The United States Preventive Services Task Force (USPSTF) recommends breast cancer screening every two years for women aged 50 to 74.1 Screenings every two years continued to be recommended in a draft released in May 2023 by the USPSTF.1 The American Cancer Society (ACS) recommends annual screenings for those aged 40 to 54, with the option for screenings every year or every two years for those aged 55 and older.2 The optimal interval for mammography has been debated as there is a potential trade-off between the benefits and harms of screening annually versus every two years.
We evaluated all-cause mortality rates after breast cancer diagnosis by whether a woman had a mammogram every year or every two years prior to her diagnosis. If the patient’s two most recent screening mammograms were 9 to 15 months apart, she was classified as being screened every year, and if her two most recent screening mammograms were 18 to 30 months apart, she was classified as being screened every two years.
The study included 25,512 women aged 50 to 74 diagnosed with breast cancer between January 1, 2018, and August 1, 2022, who were not identified as high risk for breast cancer prior to their diagnosis. We found that women screened annually had a 17% lower risk of all-cause mortality after diagnosis during the study period compared with those screened every two years, as seen in Figure 1. We found that women who are over age 60, who are Black, who live in a more socially vulnerable area, or who live in a rural area also had an increased risk of all-cause mortality after a breast cancer diagnosis compared with women who are under age 60, who are White, who live in a less socially vulnerable area, or who live in an urban area, respectively.
Screenings and deaths are likely undercounted in this analysis, as these events might not be documented if they occur outside of a Cosmos healthcare organization.3 This analysis does not adjust for comorbidities or health-related behaviors, which may differ between patients who choose yearly mammograms and those who elect screening less frequently.
