Technical Report No. 5-91
Thyroid cancer incidence among atomic bomb survivors, 1958-79
Akiba S, Lubin J, Ezaki H, Ron E, Ishimaru T, Asano M, Shimizu Y, Kato HSummary
One hundred and twelve cases of thyroid cancer diagnosed during the period 1958-79 among the extended Life Span Study cohort in Hiroshima and Nagasaki were studied. There was a statistically significant association between thyroid cancer incidence and exposure to atomic bomb radiation. The adjusted excess relative risk (ERR) per gray was 1.1 (95% confidence interval = 0.3-2.5) and the adjusted absolute risk per 104 PYGy was 0.59 (95% confidence interval = 0.2-1.7). Based on a comparison of the deviances obtained from relative and absolute risk models, a simple linear relative risk model appeared to fit the data better than an absolute risk model; however, it would not be appropriate to conclude that the data conform strictly to a relative risk pattern.
The incidence of thyroid cancer among the members of the Adult Health Study (AHS) population, who have received biennial medical examinations at the Atomic Bomb Casualty Commission and its successor, the Radiation Effects Research Foundation, since 1958, was 70% higher than that among the rest of the extended LSS cohort after adjustments for city, sex, log age, calendar year, and Dosimetry System 1986 dose. There was no significant difference between the slope of the dose-response curve for AHS and non-AHS participants, although the estimated ERRs at 1 Gy for the AHS and non-AHS populations were 1.6 and 0.3, respectively. The elevated risk appeared to be confined to women, and there was an increasing risk with decreasing attained age and age at exposure.
One hundred and twelve cases of thyroid cancer diagnosed during the period 1958-79 among the extended Life Span Study cohort in Hiroshima and Nagasaki were studied. There was a statistically significant association between thyroid cancer incidence and exposure to atomic bomb radiation. The adjusted excess relative risk (ERR) per gray was 1.1 (95% confidence interval = 0.3-2.5) and the adjusted absolute risk per 104 PYGy was 0.59 (95% confidence interval = 0.2-1.7). Based on a comparison of the deviances obtained from relative and absolute risk models, a simple linear relative risk model appeared to fit the data better than an absolute risk model; however, it would not be appropriate to conclude that the data conform strictly to a relative risk pattern.
The incidence of thyroid cancer among the members of the Adult Health Study (AHS) population, who have received biennial medical examinations at the Atomic Bomb Casualty Commission and its successor, the Radiation Effects Research Foundation, since 1958, was 70% higher than that among the rest of the extended LSS cohort after adjustments for city, sex, log age, calendar year, and Dosimetry System 1986 dose. There was no significant difference between the slope of the dose-response curve for AHS and non-AHS participants, although the estimated ERRs at 1 Gy for the AHS and non-AHS populations were 1.6 and 0.3, respectively. The elevated risk appeared to be confined to women, and there was an increasing risk with decreasing attained age and age at exposure.