Tumor Characteristics Associated with Tomosynthesis Versus Digital Mammography in Older Women with Screen-Detected Breast Cancer.

Digital breast tomosynthesis (DBT) has demonstrated improved cancer detection compared with digital mammography (DM) in trials of women aged 50–74, identifying more invasive cancers and detecting tumors at smaller sizes. However, its benefits for women over the age of 75 have not been examined. To assess whether DBT versus DM is associated with favorable tumor characteristics and detection of less conspicuous histologic subtypes in women aged ≥ 75 compared with those aged 67–74, thereby informing screening strategies and overdiagnosis risks. We conducted a SEER-Medicare retrospective cohort study of women aged ≥ 67 diagnosed with screen-detected ER+/HER2- breast cancer from 2015 to 2021. The primary exposure was screening modality (DBT vs. DM). Outcomes included tumor size, nodal involvement, grade, and histology (invasive lobular carcinoma [ILC] vs. other). Multivariable logistic regression was used to assess the association between screening modality and tumor characteristics among women aged 67–74 and ≥ 75. Among 17,201 women with screen-detected breast cancer, 43.6