Breast Imaging

 

Age-based versus Risk-based Mammography Screening in Women 40–49 Years Old: A Cross-sectional Study

 

Hypothetical screening scenarios show that for women 40–49 years old, initiating age-based mammography screening starting at age 45 reveals more cancers and results in more false-positive mammograms and benign biopsy results than risk-based screening; however, short-term outcome differences depended on age range: 40–44-year-olds in both scenarios had similar outcomes, which resembled those of not screening, while 45–49-year-olds showed significant differences for all outcomes.   

Elizabeth S. Burnside, Amy Trentham-Dietz...Lee G. Wilke

Original Research

Breast Imaging

Age-based versus Risk-based Mammography Screening in Women 40–49 Years Old: A Cross-sectional Study

Elizabeth S. Burnside , Amy Trentham-Dietz, Christina M. Shafer, John M. Hampton, Oguz Alagoz,  Jennifer R. Cox, Eric Mischo, Sarina B. Schrager, Lee G. Wilke

Author Affiliations

From the Department of Radiology (E.S.B., C.M.S., J.R.C., E.M.), Department of Population Health Sciences and Carbone Cancer Center (A.T., J.M.H.), Department of Family Medicine (S.B.S.), and Department of Surgery (L.G.W.), University of Wisconsin-Madison School of Medicine and Public Health, E3/311 Clinical Science Center, 600 Highland Ave, Madison, WI 53792-3252; and Department of Industrial & Systems Engineering, University of Wisconsin-Madison College of Engineering, Madison, Wis (O.A.).

Address correspondence to E.S.B. (e-mail: eburnside@uwhealth.org).

Published Online:Jun 11 2019https://doi.org/10.1148/radiol.2019181651

See editorial byBonnie N. Joe

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Abstract

Hypothetical screening scenarios show that for women 40–49 years old, initiating age-based mammography screening starting at age 45 reveals more cancers and results in more false-positive mammograms and benign biopsy results than risk-based screening; however, short-term outcome differences depended on age range: 40–44-year-olds in both scenarios had similar outcomes, which resembled those of not screening, while 45–49-year-olds showed significant differences for all outcomes.

Background

Risk-based screening in women 40–49 years old has not been evaluated in routine screening mammography practice.

Purpose

To use a cross-sectional study design to compare the trade-offs of risk-based and age-based screening for women 45 years of age or older to determine short-term outcomes.

Materials and Methods

A retrospective cross-sectional study was performed by using a database of 20 539 prospectively interpreted consecutive digital screening mammograms in 10 280 average-risk women aged 40–49 years who were screened at an academic medical center between January 1, 2006, and December 31, 2013. Two hypothetical screening scenarios were compared: an age-based (≥45 years) scenario versus a risk-based (a 5-year risk of breast cancer greater than that of an average 50-year-old) scenario. Risk factors for risk-based screening included family history, race, age, prior breast biopsy, and breast density. Outcomes included breast cancers detected at mammography, false-positive mammograms, and benign biopsy findings. Short-term outcomes were compared by using the χ2 test.

Results

The screening population included 71 148 screening mammograms in 24 928 women with a mean age of 55.5 years ± 8.9 (standard deviation) (age range, 40–74 years). In women 40–49 years old, usual care included 50 screening-detected cancers, 1787 false-positive mammograms, and 384 benign biopsy results. The age-based (≥45 years) screening strategy revealed more cancers than did the risk-based strategy (34 [68%] vs 13 [26%] of 50; P < .001), while prompting more false-positive mammograms (899 [50.3%] vs 216 [12.1%] of 1787; P < .001) and benign biopsy results (175 [45.6%] vs 49 [12.8%] of 384; P < .001). The risk-based strategy demonstrated low levels of eligibility (few screenings) in the 40–44-year age group. Differences in outcomes in the 45–49-year age group explained the overall hypothetical screening strategy differences.

Conclusion

Risk-based screening for women 40–49 years old includes few women in the 40–44-year age range. Significant trade-offs in the 45–49-year age group explain the overall difference between hypothetical screening scenarios, both of which reduce the benefits as well as the harms of mammography for women 40–49 years old.

© RSNA, 2019

Online supplemental material is available for this article.

See also the editorial by Joe and Hayward in this issue.