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Socioeconomic differences in overall survival from childhood cancer have been shown previously, but the underlying mechanisms remain unclear. We aimed to investigate if social inequalities were seen already for early mortality in settings with universal healthcare. From national registers, all children diagnosed with cancer at ages 0-19 years, during 1991-2014, in Sweden and Denmark, were identified, and information on parental social characteristics was collected. We estimated odds ratios (OR) and 95% confidence intervals (CI) of early mortality (death within 90 days after cancer diagnosis) by parental education, income, employment, cohabitation, and country of birth using logistic regression. For children with acute lymphoblastic leukaemia (ALL), clinical characteristics were obtained. Among 13,926 included children, 355 (2.5%) died within 90 days after diagnosis. Indications of higher early mortality were seen among the disadvantaged groups, with the most pronounced associations observed for maternal education (OR adj_Low_vs_High 1.65 [95% CI 1.22-2.23]) and income (OR adj_Q1(lowest)_vs_Q4(highest) 1.77 [1.25-2.49]). We found attenuated or null associations between social characteristics and later mortality (deaths occurring 1-5 years after cancer diagnosis). In children with ALL, the associations between social factors and early mortality remained unchanged when adjusting for potential mediation by clinical characteristics. In conclusion, this population-based cohort study indicated differences in early mortality after childhood cancer by social background, also in countries with universal healthcare. Social differences occurring this early in the disease course requires further investigation, also regarding the timing of diagnosis., (© 2024 The Authors. International Journal of Cancer published by John Wiley & Sons Ltd on behalf of UICC.)

Although recent studies have demonstrated associations between nonchromosomal birth defects and several pediatric cancers, less is known about their role on childhood leukemia susceptibility. Using data from the Childhood Cancer and Leukemia International Consortium, we evaluated associations between nonchromosomal birth defects and childhood leukemia. Pooling consortium data from 18 questionnaire-based and three registry-based case-control studies across 13 countries, we used multivariable logistic regression models to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for the association between a spectrum of birth defects and leukemia. Our analyses included acute lymphoblastic leukemia (ALL, n = 13 115) and acute myeloid leukemia (AML, n = 2120) cases, along with 46 172 controls. We used the false discovery rate to account for multiple comparisons. In the questionnaire-based studies, the prevalence of birth defects was 5% among cases vs 4% in controls, whereas, in the registry-based studies, the prevalence was 11% among cases vs 7% in controls. In pooled adjusted analyses, there were several notable associations, including (1) digestive system defects and ALL (OR = 2.70, 95% CI: 1.46-4.98); (2) congenital anomalies of the heart and circulatory system and AML (OR = 2.86, 95% CI: 1.81-4.52) and (3) nervous system defects and AML (OR = 4.23, 95% CI: 1.50-11.89). Effect sizes were generally larger in registry-based studies. Overall, our results could point to novel genetic and environmental factors associated with birth defects that could also increase leukemia susceptibility. Additionally, differences between questionnaire- and registry-based studies point to the importance of complementary sources of birth defect phenotype data when exploring these associations., (© 2023 UICC.)

Childhood cancer is the leading disease-related cause of death among under 15 year olds in Europe. Since primary preventive measures are lacking, improving survival probabilities and long-term well-being remain primary goals. With this report, we provide the first long-term assessment and interpretation of patterns in childhood cancer survival in Germany, covering a period of 30 years. Using data from the German Childhood Cancer Registry, we assessed temporal patterns of cancer survival among children (0-14 years) diagnosed in Germany from 1991 to 2016, by cancer type, age at diagnosis and sex. We calculated overall survival (OS) and average annual percentage changes of the respective 5-year OS estimates. OS improved across all cancer types, age groups as well as for boys and girls over time. Five-year OS for all childhood cancers combined increased from 77.8% in 1991-1995 to 86.5% in 2011-2016, with stronger improvements during the early 1990s. The most pronounced survival improvement was seen for acute myeloid leukaemia, at 2% annually and 5-year OS recently reaching 81.5%. Survival improvements for some diagnoses such as neuroblastoma, renal tumours and bone tumours have flattened out. Tremendous enhancements in diagnostics, treatment and supportive care have affected average survival improvements for most cancer types. Recently, survival improvements have decelerated overall and for some cancer types, it plateaued at an unsatisfactory level. As not all children benefited equally from the survival improvements, personal factors (eg, socioeconomic circumstances, health literacy, access to care) likely affect individual prognosis and warrant further investigation., (© 2023 The Authors. International Journal of Cancer published by John Wiley & Sons Ltd on behalf of UICC.)

