Lung cancer at autopsy in a-bomb survivors and controls, Hiroshima and Nagasaki, 1961–1970.I. Autopsy findings and relation to radiation

Previous studies indicated there was a probable increase of lung cancer in atom bomb survivors in Hiroshima and Nagasaki. In re-examination of this problem, lung cancer was found in 204 of 3778 autopsies on radiation exposed survivors and controls performed during 1961–1970. Using the W.H.O. classification, 32% were epidermoid, 19% small cell anaplastic, 29% bronchogenic adenocarcinoma, 9% bronchiolo-alveolar, and 11% other types of carcinoma. Small cell anaplastic carcinomas were definitely increased in irradiated persons compared to controls (relative risk 3.9; p < 0.5). Epidermoid and bronchogenic adenocarcinoma showed increased risk, but this was not statistically significant. In this entire series, 89% were 60 years old or older; 67% were in men with male:female ratios of 2.4:1 for epidermoid, 2.9:1 for small cell anaplastic, and 1.3:1 for bronchogenic adenocarcinoma. No data were available for a study of the possible effect of internal irradiation. An analysis of the effect of smoking and occupation on the interpretation of single dose whole body ionizing irradiation as a cause of lung cancer will be reported separately. Cancer 33:1580–1588, 1974.