Risk Factor For Childhood Acute Leukemia Research Articles

Prenatal exposure to traffic-related air pollution and childhood acute leukaemia in France - GEOCAP Birth 2010-2015

Background and aim: Acute leukemia (AL) affect approximately 500 children under 15 each year in France. Living near major roads and being exposed to traffic-related air pollutants are increasingly suggested as risk factors for childhood AL. The present GIS-based registry-based case-control study investigates the hypothesis that prenatal exposures to traffic-related pollutants increase the risk of AL, using exposure at the residence at birth as a proxy of prenatal exposure. Methods: the study included all the AL cases born and diagnosed in France during 2010-2015 (n=728) and 11,908 controls representative of the French births during the same period. Addresses of residence at birth were geocoded. Exposure indicators were the length of major roads within 150 m of the address, and the concentrations of NO2, fine particulate matter (PM2.5) and black carbon (BC) estimated by land use regression models. Odds-ratios were estimated for several exposure categories and under the hypothesis of a log-linear increase in childhood AL risk with increasing level of exposure, using unconditionnal logistic regression models (all AL) and polytomic logistic models (AL subtypes). The analyses were also stratified according to the degree of urbanization of the municipality. Results: childhood AL was not associated with major road length. Overall, PM2.5 and BC concentrations were associated with an increased risk of childhood AL (OR=1.3 [1.2-1.4] and OR=1.1 [1.0-1.2] per inter-quartile range increase, respectively). However, no positive association was observed for BC when the effect of BC was isolated from that of total PM2.5. Stratifying by urbanization status did not change the results for PM2.5 but the associations were weaker for BC especially in most urban areas. Non-significant positive associations were observed for NO2. Conclusions: our findings suggest a role of prenatal exposure to traffic-related air pollution in childhood AL. Keywords: Childhood leukemia; road traffic; air pollution; prenatal exposure

Parental smoking, maternal alcohol, coffee and tea consumption during pregnancy, and childhood acute leukemia: the ESTELLE study.

To investigate the role of parental smoking during pre-conception and pregnancy, maternal beverage consumption (alcohol, coffee and tea) during pregnancy and their possible interactions, in the etiology of childhood acute leukemia (CL). The ESTELLE study included 747 cases of CL [636 cases of acute lymphoblastic leukemia (ALL) and 100 cases of acute myeloblastic leukemia (AML)] diagnosed in France in 2010-2011 and 1,421 population controls frequency-matched with the cases on age and gender. Data were obtained from structured telephone questionnaires administered to the mothers. The odds ratios (OR) and their 95 % confidence intervals were estimated using unconditional logistic regression models adjusted for potential confounders. AML, but not ALL, was non-significantly associated with alcohol drinking during pregnancy [OR = 1.3 (0.8-2.0)] with a significant positive dose-response trend (p-trend = 0.02). Pre-conception paternal smoking was significantly associated with ALL [OR = 1.2 (1.1-1.5)] and AML [OR = 1.5 (1.0-2.3)]. CL was not associated with maternal smoking [OR = 1.0 (0.8-1.2)], or maternal coffee [OR = 0.9 (0.8-1.1)] or tea drinking [OR = 0.9 (0.8-1.1)] during pregnancy. However, a high consumption of coffee (>2 cups/day) was significantly associated with ALL [OR = 1.3 (1.0-1.8)]. The findings constitute additional evidence that maternal alcohol drinking during pregnancy may be involved in AML, and that paternal smoking before pregnancy may be a risk factor for CL. The role of maternal coffee drinking in CL remains unclear and should be investigated further in consortium analyses and in large birth cohort studies with exposure assessment more contemporaneous with the exposure, before the occurrence of the disease.

PESTICIDES EXPOSURE AND THE RISK OF CHILDHOOD ACUTE LEUKEMIA

Background and Aims: Acute leukemia (AL) is one of the most common malignant tumors among children below the age of 15, and pesticide has been hypothesized as one of the risk factors for AL. In this study, the association between pesticide exposure and the risk of childhood AL is evaluated. Methods: A total of 248 patients with newly diagnosed AL were recruited from four pediatric hospitals in Shanghai between January 1, 2006 and December 31, 2010, and 111 controls were matched with the cases based on gender and age. Pesticide exposure was determined by questionnaire and by measuring of organophosphate pesticide (OP) metabolites including Diethyl phosphrate (DEP), Dimethyl phophrate (DMP), Dimethyl thiophosphrate (DMTP), Diethyl thiophosphrate (DETP) and Diethyl dithiophosphrate (DEDTP) in the subjects’ urine using gas chromatography with a flame photometric detector. Results: Total environmental chemical exposure of children [odds ratio (OR)= 9.320, 95% confidence interval (CI):2.842-30.568], maternal chemical exposure during pre-gestation and pregnancy (OR=3.333; 95%CI:1.524-7.289), household use of pesticides (OR=1.786; 95%CI:1.128-2.830), and household use of mosquito insecticides (OR=2.225; 95%CI:1.304-3.796) increased the risk of childhood AL. Median concentrations of organophosphate metabolites (DEP, DMP, DMTP, DETP and DEDTP) in the cases (5.7296, 9.6673, 14.0634, 4.3642, 3.8472µg/gCr respectively) were significantly higher than those in the controls (1.6901, 1.6828, 0.8451, 0.7221, 0.7221µg/gCr respectively) (P<0.05). Conclusions: This study found that chemical exposure and household use of pesticides, especially mosquito insecticides, might be associated with childhood AL, based on higher urine OPs levels in children with AL compared with those in the controls. Our findings add some evidence to the hypothesis that pesticides might be a risk factor for childhood AL. This association of AL risk with pesticide exposure merits further studies to confirm the association.