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Background: Domestic and parental occupational pesticide exposures are suspected of involvement in the occurrence of childhood acute leukaemia (AL), but the role of exposure to agricultural activities is little known. In a previous ecological study conducted in France, we observed an increase in acute lymphoblastic leukaemia (ALL) incidence rate with increasing viticulture density in the municipalities of residence at diagnosis.Objectives: This study aimed to test the hypothesis that residential proximity to croplands at birth increases the risk of childhood AL, with a particular focus on vineyards.Methods: We identified all the primary AL cases diagnosed before the age of 15 years in the cohorts of children born in the French municipalities between 1990 and 2015. We estimated crop densities in each municipality of residence at birth using agricultural census data, for ten crop types. Variations in standardized incidence ratios (SIR) were evaluated with Poisson regression models, for all AL, ALL and acute myeloid leukaemia (AML), separately.Results: Among the 19,809,700 children born and residing in mainland France at birth in 1990-2015, 8,747 AL cases (7,236 ALL and 1,335 AML) were diagnosed over the period. We did not evidence any statistically significant positive association between total crop density or any specific crop density in the municipality of residence at birth and all AL, ALL or AML. Interestingly, we observed a higher ALL incidence rate in the municipalities with the highest viticulture densities (SIR = 1.25 95%CI [1.01-1.54]). Adjusting for the main potential confounders did not change the results.Conclusion: Our study does not support the hypothesis that residential proximity to croplands, particularly vineyards, around birth plays a role in childhood leukaemia. The slightly higher ALL incidence rate in children born in the municipalities with the highest viticulture densities may reflect the previously-observed association at diagnosis. [ABSTRACT FROM AUTHOR]

BACKGROUND: Pesticide exposures are suspected of being a risk factor for several childhood cancers, particularly acute leukemia (AL). Most of the evidence is based on self-reported parental domestic use of pesticides, but some studies have also addressed associations with agricultural use of pesticides near the place of residence. OBJECTIVES: The objective of the study was to evaluate the risk of AL in children living close to vines, a crop subject to intensive pesticide use. METHODS: Data were drawn from the national registry-based GEOCAP study. We included all of the AL cases under the age of 15 years diagnosed in 2006–2013 (푛 = 3,711) and 40,196 contemporary controls representative of the childhood population in France. The proximity of the vines (probability of presence within 200, 500, and 1,000 m) and the viticulture density (area devoted to vines within 1,000 m) were evaluated around the geocoded addresses in a geographic information system combining three national land use maps. Logistic regression models were used to estimate odds ratios (ORs) for all AL and for the lymphoblastic (ALL) and myeloid (AML) subtypes. Heterogeneity between regions was studied by stratified analyses. Sensitivity analyses were carried out to take into account, in particular, geocoding uncertainty, density of other crops and potential demographic and environmental confounders. RESULTS: In all, about 10% of the controls lived within 1 km of vines. While no evidence of association between proximity to vines and AL was found, viticulture density was positively associated with ALL [OR=1.05 (1.00–1.09) for a 10% increase in density], with a statistically significant heterogeneity across regions. No association with AML was observed. The results remained stable in all the sensitivity analyses. CONCLUSION: We evidenced a slight increase in the risk of ALL in children living in areas with high viticulture density. This finding supports the hypothesis that environmental exposure to pesticides may be associated with childhood ALL. [ABSTRACT FROM AUTHOR]

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. With 25 877 cases registered nationwide over 15 years, this study provides substantial information on the spatial and temporal variations of childhood cancer. A review of recent published papers on spatial and temporal variations of childhood cancer is also provided. Several complementary methods were used to highlight main spatial and temporal trends in the incidence rate of all childhood cancers in France. Several types of childhood cancer displayed some spatial heterogeneity, and two large unexplained clusters were detected. Spatial differences in case ascertainment cannot be ruled out. Overall, the results do not support a sustained increase in incidence rates of childhood cancer in recent years. [ABSTRACT FROM AUTHOR]

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 (ORQ5vsConclusion: 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. [ABSTRACT FROM AUTHOR]

