γ-Radiation Sensitivity and Risk of Glioma

• Published in: JNCI : Journal of the National Cancer Institute 2001-10, Vol.93 (20), p.1553-1557
• Main Authors: Bondy, Melissa L., Wang, Li-E., El-Zein, Randa, de Andrade, Mariza, Selvan, Mano S., Bruner, Janet M., Levin, Victor A., Alfred Yung, W. K., Adatto, Phyllis, Wei, Qingyi
• Format: Article
• Language: English
• Subjects: Adult; Animals; Brain Neoplasms - epidemiology; Brain Neoplasms - etiology; Brain Neoplasms - genetics; Case-Control Studies; Chromatids - radiation effects; Chromatids - ultrastructure; Chromosome Breakage; Demecolcine - pharmacology; DNA - radiation effects; DNA Damage; DNA Repair - genetics; DNA Repair - radiation effects; DNA, Single-Stranded - radiation effects; Female; Gamma Rays - adverse effects; Genetic Predisposition to Disease; Glioma - epidemiology; Glioma - etiology; Glioma - genetics; Humans; Lymphocytes - pathology; Lymphocytes - radiation effects; Male; Middle Aged; Neoplasms, Radiation-Induced - epidemiology; Neoplasms, Radiation-Induced - etiology; Neoplasms, Radiation-Induced - genetics; Odds Ratio; Radiation Tolerance - genetics; Risk; Smoking - epidemiology
• ISSN: 0027-8874; 1460-2105
• DOI: 10.1093/jnci/93.20.1553

Background: About 9% of human cancers are brain tumors, of which 90% are gliomas. γ-Radiation has been identified as a risk factor for brain tumors. In a previous pilot study, we found that lymphocytes from patients with glioma were more sensitive to γ-radiation than were lymphocytes from matched control subjects. In this larger case–control study, we compared the γ-radiation sensitivity of lymphocytes from glioma patients with those from control subjects and investigated the association between mutagen sensitivity and the risk for developing glioma. Methods: We used a mutagen sensitivity assay (an indirect measure of DNA repair activity) to assess chromosomal damage. We γ-irradiated (1.5 Gy) short-term lymphocyte cultures from 219 case patients with glioma and from 238 healthy control subjects frequency matched by age and sex. After irradiation, cells were cultured for 4 hours, and then Colcemid was added for 1 hour to arrest cells in mitosis. Fifty metaphases were randomly selected for each sample and scored for chromatid breaks. All statistical tests were two-sided. Results: We observed a statistically significantly higher frequency of chromatid breaks per cell from case patients with glioma (mean = 0.55; 95% confidence interval [CI] = 0.50 to 0.59) than from control subjects (mean = 0.44; 95% CI = 0.41 to 0.48) (P