Handedness and the risk of glioma.

Gliomas are the most common type of malignant primary brain tumor and few risk factors have been linked to their development. Handedness has been associated with several pathologic neurological conditions such as schizophrenia, autism, and epilepsy, but few studies have evaluated a connection between handedness and risk of glioma. In this study, we examined the relationship between handedness and glioma risk in a large case-control study (1849 glioma cases and 1354 healthy controls) and a prospective cohort study (326,475 subjects with 375 incident gliomas). In the case-control study, we found a significant inverse association between left handedness and glioma risk, with left-handed persons exhibiting a 35% reduction in the risk of developing glioma [odds ratio (OR) = 0.65, 95% confidence interval (CI) 0.51-0.83] after adjustment for age, gender, race, education, and state of residence; similar inverse associations were observed for GBM (OR = 0.69, 95% CI 0.52-0.91), and non-GBM (OR = 0.59, 95% CI 0.42-0.82) subgroups. The association was consistent in both males and females, and across age strata, and was observed in both glioblastoma and in lower grade tumors. In the prospective cohort study, we found no association between handedness and glioma risk (hazards ratio = 0.92, 95% CI 0.67-1.28) adjusting for age, gender, and race. Further studies on this association may help to elucidate mechanisms of pathogenesis in glioma.

Older age at the completion of linear growth is associated with an increased risk of adult glioma.

PURPOSE: To examine the association of age when adult height was attained with glioma risk. METHODS: We analyzed data from a US-based case-control study of glioma risk factors. Logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (CI) associated between age at attainment of adult height and glioma risk. Multivariate models were adjusted for age, race, sex, education, and state of residence. We examined associations overall, and according to glioma grade, sex, and final adult height. RESULTS: The study set included n = 951 controls and n = 776 cases, with a median age of 56 (18-92); the majority was male (53.8%) and identified as Caucasian. Older age at height completion was associated with an increased risk of glioma. A significant positive trend was observed both for glioblastoma (OR 1.10; 95% CI 1.04-1.17 per 1-year increase in age) and lower grade non-glioblastoma subtypes combined (OR 1.18; 95% CI 1.10-1.28 per year increase in age). The association was observed in men and women, and in all categories of final adult height. CONCLUSIONS: We observed for the first time a positive association between glioma risk and a prolonged adolescent growth phase. Our results suggest a role for factors governing the timing and intensity of growth in adolescence as risk-determining exposures in adult glioma.

Analgesic use and the risk of primary adult brain tumor.

Glioma and meningioma are uncommon tumors of the brain with few known risk factors. Regular use of aspirin has been linked to a lower risk of gastrointestinal and other cancers, though evidence for an association with brain tumors is mixed. We examined the association of aspirin and other analgesics with the risk of glioma and meningioma in a large US case-control study. Cases were persons recently diagnosed with glioma or meningioma and treated at medical centers in the southeastern US. Controls were persons sampled from the same communities as the cases combined with friends and other associates of the cases. Information on past use of analgesics (aspirin, other anti-inflammatory agents, and acetaminophen) was collected in structured interviews. Logistic regression was used to estimate odds ratios (ORs) and 95 % confidence intervals (CIs) for analgesic use adjusted for potential confounders. All associations were considered according to indication for use. A total of 1123 glioma cases, 310 meningioma cases and 1296 controls were included in the analysis. For indications other than headache, glioma cases were less likely than controls to report regular use of aspirin (OR 0.69; CI 0.56, 0.87), in a dose-dependent manner (P trend < 0.001). No significant associations were observed with other analgesics for glioma, or any class of pain reliever for meningioma. Results suggest that regular aspirin use may reduce incidence of glioma.