Evaluating the Impact of Supplemental Breast MRI Screening Based on Breast Density and Cancer Risk

A recent study published in Annals of Internal Medicine examines the health outcomes and economic complexities associated with supplemental breast MRI screening, particularly for women categorized by their breast density and cancer risk. This investigation utilized computer modeling to simulate scenarios involving digital breast tomosynthesis (DBT) with or without the addition of MRI targeted by breast density among women aged 40 and older.

The study addressed four levels of breast cancer relative risk, ranging from average to four times higher than average. It evaluated various screening strategies, including starting age and frequency (annual or biennial), alongside breast cancer risk and density data sourced from the Breast Cancer Surveillance Consortium.

The analysis found that combining DBT with supplemental MRI screening provided incremental benefits in preventing breast cancer deaths, particularly in women with extremely dense breasts. Supplemental MRI directed at these women averted additional breast cancer deaths, although it also increased the frequency of false-positive biopsy recommendations.

For women at a twofold higher risk, the harm-to-benefit ratio of adding supplemental MRI mirrored those associated with the current biennial DBT screening practices for average-risk women. However, false-positive biopsy recommendations increased significantly as screening started at younger ages and as MRI use was extended to women with less dense breasts.

Moreover, cost-effectiveness analyses indicated that biennial DBT screening starting at age 50 was the most economical, with strategies incorporating supplemental MRI nearing cost-effectiveness when targeted at women with extremely dense breasts. The incremental cost-effectiveness ratios (ICERs) varied, with biennial DBT plus MRI strategies for women starting at age 50 costing less than $50,000 per quality-adjusted life year (QALY) gained, a threshold often used to evaluate medical interventions.

The study acknowledges limitations, such as screening adherence assumptions and the exclusion of risk predictions based on comprehensive tools. Nonetheless, it provides valuable insights for decision-makers by highlighting that supplemental MRI is potentially beneficial and economically viable when directed at women with higher risk and dense breast tissue. It suggests that optimizing MRI costs and reducing false-positive biopsy rates could enhance the value of these strategies.

Overall, this research underscores the potential role of targeted MRI screening in breast cancer prevention, particularly as breast density notification laws become more widespread in the United States. These findings may inform future guidelines and help clinicians in advising at-risk women regarding their screening options.