 1,442 (30.4%); and 10-14 years, 1,313 (27.6%). Leukemias were the most common group, with a CR and an ASRE of 44.0 (95%CI: 42.5; 45.5) and 44.1 (95%CI: 42.6; 45.7), respectively. The CR and ASRE of lymphomas were 20.1 (95%CI: 19.1; 21.1) and 20.0 (95%CI: 19.0; 21.1), respectively. The comparable incidence rates between our results and those of other southern European countries were similar for lymphomas, while some differences were observed for leukemias. From 1988 to 2016, the trend in leukemia incidence was stable for both sexes, with an APC of 0.0 (95%CI: -0.5; 0.7), whereas a constant overall increase was observed for lymphoma in both sexes, with an APC of 1.0 (95%CI: 0.4; 1.6).

CONCLUSION

Leukemias are the most common HNs in children, and their incidence has remained stable since 1988, whereas the incidence of lymphomas has increased every year. Lymphoma incidence is like that of other southern European countries, while leukemia incidence is similar only to that of southwestern European countries. Collaborative cancer registry projects allow for assessing epidemiological indicators for cancers such as HNs, which helps health authorities and clinicians provide more knowledge about these malignancies.

Prognostic Factors for Cardiotoxicity among Children with Cancer: Definition, Causes, and Diagnosis with Omics Technologies

Improvements in the treatment of childhood cancer have considerably enhanced survival rates over the last decades to over 80% as of today. However, this great achievement has been accompanied by the occurrence of several early and long-term treatment-related complications major of which is cardiotoxicity. This article reviews the contemporary definition of cardiotoxicity, older and newer chemotherapeutic agents that are mainly involved in cardiotoxicity, routine process diagnoses, and methods using omics technology for early and preventive diagnosis. Chemotherapeutic agents and radiation therapies have been implicated as a cause of cardiotoxicity. In response, the area of cardio-oncology has developed into a crucial element of oncologic patient care, committed to the early diagnosis and treatment of adverse cardiac events. However, routine diagnosis and the monitoring of cardiotoxicity rely on electrocardiography and echocardiography. For the early detection of cardiotoxicity, in recent years, major studies have been conducted using biomarkers such as troponin, N-terminal pro b-natriuretic peptide, etc. Despite the refinements in diagnostics, severe limitations still exist due to the increase in the above-mentioned biomarkers only after significant cardiac damage has occurred. Lately, the research has expanded by introducing new technologies and finding new markers using the omics approach. These new markers could be used not only for early detection but also for the early prevention of cardiotoxicity. Omics science, which includes genomics, transcriptomics, proteomics, and metabolomics, offers new opportunities for biomarker discovery in cardiotoxicity and may provide an understanding of the mechanisms of cardiotoxicity beyond traditional technologies.

Leukemia mortality in children from Latin America: trends and predictions to 2030

Background

Reports suggest that Latin American and Caribbean (LAC) countries have not reduced leukemia mortality compared to high-income countries. However, updated trends remain largely unknown in the region. Given that leukemia is the leading cause of cancer-related death in LAC children, we evaluated mortality trends in children (0-14y) from 15 LAC countries for the period 2000–2017 and predicted mortality to 2030.

Methods

We retrieved cancer mortality data using the World Health Organization Mortality Database. Mortality rates (standardized to the world standard SEGI population) were analyzed for 15 LAC countries. We evaluated the average mortality rates for the last 5 years (2013–2017). Joinpoint regression analysis was used to evaluate leukemia mortality trends and provide an estimated annual percent change (EAPC). Nordpred was utilized for the calculation of predictions until 2030.

Results

Between 2013 and 2017, the highest mortality rates were reported in Venezuela, Ecuador, Nicaragua, Mexico, and Peru. Upward mortality trends were reported in Nicaragua (EAPC by 2.9% in boys, and EAPC by 2.0% in girls), and Peru (EAPC by 1.4% in both sexes). Puerto Rico experienced large declines in mortality among both boys (EAPC by − 9.7%), and girls (EAPC by − 6.0%). Leukemia mortality will increase in Argentina, Ecuador, Guatemala, Panama, Peru, and Uruguay by 2030.

