Radiation exposure ups aggressive thyroid cancer risk

Nuclear power plant accidents could be devastating and researchers have now found that exposure to radioactive iodine is associated with more aggressive forms of thyroid cancer.

"Our group has previously shown that exposures to radioactive iodine significantly increase the risk of thyroid cancer in a dose-dependent manner," said lead author of the study Lydia Zablotska from University of California San Francisco.

"The new study shows that radiation exposures are also associated with distinct clinical features that are more aggressive," Zablotska added.

For the study, the researchers carefully examined 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.

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.

The study is appearing in the journal Cancer.