Technical Report No. 4-90
Frequency of malignant tumors during the first two decades of life in the offspring (F1) of atomic bomb survivors
Yoshimoto Y, Neel JV, Schull WJ, Kato H, Soda M, Eto R, Mabuchi KEditor’s note: A publication based on this report was published in Am J Hum Genet 46:1041-52, 1990.
Summary
The incidence of cancer prior to age 20 has been determined in children born to atomic bomb survivors and to a suitable comparison group. Tumor ascertainment was through death certificates and the tumor registries maintained in Hiroshima and Nagasaki. The rationale for the study stemmed from the evidence that a significant proportion of childhood tumors such as retinoblastoma and Wilms’ tumor arise on the basis of a mutant gene inherited from one parent plus a second somatic cell mutation involving the allele of this gene. Gonadal radiation doses were calculated using the recently established DS86 system, supplemented by an ad hoc system for those children whose parents’ (one or both) DS86 dose could not be computed but for whom a dose could be developed on the basis of the available information. The total data set consisted of: 1) a cohort of 31,150 liveborn children, one or both of whose parents received greater than or equal to 0.01 Sv of radiation at the time of the A-bombings (an average conjoint gonad exposure of 0.435 Sv), and 2) two suitable comparison groups, totaling 41,066 children. A total of 92 cancer cases at age less than 20 years was confirmed; 49 and 43 cases, respectively, in the 0 Sv and greater than or equal to 0.01 Sv groups. A multiple linear regression analysis revealed no increase in malignancy in the children of exposed parents. However, examination of the data suggested that only 3.0% to 5.0% of the tumors of childhood observed in the comparison groups are associated with an inherited genetic predisposition that would be expected to exhibit an altered frequency if the parental mutation rate were increased. There is thus far no confirmation of the positive findings of Nomura in a mouse system.
The incidence of cancer prior to age 20 has been determined in children born to atomic bomb survivors and to a suitable comparison group. Tumor ascertainment was through death certificates and the tumor registries maintained in Hiroshima and Nagasaki. The rationale for the study stemmed from the evidence that a significant proportion of childhood tumors such as retinoblastoma and Wilms’ tumor arise on the basis of a mutant gene inherited from one parent plus a second somatic cell mutation involving the allele of this gene. Gonadal radiation doses were calculated using the recently established DS86 system, supplemented by an ad hoc system for those children whose parents’ (one or both) DS86 dose could not be computed but for whom a dose could be developed on the basis of the available information. The total data set consisted of: 1) a cohort of 31,150 liveborn children, one or both of whose parents received greater than or equal to 0.01 Sv of radiation at the time of the A-bombings (an average conjoint gonad exposure of 0.435 Sv), and 2) two suitable comparison groups, totaling 41,066 children. A total of 92 cancer cases at age less than 20 years was confirmed; 49 and 43 cases, respectively, in the 0 Sv and greater than or equal to 0.01 Sv groups. A multiple linear regression analysis revealed no increase in malignancy in the children of exposed parents. However, examination of the data suggested that only 3.0% to 5.0% of the tumors of childhood observed in the comparison groups are associated with an inherited genetic predisposition that would be expected to exhibit an altered frequency if the parental mutation rate were increased. There is thus far no confirmation of the positive findings of Nomura in a mouse system.