Conclusion

Leukemia mortality is predicted to increase in some LAC countries by 2030. Interventions to prevent this outcome should be tailor to reduce the socioeconomic inequalities and ensure universal healthcare coverage.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12887-020-02408-y.

Epidemiology and Outcome of Critically Ill Pediatric Cancer and Hematopoietic Stem Cell Transplant Patients Requiring Continuous Renal Replacement Therapy: A Retrospective Nationwide Cohort Study

Supplemental Digital Content is available in the text.

Acute kidney injury requiring continuous renal replacement therapy is a serious treatment-related complication in pediatric cancer and hematopoietic stem cell transplant patients. The purpose of this study was to assess epidemiology and outcome of these patients requiring continuous renal replacement therapy in the PICU.

PICU mortality of children with cancer admitted to pediatric intensive care unit a systematic review and meta-analysis

BACKGROUND

Outcomes for children diagnosed with cancer have improved dramatically over the past 20 years. However, although 40% of pediatric cancer patients require at least one intensive care admission throughout their disease course, PICU outcomes and resource utilization by this population have not been rigorously studied in this specific group.

METHODS

Using a systematic strategy, we searched Medline, Embase, and CINAHL databases for articles describing PICU mortality of pediatric cancer patients admitted to PICU. Two investigators independently applied eligibility criteria, assessed data quality, and extracted data. We pooled PICU mortality estimates using random-effects models and examined mortality trends over time using meta-regression models.

RESULTS

Out of 1218 identified manuscripts, 31 studies were included covering 16,853 PICU admissions with the majority being retrospective in nature. Overall pooled weighted mortality was 27.8% (95% confidence interval (CI), 23.7-31.9%). Mortality decreased slightly over time when post-operative patients were excluded. The use of mechanical ventilation (odds ratio (OR): 18.49 [95% CI 13.79-24.78], p < 0.001), inotropic support (OR: 14.05 [95% CI 9.16-21.57], p < 0.001), or continuous renal replacement therapy (OR: 3.24 [95% CI 1.31-8.04], p = 0.01) was significantly associated with PICU mortality.

CONCLUSIONS

PICU mortality rates of pediatric cancer patients are far higher when compared to current mortality rates of the general PICU population. PICU mortality has remained relatively unchanged over the past decades, a slight decrease was only seen when post-operative patients were excluded. This compared infavorably with the improved mortality seen in adults with cancer admitted to ICU, where research-led improvements have led to the paradigm of unlimited, aggressive ICU management without any limitations on resuscitations status, for a time-limited trial.

Rural/urban residence and childhood and adolescent cancer survival in the United States

BACKGROUND

To the authors' knowledge, no previous study has examined the relationship between rural/urban residence and childhood or adolescent cancer survival in the United States. Using the Surveillance, Epidemiology, and End Results 18 registries database, the authors examined childhood and adolescent cancer survival by rural/urban residence as defined by Rural-Urban Continuum Codes (RUCCs).

METHODS

The authors obtained data from Surveillance, Epidemiology, and End Results 18 registries for individuals diagnosed at ages birth to 19 years with a first primary malignant cancer from 2000 through 2010. Rural/urban residence at the time of diagnosis was defined using both metropolitan/nonmetropolitan county classifications and individual RUCC categories. Cox proportional hazards regression was used to compute adjusted hazard ratios (HRs) and 95% confidence intervals (95% CIs) for the association between rural/urban residence and cancer survival. The authors also examined effect modification by age group, sex, race/ethnicity, and cancer type.

RESULTS

Among 41,879 cancer cases, approximately 54.7% were non-Hispanic white, 54.3% were male, and 90.4% lived in a metropolitan county. Individuals living in nonmetropolitan counties versus metropolitan counties had a similar risk of cancer death (HR,  1.03; 95% CI, 0.94-1.13) as did those living in nonmetropolitan rural counties with <2500 individuals nonadjacent to a metropolitan area versus those living in metropolitan counties of ≥1 million individuals (HR,  0.98; 95% CI, 0.71-1.37). Evidence for effect modification largely was absent.

CONCLUSIONS

The results of the current study suggest that childhood and adolescent cancer survival in the United States does not vary by rural/urban residence at the time of diagnosis as defined by RUCCs. The widespread availability of public health insurance for children and adolescents and a nationwide network of pediatric cancer providers may explain this finding.

