Reactions: Study quantifies overdiagnosis of breast cancer in women over 70 in the US
A US study measures the risk of breast cancer overdiagnosis in screening campaigns for women over 70. These are women who are misdiagnosed with cancer after a mammogram, leading to unnecessary treatments that can cause complications, anxiety and financial costs. The study includes more than 54,000 women over the age of 70 who have had a screening mammogram. The retrospective analysis compares the cumulative incidence of breast cancer between two groups: women who continued screening up to 15 years later, and women who did not. The research estimates that 31% of breast cancer cases in women aged 70-74 result from overdiagnosis: it finds 6.1 cases per 100 women who had continued screening, compared with 4.2 cases per 100 women in the second group. The percentage of overdiagnosis increases with the age of the women. The article is published in the Annals of Internal Medicine, along with an editorial.