Cost-effectiveness of abbreviated breast MRI and contrast-enhanced mammography for women with extremely dense breasts in a national breast cancer screening program: a micro-simulation study

Background Extremely dense breast tissue is associated with increased breast cancer risk and reduced sensitivity of digital mammography (DM). This study evaluated the cost-effectiveness of abbreviated breast MRI (AB-MRI) and contrast-enhanced mammography (CEM) versus DM for screening women with extremely dense breasts.Methods This micro-simulation study applied the validated SimRisc Breast model. Screening strategies included biennial supplemental full-protocol MRI (FP-MRI), supplemental AB-MRI, supplemental CEM, AB-MRI alone and CEM alone, with biennial DM (ages 50-74) as reference. Costs and life-years gained (LYG) were discounted at 3%. Average cost-effectiveness ratios (ACERs) were calculated versus the reference, and incremental cost-effectiveness ratios (ICERs) for pairwise comparisons. A willingness-to-pay threshold of €20,000 per LYG was applied.Results Compared with the reference, all alternative screening strategies increased cancer detection and LYG, while reducing interval cancers and breast cancer deaths. CEM alone and supplemental CEM slightly increased in radiation-induced tumors. In cost-effectiveness analysis, supplemental AB-MRI and supplemental FP-MRI were not favorable (ACERs of €24,700-€34,400 per LYG), whereas CEM alone, AB-MRI alone, and supplemental CEM were cost-effective (ACERs €13,400-€19,600 per LYG). Incremental comparisons indicated that all supplemental strategies were dominated, with CEM alone optimal (ICER €13,400 per LYG vs. reference) and AB-MRI alone at €49,400 per LYG relative to CEM alone.Conclusion Both AB-MRI and CEM could reduce breast cancer mortality through earlier detection, with low additional risks and reasonable incremental costs. Among the modeled strategies, CEM was estimated to be the most cost-effective, although further prospective clinical studies are needed to confirm these findings.