Long-term trend of thyroid cancer risk among Japanese atomic-bomb survivors: 60 years after exposure

Furukawa K, Preston DL, Funamoto S, Yonehara S, Ito M, Tokuoka S, Sugiyama H, Soda M, Ozasa K, Mabuchi K
Int J Cancer 2013 (March); 132(5):1222–6
doi:10.1002/ijc.27749

Abstract

Thyroid cancer risk following exposure to ionizing radiation in childhood and adolescence is a topic of public concern. To characterize the long-term temporal trend and age-at-exposure variation in the radiation-induced risk of thyroid cancer, we analyzed thyroid cancer incidence data for the period from 1958 through 2005 among 105,401 members of the Life Span Study cohort of Japanese atomic-bomb survivors. During the follow-up period, 371 thyroid cancer cases (excluding those with microcarcinoma with a diameter <10 mm) were identified as a first primary among the eligible subjects. using linear dose-response model, excess relative risk of thyroid cancer at 1 gy radiation exposure was estimated 1.28 (95% confidence interval: 0.59-2.70) age 60 after acute 10. decreased sharply with increasing age-at-exposure and there little evidence increased rates for those exposed 20. about 36% cases before 20 to be attributable exposure. while magnitude has attained or time since exposure, associated childhood persisted>50 years after exposure.