Breast cancer is a major cause of cancer death in older women and screening mammography has proven to be effective in reducing breast cancer mortality in women aged 50-69 years. However, screening mammography has not been proven beneficial in women aged 70 and older and diminished life expectancy with aging decreases the potential chance of screening benefit and likely increases the risk of harms, which tend to be immediate. Randomized trials of screening mammography cannot provide the answers because the trials excluded women older than age 75 and those with significant comorbidity. To address this clinical and policy conundrum, the proposal makes innovative use of data from the Breast Cancer Surveillance Consortium (BCSC)?the largest collection of breast cancer surveillance data in the nation? and Medicare claims-based data to determine the consequences following screening in older women. The proposal also applies simulation modeling to compare benefits and harms of screening across levels of advancing age, comorbid illness and functional status. We will use data from 351,566 multi-ethnic women aged 66 years and older who underwent screening mammography in the BCSC between 1998 and 2016. This large-scale study enables the evaluation of benefits and harms of screening by including subgroups of women with favorable 10-year life expectancy and women with limited life expectancy.
Our specific aims are: 1) Determine cumulative risk of screening outcomes, including benefits and harms, over the course of 10 years of screening mammography among older women across levels of advancing age, comorbidity and functional status. 2) Determine 10-year risk of mortality among older women undergoing screening mammography across levels of advancing age, comorbidity and functional status. 3) Evaluate comparative effectiveness of screening mammography strategies in older women using a simulation model across levels of advancing age, comorbidity and functional status. To optimize the delivery of high quality health care to older women, there is an urgent need to compare the benefits and harms of screening mammography according to age, comorbidity and functional status, which are key predictors of life expectancy. By identifying subgroups of older women most and least likely to benefit from screening mammography, our proposal speaks directly to the National Cancer Institute?s precision cancer screening initiative.

Public Health Relevance

This study will have unique public health importance because it will be the largest 'real world' study of the benefits and harms of screening mammography among older women according to comorbidity and life expectancy. The findings of this study are critical to providing previously unavailable high quality evidence to refine national screening guidelines and decision aids for women and providers and to improving informed decisions about screening mammography in older women.

National Institute of Health (NIH)
National Cancer Institute (NCI)
Research Project (R01)
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Health Services Organization and Delivery Study Section (HSOD)
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Breslau, Erica S
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University of California San Francisco
Public Health & Prev Medicine
Schools of Medicine
San Francisco
United States
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Demb, Joshua; Akinyemiju, Tomi; Allen, Isabel et al. (2018) Screening mammography use in older women according to health status: a systematic review and meta-analysis. Clin Interv Aging 13:1987-1997