Automated and clinical breast imaging reporting and data system density measures predict risk of screen-detected and interval cancers
Menée à partir de données mammographiques portant sur 1 609 patientes atteintes d'un cancer du sein, 351 patientes avec cancer mammaire invasif diagnostiqué entre deux examens de dépistage et sur 4 409 témoins, cette étude montre que la densité mammographique, qu'elle soit estimée par un radiologue ou mesurée par un système automatisé, peut prédire le risque de cancer de l'intervalle ou de cancer diagnostiqué dans le cadre d'un programme de dépistage
Background : In 30 states, women who have had screening mammography are informed of their breast density on the basis of Breast Imaging Reporting and Data System (BI-RADS) density categories estimated subjectively by radiologists. Variation in these clinical categories across and within radiologists has led to discussion about whether automated BI-RADS density should be reported instead.
Objective : To determine whether breast cancer risk and detection are similar for automated and clinical BI-RADS density measures.
Design : Case–control.
Setting : San Francisco Mammography Registry and Mayo Clinic.
Participants : 1609 women with screen-detected cancer, 351 women with interval invasive cancer, and 4409 matched control participants.
Measurements : Automated and clinical BI-RADS density assessed on digital mammography at 2 time points from September 2006 to October 2014, interval and screen-detected breast cancer risk, and mammography sensitivity.
Results : Of women whose breast density was categorized by automated BI-RADS more than 6 months to 5 years before diagnosis, those with extremely dense breasts had 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) than those with scattered fibroglandular densities. 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. Automated and clinical BI-RADS density measures had similar discriminatory accuracy, which 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). Mammography sensitivity was similar for automated and clinical BI-RADS categories: fatty, 93% versus 92%; scattered fibroglandular densities, 90% versus 90%; heterogeneously dense, 82% versus 78%; and extremely dense, 63% versus 64%, respectively.
Limitation : Neither automated nor clinical BI-RADS density was assessed on tomosynthesis, an emerging breast screening method.
Conclusion : Automated and clinical BI-RADS density similarly predict interval and screen-detected cancer risk, suggesting that either measure may be used to inform women of their breast density.
Primary Funding Source : National Cancer Institute.
Annals of Internal Medicine , résumé, 2017