The association between leukemia and proximity to nuclear-power-plants (NPPs) has been assessed in several countries with inconsistent results. A case-control study from Germany had shown an increased risk for childhood leukemia (diagnoses 1980-2003) near NPPs. Germany began shutting down nuclear reactors in 2011, following the Fukushima disaster. We tested whether the previously observed association between leukemia and proximity to NPP persisted despite the shutdown. We used an ecological study design to investigate the incidence of leukemia during 2004 to 2019 in children aged 0 to 14 years living near NPPs where at least one reactor was shut down in 2011. We defined study and control areas as municipalities whose surface area was at least 75% within 10 km or between 10 and 50 km of NPPs, respectively. We calculated age-standardized rates and incidence rate ratios (IRR) using control-areas as the reference. We also computed standardized incidence ratios (SIR) separately for each NPP using incidence rates of the German population as a reference. IRR decreased from 1.20 (95% confidence interval: 0.81-1.77) in 2004 to 2011 to 1.12 (0.75-1.68) in 2012 to 2019. Analyses of single plants showed an excess of childhood leukemia during 2004 to 2019 for the Unterweser-NPP, based only on three cases, and the Krümmel-NPP (n = 14; SIR: 1.98, 1.17-3.35). We found slightly decreasing of leukemia incidence rate ratios after the shutdown of nuclear reactors in 2011. Due to the small number of cases, risk estimates have large uncertainty. Further research including a longer follow-up is warranted. The consistent excess of incidence cases around Krümmel may require analytical epidemiological analysis., (© 2022 The Authors. International Journal of Cancer published by John Wiley & Sons Ltd on behalf of UICC.)

The aetiology of childhood leukaemia is poorly understood. Knowledge about differences in risk by socioeconomic status (SES) may enhance etiologic insights. We conducted a nationwide register-based case-control study to evaluate socioeconomic differences in the risk of childhood leukaemia in Denmark and to access whether associations varied by different measures of SES, time point of assessment, leukaemia type and age at diagnosis. We identified all cases of leukaemia in children aged 0 to 19 years, born and diagnosed between 1980 and 2013 from the Danish Cancer Registry (N = 1336) and sampled four individually matched controls per case (N = 5330). We used conditional logistic regression models for analysis. Medium and high level of parental education was associated with a higher risk of acute myeloid leukaemia (AML) in the offspring, mainly driven by children diagnosed at ages 0 to 4 years [odds ratio (OR) for high maternal education = 3.07; 95% confidence interval (CI): 1.44-6.55]. We also observed a modestly increased risk for lymphoid leukaemia (LL) in association with higher level of parental education, but only in children diagnosed at ages 5 to 19 years. Higher parental income was associated with an increased risk of LL but not AML among children aged 5 to 19 years at diagnosis (OR for high maternal income = 2.78; 95% CI: 1.32-5.89). Results for neighbourhood SES measures indicated null associations. Bias or under-ascertainment of cases among families with low income or basic education are unlikely to explain the observed socioeconomic differences. Future research addressing explicitly the underlying mechanisms of our results may help to enhance etiologic insights of the disease., (© 2020 The Authors. International Journal of Cancer published by John Wiley & Sons Ltd on behalf of UICC.)

Having a child with cancer may affect the socioeconomic situation of the parents. We aimed to assess the impact of childhood cancer on parental working status and income and to identify determinants of adverse changes after the child's cancer diagnosis by calendar period. We conducted a nationwide cohort study using Danish registry data. Parents of children diagnosed with cancer in 1982-2014 (n = 12,418) were matched with comparison parents of cancer-free children (n = 125,014). We analysed annual working status (working/not working) and annual disposable income (lowest quintile/not lowest quintile) of case and comparison parents over a period of 10 years after diagnosis by calendar period (1982-1999 vs. 2000-2014). Logistic regression models were used to identify determinants of adverse changes after diagnosis. Mothers of children diagnosed in 1982-1999 were more likely not working or having a low income than comparison mothers up to 10 years after diagnosis. This risk of not working or low income was lower in mothers of children diagnosed in 2000-2014 compared to 1982-1999 in the first years after diagnosis (p interaction  < 0.05). We observed no consistent patterns among fathers. Low parental education, diagnosis of lymphoid leukaemia and younger age of the child at diagnosis were the main determinants of adverse changes in working status or income after diagnosis. Childhood cancer adversely interfered with parents' socioeconomic situation in the earlier calendar period, particularly among mothers. The absence of such an effect in more recent years emphasises the supportive role of a countries' welfare system alongside the general advances in childhood cancer treatment., (© 2020 UICC.)

