Poverty and childhood cancer incidence in the United States

Exploration of genetic ancestry and socioeconomic status in the incidence of neuroblastoma: An ecological study

Although global differences in the incidence of neuroblastoma have been examined, the underlying mechanism has yet to be elucidated. Previous studies have suggested genetic ancestry and human development index (HDI) as contributing factors, but few studies have been conducted at the international level. Here, we aimed to examine whether the frequency of common genomic variation associated with neuroblastoma can affect its risk at the ecological level with consideration of the HDI. Minor allele frequencies (MAFs) for 22 single-nucleotide polymorphisms (SNPs) were abstracted from the Geography of Genetic Variants Browser. The number of incident neuroblastomas for each population was obtained from the Cancer Incidence in Five Continents series. Further, population pseudo-polygenic risk scores (pp-PRSs) were calculated as a sum of MAFs at the population level, each of which was weighted by effect sizes from prior studies. Negative binomial regression was used to estimate the incidence rate ratios (IRRs) and the 95% confidence intervals (CIs) to examine whether differences in MAFs across the population influence the risk of neuroblastoma, with and without adjustment for HDI and whether pp-PRSs can be a predictor of the risk of neuroblastoma. Overall, our results indicated that the neuroblastoma risk associated with variation in SNP frequency could not be differentiated from that of HDI at the ecological level. Additionally, pp-PRSs were not significantly associated with the risk of neuroblastoma (IRR: 0.99, 95% CI: 0.62-1.60). Further study using individual-level data is warranted to minimize the bias related to the use of population-level data in this study.

Individual and neighbourhood socioeconomic measures and the risk of non-central nervous system solid tumours in children: A nationwide register-based case-control study in Denmark

BACKGROUND

The aetiology for most solid tumours in childhood is largely unknown. The lack of evidence concerns also the relationship between socioeconomic position (SEP) and risk of childhood solid tumours other than in the central nervous system (CNS). We sought to access the association between individual and neighbourhood SEP measures and risk of childhood non-CNS solid tumours in Denmark and to evaluate whether associations varied by measure of SEP, time point of SEP assessment (during pregnancy versus before diagnosis) and tumour type.

METHODS

We conducted a nationwide case-control study based on Danish registry data. We identified all children born in 1980-2013 and diagnosed with a non-CNS solid tumour at ages 0-19 years (N = 1961) from the Danish Cancer Registry and sampled four individually matched controls per case using the Population Registry. We fitted conditional logistic regression models to estimate associations with register-based individual-level and neighbourhood-level SEP measures.

RESULTS

We observed a tendency of increased odd ratios (OR) in association with medium and high maternal income for most tumour types (e.g. OR for the highest income quintile and malignant bone tumours = 2.11; 95 % CI: 1.01, 4.38) and for parental education in association with higher education for some tumour types. For malignant epithelial neoplasms, higher parental education and income level were overall associated with an increased risk, e.g. OR = 1.63 (95 % CI: 1.00, 2.65) for the fourth group of maternal income during pregnancy. We found no risk pattern for neighbourhood SEP.

CONCLUSION

This large register-study with minimal risk of bias found a tendency of slightly to moderately increased risks for most childhood non-CNS solid tumours in association with higher maternal income and parental education. Future research examining the underlying mechanisms of these socioeconomic differences in non-CNS solid tumours as well as other childhood cancer types are warranted.

Racial and ethnic disparities among children with primary central nervous system tumors in the US

INTRODUCTION

Primary central nervous system (CNS) tumors are among the most common and lethal types of cancer in children. However, the existence of health disparities in CNS tumors by race or ethnicity remains poorly understood. This systematic review sought to determine whether racial and ethnic disparities in incidence, healthcare access, and survival exist among pediatric patients diagnosed with CNS tumors.

METHODS

A search of MEDLINE, Embase, CINAHL, Web of Science, and Scopus was conducted. Inclusion criteria selected for studies published between January 1, 2005 and July 15, 2020 that focused on pediatric populations in the US, evaluated for potential differences based on racial or ethnic backgrounds, and focused on CNS tumors. A standardized study form was used to collect study information, population of interest, research design, and quality of analysis, sample size, participant demographics, pathology evaluated, and incidence or outcomes observed.

