title: Risk of thyroid follicular adenoma among children and adolescents in Belarus exposed to iodine-131 after the Chornobyl accident.
abstract: Several studies reported an increased risk of thyroid cancer in children and adolescents exposed to radioactive iodines, chiefly iodine-131 ((131)I), after the 1986 Chornobyl (Ukrainian spelling) nuclear power plant accident. The risk of benign thyroid tumors following such radiation exposure is much less well known. We have previously reported a novel finding of significantly increased risk of thyroid follicular adenoma in a screening study of children and adolescents exposed to the Chornobyl fallout in Ukraine. To verify this finding, we analyzed baseline screening data from a cohort of 11,613 individuals aged ≤18 years at the time of the accident in Belarus (mean age at screening = 21 years). All participants had individual (131)I doses estimated from thyroid radioactivity measurements and were screened according to a standardized protocol. We found a significant linear dose response for 38 pathologically confirmed follicular adenoma cases. The excess odds ratio per gray of 2.22 (95% confidence interval: 0.41, 13.1) was similar in males and females but decreased significantly with increasing age at exposure (P < 0.01), with the highest radiation risks estimated for those exposed at <2 years of age. Follicular adenoma radiation risks were not significantly modified by most indicators of past and current iodine deficiency. The present study confirms the (131)I-associated increases in risk of follicular adenoma in the Ukrainian population and adds new evidence on the risk increasing with decreasing age at exposure.
authors.forename: Lydia B
authors.initials: LB
authors.lastname: Zablotska
authors.forename: Eldar A
authors.initials: EA
authors.lastname: Nadyrov
authors.forename: Olga N
authors.initials: ON
authors.lastname: Polyanskaya
authors.forename: Robert J
authors.initials: RJ
authors.lastname: McConnell
authors.forename: Patrick
authors.initials: P
authors.lastname: O'Kane
authors.forename: Jay
authors.initials: J
authors.lastname: Lubin
authors.forename: Maureen
authors.initials: M
authors.lastname: Hatch
authors.forename: Mark P
authors.initials: MP
authors.lastname: Little
authors.forename: Alina V
authors.initials: AV
authors.lastname: Brenner
authors.forename: Ilya V
authors.initials: IV
authors.lastname: Veyalkin
authors.forename: Vasilina V
authors.initials: VV
authors.lastname: Yauseyenka
authors.forename: Andre
authors.initials: A
authors.lastname: Bouville
authors.forename: Vladimir V
authors.initials: VV
authors.lastname: Drozdovitch
authors.forename: Viktor F
authors.initials: VF
authors.lastname: Minenko
authors.forename: Yuri E
authors.initials: YE
authors.lastname: Demidchik
authors.forename: Kiyohiko
authors.initials: K
authors.lastname: Mabuchi
authors.forename: Alexander V
authors.initials: AV
authors.lastname: Rozhko
mesh_terms: D000236:Adenoma / Q000453:epidemiology* / Q000209:etiology*; D000293:Adolescent; D000328:Adult; D047852:Chernobyl Nuclear Accident; D002648:Child; D004307:Dose-Response Relationship, Radiation; D004781:Environmental Exposure; D005260:Female; D006801:Humans; D007457:Iodine Radioisotopes / Q000633:toxicity*; D008297:Male; D009381:Neoplasms, Radiation-Induced / Q000453:epidemiology / Q000209:etiology*; D015995:Prevalence; D012307:Risk Factors; D013964:Thyroid Neoplasms / Q000453:epidemiology / Q000209:etiology*
chemical_list: D007457:Iodine Radioisotopes
keywords: Chornobyl nuclear accident; adenoma; dose-response relationship; interaction; iodine deficiency; iodine radioisotopes; radiation; thyroid neoplasms