Radiation and cancer risk in atomic-bomb survivors

Abstract

With the aim of accurately assessing the effects of radiation exposure in the Japaneseatomic-bomb survivors, the Radiation Effects Research Foundation has, over severaldecades, conducted studies of the Life Span Study (LSS) cohort, comprising 93 000atomic-bomb survivors and 27 000 controls.Solid cancer: the recent report on solid cancer incidence found that at age 70years following exposure at age 30 years, solid cancer rates increase by about 35% Gy−1 for menand 58% Gy−1 for women. Age-at-exposure is an important risk modifier. In the case of lung cancer,cigarette smoking has been found to be an important risk modifier. Radiation has similareffects on first-primary and second-primary cancer risks. Finally, radiation-associatedincreases in cancer rates appear to persist throughout life.Leukaemia: the recent report on leukaemia mortality suggests that radiation effects onleukaemia mortality persisted for more than 50 years. Moreover, significant dose–responsefor myelodysplastic syndrome was observed in Nagasaki LSS members even 40–60 yearsafter radiation exposure.Future perspective: given the continuing solid cancer increase in the survivor population,the LSS will likely continue to provide important new information on radiation exposureand solid cancer risks for another 15–20 years, especially for those exposed at a youngage.