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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]

This study investigated the role of factors considered related to early stimulation of the immune system in the etiology of childhood acute leukemia. The national registry-based case-control study ESCALE was carried out in France in 2003–2004. Population controls were frequency matched to cases on age and gender. Data were obtained from structured telephone questionnaires administered to mothers. Odds ratios were estimated using unconditional regression models adjusted for potential confounders. Included were 634 acute lymphoblastic leukemia cases, 86 acute myeloblastic leukemia cases, and 1,494 controls aged ≥1 year. Negative associations were observed between acute lymphoblastic leukemia and birth order (P for trend < 0.0001), attendance at a day-care center before age 1 year (odds ratio (OR) = 0.8, 95% confidence interval (CI): 0.6, 1.1), prolonged breastfeeding (OR = 0.7, 95% CI: 0.5, 1.0), repeated early common infections (OR = 0.7, 95% CI: 0.6, 0.9), regular contact with farm animals (OR = 0.6, 95% CI: 0.5, 0.8), frequent farm visits in early life (OR = 0.4, 95% CI: 0.3, 0.6), and history of asthma (OR = 0.7, 95% CI: 0.4, 1.0) or eczema (OR = 0.7, 95% CI: 0.6, 0.9). Results support the hypothesis that repeated early infections and asthma may play a role against childhood acute leukemia. [ABSTRACT FROM PUBLISHER]

Background: The risk of bladder cancer has been shown to be increased in occupations which are likely to involve exposure to polycyclic aromatic hydrocarbons (PAH), but up to now, most studies have considered this exposure in terms of job title.Methods: A hospital-based case-control study of 658 male cases of bladder cancer and 658 male controls was carried out in five areas of France from 1984 to 1987. For each subject, occupational exposure to PAH was assessed from questionnaires by an expert according to a semi-quantitative index of exposure.Results: The overall odds ratio for PAH exposure, adjusted for smoking, coffee drinking and occupational exposure to aromatic amines was estimated at 1.3 (95% CI: 1.0-1.7, P < 0.05). A slight but clear dose-response relationship was observed, and the trend remained significant after adjustment for cumulative smoking, with odds ratios of 1.2 (95% CI: 0.9-1.7), 1.4 (95% CI: 0.9-2.2) and 1.8 (95% CI: 0.8-3.9) for low, medium and high average exposures respectively compared to subjects unexposed to PAH (P for trend < 0.05). Moreover, the association between bladder cancer and PAH exposure was also investigated in a category of smokers homogeneous with respect to their tobacco consumption. In this heavy-smoker group, a stronger association with PAH was detected.Conclusions: These results support the hypothesis of a causal relationship between occupational exposure to PAH and bladder cancer risk. [ABSTRACT FROM AUTHOR]