Spatial and temporal variations of childhood cancers: Literature review and contribution of the French national registry

BACKGROUND

Significant increases in childhood cancer incidence since the 1970s have been consistently reported worldwide, but the persistence of the increase on recent periods is discussed. No conclusion can be drawn concerning the spatial variations of childhood cancer, either. This study is an in-depth investigation of the spatial and temporal variations of childhood cancer in France. An extensive review of all the studies published since 2000 on those issues is provided.

METHODS

The study included 25 877 cases of childhood cancer registered nationwide over 2000-2014. The spatial heterogeneity (overdispersion, autocorrelation, overall heterogeneity) was tested, on two geographic scales, and two spatial scan methods were used to detect clusters of cases. The annual average percent change (AAPC) in incidence rate was estimated with Poisson regression models, and joinpoint analyses were considered.

RESULTS

Glioma and non-Hodgkin lymphoma cases exhibited some spatial heterogeneity and two large clusters were detected. Overall, the incidence rate of childhood cancer was stable over 2000-2014 (AAPC = -0.1% [-0.3%; 0.2%]). A log-linear positive trend was significantly evidenced for gliomas other than pilocytic astrocytomas (AAPC = 1.8% [0.9%; 2.7%]), with some suggestion of a leveling-off at the end of the period, while Burkitt lymphoma and germ cell tumor incidence rates decreased (AAPC = -2.2% [-3.8%; -0.5%] and AAPC = -1.9% [-3.4%; -0.3%], respectively). No spatial heterogeneity or significant time variation was evidenced for other cancers.

CONCLUSION

Several types of childhood cancer displayed some spatial heterogeneity and two large clusters were detected, the origins of which are to be investigated and might include differences in case ascertainment. Overall, the results do not support a sustained increase in incidence rates of childhood cancer in recent years.

Advanced parental age as risk factor for childhood acute lymphoblastic leukemia: results from studies of the Childhood Leukemia International Consortium

Advanced parental age has been associated with adverse health effects in the offspring including childhood (0-14 years) acute lymphoblastic leukemia (ALL), as reported in our meta-analysis of published studies. We aimed to further explore the association using primary data from 16 studies participating in the Childhood Leukemia International Consortium. Data were contributed by 11 case-control (CC) studies (7919 cases and 12,942 controls recruited via interviews) and five nested case-control (NCC) studies (8801 cases and 29,690 controls identified through record linkage of population-based health registries) with variable enrollment periods (1968-2015). Five-year paternal and maternal age increments were introduced in two meta-analyses by study design using adjusted odds ratios (OR) derived from each study. Increased paternal age was associated with greater ALL risk in the offspring (ORCC 1.05, 95% CI 1.00-1.11; ORNCC 1.04, 95% CI 1.01-1.07). A similar positive association with advanced maternal age was observed only in the NCC results (ORCC 0.99, 95% CI 0.91-1.07, heterogeneity I2 = 58%, p = 0.002; ORNCC 1.05, 95% CI 1.01-1.08). The positive association between parental age and risk of ALL was most marked among children aged 1-5 years and remained unchanged following mutual adjustment for the collinear effect of the paternal and maternal age variables; analyses of the relatively small numbers of discordant paternal-maternal age pairs were not fully enlightening. Our results strengthen the evidence that advanced parental age is associated with increased childhood ALL risk; collinearity of maternal with paternal age complicates causal interpretation. Employing datasets with cytogenetic information may further elucidate involvement of each parental component and clarify underlying mechanisms.

Parental alcohol consumption and risk of leukemia in the offspring: a systematic review and meta-analysis

