Radiation from the 1945 atomic bomb blasts in Hiroshima and Nagasaki, Japan, most likely rearranged chromosomes in some survivors who later developed papillary thyroid cancer as adults, according to a new study out of Japan.
Researchers from the Hiroshima-based Radiation Effects Research Foundation (RERF) reported that young subjects, who lived close to the blast sites and developed cancer quickly once they reached adulthood, were likely to have a chromosomal rearrangement known as RET/PTC.
This genetic anomaly is not commonly found in adult onset thyroid cancer, according to Kiyohiro Hamatani, MD, and colleagues in the foundation’s department radiobiology and molecular epidemiology (Cancer Research 68: 7176-7182, 2008).
Dr. Hamatani and colleagues made a comparison between adult-onset papillary thyroid cancers with RET/PTC rearrangements and those with a BRAF mutation.
The researchers looked at the genetic profile of cancer patients (50 exposed to atomic bomb radiation and 21 who were not) in the RERF’s follow-up study. Three factors were independently associated with the development of adult-onset papillary thyroid cancer with RET/PTC rearrangements: greater radiation dose, shorter time elapsed since radiation exposure, and younger age at the time of the bombings.