THURSDAY, March 5, 2026 (HealthDay News) -- For women aged 40 years and older with extremely dense breasts, digital breast tomosynthesis (DBT) with supplemental magnetic resonance imaging (MRI) averts additional breast cancer deaths and results in more false-positive biopsy recommendations, according to a study published online March 2 in Annals of Internal Medicine.Anna N.A. Tosteson, Sc.D., from the Geisel School of Medicine at Dartmouth in Lebanon, New Hampshire, and colleagues examined supplemental breast MRI strategies in a simulation of women with an average to four times higher-than-average relative risk (RR) for breast cancer incidence.The researchers found that DBT averted 7.4 to 10.5 breast cancer deaths per 1,000 average-risk women screened and 23.2 to 33.6 per 1,000 women with four times higher-than-average risk across all starting ages (40, 45, or 50 years). For women with extremely dense breasts, DBT with supplemental MRI (DBT + MRId) averted 0.1 to 0.8 additional breast cancer deaths across all RR levels and resulted in 22 to 186 additional false-positive biopsy recommendations. For women with two times higher-than-average risk, false-positive biopsies per breast cancer death averted for biennial DBT + MRId were similar to those associated with DBT in average-risk women. Biennial DBT + MRId starting at age 50 years was more effective but less cost-effective than DBT starting at age 45 years for all risk groups. In a sensitivity analysis, the incremental cost-effectiveness ratios (ICERs) were sensitive to cancer risk, MRI costs, and false-positive biopsy rates."Supplemental breast MRI directed to all higher-risk women (RR ≥2) with dense breasts could provide reasonable value (ICER <$100,000) if both MRI costs and false-positive biopsy recommendation rates are reduced," the authors write.Several authors disclosed ties to the biopharmaceutical industry and/or various institutions.Abstract/Full Text (subscription or payment may be required)Editorial (subscription or payment may be required).Sign up for our weekly HealthDay newsletter