RESULTS

A total of 30 studies were inlcuded. Studies suggest White children may be more likely to be diagnosed with a CNS tumor and Hispanic children to present with advanced-stage disease and have worse outcomes. The degree of influence derived from socioeconomic factors is unclear. This review was limited by few available studies that included race and ethnicity as a variable, the overlap in databases used, and unclear categorization of race and ethnicity.

CONCLUSIONS

This review identified notable and at times contradicting variations in racial/ethnic disparities among children with CNS tumors, suggesting that the extent of these disparities remains largely unknown and prompts further research to improve health equity.

Is the risk of childhood leukaemia associated with socioeconomic measures in Denmark? A nationwide register-based case-control study

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.

Racial and Ethnic Differences in Sarcoma Incidence Are Independent of Census-Tract Socioeconomic Status

BACKGROUND

Epidemiologic analyses of sarcoma are limited by the heterogeneity and rarity of the disease. Utilizing population-based surveillance data enabled us to evaluate the contribution of census tract-level socioeconomic status (CT-SES) and race/ethnicity on sarcoma incidence rates.

METHODS

We utilized the Surveillance, Epidemiology, and End Results program to evaluate associations between CT-SES and race/ethnicity on the incidence rates of sarcoma. Incidence rate ratios and 99% confidence intervals were estimated from quasi-Poisson models. All models were stratified by broad age groups (pediatric: <20 years, adult: 20-65 years, older adult: 65+ years) and adjusted for sex, age, and year of diagnosis. Within each age group, we conducted analyses stratified by somatic genome (fusion-positive and fusion-negative sarcomas) and for subtypes with >200 total cases. A P value less than 0.01 was considered statistically significant.

RESULTS

We included 55,415 sarcoma cases in 35 sarcoma subtype-age group combinations. Increasing CT-SES was statistically significantly associated with 11 subtype-age group combinations, primarily in the older age group strata (8 subtypes), whereas malignant peripheral nerve sheath tumors in adults were associated with decreasing CT-SES. Nearly every sarcoma subtype-age group combination displayed racial/ethnic disparities in incidence that were independent of CT-SES.

CONCLUSIONS

We found race/ethnicity to be more frequently associated with sarcoma incidence than CT-SES. Our findings suggest that genetic variation associated with ancestry may play a stronger role than area-level SES-related factors in the etiology of sarcoma.

IMPACT

These findings provide direction for future etiologic studies of sarcomas.

Race, ethnicity, and socioeconomic differences in incidence of pediatric embryonal tumors in the United States

BACKGROUND

The etiology of childhood cancers and its social patterning remains largely unknown. Accounting for socioeconomic status (SES) when exploring the association between race/ethnicity and cancer incidence is necessary to better understand such etiology. We aimed to investigate differences in the incidence of embryonal tumors (ETs) by SES and race/ethnicity in the United States using population-based registries of the Surveillance, Epidemiology, and End Results (SEER) Program.

PROCEDURE

Children with ETs aged 0-19 years diagnosed between 2000 and 2015 were ascertained from the census tract-level SEER database. SES was measured using a tract-level composite index. Incidence rate ratios (IRRs) with 95% confidence intervals (CIs) by SES quintile and race/ethnicity were estimated using multivariable Poisson regression models.

RESULTS

The majority of tumors had lower incidence among nonwhite children compared with non-Hispanic (NH) white children, after controlling for SES. NH blacks had a higher incidence of Wilms tumor than NH whites (IRR: 1.26; 95% CI, 1.13-1.39). There was an increasing linear trend (P = 0.0001) across increasing SES quintile for embryonal rhabdomyosarcoma after controlling for race/ethnicity. Effect modification by race/ethnicity of the relationship between SES and tumor incidence was observed for several groups. Hispanics had a significant, linear trend (P = 0.0005) in the incidence of Wilms tumor, while Asian/Pacific Islanders experienced a significant inverse trend (P = 0.0002).

CONCLUSIONS

Results from this study suggest differences in the incidence of several ETs by race/ethnicity and that these differences may be modified by SES. Investigation of potential risk factors that are socially patterned is warranted.

Socioeconomic differences in the risk of childhood central nervous system tumors in Denmark: a nationwide register-based case-control study

PURPOSE

Differences in the risk of childhood central nervous system (CNS) tumors 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 CNS tumors in Denmark and examined whether associations varied by different SES measures, time points of assessment, specific tumor types, and age at diagnosis.

