Abstract
Background Studies have reported the value of contrast-enhanced mammography (CEM) for screening women at increased risk for breast cancer, based on prevalence ("baseline") screening. Purpose To compare the performance of CEM between prevalence and incidence screens in women at increased risk for breast cancer. Materials and Methods This retrospective study included CEM screens from January 2015 through December 2021. Screens were categorized as prevalence if there was no prior breast MRI in the past 3 years or no prior CEM; all others were incidence screens. Performance metrics, including cancer detection rate (CDR), incremental CDR (cancers found through enhancement on recombined images with negative low-energy [26-30 kVp] images), sensitivity, specificity, positive predictive value, negative predictive value, and accuracy, were compared between prevalence and incidence screens. Reference standards for malignant and benign results were biopsy or negative imaging follow-up in 1 year. P values were estimated using a generalized estimating equation model. Results Of 6911 screens in 2756 women (median age, 52 years [IQR, 46-58 years]), 1575 (22.8%) were prevalence screens and 5336 (77.2%) were incidence screens. Adjusting for the number of screens per individual, there was no evidence of a difference in CDR between prevalence and incidence screens (19 cancers per 1000 prevalence screens vs 11.6 cancers per 1000 incidence screens; P = .65) or in incremental CDR (11.4 per 1000 prevalence screens vs 6.7 per 1000 incidence screens; P = .10). Incidence CEM had higher specificity than prevalence CEM (91.5% [95% CI: 90.7, 92.2] vs 83.4% [95% CI: 81.6, 85.4]; P = .008), and higher accuracy (91.4% [95% CI: 90.6, 92.2] vs 83.5% [95% CI: 81.7, 85.4]; P = .01). Contrast enhancement alone helped detect 18 of 30 (60%) cancers during prevalence screening and 36 of 62 (58%) during incidence screening. Conclusion CEM continues to help detect cancers during incidence screening with improved specificity compared with prevalence screens. © RSNA, 2026 Supplemental material is available for this article. See also the editorial by Freitas in this issue.