Radiation-induced breast cancer.

Between 1975 and 1983, sixteen patients with a history of irradiation at an early age to the head, neck, or chest areas for a variety of conditions in whom breast cancer subsequently developed were seen at out institute. The median latent period between the irradiation and the development of breast cancer was 420 months. The distribution of patients by stage of the disease and the median age at diagnosis of this subgroup was similar to the breast cancer observed in the general population. The subsequent course of this disease was also similar to the breast cancer observed in the general population. A substantial number of women have been exposed to irradiation at a young age, and these women are at a higher risk of having breast cancer develop. These women should be closely observed to discover the disease in an early curable stage.