PROLIFERATIVE AND NONPROLIFERATIVE BREAST DISEASE IN ATOMIC-BOMB SURVIVORS - RESULTS OF A HISTOPATHOLOGIC REVIEW OF AUTOPSY BREAST-TISSUE

Background. The risk of female breast cancer in association with radia tion dose is well established, on the basis of follow-up studies of th e atomic bomb survivors and other exposed populations. This associatio n is especially strong for women exposed before 20 years of age and ap pears to be much weaker among women exposed after 40 years of age. Met hods. Breast tissue samples from 88 high-dose and 225 low-dose autopsy cases from the Radiation Effects Research Foundation Life Span Study sample were examined in detail to determine whether nonproliferative a nd proliferative breast lesions are associated with radiation dose, Re sults. Prevalence of proliferative disease in general and atypical hyp erplasia in particular were positively associated with radiation dose. The associations were strongest for subjects who were between 40 and 49 years of age at the time of the bombing. Conclusions. It is hypothe sized that the strongest association in women 40 to 49 years of age ma y be related to the age dependence of radiation-induced breast cancer, in that potential cancers induced in this age group by radiation expo sure may receive too little hormonal promotion to progress to frank ca ncers.