METHODS

We identified all children born between 1981 and 2013 and diagnosed with a CNS tumor at ages 0-19 years (n = 1,273) from the Danish Cancer Registry and sampled four individually matched controls per case (n  = 5,086). We used conditional logistic regression models to estimate associations with individual-level and neighborhood-level socioeconomic measures.

RESULTS

We observed elevated risks of ependymoma and embryonal CNS tumors in association with higher parental education (odds ratios (ORs) of 1.6-2.1 for maternal or paternal high education and ependymoma) and higher risk of all tumor types in association with higher maternal income, e.g., OR  1.93; 95% CI 1.05-3.52 for high versus low income for astrocytoma and other gliomas. Associations were often stronger in children diagnosed at ages 5-19 years. We found little evidence for an association with neighborhood SES.

CONCLUSION

This large nationwide register study with minimal risk of bias showed that having parents with higher educational level and a mother with higher income was associated with a higher risk of childhood CNS tumors. Bias or under-ascertainment of cases among families with low income or basic education is unlikely to explain our findings.

Socioeconomic Status and Childhood Cancer Incidence: A Population-Based Multilevel Analysis

The etiology of childhood cancers remains largely unknown, especially regarding environmental and behavioral risk factors. Unpacking the association between socioeconomic status (SES) and incidence may offer insight into such etiology. We tested associations between SES and childhood cancer incidence in a population-based case-cohort study (source cohort: Minnesota birth registry, 1989-2014). Cases, ages 0-14 years, were linked from the Minnesota Cancer Surveillance System to birth records through probabilistic record linkage. Controls were 4:1 frequency matched on birth year (2,947 cases and 11,907 controls). We tested associations of individual-level (maternal education) and neighborhood-level (census tract composite index) SES using logistic mixed models. In crude models, maternal education was positively associated with incidence of acute lymphoblastic leukemia (odds ratio (OR) = 1.10, 95% confidence interval (CI): 1.02, 1.19), central nervous system tumors (OR = 1.12, 95% CI: 1.04, 1.21), and neuroblastoma (OR = 1.15, 95% CI: 1.02, 1.30). Adjustment for established risk factors-including race/ethnicity, maternal age, and birth weight-substantially attenuated these positive associations. Similar patterns were observed for neighborhood-level SES. Conversely, higher maternal education was inversely associated with hepatoblastoma incidence (adjusted OR = 0.70, 95% CI: 0.51, 0.98). Overall, beyond the social patterning of established demographic and pregnancy-related exposures, SES is not strongly associated with childhood cancer incidence.

Racial and Ethnic Differences in Socioeconomic Position and Risk of Childhood Acute Lymphoblastic Leukemia

Racial and ethnic differences in associations between socioeconomic position (SEP) and risk of childhood acute lymphoblastic leukemia (ALL) were investigated using data from population-based cancer registries in the Surveillance, Epidemiology, and End Results Program in the United States. The study included 8,383 ALL cases diagnosed at age ≤19 years in 2000-2010. Census tract-level composite SEP index in quintiles was assigned based on residence at the time of diagnosis. Incidence rate ratios and 95% confidence intervals associated with SEP and race/ethnicity, adjusted for sex, age, and year of diagnosis, were estimated using Poisson regression models. The incidence rate of childhood ALL was negatively associated with SEP among Hispanics but was positively associated among children of other races/ethnicities. As compared with the lowest SEP, the adjusted incidence rate ratios for children with the highest SEP were 1.29 (95% confidence interval (CI): 1.15, 1.44) for non-Hispanic whites, 1.67 (95% CI: 1.20, 2.34) for non-Hispanic blacks, 1.57 (95% CI: 1.17, 2.09) for Asians/Pacific Islanders, 2.33 (95% CI: 0.93, 5.83) for American Indians/Alaska Natives, and 0.70 (95% CI: 0.60, 0.81) for Hispanics. The findings of a reverse association in Hispanics need to be confirmed and further explained in future studies using different measures of SEP.

The burden of childhood cancer in Mexico: Implications for low- and middle-income countries

In Mexico, childhood cancer incidence and mortality have increased in the last decade. Through government actions since 2005, the Popular Medical Insurance (PMI) program for childhood cancer was created. The objective of PMI was to offer early cancer diagnosis, standardized treatment regimens, and numerous pediatric oncology residency programs. It has also accredited 55 national hospitals for the care of these children. Current problems still present under the PMI include shortage of pediatric oncologists and nurses and high rate of abandonment of treatment. Our aim is to describe the current scenario of childhood cancer care in Mexico, especially from the perspective of the PMI and how it has impacted human resources, infrastructure, and medical education.

