Exposure to large amounts of radiation early in life—such as the atomic bomb explosions in Japan and radiation treatment for childhood cancer—is linked to an increased risk of breast cancer [50-56]. Women treated with radiation therapy for Hodgkin's disease at a young age have about three to seven times the risk of breast cancer compared to women with Hodgkin's disease who were never treated with radiation therapy [50-53,55]. Although radiation therapy increases the risk of breast cancer later in life, its benefits in the treatment of Hodgkin's disease or other cancers far outweigh this risk.
The amount of radiation and age at the time of the exposure play important roles in breast cancer risk later in life. In general, the more radiation a person is exposed to and the younger the age at exposure, the greater the risk. For example, the risk of breast cancer from therapeutic radiation exposure is very high for a woman exposed before age 20 but is very small if she is exposed after age 40. Learn about breast cancer screening recommendations for women exposed to radiation therapy at an early age.
Mammography and X-rays
Very low doses of radiation—such as from X-rays—do not have much, if any, impact on breast cancer risk. While the radiation during mammography can increase the risk of breast cancer, this increase is very slight. Any risks of screening tests like mammography are thought to be far outweighed by their benefits. Studies show that the benefits of screening mammography outweigh the risks for women aged 40-50. For women aged 50 and older, these benefits are far greater [57-59].
Learn more about mammography.
Updated 11/09/09