Parental alcohol consumption before and during pregnancy has been linked to adverse outcomes in the offspring including leukemogenesis. We, therefore, aimed to systematically assess and quantitatively synthesize published data on the association of paternal consumption during preconception and maternal consumption during pregnancy with leukemia risk in childhood (0-14 years). Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we searched PubMed (until February 2016) and the reference lists of the relevant studies. Observational studies examining the association between parental alcohol consumption and childhood leukemia were considered eligible. Data extracted from 39 case-control studies (over 16 000 leukemia cases and 30 000 controls) were pooled and summary-effect estimates were calculated. Subgroup analyses were carried out by main acute leukemia type [lymphoblastic or myeloid), cytogenetics/genetic polymorphisms, and specific alcohol beverages. We found a statistically significant dose-response association of any level of maternal alcohol consumption compared with nondrinking during pregnancy exclusively with acute myeloid leukemia (AML) [odds ratio (OR)moderate consumption: 1.64, 95% confidence intervals (CIs): 1.23-2.17 and ORhigh consumption: 2.36, 95% CI: 1.60-3.49]. In contrast, no association of paternal preconception consumption with any leukemia type was noted. In beverage-specific analyses, only a positive association of maternal wine drinking with childhood AML was found, which was more pronounced in analyses including only studies on infant leukemia (ORwine: 2.12, 95% CI: 1.16-3.90). The largest ever meta-analysis shows a sizeable, statistically significant dose-response association of maternal alcohol consumption during index pregnancy with AML risk. Future research exploring the role of genetic polymorphisms is anticipated to shed light on the underlying pathophysiology.

Survival from tumours of the central nervous system in Danish children: Is survival related to family circumstances?

Little is known about social inequalities in childhood cancer survival. We investigated the impact of family circumstances on survival from paediatric central nervous system (CNS) tumours in a nationwide, register-based cohort of Danish children. All children born between 1973 and 2006 and diagnosed with a CNS tumour before the age of 20 years (N = 1,261) were followed until 10 years from diagnosis. Using Cox proportional hazards models, the impact of various family characteristics on overall survival was estimated. Hazard ratios (HRs) for all CNS tumours combined did not show strong associations between survival and any family characteristic. Analyses by CNS tumour subtypes showed reduced survival for children with glioma when living outside of Copenhagen (HR 1.55; CI 1.03; 2.35). For embryonal CNS tumours, the number of full siblings was associated with worse survival (HR for having 3+ siblings 3.60; CI 1.52; 8.53) and a trend of better survival was observed for children with parents of younger age at child's diagnosis and poorer survival of children with parents of older age. Despite free and uniform access to health care services, some family circumstances appear to affect survival from specific CNS tumour types in Danish children. Further research is warranted to gain a more comprehensive understanding of the impact of family factors on childhood cancer survival in other populations and to elaborate underlying mechanisms and pathways of those survival inequalities observed.

Mortality and survival patterns of childhood lymphomas: geographic and age-specific patterns in Southern-Eastern European and SEER/US registration data

Childhood (0-14 years) lymphomas, nowadays, present a highly curable malignancy compared with other types of cancer. We used readily available cancer registration data to assess mortality and survival disparities among children residing in Southern-Eastern European (SEE) countries and those in the United States. Average age-standardized mortality rates and time trends of Hodgkin (HL) and non-Hodgkin (NHL; including Burkitt [BL]) lymphomas in 14 SEE cancer registries (1990-2014) and the Surveillance, Epidemiology, and End Results Program (SEER, United States; 1990-2012) were calculated. Survival patterns in a total of 8918 cases distinguishing also BL were assessed through Kaplan-Meier curves and multivariate Cox regression models. Variable, rather decreasing, mortality trends were noted among SEE. Rates were overall higher than that in SEER (1.02/106 ), which presented a sizeable (-4.8%, P = .0001) annual change. Additionally, remarkable survival improvements were manifested in SEER (10 years: 96%, 86%, and 90% for HL, NHL, and BL, respectively), whereas diverse, still lower, rates were noted in SEE. Non-HL was associated with a poorer outcome and an amphi-directional age-specific pattern; specifically, prognosis was inferior in children younger than 5 years than in those who are 10 to 14 years old from SEE (hazard ratio 1.58, 95% confidence interval 1.28-1.96) and superior in children who are 5 to 9 years old from SEER/United States (hazard ratio 0.63, 95% confidence interval 0.46-0.88) than in those who are 10 to 14 years old. In conclusion, higher SEE lymphoma mortality rates than those in SEER, but overall decreasing trends, were found. Despite significant survival gains among developed countries, there are still substantial geographic, disease subtype-specific, and age-specific outcome disparities pointing to persisting gaps in the implementation of new treatment modalities and indicating further research needs.

Survival From Childhood Hematological Malignancies in Denmark: Is Survival Related to Family Characteristics?

