Diagnostic X-rays and risk of epithelial ovarian carcinoma in Jews

PURPOSE: To test the hypothesis that there would be ethnic differences in susceptibility to ionizing radiation from diagnostic x-rays. METHODS: In a hospital-based study we compared reports of diagnostic x-rays to the lower abdomen and pelvis in incident cases of epithelial ovarian carcinoma (N = 161), community controls (N = 156) and convenience controls (N = 87). RESULTS: Thirty-nine per cent of cases and 31% of controls recalled x-rays more than 10 years before; 27% of cases and 14% of controls reported four Jewish grandparents. Comparing the cases with community controls, the odds ratio (95% confidence interval) for Jews versus non-Jews among women reporting no x-rays was 1.02 (0.37-2.79); among women reporting x-rays the estimate for Jews was 8.91 (2.00-39.6). Consistent results were seen with inclusion of convenience controls. Jewish cases reported an excess of pelvic diagnostic x-rays from age 20 onward and an excess of barium enemas and pyelograms. CONCLUSIONS: These preliminary findings require confirmation in other studies. They suggest that the known excess risk of this carcinoma in Jews might be associated with exposure to x-rays and add to a previous observation of an altered susceptibility to ionizing radiation in Jews. If confirmed, they would suggest a need for continued vigilance to evaluate the risks and benefits of diagnostic x-rays in individuals, regardless of ethnic origin, who might carry mutations in DNA repair genes.