New! Sign up for our free email newsletter.
Science News
from research organizations

Radiation exposure linked to aggressive thyroid cancers, researchers confirm for the first time

Date:
October 28, 2014
Source:
University of California, San Francisco (UCSF)
Summary:
Exposure to radioactive iodine is associated with more aggressive forms of thyroid cancer, according to a careful study of nearly 12,000 people in Belarus who were exposed when they were children or adolescents to fallout from the 1986 Chernobyl nuclear power plant accident.
Share:
FULL STORY

For the first time, researchers have found that exposure to radioactive iodine is associated with more aggressive forms of thyroid cancer, according to a careful study of nearly 12,000 people in Belarus who were exposed when they were children or adolescents to fallout from the 1986 Chernobyl nuclear power plant accident.

Researchers examined thyroid cancers diagnosed up to two decades after the Chernobyl accident and found that higher thyroid radiation doses estimated from measurements taken shortly after the accident were associated with more aggressive tumor features.

"Our group has previously shown that exposures to radioactive iodine significantly increase the risk of thyroid cancer in a dose-dependent manner. The new study shows that radiation exposures are also associated with distinct clinical features that are more aggressive," said the paper's first author, Lydia Zablotska, MD, PhD, associate professor in the Department of Epidemiology and Biostatistics at UC San Francisco (UCSF). The paper will be published online in the journal Cancer.

Zablotska said the findings have implications for those exposed to radioactive iodine fallout from the 2011 nuclear reactor incidents in Fukushima, Japan, after the reactors were damaged by an earthquake-induced tsunami.

"Those exposed as children or adolescents to the fallout are at highest risk and should probably be screened for thyroid cancer regularly, because these cancers are aggressive, and they can spread really fast," Zablotska said. "Clinicians should be aware of the aggressiveness of radiation-associated tumors and closely monitor those at high risk."

Chernobyl studies led by Zablotska also showed for the first time that exposures to the radioactive iodine after the Chernobyl nuclear plant accident are associated with a whole spectrum of thyroid diseases, from benign to malignant. Benign encapsulated tumors of the thyroid gland are called follicular adenomas, and are treated in the same way as thyroid cancer -- by removing the thyroid gland, then giving patients pills to replace the hormones that are lost. Lifelong hormone supplementation treatment is both costly and complicated for patients.

Thyroid cancer is ordinarily rare among children, with less than one new case per million diagnosed each year. Among adults, about 13 new cases will be diagnosed each year for every 100,000 people, according to the Surveillance, Epidemiology and End Results (SEER) Program of the National Cancer Institute (NCI). But in the Belarus cohort, the researchers diagnosed 158 thyroid cancers among 11,664 subjects during three rounds of screening. Those who had received higher radiation doses also were more likely to have solid or diffuse variants of thyroid cancer, as well as to have more aggressive tumor features, such as spread to lymphatic vessels and several simultaneous cancer lesions in the thyroid gland.


Story Source:

Materials provided by University of California, San Francisco (UCSF). Original written by Laura Kurtzman. Note: Content may be edited for style and length.


Journal Reference:

  1. Lydia B. Zablotska, Eldar A. Nadyrov, Alexander V. Rozhko, Zhihong Gong, Olga N. Polyanskaya, Robert J. McConnell, Patrick O'Kane, Alina V. Brenner, Mark P Little, Evgenia Ostroumova, Andre Bouville, Vladimir Drozdovitch, Viktor Minenko, Yuri Demidchik, Alexander Nerovnya, Vassilina Yauseyenka, Irina Savasteeva, Sergey Nikonovich, Kiyohiko Mabuchi, Maureen Hatch. Analysis of thyroid malignant pathologic findings identified during 3 rounds of screening (1997-2008) of a cohort of children and adolescents from belarus exposed to radioiodines after the Chernobyl accident. Cancer, 2014; DOI: 10.1002/cncr.29073

Cite This Page:

University of California, San Francisco (UCSF). "Radiation exposure linked to aggressive thyroid cancers, researchers confirm for the first time." ScienceDaily. ScienceDaily, 28 October 2014. <www.sciencedaily.com/releases/2014/10/141028082133.htm>.
University of California, San Francisco (UCSF). (2014, October 28). Radiation exposure linked to aggressive thyroid cancers, researchers confirm for the first time. ScienceDaily. Retrieved March 19, 2024 from www.sciencedaily.com/releases/2014/10/141028082133.htm
University of California, San Francisco (UCSF). "Radiation exposure linked to aggressive thyroid cancers, researchers confirm for the first time." ScienceDaily. www.sciencedaily.com/releases/2014/10/141028082133.htm (accessed March 19, 2024).

Explore More

from ScienceDaily

RELATED STORIES