AB MRI Shown to Improve Cancer Detection Rate in Women With Dense Breast Tissue

Not all women with dense breast tissue have a high risk of breast cancer, but they all have an increased risk compared with women who have average tissue density. Can this patient population benefit from screening with abbreviated breast magnetic resonance imaging (AB MRI) over digital breast tomosynthesis (DBT)?

A team of investigators from the United States and Germany, for the ECOG-ACRIN Cancer Research Group, conducted the multicenter, intraindividual, comparative cross-sectional EA1141 study of 48 (47 in the United States and 1 in Germany) academic, community hospital, and private practice sites that screened for breast cancer. They compared the effectiveness of AB MRI and DBT at detecting invasive cancer and ductal carcinoma in situ (DCIS); this was their primary outcome. Sensitivity, specificity, additional imaging recommendation rate, and positive predictive value were the secondary outcomes. Their results appeared in a recent issue of JAMA.

The study was conducted between December 2016 and November 2017, with longitudinal follow-up completed by September 12, 2016. The patient population comprised 1444 women, with a median age of 54 (range, 40-75) years and heterogeneously dense (77% of participants) or extremely dense (15%) breast tissue, who underwent random screening via both methods.

Each of the women were screened both ways at study baseline and 1 year later. To be included in the study, their breast density had to be determined by a prior mammogram; previous MRI scans were not allowed. Their results were interpreted independently by 2 board-certified breast radiologists blinded to each method’s results while reading the other.

Overall, the cancer detection rate per 1000 women was 15.2 (95% CI, 10.1-23.0) for AB MRI compared with 6.2 (95% CI, 3.3-11.8; P = .001) for DBT. Broken out by cancer type, invasive cancer with or without DCIS was found in 17 women, while DCIS was found in another 6.

AB MRI was more successful at detecting both compared with DBT: 100% and 83%, respectively, versus 41% and 33%. Per 1000 women, this equates to an invasive cancer detection rate of 11.8 (95% CI, 7.4-18.8) for AB MRI but just 4.8 (95% CI, 2.4-10.0) for DBT. AB MRI also had significantly higher sensitivity at detecting invasive cancer and DCIS: 95.7% (95% CI, 79.0%-99.2%) versus 39.1% (95% CI, 22.2%-59.2%; P = .001).

“While these early results are promising, further studies are needed to evaluate the cost-effectiveness of widespread screening with abbreviated breast MRI and its impact on reducing breast cancer mortality. Our hope is that study EA1141 will provide the impetus for more centers to provide this new test and that insurers will see its benefit to improve early detection of breast cancer,” stated lead author Christopher E. Comstock, MD, attending radiologist at Memorial Sloan Kettering Cancer Center.

The study did not investigate mortality as it pertained to AB MRI, and the investigators cautioned against interpretation of their results toward that outcome.

Reference

Comstock CE, Gatsonis C, Newstead GM, et al. Comparison of abbreviated breast MRI vs digital breast tomosynthesis for breast cancer detection among women with dense breasts undergoing screening. JAMA. 2020;323(8):746-756. doi: 10.1001/jama.2020.0572.