Epidemiologic study of skin cancer in Nagasaki atomic-bomb survivors

This study was designed to investigate the correlation between the incidence of skin cancer and exposure distance in Nagasaki A-bomb survivors. When 140 A-bomb survivors, collected from 31 medical facilities in Nagasaki and its surrounding areas, were analyzed using logistic regression model based on the data of 66,276 A-bomb survivors, the incidence of skin cancer was found to be significantly lower in A-bomb survivors exposed farther from the hypocenter. This was also noted when confining to either men or women. Among 25,942 A-bomb survivors, available using DS85 dosimetry system, in the RERF-Life Span Study sample and RERF-Adult Health Study sample (1958-1985), 47 A-bomb survivors were found to have skin cancer. For them, higher incidence of skin cancer was associated with larger radiation doses. Dose-response relationship for skin cancer was linear. Twenty five of the 47 A-bomb survivors (53%) histologically had basal cell carcinoma. Since 1975, an increased rate in the incidence of skin cancer has been noticeable in A-bomb survivors exposed at ≤2,500 m than those exposed at ≥3,000 m. The number of excess cases of skin cancer was found to have been steadily increased since 1958. (N.K.)