BACKGROUND

Due to diverse findings as to the role of family factors for childhood cancer survival even within Europe, we explored a nationwide, register-based cohort of Danish children with hematological malignancies.

METHODS

All children born between 1973 and 2006 and diagnosed with a hematological malignancy before the age of 20 years (N = 1,819) were followed until 10 years from diagnosis. Kaplan-Meier curves and Cox proportional hazards models estimating hazard ratios (HR) and 95% confidence intervals (CI) were used to assess the impact of family characteristics on overall survival in children with hematological malignancies.

RESULTS

Having siblings and increasing birth order were associated with reduced survival from acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML). Associations with AML were strongest and statistically significant. HRs of 1.62 (CI 0.85; 3.09) and 5.76 (CI 2.01; 16.51) were observed for the fourth or later born children with ALL (N = 41) and AML (N = 9), respectively. Children with older parents showed a tendency toward inferior ALL survival, while for AML young maternal age was related to poorer survival. Based on small numbers, a trend toward poorer survival from non-Hodgkin lymphoma was observed for children having siblings and for children of younger parents.

CONCLUSIONS

Further research is warranted to gain further knowledge on the impact of family factors on childhood cancer survival in other populations and to elaborate potential underlying mechanisms and pathways of those survival inequalities.

Early childhood leukemia incidence trends in Brazil

Incidence rates of childhood leukemia vary between different regions of the world. The objective of this study was to test possible trends in incidence rate of early childhood leukemia (children <5 years old at the diagnosis) in Brazil. Data from 18 population-based cancer registries (PBCRs) were analyzed (period 1999-2010). The analysis consisted of frequencies, age-adjusted incidence rates, and joinpoint regression results, including annual average percent change (AAPC) in incidence rates and 95% confidence intervals (CIs). The median age-adjusted incidence rate (AAIR) of overall early childhood leukemia was 61 per million. The AAIR for acute lymphoid leukemia (ALL) was 44 per million and nonlymphoid acute leukemia (NLAL) was 14 per million. The median ALL/NLAL ratio was 3.0, suggesting higher incidence rate of NLAL in these settings. The joinpoint analysis demonstrated increased leukemia incidence rate in João Pessoa (AAPC = 20; 95% CI: 3.5, 39.4) and Salvador (AAPC = 8.68; 95% CI: 1.0, 16.9), respectively, whereas incidence rate in São Paulo PBCR decreased (AAPC = -4.02%; 95% CI: -6.1%, -1.9%). Correlation between ALL AAIR and selected variables of socioeconomic (SES) factors was not observed. Increased AAIR regionally overtime was observed. However, the interpretation for such phenomenon should be cautious because it might reflect the access to health care, diagnosis procedures, and improvement of PBCR´s quality. The observed trend supports the necessity of further ecological studies.

Childhood central nervous system tumour mortality and survival in Southern and Eastern Europe (1983-2014): Gaps persist across 14 cancer registries

AIM

Childhood central nervous system (CNS) tumour registration and control programs in Southern and Eastern Europe remain thin, despite the lethal nature of the disease. Mortality/survival data were assembled to estimate the burden of malignant CNS tumours, as well as the potential role of sociodemographic survival determinants across 14 cancer registries of this region.

METHODS

Average age-adjusted mortality rates were calculated, whereas time trends were quantified through Poisson and Joinpoint regressions. Kaplan-Meier curves were derived for the maximum and the more recent (10 and 5 year) registration periods. Multivariate Cox regression models were used to assess demographic and disease-related determinants.

RESULTS

Variations in mortality (8-16 per million) and survival (5-year: 35-69%) were substantial among the participating registries; in most registries mortality trend was stable, whereas Bulgaria, having the highest starting rate, experienced decreasing annual mortality (-2.4%, p=0.001). A steep decrease in survival rates was evident before the second year of follow-up. After controlling for diagnostic subgroup, age, gender and diagnostic year, Greece seemed to present higher survival compared with the other contributing registries, although the follow-up period was short. Irrespective of country, however, rural residence was found to impose substantial adverse repercussions on survival (hazard ratio (HR): 1.2, 95% confidence interval (CI): 1.1-1.4).

