Abstract 4797: Impact of COVID-19 pandemic on breast cancer screening and diagnosis stage in a large midwestern United States academic medical center

Abstract Background: Access to breast cancer screening mammogram services decreased in association with the COVID-19 pandemic. There is also evidence for increases in late-stage breast cancer diagnoses. Our objectives were to determine: 1) the COVID-19-affected period on mammogram screening, 2) the proportion of pandemic-associated missed or delayed mammogram screening visits overall and by race/ethnicity and age group, and 3) evidence for pandemic-associated shifts in diagnosis stage. Methods: Screening mammogram encounter data between 1-1-2019 and 12-31-2022 were extracted from EPIC for females ≥ 40 years old for the screening analysis. We used Bayesian state space models to describe weekly screening mammogram counts, modeling an interruption that phased in and out from 3-1-2020 to 9-1-2020. We used the posterior predictive distribution to simulate differences between a predicted, uninterrupted process and the observed screening mammogram counts. Breast cancer diagnoses at ≥ 21 years from the tumor registry between 12-1-2018 and 11-30-2021 were included in the stage analysis. We used logistic regression models to estimate late-stage diagnosis odds comparing matched three-month periods during the pandemic to before the pandemic. Results: A total of 319, 492 encounters among 146, 644 women were included. Model-estimated screening mammograms dropped by 98. 8% (95% CI 95. 1 to 100) between 3-15-2020 and 5-24-2020, returning to pre-pandemic levels or higher after this period. Drops in screening mammogram encounters did not vary significantly by race/ethnicity or age group (p. 75). Among 4, 669 breast cancer diagnoses, we found no significant differences in the odds of late-stage diagnoses for any period vs. the same period before the pandemic (Table). Conclusions: These data suggest a short-term pandemic effect on screening mammograms. Evidence for increases in late-stage diagnoses is limited. These results may inform future pandemic planning. OR (95% CI) Period comparison 1. 19 (0. 74 to 1. 91) 3/2020 to 5/2020 vs. 3/2019 to 5/2019 1. 05 (0. 69 to 1. 60) 6/2020 to 8/2020 vs. 6/2019 to 8/2019 1. 14 (0. 73 to 1. 78) 9/2020 to 11/2020 vs. 9/2019 to 11/2019 0. 92 (0. 60 to 1. 41) 12/2020 to 2/2021 vs. 12/2019 to 2/2020 1. 08 (0. 71 to 1. 65) 3/2021 to 5/2021 vs. 3/2019 to 5/2019 0. 89 (0. 59 to 1. 33) 6/2021 to 8/2021 vs. 6/2019 to 8/2019 1. 31 (0. 84 to 2. 04) 9/2021 to 11/2021 vs. 9/2019 to 11/2019 Citation Format: Kimberly J. Johnson, RJ Waken, Caitlin P. O'Connell, Derek Brown. Impact of COVID-19 pandemic on breast cancer screening and diagnosis stage in a large midwestern United States academic medical center abstract. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts) ; 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84 (6Suppl): Abstract nr 4797.