Breast cancer risk after radiation treatment at infancy: potential consequences of radiation-induced genomic instability.

Swedish hemangioma patients were treated in infancy mainly by external application of radium-226 starting from 1920. This work analysed the radiation risk among 17,158 women with a total of 678 breast cancer incidence cases with models of carcinogenesis and empirical excess relative risk models. Models incorporating effects of genomic instability were developed and applied to the hemangioma cohort. The description of the radiation risk was significantly improved with a model of genomic instability at an early stage of carcinogenesis.