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Background: High birthweight is a potential risk factor for childhood brain tumours, particularly astrocytomas. We investigated several birth characteristics in relationship to brain cancers in young children., Methods: We obtained 849 invasive central nervous system (CNS) cancer cases, ages 0-4 years, from California's population-based cancer registry for 1988-1997. We matched 746 (88%) of these cases to a California live birth certificate. We randomly selected two control birth certificates for each case, matched on date of birth and gender. We used conditional logistic regression to obtain odds ratios (OR) and 95% CI. The birth characteristics examined included birthweight, gestational age, race, parental age, and parental education., Results: Analysing all CNS tumours combined, we found that children of other racial/ ethnic groups had OR below one compared with non-Hispanic white children. When adjusted for gestational age, race/ethnicity, and mother's place of birth, the OR for high birthweight (>/=4000 g) was 1.05 (95% CI: 0.79-1.38) compared with children with birthweights of 2500-3999 g. For astrocytomas (313 cases), the adjusted OR for high birthweight was 1.40 (95% CI: 0.90-2.18). When parental education was included in the model (available for only a subset of the birth years), the adjusted OR was 1.71 (95% CI: 1.01-2.90). High birthweight did not appear to be a risk factor for primitive neuroectodermal tumours (PNET)., Conclusions: We found high birthweight associated with increased risk of astrocytomas, but not PNET, in young children.

Racial patterns of childhood brain cancer by histologic type were studied using data from the Third National Cancer Survey and the Surveillance, Epidemiology, and End Results Program. Incidence rates for whites of all types combined and of astrocytic glioma and medulloblastoma were slightly higher than those for blacks. Proportionately more black than white cases of astrocytic glioma were diagnosed between the ages of 5-9 years; this difference corresponded to twofold-higher rates at ages of 0-4 and 10-14 years and similar rates at ages of 5-9 years among whites compared to rates among nonwhites. A real difference in age-incidence curves rather than diagnostic delay among blacks appeared to explain the differences. For medulloblastoma, the male-female rate ratio differed between whites (1.7) and blacks (1.0). Time trend analyses revealed statistically significant increases in medulloblastoma and glioma not otherwise specified (NOS) for incidences among blacks. The rate of microscopic confirmation was significantly higher among whites than among blacks, a difference apparently not explained by differences in the accessibility of tumors for biopsy. For avoidance of biased comparisons, differences in rates of microscopic confirmation and time trends for glioma NOS should be considered in studies of racial patterns of childhood brain cancer incidence by histologic type.

All Canadian deaths due to malignant brain tumour for the years 1970-73 were identified and analysed for country of birth. The years 1970-73 were chosen since in later years country of birth was no longer available for each death. The brain tumour population consisted of 1551 male and 1058 female deaths and matched controls were chosen from deaths due to other causes. Americans who died of brain tumour in Canada had a standardized mortality ratio (SMR) of 1.0 compared to their fellow Americans in the USA. Italian, German, Dutch and British immigrants had SMR between 1.5 and 2.6 compared to rates in their home countries and between 1.24 and 2.09 when compared to Canadian rates. A series of graphs shows the increased risk for male immigrants quite dramatically, and indicates that for females the increases were less pronounced. Further analysis showed that the excess risk is confined to those who were born in Western Europe while their Canadian-born children experienced the same rates as all Canadians. Based on the limited information available, occupation could not be shown to play a role in establishing risk. An attempt was made to pinpoint the years of immigration which showed the greatest risk. It is concluded that the determination of risk of brain tumour has a strong environmental component. The possibilities for identification of this component are discussed.