Atomic bomb survivors may offer clues on cancer treatment risks

DNA from survivors of the atomic bombs dropped on Hiroshima and Nagasaki 65 years ago may help doctors gauge whether certain cancer treatments can trigger genetic defects that can be passed on to patients’ children.

Scientists at the Radiation Effects Research Foundation in Hiroshima, Japan, are investigating whether the health consequences of the bombs continue beyond those survivors who developed cancer. They are looking for gene changes linked with conditions including leukemia and heart disease, and checking whether those alterations can be inherited, said Evan Douple, the foundation’s associate chief of research.

The findings may help doctors better understand the levels of radiation to which cancer patients can be safely exposed, Douple said. Survivors’ children born after the August 1945 attacks are reaching ages when malignancies are more likely to appear.

“As they enter their cancer-prone years, the next 20 years are going to be very important,” Douple said. “We don’t want to overlook that as a possible mechanism for the disease.”

The genetic basis of cancer has been recognized for a century. The researchers in Hiroshima will examine the descendants of survivors to see whether the environment changed the activity of genes, a field of study known as epigenetics.

Genes’ behavior

The field has emerged since the 1940s to bridge the gap between nature and nurture. Epigenetic processes can change the behavior of a gene without altering the DNA sequence, prompting “good” genes—such as those suppressing tumors—to switch off and “bad” genes—those promoting tumors —to

... contd.