Effects of radiation on incidence of primary liver cancer among atomic bomb survivors.
We describe the radiation risk for primary liver cancers between 1958 and 1987 in a cohort of atomic bomb survivors in Hiroshima and Nagasaki, Japan. The analysis is based on a comprehensive pathology review of known or suspected liver neoplasms that generated 518 incident, first primary cases, mostly hepatocellular carcinoma. Excess relative risk from atomic bomb radiation was linear: 0.81 per sievert weighted liver dose (95% CI [0.32, 1.43]; P < 0.001). Males and females had similar relative risk so that, given a threefold higher background incidence in males, the radiation-related excess incidence was substantially higher in males. Excess risk peaked for those with age at exposure in the early 20s; there was essentially no excess risk in those exposed before age 10 or after age 45. Whether this was due to a difference in sensitivity or possible confounding by other factors could not be addressed retrospectively in the full cohort. A paucity of cholangiocarcinoma and hemangiosarcoma cases suggested that they are not significantly associated with whole-body radiation exposure, as they are with the internal alpha-particle-emitting radiological contrast medium Thorotrast. Because most of the radiation-related excess cases occurred among males, it is important to ascertain what factors put men at greater risk of radiation-related liver cancer.
Cologne
J B
JB
Department of Statistics, Radiation Effects Research Foundation, 5-2 Hijiyama Park, Minami-ku, Hiroshima, Japan 732-0815.
Tokuoka
S
S
Beebe
G W
GW
Fukuhara
T
T
Mabuchi
K
K
D015331:Cohort Studies; D003644:Death Certificates; D005260:Female; D006801:Humans; D015994:Incidence; D007564:Japan; D008113:Liver Neoplasms / Q000453:epidemiology / Q000209:etiology*; D008297:Male; D009381:Neoplasms, Radiation-Induced / Q000453:epidemiology*; D009689:Nuclear Warfare; D017741:Survivors