Outcomes of Density-Targeted Supplemental Breast Magnetic Resonance Imaging Screening by Breast Cancer Risk: Long-Term Health and Economic Considerations

BACKGROUND: Federally mandated breast density notifications motivate consideration of supplemental breast magnetic resonance imaging (MRI). OBJECTIVE: To evaluate supplemental breast MRI strategies. DESIGN: Simulation of women at average to 4 times higher-than-average relative risk (RR) for breast cancer incidence undergoing screening digital breast tomosynthesis (DBT) with or without supplemental MRI. DATA SOURCES: Breast Cancer Surveillance Consortium and literature. TARGET POPULATION: Women aged 40 years or older. TIME HORIZON: Lifetime. PERSPECTIVE: U.S. federal payer. INTERVENTION: Screening with DBT with or without breast density-targeted MRI by starting age (40, 45, or 50 years) and interval (annual or biennial). OUTCOME MEASURES: Breast cancer deaths averted, false-positive biopsy recommendations, harm-benefit ratios, and incremental cost-effectiveness ratios (ICERs). RESULTS OF BASE-CASE ANALYSIS: Across all starting ages and intervals, DBT averted 7.4 to 10.5 breast cancer deaths per 1000 average-risk women screened and 23.2 to 33.6 per 1000 women with 4 times higher-than-average risk. Across all RR levels, DBT with supplemental MRI for women with extremely dense breasts (DBT+MRId) averted 0.1 to 0.8 additional breast cancer deaths and resulted in 22 to 186 additional false-positive biopsy recommendations. False-positive biopsies per breast cancer death averted for biennial DBT+MRId for women with 2 times higher-than-average risk were similar to those associated with DBT in average-risk women. For all risk groups, biennial DBT+MRId starting at age 50 years was more effective but less cost-effective than DBT starting at age 45 years. RESULTS OF SENSITIVITY ANALYSIS: The ICERs were sensitive to cancer risk, MRI costs, and false-positive biopsy rates. LIMITATION: Subgroups considered risk and breast density only. CONCLUSION: Supplemental MRI for women aged 40 years or older with extremely dense breasts and higher-than-average risk (RR ≥2.0) had harm-benefit ratios similar to biennial DBT alone and could be cost-effective if MRI costs and false-positive biopsy rates are reduced. PRIMARY FUNDING SOURCE: National Cancer Institute.