Socioeconomic status and global variations in the incidence of neuroblastoma: call for support of population-based cancer registries in low-middle-income countries

Global variations in the incidence of pediatric cancers have been described; however, the causes of such differences are not known. We investigated the relationship between the incidence of embryonal tumors and human development index on a global scale. Increasing incidence of neuroblastoma correlates significantly with an increasing index of human development, with greater incidence among countries with high socioeconomic development, in apparent contrast to the incidence of retinoblastoma. While more data are needed to corroborate this observation, our findings suggest new avenues for etiological research and serve as a call for support of population-based cancer registries in low-middle-income countries.

Risk of malignant childhood germ cell tumors in relation to demographic, gestational, and perinatal characteristics

BACKGROUND

Childhood germ cell tumors (GCTs) are a rare assortment of neoplasms, with mostly unknown etiology, that are believed to originate very early in life. Few studies have examined risk factors by histologic subtype, despite evidence of different risk profiles.

MATERIALS AND METHODS

In this population-based case-control study, 451 childhood malignant GCT cases ages 0-5 years were identified from the California Cancer Registry. Differentiating between common histologic subtypes, we identified 181 yolk sac tumors, 216 teratomas, and 54 rarer subtypes. Cases were linked to their birth certificates and 271,381 controls, frequency matched by birth year, were randomly selected from California birthrolls to investigate the contributions of demographic, gestational, and pregnancy factors using unconditional logistic regression analysis.

RESULTS

Compared to non-Hispanic whites, Asian/Pacific Islander children were at an increased risk for developing GCTs (odds ratio [OR]=1.94; 95% confidence interval [CI]=1.47, 2.56). Among pregnancy complications and procedures, yolk sac tumors were positively associated with the presence of fetopelvic disproportion (OR=2.97; 95% CI=1.55, 5.68), while teratomas were strongly associated with polyhydramnios or oligohydramnios (OR=14.76; 95% CI=7.21, 30.19) and the presence of an ear, face, or neck anomaly at birth (OR=93.70; 95% CI=42.14, 208.82).

CONCLUSIONS

Malignant yolk sac tumors and malignant teratomas exhibited distinct demographic and gestational characteristics; additionally, complications in pregnancy and labor may be brought on by specific histologic subtypes.

Current outlook of childhood cancer epidemiology in a middle-income country under a public health insurance program

In Mexico, childhood cancer (0-18 years) is treated in a multidisciplinary way while providing care for more than half of the affected children through a public medical insurance. This insurance is given to all children who do not have any health care coverage in Mexico. This program is offered to the poorest of all Mexicans. All the children with this disease are submitted to pathology diagnosis and treatment according to national treatment protocols from 57 accredited medical institutions. From 2007 to 2015, a total of 24,039 children with cancer have been registered; the male gender predominates by 55%. The highest incidence was in the group aged between 0 and 4 years. Every year, there has been an increment in registration. In 2015, there were 3,433 new patients with an incidence of 150.1/million. In the same year, the incidence for all types of leukemia increased to 89.5/million. But for acute lymphoblastic leukemia, the incidence was found to be 79.8/million, which is extremely high. The mortality rate for all these patients in 2015 was 5.3/100,000. However, with regard to children aged between 15 and 18 years, the mortality rate was 8.5/100,000. Abandonment rate was 10%, and there were nine state institutions that had a mortality rate between 25% and 50% among their patients. Coincidentally, as per the Human Development Index, the parameters for education, health, and income were low for those nine institutions. The purpose of this work is to show the epidemiology and the burden we are facing due to this disease.

Risk of Childhood Cancer and Socio-economic Disparities: Results of the French Nationwide Study Geocap 2002-2010

BACKGROUND

Socio-economic status is related to many life style and environmental factors, some of which have been suggested to influence the risk of childhood cancer. Studies requiring subject participation are usually hampered by selection of more educated parents. To prevent such bias, we used unselected nationwide Geographical Information System (GIS)-based registry data, to investigate the influence of socio-economic disparities on the risk of childhood cancer.