CONCLUSION

Cross-country mortality and survival variations possibly reflect suboptimal levels of health care delivery and cancer control in some regions of Southern and Eastern Europe, notwithstanding questionable death certification patterns or follow-up procedures. Continuous childhood cancer registration and linkage with clinical data are prerequisite for the reduction of survival inequalities across Europe.

Childhood central nervous system tumours: Incidence and time trends in 13 Southern and Eastern European cancer registries

AIM

Following completion of the first 5-year nationwide childhood (0-14 years) registration in Greece, central nervous system (CNS) tumour incidence rates are compared with those of 12 registries operating in 10 Southern-Eastern European countries.

METHODS

All CNS tumours, as defined by the International Classification of Childhood Cancer (ICCC-3) and registered in any period between 1983 and 2014 were collected from the collaborating cancer registries. Data were evaluated using standard International Agency for Research on Cancer (IARC) criteria. Crude and age-adjusted incidence rates (AIR) by age/gender/diagnostic subgroup were calculated, whereas time trends were assessed through Poisson and Joinpoint regression models.

RESULTS

6062 CNS tumours were retrieved with non-malignant CNS tumours recorded in eight registries; therefore, the analyses were performed on 5191 malignant tumours. Proportion of death certificate only cases was low and morphologic verification overall high; yet five registries presented >10% unspecified neoplasms. The male/female ratio was 1.3 and incidence decreased gradually with age, apart from Turkey and Ukraine. Overall AIR for malignant tumours was 23/10(6) children, with the highest rates noted in Croatia and Serbia. A statistically significant AIR increase was noted in Bulgaria, whereas significant decreases were noted in Belarus, Croatia, Cyprus and Serbia. Although astrocytomas were overall the most common subgroup (30%) followed by embryonal tumours (26%), the latter was the predominant subgroup in six registries.

CONCLUSION

Childhood cancer registration is expanding in Southern-Eastern Europe. The heterogeneity in registration practices and incidence patterns of CNS tumours necessitates further investigation aiming to provide clues in aetiology and direct investments into surveillance and early tumour detection.

Registration of childhood cancer: Moving towards pan-European coverage?

Cancer is relatively rare in childhood, but it contributes considerably to childhood mortality, years of life lost per person and late effects in survivors. Large populations need to be covered to set up meaningful studies of these rare conditions. Cancer registries ensure cancer surveillance, thus providing the basis for research as well as policy decisions. In this paper we examine coverage of childhood population by cancer registries in Europe and encourage national cancer registration. Over 200 cancer registries in various stages of development were identified as collecting data on childhood cancer patients in Europe. They cover 52% of the childhood population in the World Health Organisation (WHO) European region and 83% in the European Union (EU). More than 80% of this coverage is ensured by nationwide data collection, which is ongoing in 29 European countries. Overall coverage of the childhood population could increase to around 98%, if the recently established cancer registries start producing results and others improve their quality and dissemination plans. Paediatric cancer registries are being established with increasing frequency even in the areas covered by general cancer registries, and they tend to be national. Compared with regional registration, national cancer registries are more cost-effective, record larger number of cases, they can achieve higher completeness, less biased incidence and survival estimates and they are conditioned for national and international research. National registration of childhood cancer should be the rule in Europe, so that accurate regional, nation-wide and international statistics can provide solid baselines for research, clinical practice and public health policy. Governmental support and stakeholders' involvement are indispensable to guarantee optimal data quality and completeness.

Family circumstances and survival from childhood acute lymphoblastic leukaemia in West Germany

BACKGROUND

Little is known about the relationship between family characteristics and survival from childhood acute lymphoblastic leukaemia (ALL), which we studied for the first time in German children.

METHODS

ALL cases were diagnosed between 1992 and 1994 and information on family characteristics was collected during a previously conducted nationwide case-control study. Children were followed for 10 years after diagnosis, as few disease-related events occur afterwards. Cox proportional hazards models estimating hazard ratios (HR) were calculated using overall as well as event-free survival methods.

RESULTS

Second born children showed statistically significant better survival compared to first or later born children, with HRs ranging between 0.54 and 0.64 compared to firstborns. Somewhat poorer survival was observed for children having 3 or more siblings. A relationship was found for parental age at child's diagnosis, with poorer survival for children with younger parents (≤25 years of age at child's diagnosis), or with older fathers. The HR was statistically significant for fathers being ≥41years of age (HR of 2.1). No relationship between degree of urbanization of the place of residence at diagnosis and ALL survival was observed.

