Abstract A005: Would black women benefit from a screening mammography schedule that differs from that recommended for the overall population? A simulation modeling study
Authors: Chapman Christina H , Schechter Clyde , Trentham Amy , Gangnon Ron , Cadham Chris , Mandelblatt Jeanne 
Published: September 2020

Abstract
Background: For breast cancer, black women experience younger mean age at diagnosis, higher incidence of triple negative disease, and higher mortality compared to the overall population. These epidemiological differences raise the question of whether different screening mammography schedules for black women might produce similar benefit-to-harm ratio as those currently recommended for the overall population. Methods: We used the Georgetown-Einstein Cancer Intervention and Surveillance Modeling Network (CISNET) model to compare the benefit-to-harm ratios of a variety of digital mammography screening schedules for black women and white women. We updated the models with a variety of race-specific inputs, including non-breast cancer (competing) mortality, breast density, mammography sensitivity, breast cancer incidence with and without screening, estrogen (ER) and Her-2 receptor distributions, and stage distributions. Within age, stage, and ER/Her-2 receptor strata, we assumed that breast cancer biology was the same across races, as reflected by equal sojourn, stage dwell time and treatment efficacy. The objective of this study was to isolate the impact of screening mammography, not to quantify the impact of differences in screening or treatment completion on disparities. Therefore, in keeping with previously published methods, we assumed 100% dissemination of screening mammography and adjuvant treatment for all races. We investigated annual, biennial, and hybrid screening strategies beginning at age 40, 45, or 50 and concluding at age 74 (e.g. “A40-B50-74” means annually starting at age 40, then biennially at age 50, then stopping at age 74). We quantified the number of mammograms (M), overdiagnoses, false positives (FP), breast cancer deaths averted (BCDA), life years gained (LYG) and their benefit-to-harm ratios (LYG:M, BCDA:M, LYG:FP, BCDA:FP). Results: Biennial strategies (B50-74, B45-74, B40-74) have approximately equal incremental benefit:harm ratios and are superior to annual or hybrid strategies. Hybrid strategies A40B50-74 and B40A50-74 are sometimes efficient, depending on the metric, but have lower incremental benefit:harm ratios than the biennial strategies. Results were similar for black and white women. Conclusions: Despite the fact that black women have a younger mean age at diagnosis, higher incidence of triple negative disease, and higher breast cancer mortality, the relative benefits of different screening mammography schedules do not appear to differ between black and white women. These findings do not support different screening guidelines for black and white women. Future analyses will investigate whether potential racial differences in treatment efficacy might change the relative benefits of different screening mammography schedules.
Citation Format: Christina H Chapman, Clyde Schechter, Amy Trentham, Ron Gangnon, Chris Cadham, Jeanne Mandelblatt. Would black women benefit from a screening mammography schedule that differs from that recommended for the overall population? A simulation modeling study [abstract]. In: Proceedings of the Twelfth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2019 Sep 20-23; San Francisco, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl_2):Abstract nr A005.