Surveillance, Epidemiology, and End Results Data Show Increasing Rates of Distant-Stage Breast Cancer at Presentation in U.S. Women

Background The incidence of distant-stage (metastatic) breast cancer at initial presentation has increased significantly in U.S. women under 40 years of age, but no clear trend in older women has been reported. Purpose To investigate trends in distant-stage breast cancer incidence using the latest available Surveillance, Epidemiology, and End Results (SEER) data, including the COVID-19 pandemic years 2020 and 2021. Materials and Methods In this retrospective study of 71 million to 80 million women annually, SEER 22 stage-specific breast cancer incidence rates from January 2004 to December 2021 were analyzed using Joinpoint software to evaluate trends in distant-stage disease in U.S. women overall, by age group, and by race and ethnicity. Results Distant-stage breast cancer incidence rates at presentation increased significantly for U.S. women overall, with an annual percentage change (APC) of 1.16% (95% CI: 0.92, 1.42;