People exposed to large amounts of radiation early in life, such as radiation therapy to the chest area for childhood cancer, have an increased risk of breast cancer [308-309,316-317].
Learn about other factors linked to the risk of breast cancer.
Radiation treatment for Hodgkin’s disease (Hodgkin lymphoma) or other cancers
Some women who had Hodgkin’s disease (Hodgkin lymphoma) at a young age were treated with radiation therapy to the chest area. Those treated with radiation therapy have a 3-7 times higher risk of breast cancer than women who had Hodgkin’s disease at a young age but weren’t treated with radiation therapy to the chest area .
Although radiation therapy is linked to an increased risk of breast cancer later in life, its benefits for the treatment of Hodgkin’s disease (or other cancer) far outweigh this risk.
Amount of radiation and age at exposure
The amount of radiation given and a person’s age at the time of the treatment for Hodgkin’s disease or other cancer play important roles in breast cancer risk.
In general, the more radiation a person is exposed to and the younger the age at exposure, the greater the risk [308,317].
For example, the risk of breast cancer is very high for a woman treated with radiation therapy to the chest area before age 20, but is very small for a woman treated after age 40 .
There are special breast cancer screening recommendations for women treated with radiation therapy at an early age.
Radiation during mammography
People exposed to very low doses of radiation (such as from X-rays) don’t have much, if any, increase in breast cancer risk [229-230].
Although the radiation during a mammogram is linked to an increased risk of breast cancer over time, this increase in risk is very small [229-230].
Studies show the benefits of screening mammography outweigh the risk from radiation exposure, especially for women ages 50 and older [229-230].
Airline crew exposure to radiation
The limited amount of radiation exposure to airline crews is unlikely to be linked to breast cancer risk.
Female flight crews tend to have slightly higher rates of breast cancer than other women [318-320]. However, this is likely related to reproductive and lifestyle factors, as well as the night shift/light at night work related to the job [318-320].
For example, women who work night shifts for many years have a small increased risk of breast cancer [261-263].
Learn more about night shift work and breast cancer risk.