The sensitivity of breast cancer detection with digital breast tomosynthesis (DBT) is limited by breast density. In the baseline screening round of the EA1141 trial, an abbreviated breast magnetic resonance imaging (AB-MR) screening method was shown to have a 2.45-fold increased cancer detection rate (CDR) versus DBT. Lead author, Christiane Kuhl, MD, discussed 1-year data from the incidence screening portion of the trial during an oral abstract session at the ASCO 2023 Annual Meeting in Chicago, IL.
According to Dr. Kuhl, AB-MR was able to locate additional invasive breast cancers not detected by DBT. Notably, while AB-MR had a lower need for additional imaging than DBT, DBT demonstrated a higher specificity. The authors added that the overall interval cancer rate was low due to the combined screening methods.
Cancer Screening With MRI Technique Improves Detection Rate
The study enrolled 1516 asymptomatic, average-risk women aged 40-75 years scheduled for routine screening with DBT. Both baseline and 1-year DBT and AB-MR screens were independently assessed by radiologists blinded to the other screening method. The reference for CDR and positive predictive value was the pathology of biopsy.
A total of 1444 participants completed the baseline screen and 1291 completed the incidence screen, 9 of which were diagnosed with cancer. According to the report, DBT detected 3 DCIS and 2 invasive cancers for a CDR of 3.9/1000 (5/1291; 95% CI, 1.7-9.0), whereas AB-MR detected 0 DCIS and 6 invasive—4 of which were not detected on DBT—and had a CDR of 4.6/1000 (6/1291; 95% CI, 2.1-10.1).
The rate of additional imaging required for DBT was 7.9% (102/1291; 95% CI, 6.6-9.5) compared with 3.7% (48/1291; 95% CI, 2.8-4.9) for AB-MR (P<.001). In addition, the positive predictive value of biopsy for DBT was 29.4% (5/17; 95% CI, 13.5-52.6) compared with 15.0% (6/40; 95% CI, 6.9-29.6) for AB-MR.
Finally, DBT had a sensitivity of 50.0% (5/10; 95% CI, 23.7-76.3) and a specificity of 98.5% (1261/1280; 95% CI 97.7-99.0), while AB-MR had a sensitivity of 60% (6/10; 95% CI, 31.3-83.2) and a specificity of 93.3% (1193/1278; 95% CI, 91.8-94.6; P<.001).
The authors concluded that AB-MR was an effective screening technique for breast cancer, including patients with dense breasts, which can be a limited factor for cancer detection in other screening methods.
More highlights from the ASCO 2023 Annual Meeting