Mutation of the p53 tumor suppressor gene is the most common mutation yet found in human cancer. Preliminary evidence suggests that at least 30% of newly diagnosed astrocytomas contain p53 mutations. The characteristics of p53 mutation in astrocytoma indicate that such mutations may be associated with agents which increase cell proliferation. Vitamins E and C may increase cell growth and therefore may be related to the occurrence of p53 mutation. Paradoxically, these antioxidants also inhibit carcinogenesis. The purpose of this case-control study is to determine: 1) whether vitamins E or C increase or decrease the risk of astrocytoma; 2) whether odds ratios for these antioxidants are modified by stratification on the presence of p53 tumor suppressor gene mutation. First, dietary intake and plasma levels of vitamins E and C of astrocytoma cases will be compared with plasma levels and dietary intake of controls. Second, subgroups among whom the odds ratios for vitamins E or C differ from those for the data set as a whole will be identified. Third, odds ratios for these antioxidants among cases having p53 mutation will be compared with odds ratios among cases showing no evidence of p53 mutation. If vitamins E or C alter the risk of astrocytoma by being positively or negatively correlated with mutation of the p53 gene, then stratification on p53 status will strengthen these antioxidant odds ratios. This study is designed as an age-sex-race matched case-control study. Patients newly diagnosed with astrocytoma will be identified at The Ohio State University, Columbus Children's, and Riverside Hospitals. Controls will be selected from among patients attending the clinic where the case was first diagnosed. We expect to interview 190 astrocytoma patients and their 190 matched controls. This sample size has 80% power to detect an odds ratio of 1.8. We will use conditional logistic regression to estimate the odds ratios and adjust for potential confounders.
