Title

I-131 dose response for incident thyroid cancers in Ukraine related to the Chornobyl accident.

Authors

Alina V Brenner, National Cancer Institute, National Institutes of Health, Department of Health and Human Services, Bethesda, Maryland, USA
Mykola D Tronko, Institute of Endocrinology and Metabolism, Kyiv, Ukraine
Maureen Hatch, National Cancer Institute, National Institutes of Health, Department of Health and Human Services, Bethesda, Maryland, USA
Tetyana I Bogdanova, Institute of Endocrinology and Metabolism, Kyiv, Ukraine
Valery A Oliynik, Institute of Endocrinology and Metabolism, Kyiv, Ukraine
Jay H Lubin, National Cancer Institute, National Institutes of Health, Department of Health and Human Services, Bethesda, Maryland, USA
Lydia B Zablotska, University of California–San Francisco, San Francisco, California, USA
Valery P Tereschenko, Institute of Endocrinology and Metabolism, Kyiv, Ukraine
Robert J McConnell, The Thyroid Clinic, College of Physicians and Surgeons, Columbia University, New York, New York,
Galina A Zamotaeva, Institute of Endocrinology and Metabolism, Kyiv, Ukraine
Patrick O'Kane, Thomas Jefferson UniversityFollow
Andre C Bouville, National Cancer Institute, National Institutes of Health, Department of Health and Human Services, Bethesda, Maryland, USA
Ludmila V Chaykovskaya, Institute of Endocrinology and Metabolism, Kyiv, Ukraine
Ellen Greenebaum, College of Physicians and Surgeons, Columbia University, New York, New York
Ihor P Paster, Institute of Endocrinology and Metabolism, Kyiv, Ukraine
Victor M Shpak, Institute of Endocrinology and Metabolism, Kyiv, Ukraine
Elaine Ron, National Cancer Institute, National Institutes of Health, Department of Health and Human Services, Bethesda, Maryland, USA

Document Type

Article

Publication Date

7-1-2011

Comments

This article has been peer reviewed. It was published in: Environmental Health Perspectives.

Volume 119, Issue 7, July 2011, Pages 933-939.

The published version is available at DOI: 10.1289/ehp.1002674. Copyright © National Institute of Environmental Health Sciences.

Abstract

BACKGROUND: Current knowledge about Chornobyl-related thyroid cancer risks comes from ecological studies based on grouped doses, case-control studies, and studies of prevalent cancers.

OBJECTIVE: To address this limitation, we evaluated the dose-response relationship for incident thyroid cancers using measurement-based individual iodine-131 (I-131) thyroid dose estimates in a prospective analytic cohort study.

METHODS: The cohort consists of individuals < 18 years of age on 26 April 1986 who resided in three contaminated oblasts (states) of Ukraine and underwent up to four thyroid screening examinations between 1998 and 2007 (n = 12,514). Thyroid doses of I-131 were estimated based on individual radioactivity measurements taken within 2 months after the accident, environmental transport models, and interview data. Excess radiation risks were estimated using Poisson regression models.

RESULTS: Sixty-five incident thyroid cancers were diagnosed during the second through fourth screenings and 73,004 person-years (PY) of observation. The dose-response relationship was consistent with linearity on relative and absolute scales, although the excess relative risk (ERR) model described data better than did the excess absolute risk (EAR) model. The ERR per gray was 1.91 [95% confidence interval (CI), 0.43-6.34], and the EAR per 10⁴ PY/Gy was 2.21 (95% CI, 0.04-5.78). The ERR per gray varied significantly by oblast of residence but not by time since exposure, use of iodine prophylaxis, iodine status, sex, age, or tumor size.

CONCLUSIONS: I-131-related thyroid cancer risks persisted for two decades after exposure, with no evidence of decrease during the observation period. The radiation risks, although smaller, are compatible with those of retrospective and ecological post-Chornobyl studies.

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