Epidemiology of ovarian cancer in Nagasaki city with reference to atomic bomb exposure, 1973∼1982

Epidemiological study was conducted on 151 cases (67 exposed and 84 nonexposed) of ovarian cancer registered at the Nagasaki Tumor Registry from 1973 to 1982, with emphasis on the relation to radiation exposure. Although the crude incidence rate of ovarian cancer in the exposed group was higher than in the nonexposed group, the age-adjusted relative risk was not significantly different. The relative risk of ovarian cancer incidence by age at the time of the A-bomb was high in the 10-19 group (puberty), and was low in the 40-49 group. It suggested the possibility that radiation carcinogenesis in the ovary was closely related to the secondary excess of gonadotrophic hormones following radiation injury of the ovary. No significant different in histological type between the exposed and nonexposed groups could be found. (author)