This study examines the temporal trends in geographic disparities in five breast cancer screening indicators (in situ, stage I, lymph-node positive, locally advanced, and mortality) from 1988 to 2005 using data from 200 counties in the Surveillance, Epidemiology, and End Results (SEER) Program. The analysis employs hierarchical Bayesian spatiotemporal methods to smooth county-level rates and calculate measures of absolute and relative geographic disparity. Key findings include: - **In situ breast cancer**: Absolute disparity increased by 93.7% from 1988 to 2005, while relative disparity declined by 61.5%. - **Stage I breast cancer**: Absolute disparity declined by 18.5%, and relative disparity by 41.4%. - **Lymph-node positive breast cancer**: Absolute disparity declined by 37.9%, and relative disparity by 17.6%. - **Locally advanced breast cancer**: Absolute disparity declined by 66.5%, and relative disparity by 17.8%. - **Breast cancer mortality**: Absolute disparity declined by 60.5%, and relative disparity by 19.8%. The study concludes that while progress has been made in reducing geographic disparities, particularly in advanced-stage breast cancer incidence and mortality rates, disparities remain in some areas. The findings highlight the need for continued monitoring and targeted interventions to address these disparities.This study examines the temporal trends in geographic disparities in five breast cancer screening indicators (in situ, stage I, lymph-node positive, locally advanced, and mortality) from 1988 to 2005 using data from 200 counties in the Surveillance, Epidemiology, and End Results (SEER) Program. The analysis employs hierarchical Bayesian spatiotemporal methods to smooth county-level rates and calculate measures of absolute and relative geographic disparity. Key findings include: - **In situ breast cancer**: Absolute disparity increased by 93.7% from 1988 to 2005, while relative disparity declined by 61.5%. - **Stage I breast cancer**: Absolute disparity declined by 18.5%, and relative disparity by 41.4%. - **Lymph-node positive breast cancer**: Absolute disparity declined by 37.9%, and relative disparity by 17.6%. - **Locally advanced breast cancer**: Absolute disparity declined by 66.5%, and relative disparity by 17.8%. - **Breast cancer mortality**: Absolute disparity declined by 60.5%, and relative disparity by 19.8%. The study concludes that while progress has been made in reducing geographic disparities, particularly in advanced-stage breast cancer incidence and mortality rates, disparities remain in some areas. The findings highlight the need for continued monitoring and targeted interventions to address these disparities.