Childhood head and neck cancers (HNC) are rare and represent a complex group of anatomical topographies. The aim of this study is to describe the distribution, the incidence and survival rates of children with malignant HNC in France. A population-based study was conducted between 2000 and 2015 in children less than 15 years with a diagnosis of HNC using the French National Registry of Childhood Cancers database (RNCE). Age-standardized incidence rates (ASR) and survival analysis were performed. The 1623 included HNC represented 5.6% of all cancers included in the RNCE. The thyroid was the leading tumor site category (26.6%), followed by head and neck soft tissue location (15.4%) and the nasopharynx (10.8%). The most common cancers were thyroid gland carcinomas (26.1%), rhabdomyosarcomas (23.9%) and Burkitt Lymphomas (8.6%). Nasopharynx cancers and soft-tissue sarcomas were statistically more frequent in boys, while thyroid carcinomas were significantly more frequent in girls. The annual ASR was 8.6 new cancer cases per million children. For all HNC combined, the 5-year overall survival (OS) was 87.7% [95%CI: 85.9–89.2]. There was no statistically significant variation in 5-year OS between 2000-2007 and 2008–2015. Epidemiological data on HNC distribution, incidence and survival contributes to better understand these tumors by quantifying their impact on the French population and assessing their burden. Regarding the exclusion of topographies and some histological origins performed by some authors, this report proposes new recommendations to study HNC in a pediatric population. • Main sites: thyroid (27%), pharynx (17%), and head and neck soft tissue (15%) • Histologies: carcinomas (37%), rhabdomyosarcomas (24%), Burkitt lymphomas (9%) • Annual age-standardized incidence rate, 8.6 per million children, stable over time • 5-year overall survival: 88%, lowest for rhabdoid tumors (29%), osteosarcomas (65%) • Better 5-year OS for H&N compared to all sites for neuroblastomas and Ewing tumors [ABSTRACT FROM AUTHOR]

Pesticide exposure is suspected to play a role in the etiology of childhood leukemia (AL). Various sources of exposure have been explored, but few studies have investigated the risk of childhood AL in relation to residential exposure to agricultural pesticides. Since around 50% of France is agricultural land, with marked pesticide use, France is a suitable location to investigate for an association. We aimed to analyze the association between the agricultural crop density in the municipalities of France and the incidence of childhood AL between 1990 and 2014. 11,487 cases of AL diagnosed in children aged 0–14 years were registered by the French National Registry of Childhood Hematological Malignancies over 1990–2014. National agricultural census data for 1990, 2000 and 2010 were used to estimate the densities of the most common crops in France. The incidence of AL was estimated in the 35,512 municipalities, by age and gender, and 3 observation periods, and expressed as the standardized incidence ratio (SIR). We observed a moderate log-linear association between viticulture density and the incidence of AL, with a 3% increase in SIR for a 10% increase in viticulture density (SIRR = 1.03; 95%CI [1.00–1.06]). The association remained for lymphoblastic AL but not for myeloid AL. The association was stable after stratification by geographic area, age and period, and after adjustment on UV radiation and a French deprivation index. No consistent association was observed for other crop types. This nationwide study shows a moderate increase in incidence of childhood AL in municipalities where viticulture is common. Future individual studies are needed to know whether this observation is confirmed and related to particular use of pesticides. • Children living close to agricultural crops may be exposed to pesticides, and therefore at increased risk of leukemia. • Nationwide registry-based study on the link between crop density in the municipalities and incidence of childhood leukemia. • We found a moderate increase in incidence of childhood leukemia in municipalities with the highest density of viticulture. • Further works needed on individual exposures to pesticides used for viticulture and other crops close to the residences. [ABSTRACT FROM AUTHOR]

