Benefits versus risks from mammography: a critical reassessment

The use of mammography has increased rapidly over the last decade. The justification for mammographic examinations is the potential benefit they provide in detecting breast cancer at an early stage and reducing mortality. However, this benefit must be balanced against the associated potential risk of radiation carcinogenesis, economic costs, and a number of other factors. Most publications to date have used radiation risk factors and data from studies that were published over a decade ago, which now have been superseded by the results of more recent epidemiological studies. This report examines the current literature regarding the benefits of cancer detection and the risk of radiation carcinogenesis, and calculates the ratio of benefit and risk for women who begin annual mammography screening at different ages. We have used current data to calculate the expected individual benefits and radiation risks associated with annual mammographic screening. It now appears that there is little risk of breast cancer associated with radiation exposure from annual mammography in women over the age of 35, although there is some indication that exposure of younger women may pose a risk for those women in a genetically sensitive subgroup. New data document that for a woman beginning annual mammographic screening at age 50 and continuing until age 75, the benefit exceeds the radiation risk by a factor of almost 100. Even for a woman who begins annual screening at age 35 and continues until age 75, the benefit of reduced mortality is projected to exceed the radiation risk by factor of more than 25.