Abstract 2531: Function-related indicator and outcomes of screening mammography in older women from the BCSC-Medicare Cohort
Authors: Zhang Dongyu , Abraham Linn , Demb Joshua , Miglioretti Diana L. , Advani Shailesh , Sprague Brian L. , Henderson Louise M. , Onega Tracy , Wernli Karen , Walter Louise C. , Kerlikowske Karla , Schousboe John T. , O'Meara Ellen S. , Braithwaite Dejana 
Published: July 2021

Abstract
Background: Although there is evidence pointing to the role of comorbidity and age in screening mammography outcomes among older women, the impact of functional decline on mortality in this population is unknown.
Methods: We used data from 238,849 women in the Breast Cancer Surveillance Consortium-Medicare (BCSC) linked database from 1999-2015 who had at least one screening mammogram at ages 66-94 years. We estimated the 10-year cumulative incidence of breast cancer, breast cancer death, and non-breast cancer death by function-related indicator (FRI) which incorporated 16 claims-based items reflecting functional or health status in older people. In the analysis, FRI score was categorized as an ordinal variable (0, 1, and 2+) and a higher score indicated a higher burden of functional limitations. Fine and Gray proportional sub-distribution hazards models were applied with incident breast cancer and death treated as competing events. Risk estimates by FRI scores (0, 1, and 2+) were adjusted by age and NCI comorbidity index separately and stratified by these factors.
Results: During a median follow-up of 101 months, 9,252 women were diagnosed with breast cancer. During follow-up, 406 women died of breast cancer and 41,640 died from non-breast cancer causes. The 10-year age-adjusted cumulative incidence of invasive breast cancer slightly decreased with increasing FRI score (FRI=0: 4.0%, 95% CI=3.8%-4.1%; FRI=1: 3.9%, 95% CI=3.7%-4.2%; FRI=2+: 3.5%, 95% CI=3.1%-3.9%). Risk of death from non-breast cancer causes increased with FRI score (FRI=0: 18.8%, 95% CI=18.5%-19.1%; FRI=1: 24.4%, 95% CI=23.9%-25.0%; FRI=2+: 39.8%, 95% CI=38.8%-40.9%). Risk of breast cancer death was low with minimal risk differences across FRI scores (FRI=0: 0.24%, 95%CI=0.20%-0.28%; FRI=1: 0.20%, 95%CI=0.14%-0.26%; FRI=2+: 0.30%, 95% CI=0.18%-0.42%). Risk estimates in NCI comorbidity index-adjusted models were largely similar to outcomes in age-adjusted models. Stratified analyses suggested similar patterns of risk estimates by FRI.
Conclusion: Cumulative risk of death from non-breast cancer causes substantially increases with FRI score, suggesting that the potential of screening mammography to benefit older women is low among those with a high burden of functional limitation.
Citation Format: Dongyu Zhang, Linn Abraham, Joshua Demb, Diana L. Miglioretti, Shailesh Advani, Brian L. Sprague, Louise M. Henderson, Tracy Onega, Karen Wernli, Louise C. Walter, Karla Kerlikowske, John T. Schousboe, Ellen S. O'Meara, Dejana Braithwaite. Function-related indicator and outcomes of screening mammography in older women from the BCSC-Medicare Cohort [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2531.