BACKGROUND: Exposures to high-dose ionizing radiation and high-dose rate ionizing radiation are established risk factors for childhood acute leukemia (AL). The risk of AL following exposure to lower doses due to natural background radiation (NBR) has yet to be conclusively determined. METHODS: AL cases diagnosed over 1990-2009 (9,056 cases) were identified and their municipality of residence at diagnosis collected by the National Registry of Childhood Cancers. The Geocap study, which included the 2,763 cases in 2002-2007 and 30,000 population controls, was used for complementary analyses. NBR exposures were modeled on a fine scale (36,326 municipalities) based on measurement campaigns and geological data. The power to detect an association between AL and dose to the red bone marrow (RBM) fitting UNSCEAR (United Nations Scientific Committee on the Effects of Atomic Radiation) predictions was 92%, 45% and 99% for exposure to natural gamma radiation, radon and total radiation, respectively. RESULTS: AL risk, irrespective of subtype and age group, was not associated with the exposure of municipalities to radon or gamma radiation in terms of yearly exposure at age reached, cumulative exposure or RBM dose. There was no confounding effect of census-based socio-demographic indicators, or environmental factors (road traffic, high voltage power lines, vicinity of nuclear plants) related to AL in the Geocap study. CONCLUSIONS: Our findings do not support the hypothesis that residential exposure to NBR increases the risk of AL, despite the large size of the study, fine scale exposure estimates and wide range of exposures over France. However, our results at the time of diagnosis do not rule out a slight association with gamma radiation at the time of birth, which would be more in line with the recent findings in the UK and Switzerland. CITATION: Demoury C, Marquant F, Ielsch G, Goujon S, Debayle C, Faure L, Coste A, Laurent O, Guillevic J, Laurier D, Hémon D, Clavel J. 2017. Residential exposure to natural background radiation and risk of childhood acute leukemia in France, 1990-2009. Environ Health Perspect 125:714-720; http://dx.doi.org/10.1289/EHP296 [ABSTRACT FROM AUTHOR]

Childhood leukemia may be associated with traffic-related environmental exposure to benzene, and additional data are needed. The Géolocalisation des Cancers Pédiatriques (GEOCAP) Study, a nationwide French case-control study, was designed to avoid selection bias due to differential participation and misclassification. The study compared the 2,760 childhood leukemia cases diagnosed in France between 2002 and 2007 (including 2,275 cases of acute lymphoblastic leukemia (ALL) and 418 cases of acute myeloblastic leukemia (AML)) with 30,000 contemporaneous child population controls. The residence addresses were precisely geocoded, and 3 indicators of residential proximity to traffic were considered. Estimates of benzene concentrations were also available for the Île-de-France region (including Paris). A 300-m increase in major road length within 150 m of the geocoded address was significantly associated with AML (odds ratio = 1.2, 95%confidence interval: 1.0, 1.4) but not with ALL (odds ratio = 1.0, 95% confidence interval: 0.9, 1.1), and the association was reinforced in the Île-de-France region when this indicator was combined with benzene estimates. These results, which were free from any participation bias and based on objectively determined indices of exposure, showed an increased incidence of AML associated with heavy-traffic road density near a child's home. The results support a role for traffic-related benzene exposure in the etiology of childhood AML. [ABSTRACT FROM AUTHOR]

The role of natural background radiation (NBR) in childhood acute leukemia (AL) remains unclear. Several large record based studies have recently reported heterogeneous results. Differences in exposure assessment timing may explain this heterogeneity. In a previous ecological study we did not observe any association between childhood AL incidence in France and NBR exposure at the time of diagnosis. With the same methodology, the present study focused on NBR exposure at the time of birth. Based on data from the French national registry of childhood cancer, we analyzed all AL together, and lymphoblastic and myeloid AL, separately. We included 6,059 childhood AL cases born and diagnosed in mainland France between 1990 and 2009. NBR levels in municipalities of residence at birth were estimated by cokriging models, using NBR measurements and precise geological data. The incidence rate ratio (IRR) per unit variation of exposure was estimated with Poisson regression models, with adjustment for socio-demographic indicators and ultraviolet radiation levels. NBR exposures were considered at the time of birth, and cumulatively from birth to diagnosis. We also estimated a total NBR dose to red-bone marrow (RBM). There was no evidence for an association between NBR exposure at birth and childhood AL incidence, neither overall (gamma radiation: IRR = 0.99 (0.94,1.05) per 50 nSv/h; radon: IRR = 0.97 (0.91,1.03) per 100 Bq/m3) nor for the main AL types. The conclusions were similar with the cumulative exposures, and the total RBM dose. The study was based on high quality incidence data, large numbers of AL cases, and validated models of NBR exposure assessment. In all, the results further support the hypothesis that NBR are not associated to childhood AL in France. • The initiation process of childhood leukemia might begin during the perinatal term. • Nationwide study on background radiation exposure at birth and childhood leukemia. • Complete registration of childhood leukemia in France (6,059 cases over 1990–2009). • Cockriging models based on radiation measurements (>10,000 sites) and geological maps. • Exposure to background radiation at birth not associated with childhood leukemia. [ABSTRACT FROM AUTHOR]