Researchers in Japan have found that children exposed to
atomic bombs in 1945 were more likely to develop papillary thyroid cancer as
adults because of rearrangements to their chromosomes.
The researchers working in Hiroshima, Nagasaki and
Saitama published results that found the younger a child was at exposure to the
radiation, the more likely he or she was to develop RET/PTC
The researchers enrolled 50 survivors of the attacks on
Hiroshima and Nagasaki who had been exposed to atomic radiation and 21
survivors who had not been exposed. All patients had been diagnosed with
adult-onset papillary thyroid cancer.
The researchers found that RET/PTC rearrangements
were more frequent in those patients exposed to more radiation (P=.002).
Exposed patients with BRAFV600E mutations evidenced a lower
radiation dose (P=.0002) and longer time since exposure
(P=.0003), compared with those patients without
BRAFV600E mutation. Those patients with BRAFV600E
mutations were also older at time of diagnosis (P=.0002).
“That means that a younger person living close to
the bombing site would be more likely to have adult-onset thyroid cancer having
RET/PTC rearrangements,” Kiyohiro Hamatani, PhD, one of the
study’s authors, said in a press release. “This is the first time
that’s been shown.”
Patients with papillary thyroid carcinoma and
RET/PTC rearrangements also developed the cancer earlier than those
patients with the BRAFV600E mutation (P=.03), according to
The researchers added that these results were similar to
those found in children exposed to the Chernobyl disaster in 1986.
Cancer Res. 2008;68:7176-7182.