title: Long-term trend of thyroid cancer risk among Japanese atomic-bomb survivors: 60 years after exposure.
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 a linear dose-response model, the excess relative risk of thyroid cancer at 1 Gy of radiation exposure was estimated as 1.28 (95% confidence interval: 0.59-2.70) at age 60 after acute exposure at age 10. The risk decreased sharply with increasing age-at-exposure and there was little evidence of increased thyroid cancer rates for those exposed after age 20. About 36% of the thyroid cancer cases among those exposed before age 20 were estimated to be attributable to radiation exposure. While the magnitude of the excess risk has decreased with increasing attained age or time since exposure, the excess thyroid cancer risk associated with childhood exposure has persisted for >50 years after exposure.
authors: Radiation Effects Research Foundation, Hiroshima and Nagasaki, Japan. furukawa@rerf.or.jp
authors: Kyoji
authors: K
authors: Furukawa
authors: Dale
authors: D
authors: Preston
authors: Sachiyo
authors: S
authors: Funamoto
authors: Shuji
authors: S
authors: Yonehara
authors: Masahiro
authors: M
authors: Ito
authors: Shoji
authors: S
authors: Tokuoka
authors: Hiromi
authors: H
authors: Sugiyama
authors: Midori
authors: M
authors: Soda
authors: Kotaro
authors: K
authors: Ozasa
authors: Kiyohiko
authors: K
authors: Mabuchi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D004307:Dose-Response Relationship, Radiation; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009381:Neoplasms, Radiation-Induced / Q000453:epidemiology* / Q000209:etiology; D009689:Nuclear Warfare; D054043:Nuclear Weapons; D012307:Risk Factors; D017741:Survivors; D013964:Thyroid Neoplasms / Q000453:epidemiology* / Q000209:etiology; D013995:Time; D055815:Young Adult