Supplemental MRI May Benefit Women With Dense Breasts at Higher Cancer Risk

A collaborative modeling study published in Annals of Internal Medicine suggests that adding biennial breast magnetic resonance imaging (MRI) to routine mammography screening could “avert more breast cancer deaths” among women with extremely dense breasts and higher-than-average breast cancer risk.

The study, funded by the National Cancer Institute, was conducted in response to new federally mandated breast density notification regulations. Investigators sought to determine when supplemental breast MRI offers the greatest benefit for women already undergoing standard screening.

Researchers used data from the Breast Cancer Surveillance Consortium (BCSC) and three Cancer Intervention and Surveillance Modeling Network (CISNET) simulation models. They compared population-level clinical and economic outcomes of digital breast tomosynthesis (3D mammography) alone versus 3D mammography plus MRI in women aged 40 years and older, across risk levels ranging from average to four times average risk.

Overall, mammography prevented the majority of breast cancer deaths. Adding MRI provided a “modest additional benefit” but also increased false-positive biopsy recommendations. However, when MRI was added for women with extremely dense breasts and at least double the average breast cancer risk, the balance of benefits and harms was comparable to mammography screening alone.

The authors conclude that supplemental MRI could be a reasonable option for higher-risk women with dense breasts—particularly if MRI costs decline and unnecessary biopsies can be reduced.