Importance: Hormone-modulating therapy (HMT) is a widely accepted treatment for hormone receptor-positive breast cancer, although its cognitive effects, including a potential link to Alzheimer disease and related dementias (ADRD), remain understudied.
Objective: To investigate the association between HMT for breast cancer treatment and risk of developing ADRD in women aged 65 years or older.
Design, Setting, And Participants: This cohort study used a comprehensive dataset from the Surveillance, Epidemiology, and End Results (SEER)-Medicare linked database to identify patients who did and did not receive HMT treatment within 3 years after the initial diagnosis of breast cancer and assessed their risk of developing ADRD in later life.