Adding MRI to digital mammography may prevent more cancer deaths, but it also could contribute to false-positive biopsies, according to a study published Aug. 25 in JAMA Internal Medicine.
Researchers from educational institutions across the U.S. analyzed data of patients ages 50-74 from the U.S. Breast Cancer Surveillance Consortium. Data from simulated women born in 1980 with an average breast cancer risk were also included in the analysis.
Researchers compared outcomes for digital breast tomosynthesis screenings and supplemental MRI screenings for women with extremely or heterogeneously dense breasts. The analysis was conducted between January 2020 and December 2023.
DBT screening averted 7.4 deaths and resulted in 151 false-positive biopsy recommendations per 1,000 for women who began screening at age 50. When DBT screening began at age 40, 8.5 deaths were averted and 221 false-positive biopsies per 1,000 women were recommended, according to the study.
For women with extremely dense breasts, adding MRI to DBT screening averted 7.6 deaths and resulted in 180 false-biopsy recommendations. For women with heterogeneously dense breasts, adding MRI to DBT screening averted 8.0 deaths and resulted in 343 false-positive biopsy recommendations.
"Supplemental MRI for women with dense breasts added to DBT screening led to greater benefits and increased harms," the authors wrote. "The balance of this trade-off … was more favorable when MRI was targeted to women with extremely dense breasts who comprise approximately 10% of the population."