A pooled multisite analysis of the effects of atopic medical conditions in glioma risk in different ethnic groups.

PURPOSE: The incidences of atopic conditions (allergies, asthma, or eczema) and glioma vary by ethnicity. Atopic conditions are inversely associated with gliomas. We conducted a pooled multisite study investigating the associations of atopic conditions with glioma in different race/ethnicity groups. METHODS: Using glioma cases and healthy controls, unconditional logistic regression was conducted to assess the associations of atopic conditions with glioma separately in white, black, Asian, and Hispanic subpopulations. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated. RESULTS: Glioblastoma multiforme cases were less likely than controls to report a history of atopic conditions in whites (OR = 0.46, [95% CI, 0.38-0.54]) and Asians (OR = 0.27, [95% CI, 0.10-0.73]). The same trend was seen when looking at glioma cases of all histologies. An inverse association was not seen in blacks for glioblastoma multiforme or all histologies combined. CONCLUSIONS: The inverse association between glioma and atopic conditions may vary by ethnicity due to a difference in the biology of atopic conditions in different ethnicities but may be due to chance because of the limitations of small nonwhite sample sizes.