Kerlikowske K, et al. - Researchers aimed at assessing if breast cancer risk and detection are similar for automated and clinical Breast Imaging Reporting and Data System (BI-RADS) density measures. In this work, automated and clinical BI-RADS density measures were similar regarding prediction of interval and screen-detected cancer risk, suggesting that either measure may be used to inform women of their breast density.

Methods

• Researchers conducted a case–control study in the setting of San Francisco Mammography Registry and Mayo Clinic..
• Participants included 1,609 women with screen-detected cancer, 351 women with interval invasive cancer, and 4409 matched control participants.
• They assessed automated and clinical BI-RADS density on digital mammography at 2 time points from September 2006 to October 2014, interval and screen-detected breast cancer risk, and mammography sensitivity.

Results

• Among women whose breast density was categorized by automated BI-RADS more than 6 months to 5 years before diagnosis, a 5.65-fold higher interval cancer risk (95% CI, 3.33 to 9.60) and a 1.43-fold higher screen-detected risk (CI, 1.14 to 1.79) was noted in those with extremely dense breasts than those with scattered fibroglandular densities.
• Researchers noted that associations of interval and screen-detected cancer with clinical BI-RADS density were similar to those with automated BI-RADS density, regardless of whether density was measured more than 6 months to less than 2 years or 2 to 5 years before diagnosis.
• In terms of discriminatory accuracy, automated and clinical BI-RADS density measures were similar; discriminatory accuracy was higher for interval than screen-detected cancer (C-statistics: 0.70 vs 0.62 [P < 0.001] and 0.72 vs 0.62 [P < 0.001], respectively).
• For automated and clinical BI-RADS categories, mammography sensitivity was similar: fatty, 93% vs 92%; scattered fibroglandular densities, 90% vs 90%; heterogeneously dense, 82% vs 78%; and extremely dense, 63% vs 64%, respectively.