Japanese team discovers more cancer fallout

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.