Collaborative Modeling to Compare Different Breast Cancer Screening Strategies: A Decision Analysis for the US Preventive Services Task Force

Abstract

Importance: The effects of breast cancer incidence changes and advances in screening and treatment on outcomes of different screening strategies are not well known.

Objective: To estimate outcomes of various mammography screening strategies.

Design, setting, and population: Comparison of outcomes using 6 Cancer Intervention and Surveillance Modeling Network (CISNET) models and national data on breast cancer incidence, mammography performance, treatment effects, and other-cause mortality in US women without previous cancer diagnoses.

Exposures: Thirty-six screening strategies with varying start ages (40, 45, 50 years) and stop ages (74, 79 years) with digital mammography or digital breast tomosynthesis (DBT) annually, biennially, or a combination of intervals. Strategies were evaluated for all women and for Black women, assuming 100% screening adherence and "real-world" treatment.

Main outcomes and measures: Estimated lifetime benefits (breast cancer deaths averted, percent reduction in breast cancer mortality, life-years gained), harms (false-positive recalls, benign biopsies, overdiagnosis), and number of mammograms per 1000 women.

Results: Biennial screening with DBT starting at age 40, 45, or 50 years until age 74 years averted a median of 8.2, 7.5, or 6.7 breast cancer deaths per 1000 women screened, respectively, vs no screening. Biennial DBT screening at age 40 to 74 years (vs no screening) was associated with a 30.0% breast cancer mortality reduction, 1376 false-positive recalls, and 14 overdiagnosed cases per 1000 women screened. Digital mammography screening benefits were similar to those for DBT but had more false-positive recalls. Annual screening increased benefits but resulted in more false-positive recalls and overdiagnosed cases. Benefit-to-harm ratios of continuing screening until age 79 years were similar or superior to stopping at age 74. In all strategies, women with higher-than-average breast cancer risk, higher breast density, and lower comorbidity level experienced greater screening benefits than other groups. Annual screening of Black women from age 40 to 49 years with biennial screening thereafter reduced breast cancer mortality disparities while maintaining similar benefit-to-harm trade-offs as for all women.

Conclusions: This modeling analysis suggests that biennial mammography screening starting at age 40 years reduces breast cancer mortality and increases life-years gained per mammogram. More intensive screening for women with greater risk of breast cancer diagnosis or death can maintain similar benefit-to-harm trade-offs and reduce mortality disparities.

Figure 1.

Lifetime Number of Screening Mammograms, Life-Years Gained, and Breast Cancer Mortality Reduction (%) per 1000 Women Screened from Model D (Dana-Farber Cancer Institute) According to Screening Strategy for Women Overall and for Black Women Abbreviations: A, annual; B, biennial; DBT, digital breast tomosynthesis; DM, digital mammography. Each point represents a different screening strategy, and the line represents the estimated efficiency frontier for Model D. Efficiency frontier graphs for all models are shown in the Supplement. Labels for each point are provided for efficient and near-efficient strategies. Grey shading, in which near-efficient strategies are located, shows area within 5% of the value for screening biennially during ages 50–74 with DBT. For plots of life-years gained, near-efficient strategies included those within 2.20 days of life gained per woman of the efficient frontier for all women and 3.22 days of life per Black woman. For plots of the percent reduction in breast cancer mortality, near-efficient strategies included those within 5% of the efficiency frontier on a relative scale, which is equivalent to 1.27 percentage points on an absolute scale for women overall and 1.21 percentage points on an absolute scale for Black women. Strategies vary by age at starting and stopping screening, interval between mammograms, and screening modality. *Near-efficient.

Figure 2.

Breast Cancer Deaths Averted and Benign Biopsies per 1,000 Women Screened with Various Digital Breast Tomosynthesis Mammography Screening Strategies Abbreviations: A, annual; B, biennial. All strategies use digital breast tomosynthesis. Blue bars represent the initial strategy (B50-74, biennial screening at ages 50–74), with the orange bars showing the increase in breast cancer deaths averted and benign biopsies by screening more frequently, starting screening earlier, and/or stopping screening later. Results shown as medians across six models of women overall (D, E, GE, M, S, and W) and across four models of Black women (D, GE, M, and W). Note that the differences in medians calculated by subtracting values in Table 2, Table 3, eTable 8, and eTable 9 may not be equivalent to the median of the differences across models, as shown in this figure.

Figure 2.

Breast Cancer Deaths Averted and Benign Biopsies per 1,000 Women Screened with Various Digital Breast Tomosynthesis Mammography Screening Strategies Abbreviations: A, annual; B, biennial. All strategies use digital breast tomosynthesis. Blue bars represent the initial strategy (B50-74, biennial screening at ages 50–74), with the orange bars showing the increase in breast cancer deaths averted and benign biopsies by screening more frequently, starting screening earlier, and/or stopping screening later. Results shown as medians across six models of women overall (D, E, GE, M, S, and W) and across four models of Black women (D, GE, M, and W). Note that the differences in medians calculated by subtracting values in Table 2, Table 3, eTable 8, and eTable 9 may not be equivalent to the median of the differences across models, as shown in this figure.