Did atomic bomb radiation influence the incidence of retinoblastoma in Nagasaki and Hiroshima?

The authors studied the effect of atomic bomb radiation in Nagasaki and Hiroshima on the incidence of retinoblastoma by examining the history of exposure to atomic bomb radiation among the grandparents and parents of retinoblastoma patients in Nagasaki and Hiroshima. Of 85 patients born in Nagasaki Prefecture from 1965 to 1986 and in Hiroshima Prefecture from 1966 to 1986, 42 had records to whether or not their grandparents and parents had been exposed to atomic bomb radiation. Seven had parents or grandparents exposed to atomic bomb radiation. These patients showed neither a high incidence of bilateral retinoblastoma nor a family history of retinoblastoma, although a higher incidence of cancer in the family history was found in the exposed group. Exposure to radiation showed no correlation with the onset of retinoblastoma. Moreover, the incidence of retinoblastoma in Nagasaki and Hiroshima Prefectures was almost the same as the average incidence in Japan. The authors failed to find evidence of increased incidence of retinoblastoma in the offspring of those exposed to atomic bomb radiation in Nagasaki and Hiroshima. However, this does not mean that the effect of radiation on the occurrence of retinoblastoma can be ruled out.