Screening mammography in older women: a review

Abstract

Importance: Guidelines recommend individualizing screening mammography decisions for women aged 75 years and older. However, little pragmatic guidance is available to help counsel patients.

Objective: To provide an evidence-based approach for individualizing decision-making about screening mammography in older women.

Evidence acquisition: We searched PubMed for English-language studies in peer-reviewed journals published from January 1, 1990, to February 1, 2014, to identify risk factors for late-life breast cancer in women aged 65 years and older and to quantify the benefits and harms of screening mammography for women aged 75 years and older.

Findings: Age is the major risk factor for developing and dying from breast cancer. Breast cancer risk factors that reflect hormonal exposures in the distant past, such as age at first birth or age at menarche, are less predictive of late-life breast cancer than factors indicating recent hormonal exposures such as high bone mass or obesity. Randomized trials of the benefits of screening mammography did not include women older than 74 years. Thus it is not known if screening mammography benefits older women. Observational studies favor extending screening mammography to older women who have a life expectancy of more than 10 years. Modeling studies estimate 2 fewer breast cancer deaths/1000 women who in their 70s continue biennial screening for 10 years instead of stopping screening at age 69. Potential harms of continued screening over 10 years include false-positive mammograms in approximately 200/1000 women screened and overdiagnosis (ie, finding breast cancer that would not have clinically surfaced otherwise) in approximately 13/1000 women screened. Providing information about life expectancy along with potential benefits and harms of screening may help older women's decision-making about screening mammography.

Conclusions and relevance: For women with less than a 10-year life expectancy, recommendations to stop screening mammography should emphasize increased potential harms from screening and highlight health promotion measures likely to be beneficial over the short term. For women with a life expectancy of more than 10 years, deciding whether potential benefits of screening outweigh harms becomes a value judgment for patients, requiring a realistic understanding of screening outcomes.

Figure 1

Upper, middle, and lower quartiles of life expectancy for women and men at selected ages.* *Data are from the 2008 Life Tables of the United States. This figure shows, for example, that 25% of 90-year-old women in the United States will live more than 6.8 years, 50% will live at least 4.0 years and 25% will live less than 1.9 years. See eAppendix Calculations for Figure 1.