METHODS

The Geocap study included all French residents diagnosed with cancer aged up to 15 years over the period 2002-2010 (15 111 cases) and 45 000 contemporaneous controls representative of the childhood population. Area socio-economic characteristics used to calculate the European Deprivation Index (EDI) were based on census data collected on the fine scale of the Merged Islet for Statistical Information (IRIS).

RESULTS

Overall, the risk of acute lymphoblastic leukaemia (ALL) was lower in the most deprived quintile than in the other quintiles of EDI (OR_Q5vs<Q5 0.80 (95% confidence interval (CI) 0.73, 0.88)). The odds ratio for all the other cancers taken together was close to the null (OR_Q5vs<Q5 0.99 (95% CI 0.94, 1.04)).

CONCLUSION

Living in the most deprived areas was inversely associated with the risk of ALL in childhood. There was no indication that the risk of childhood cancer of any site could be increased by deprivation. Life style or environmental factors potentially underlying the association need further investigation.

Socioeconomic Status and Childhood Leukemia Incidence in Switzerland

Socioeconomic status (SES) discrepancies exist for child and adult cancer morbidity and are a major public health concern. In this Swiss population-based matched case–control study on the etiology of childhood leukemia, we selected the cases from the Swiss Childhood Cancer Registry diagnosed since 1991 and the controls randomly from census. We assigned eight controls per case from the 1990 and 2000 census and matched them by the year of birth and gender. SES information for both cases and controls was obtained from census records by probabilistic record linkage. We investigated the association of SES with childhood leukemia in Switzerland, and explored whether it varied with different definitions of socioeconomic status (parental education, living condition, area-based SES), time period, and age. In conditional logistic regression analyses of 565 leukemia cases and 4433 controls, we found no consistent evidence for an association between SES and childhood leukemia. The odds ratio comparing the highest with the lowest SES category ranged from 0.95 (95% CI: 0.71–1.26; P_trend = 0.73) for paternal education to 1.37 (1.00–1.89; P_trend = 0.064) for maternal education. No effect modification was found for time period and age at diagnosis. Based on this population-based study, which avoided participation and reporting bias, we assume the potential association of socioeconomic status and childhood leukemia if existing to be small. This study did not find evidence that socioeconomic status, of Switzerland or comparable countries, is a relevant risk factor or strong confounder in etiological investigations on childhood leukemia.

Poverty and the risk of leukemia and cancer in the central nervous system in children: A cohort study in a high-income country

AIMS

The association between childhood cancer and socioeconomic status is inconclusive. Family income has seldom been included in large population-based studies, and the specific contributions of it remain unknown.

METHODS

A total of 712,674 children born between 1967 and 2009 in the Oslo region were included. Of these, 864 were diagnosed with leukemia or cancer in the central nervous system before the age of 15 years. The association between poverty and childhood leukemia or brain cancer was analyzed using logistic regression and Cox proportional hazards models. Family income was stratified according to poverty lines. Parents' educational level and several perinatal variables were also examined.

RESULTS

Family poverty during the first 2 years of life was associated with lymphoid leukemia before the age of 15 years: odds ratio 1.72, 95% confidence interval 1.11-2.64. In the same age group we found a significant dose response, with a 21% increased risk of lymphoid leukemia with increasing poverty. The risk for intracranial and intraspinal embryonal tumors in the whole study period was lower for children in the middle family income category. For astrocytomas there was a more than 70% increased risk in the medium income category when analyzing the two first years of life. The observed increase was reduced when all years each child contributed to the study were included. The risk of cancer in the central nervous system overall was 20% higher in the medium income category compared to the high-income category.

CONCLUSIONS

Being born into a household of low family income the first 2 years of life was found to be a risk factor for development of lymphoid leukemia. For astrocytomas we observed an increased risk among children born into the medium income category throughout the first two years of life.

Descriptive Epidemiology in Mexican children with cancer under an open national public health insurance program

Background

All the children registered at the National Council for the Prevention and Treatment of Childhood Cancer were analyzed. The rationale for this Federal Government Council is to financially support the treatment of all children registered into this system. All patients are within a network of 55 public certified hospitals nationwide.

Methods

In the current study, data from 2007 to 2012 are presented for all patients (0–18 years) with a pathological diagnosis of leukemia, lymphoma and solid tumors. The parameters analyzed were prevalence, incidence, mortality, and abandonment rate.

