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Previous studies have shown that glioma patients report allergies less frequently than controls, harbor lower atopy-associated IgE levels, and harbor different frequencies of polymorphisms in the IL13 and IL4 pathways than controls. We sought to confirm this latter result and extend the analysis to IgE levels. Glioma patients (n = 456) and controls (n = 541) were genotyped for genetic variants in IL4, IL4R, and IL13 and tested for total IgE levels (n = 248 controls and 289 cases). Among Whites, IL4 and IL4R polymorphisms and haplotypes were neither significantly associated with IgE levels in controls nor associated with glioma status. IL13 R110G and C-1112T were associated with increased IgE levels in controls (P < 0.001 and P = 0.04, respectively), and IL13 C-1112T was inversely associated with case-control status (P = 0.05, test for trend in dose model). An IL4R haplotype was borderline associated with increased risk in case-control analysis [odds ratio (OR), 1.5; 95% confidence interval (95% CI), 1.0-2.3]. In addition, a rare haplotype for IL4 was associated with decreased risk (OR, 0.23; 95% CI, 0.07-0.83), and a common haplotype in IL13 was associated with decreased risk (OR, 0.73; 95% CI, 0.53-1.00). Our data provide evidence for a role of IL13 polymorphisms on IgE levels and a role for IL4, IL4R, and IL13 haplotypes on case-control status. We did not find any evidence that the interleukin (IL) polymorphisms exerted their effect on glioma risk via their effects on IgE levels. Further exploration of immune susceptibility factors, including genetics, in glioma etiology is advisable. (Cancer Epidemiol Biomarkers Prev 2007;16(6):1229–35)

Background: Risk factors for adult glioma in the San Francisco Bay Area include well-known demographic features such as age and race/ethnicity, and our previous studies indicated that these characteristics are associated with the TP53 mutation status of patients' tumors. We enlarged our study to assess the relationships of risk factors with TP53 as well as epidermal growth factor receptor (EGFR) and murine double minute-2 (MDM2) gene amplification and expression and the germ line Leu84Phe polymorphism in the DNA repair protein O6-methylguanine-DNA-methyltransferase (MGMT). MGMT expression may depend on the TP53 status of cells.Methods: Molecular analyses were carried out on 556 incident astrocytic tumors. MGMT genotype data were collected on germ line DNA from 260 of these cases.Results: The tumor data confirm the inverse relationships between TP53 mutation and MDM2 (P = 0.04) or EGFR (P = 0.004) amplification and that patients whose tumors contain TP53 mutations are younger than those without (P < 0.001). Although there was little difference in age of patient by EGFR amplification or expression among glioblastoma multiforme cases, EGFR gene amplification was associated with much older age of onset of anaplastic astrocytoma; for example, EGFR-amplified anaplastic astrocytoma cases were on average 63 years old compared with 48 years for nonamplified cases (P = 0.005). An increased prevalence of TP53 mutation positive glioblastoma multiforme was noted among nonwhites (African American and Asian) compared with whites (Latino and non-Latino; P = 0.004). Carriers of the MGMT variant 84Phe allele were significantly less likely to have tumors with TP53 overexpression (odds ratio, 0.30; 95% confidence interval, 0.13-0.71) and somewhat less likely to have tumors with any TP53 mutation (odds ratio, 0.47; 95% confidence interval, 0.13-1.69) after adjusting for age, gender, and ethnicity. Interestingly, EGFR gene amplification and EGFR protein overexpression were also inversely associated with the MGMT 84Phe allele.Conclusions: Our results are consistent with ethnic variation in glioma pathogenesis. The data on MGMT show that an inherited factor involving the repair of methylation and other alkylation damage, specifically to the O6 position of guanine, may be associated with the development of tumors that proceed in their development without TP53 mutations or accumulation of TP53 protein and possibly also those that do not involve amplification of the EGFR locus.