Prenatal irradiation and childhood cancer

Publisher Website
Google Scholar
Abstract
Estimates of the relative risk of childhood cancer, following irradiation during fetal life, are reported. They are based upon extended case-control investigations of childhood cancer deaths in England, Wales and Scotland between 1953 and 1979 comprising 14759 geographically-matched and birth-date-matched case/control pairs. The estimates were calculated using Conditional Logistic Regression (Miettinen-Breslow) techniques. This method of risk-estimation limits the distortions caused by confounding factors or by biased selection of controls. Through analysing a range of reported exposures other than radiation, levels of general reporting and recording biases between cases and controls were also assessed. There was no evidence among cases or controls of any systematic reduction in the frequency of pregnancy x-rays between 1950 and 1979. During this period of time, about 7 per cent of all childhood cancers, and 8 per cent of those with onset between the ages of 4 and 7 years, were caused by X-ray examinations. The dose-response relationship was one death per 990 obstetric X-ray examinations; or 2000 deaths per 104 man-Gy.