Results

A diagnosis of cancer was documented in 14,178 children. The incidence was of 156.9/million/year (2012). The median age was 4.9. The most common childhood cancer is leukemia, which occurs in 49.8% of patients (2007–2012); and has an incidence rate of 78.1/million/year (2012). The national mortality rate was 5.3/100,000 in 2012, however in the group between 15 to 18 years it reaches a level of 8.6.

Conclusions

The study demonstrates that there is a high incidence of childhood cancer in Mexico. In particular, the results reveal an elevated incidence and prevalence of leukemia especially from 0 to 4 years. Only 4.7% of these patients abandoned treatment. The clinical outcome for all of the children studied improved since the establishment of this national program.

Residential traffic exposure and childhood leukemia: a systematic review and meta-analysis

CONTEXT

Exposure to elevated concentrations of traffic-related air pollutants in the near-road environment is associated with numerous adverse human health effects, including childhood cancer, which has been increasing since 1975. Results of individual epidemiologic studies have been inconsistent. Therefore, a meta-analysis was performed to examine the association between residential traffic exposure and childhood cancer.

EVIDENCE ACQUISITION

Studies published between January 1980 and July 2011 were retrieved from a systematic search of 18 bibliographic databases. Nine studies meeting the inclusion criteria were identified. Weighted summary ORs were calculated using a random effects model for outcomes with four or more studies. Subgroup and sensitivity analyses were performed.

EVIDENCE SYNTHESIS

Childhood leukemia was positively associated (summary OR=1.53, 95% CI=1.12, 2.10) with residential traffic exposure among seven studies using a postnatal exposure window (e.g., childhood period or diagnosis address) and there was no association (summary OR=0.92, 95% CI=0.78, 1.09) among four studies using a prenatal exposure window (e.g., pregnancy period or birth address). There were too few studies to analyze other childhood cancer outcomes.

CONCLUSIONS

Current evidence suggests that childhood leukemia is associated with residential traffic exposure during the postnatal period, but not during the prenatal period. Additional well-designed epidemiologic studies that use complete residential history to estimate traffic exposure, examine leukemia subtypes, and control for potential confounding factors are needed to confirm these findings. As many people reside near busy roads, especially in urban areas, precautionary public health messages and interventions designed to reduce population exposure to traffic might be warranted.

Childhood and adolescent cancer statistics, 2014

In this article, the American Cancer Society provides estimates of the number of new cancer cases and deaths for children and adolescents in the United States and summarizes the most recent and comprehensive data on cancer incidence, mortality, and survival from the National Cancer Institute, the Centers for Disease Control and Prevention, and the North American Association of Central Cancer Registries (which are reported in detail for the first time here and include high-quality data from 45 states and the District of Columbia, covering 90% of the US population). In 2014, an estimated 15,780 new cases of cancer will be diagnosed and 1960 deaths from cancer will occur among children and adolescents aged birth to 19 years. The annual incidence rate of cancer in children and adolescents is 186.6 per 1 million children aged birth to 19 years. Approximately 1 in 285 children will be diagnosed with cancer before age 20 years, and approximately 1 in 530 young adults between the ages of 20 and 39 years is a childhood cancer survivor. It is therefore likely that most pediatric and primary care practices will be involved in the diagnosis, treatment, and follow-up of young patients and survivors. In addition to cancer statistics, this article will provide an overview of risk factors, symptoms, treatment, and long-term and late effects for common pediatric cancers.

Poor treatment outcome of neuroblastoma and other peripheral nerve cell tumors may be related to under usage of radiotherapy and socio-economic disparity: a US SEER data analysis

PURPOSE

This study used receiver operating characteristic curve to analyze Surveillance, Epidemiology and End Results (SEER) neuroblastoma (NB) and other peripheral nerve cell tumors (PNCT) outcome data. This study found under usage of radiotherapy in these patients.

MATERIALS AND METHODS

This study analyzed socio-economic, staging and treatment factors available in the SEER database for NB and other PNCT. For the risk modeling, each factor was fitted by a generalized jinear model to predict the outcome (soft tissue specific death, yes/no). The area under the receiver operating characteristic curve (ROC) was computed. Similar strata were combined to construct the most parsimonious models. A random sampling algorithm was used to estimate the modeling errors. Risk of neuroendocrine (other endocrine including thymus as coded in SEER) death was computed for the predictors.

