Performance of Screening Breast MRI After Negative Full-Field Digital Mammography Versus After Negative Digital...

The objective of our study was to compare the supplemental cancer yield and performance of breast MRI in women at higher-than-average risk for breast cancer after negative 2D full-field digital mammography (FFDM) or negative digital breast tomosynthesis (DBT).

Retrospective review identified 4418 screening breast MRI examinations: 2291 were performed from January 2010 through January 2012 of patients with a negative FFDM examination in the 12 months before MRI (FFDM group), and 2127 were performed from January 2013 through January 2015 of patients with a negative DBT examination in the 12 months before MRI (DBT group). Screening indications included genetic predisposition, personal history of breast cancer or high-risk lesion, prior chest irradiation, family history, or other risk factors conferring a lifetime risk of greater than 20%. Supplemental cancer detection rate (CDR), abnormal interpretation rate (AIR), and positive predictive values (PPVs) were estimated with 95% exact CIs. Logistic regression analysis, adjusting for differences in patient demographics, was used to compare metrics.

There was no significant difference in the CDR of MRI in the FFDM group versus the DBT group (11 vs 16 cancers per 1000 examinations, respectively; odds ratio, 1.4; 95% CI, 0.4-1.2; p = 0.23). The AIR, PPV1, PPV2, and PPV3 were 7.4%, 15%, 23%, and 28% for the FFDM group and 7.3%, 22%, 33%, and 35% for the DBT group, with no statistical differences. Of the cancers detected in both groups, the majority were invasive, less than 1 cm, and node-negative.

In women at higher-than-average risk of breast cancer screened with DBT, the supplemental CDR of MRI is similar to that of MRI after FFDM screening, with most cancers being invasive, subcentimeter, and node-negative.