Substantial improvements in childhood cancer survival have resulted in a steadily increasing population of childhood cancer survivors. Whereas somatic late effects have been assessed in many studies, less is known about the impact of childhood cancer on socioeconomic outcomes in survivors. The aim of this article was to evaluate and summarise the evidence on the socioeconomic conditions of childhood cancer survivors and to identify survivors at particular risk of adverse socioeconomic outcomes. An extensive literature search of three electronic databases was conducted. Of 419 articles identified, 52 met the inclusion criteria. All the selected articles were appraised for quality, and findings were summarised in a narrative synthesis. Childhood cancer survivors were at higher risk of adverse socioeconomic outcomes with regard to educational achievement, income and social security benefits than the general population or a sibling comparison group. The risks for unemployment and a lower occupational position were significantly increased only for survivors of a central nervous system tumour. Notably, survivors of central nervous system tumours, survivors treated with cranial radiotherapy and those diagnosed at younger age independent of cancer type were determinants of particular adverse socioeconomic outcomes. Given the increasing population of childhood cancer survivors, targeted follow-up interventions and support strategies addressing not only the somatic and psychiatric late effects but also the socioeconomic difficulties that some childhood cancer survivors face is of high importance to reduce social inequity, and ensure a high quality of life after childhood cancer., (© 2018 UICC.)

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., (© 2017 UICC.)

Higher childhood cancer incidence rates are generally reported for high income countries although high quality information on descriptive patterns of childhood cancer incidence for low or middle income countries is limited, particularly in Sub-Saharan Africa. There is a need to quantify global differences by cancer types, and to investigate whether they reflect true incidence differences or can be attributed to under-diagnosis or under-reporting. For the first time, we describe childhood cancer data reported to the pathology report-based National Cancer Registry of South Africa in 2000-2006 and compare our results to incidence data from Germany, a high income country. The overall age-standardized incidence rate (ASR) for South Africa in 2000-2006 was 45.7 per million children. We observed substantial differences by cancer types within South Africa by racial group; ASRs tended to be 3-4-fold higher in South African Whites compared to Blacks. ASRs among both Black and White South Africans were generally lower than those from Germany with the greatest differences observed between the Black population in South Africa and Germany, although there was marked variation between cancer types. Age-specific rates were particularly low comparing South African Whites and Blacks with German infants. Overall, patterns across South African population groups and in comparison to Germans were similar for boys and girls. Genetic and environmental reasons may probably explain rather a small proportion of the observed differences. More research is needed to understand the extent to which under-ascertainment and under-diagnosis of childhood cancers drives differences in observed rates., (© 2014 UICC.)

The incidence of cutaneous malignant melanoma has steadily increased over the past 50 years in predominately fair-skinned populations. This increase is reported to have leveled off recently in several Northern and Western European countries, Australia, New Zealand and in North America. We studied the global patterns and time trends in incidence of melanoma by country and sex, with a focus on and age- and cohort-specific variations. We analyzed the incidence data from 39 population-based cancer registries, examining all-ages and age-truncated standardized incidence rates of melanoma, estimating the annual percentage change and incidence rate ratios from age-period-cohort models. Incidence rates of melanoma continue to rise in most European countries (primarily Southern and Eastern Europe), whereas in Australia, New Zealand, the U.S., Canada, Israel and Norway, rates have become rather stable in recent years. Indications of a stabilization or decreasing trend were observed mainly in the youngest age group (25-44 years). Rates have been rising steadily in generations born up to the end of the 1940s, followed by a stabilization or decline in rates for more recently born cohorts in Australia, New Zealand, the U.S., Canada and Norway. In addition to the birth cohort effect, there was a suggestion of a period-related influence on melanoma trends in certain populations. Although our findings provide support that primary and secondary prevention can halt and reverse the observed increasing burden of melanoma, they also indicate that those prevention measures require further endorsement in many countries., (Copyright © 2012 UICC.)