RESULTS

There were 5261 patients diagnosed from 1973 to 2009 were included in this study. The mean follow up time (S.D.) was 83.8 (97.6) months. The mean (SD) age was 18 (25) years. About 30.45% of patients were un-staged. The SEER staging has high ROC (SD) area of 0.58 (0.01) among the factors tested. We simplified the 4-layered risk levels (local, regional, distant, un-staged/others) to a simpler 3-tiered model with comparable ROC area of 0.59 (0.01). Less than 50% of PNCT patients received radiotherapy (RT) including the ones with localized disease. This avoidance of RT use occurred in adults and children.

CONCLUSION

The high under-staging rate may have prevented patients from selecting definitive radiotherapy (RT) after surgery. Using RT for, especially, adult PNCT patients is a potential way to improve outcome.

Childhood leukaemia and socioeconomic status in England and Wales 1976-2005: evidence of higher incidence in relatively affluent communities persists over time

BACKGROUND

Record-based studies have generally reported association of higher childhood leukaemia incidence with higher socioeconomic status (SES), but recent findings are less consistent.

METHODS

We examined records from the National Registry of Childhood Tumours for evidence of this association in England and Wales during 1976-2005. All eligible leukaemia registrations (N=11940) were grouped by year of diagnosis in decades centred on census years 1981, 1991 and 2001 (N=3748, 3922, 4270, respectively). Using data from the census appropriate to the decade, SES for each case was measured by the child-population-weighted quintile of the Carstairs deprivation index of the census ward containing the address at diagnosis.

RESULTS

In each decade, the age-standardised leukaemia rate in the poorest quintile was ∼90% of the rate in the most affluent. Using Poisson regression, the age-adjusted rate ratio per quintile decrease in SES was 0.96 (95% confidence interval 0.94-0.98; P<0.001 for trend) in 1976-1985, 0.97 (0.95-0.99; P=0.008) in 1986-1995 and 0.97 (0.95-0.99; P=0.009) in 1996-2005. Similar association was evident for lymphoid leukaemia, the major subgroup (N=9588 in total), but not for acute myeloid (N=1868) or other/unspecified leukaemia (N=484).

CONCLUSION

Reported childhood leukaemia incidence in England and Wales continues to be higher in relatively affluent communities. Possible explanations include under-diagnosis of leukaemia in children from poorer communities, and/or association of higher SES with hypothesised risk factors, such as population mixing and delayed exposure to infection.

Socioeconomic status and the incidence of non-central nervous system childhood embryonic tumours in Brazil

Background

Childhood cancer differs from most common adult cancers, suggesting a distinct aetiology for some types of childhood cancer. Our objective in this study was to test the difference in incidence rates of 4 non-CNS embryonic tumours and their correlation with socioeconomic status (SES) in Brazil.

Methods

Data was obtained from 13 Brazilian population-based cancer registries (PBCRs) of neuroblastoma (NB), Wilms'tumour (WT), retinoblastoma (RB), and hepatoblastoma (HB). Incidence rates by tumour type, age, and gender were calculated per one million children. Correlations between social exclusion index (SEI) as an indicator of socioeconomic status (SES) and incidence rates was investigated using the Spearman's test.

Results

WT, RB, and HB presented with the highest age-adjusted incidence rates (AAIRs) in 1 to 4 year old of both genders, whereas NB presented the highest AAIR in ≤11 month-olds. However, differences in the incidence rates among PBCRs were observed. Higher incidence rates were found for WT and RB, whereas lower incidence rates were observed for NB. Higher SEI was correlated with higher incidences of NB (0.731; p = 0.0117), whereas no SEI correlation was observed between incidence rates for WT, RB, and HB. In two Brazilian cities, the incidence rates of NB and RB were directly correlated with SEI; NB had the highest incidence rates (14.2, 95% CI, 8.6-19.7), and RB the lowest (3.5, 95% CI, 0.7-6.3) in Curitiba (SEI, 0.730). In Natal (SEI, 0.595), we observed just the opposite; the highest incidence rate was for RB and the lowest was for NB (4.6, 95% CI, 0.1-9.1).

Conclusion

Regional variations of SES and the incidence of embryonal tumours were observed, particularly incidence rates for NB and RB. Further studies are necessary to investigate risk factors for embryonic tumours in Brazil.