CONCLUSION

Family circumstances may have an impact on survival from childhood ALL in Germany. Further research is warranted to elaborate the relationship of specific family characteristics and ALL survival and to investigate possible differential adherence to therapy and interactions with physicians.

Socioeconomic status and event free survival in pediatric acute lymphoblastic leukemia: a population-based cohort study

The impact of socioeconomic status (SES) upon childhood cancer outcomes has not been extensively examined. Our objective was to determine the association between SES and event-free survival (EFS) among children with acute lymphoblastic leukemia (ALL) diagnosed in Ontario, Canada from 1995-2011 (N=1541) using Cox proportional hazards. Neither neighborhood-level median income quintile, distance from tertiary center, or rural residence significantly predicted EFS in the context of a universal healthcare system. Immigrant children experienced significantly superior EFS; confounding by ethnicity could not be ruled out. Confirmatory studies using additional individual-level SES variables are warranted.

Survival from childhood acute lymphoblastic leukaemia in West Germany: does socio-demographic background matter?

BACKGROUND

Sex, age, immunophenotype and white blood cell count at diagnosis are well accepted predictors of survival from acute lymphoblastic leukaemia (ALL) in children. Less is known about the relationship between socio-economic determinants and survival from paediatric ALL, studied here for the first time in German children.

METHODS

ALL cases were diagnosed between 1992 and 1994 and their parents interviewed during a previous nationwide case-control study. Children were followed-up for 10 years after diagnosis by the German Childhood Cancer Registry. Cox proportional hazards models estimating hazard ratios (HRs) were calculated to assess the impact of selected socio-demographic characteristics on overall and event-free survival.

RESULTS

Overall survival was 82.5%, with a higher proportion of girls than boys surviving (85% versus 81%). We found a non-linear relationship between age at diagnosis and survival, with poorer survival in infants and children aged >5 years. There was no association between socio-economic factors and survival or risk of relapse. For five levels of increasing family income, all HRs were close to one. No relationship was seen with parental educational level.

CONCLUSION

Socio-economic determinants did not affect ALL survival in West German children, in contrast to studies from some other countries. Dissimilarities in social welfare systems, including access to health care, lifestyle and differences in treatment may contribute to these differences in findings. Our observation of no social inequalities in paediatric ALL survival is reassuring, but needs continued monitoring to assess the potential impact of evolvement of treatment options and changes in paediatric health service.

Implication of IRF4 aberrant gene expression in the acute leukemias of childhood

The most frequent targets of genetic alterations in human leukemias are transcription factor genes with essential functions in normal blood cell development. The Interferon Regulatory Factor 4 (IRF4) gene encodes a transcription factor important for key developmental stages of hematopoiesis, with known oncogenic implications in multiple myeloma, adult leukemias and lymphomas. Very few studies have reported an association of IRF4 with childhood malignancy, whereas high transcript levels have been observed in the more mature immunophenotype of ALL. Our aim was to investigate the expression levels of IRF4 in the diagnostic samples of pediatric leukemias and compare them to those of healthy controls, in order to determine aberrant gene expression and whether it extends to leukemic subtypes other than the relatively mature ALL subpopulation. Quantitative real-time RT-PCR methodology was used to investigate IRF4 expression in 58 children with acute leukemias, 4 leukemic cell lines and 20 healthy children. We show that aberrant IRF4 gene expression is implicated in a variety of leukemic subtypes; higher transcript levels appear in the more immature B-common ALL subtype and in T-cell than in B-cell leukemias, with the highest expression levels appearing in the AML group. Interestingly, we show that childhood leukemia, irrespective of subtype or cell maturation stage, is characterised by a minimum of approximately twice the amount of IRF4 gene expression encountered in healthy children. A statistically significant correlation also appeared to exist between high IRF4 expression and relapse. Our results show that ectopic expression of IRF4 follows the reverse expression pattern of what is encountered in normal B-cell development and that there might be a dose-dependency of childhood leukemia for aberrantly expressed IRF4, a characteristic that could be explored therapeutically. It is also suggested that high IRF4 expression might be used as an additional prognostic marker of relapse at diagnosis.