A simulation study looked at whether adding MRI to standard digital breast tomosynthesis (DBT) improves breast cancer screening for women with dense breasts. The results show a trade-off: MRI can catch a few more cancers, but it also leads to many more false positives and unnecessary biopsies.
For most average-risk women, adding MRI prevented only a tiny number of deaths while greatly increasing recalls and biopsies. The benefit of MRI became meaningful mainly for women at very high risk (about four times higher than average) with extremely dense breasts.
Overall, the most balanced approach for most women was biennial DBT starting at age 50, or sometimes 45. MRI may still be useful for those with the highest density and elevated risk, but it is not cost-effective for everyone.