Identifying Women With Dense Breasts at High Risk for Interval Cancer

Abstract

Background Nineteen states have mandatory breast density reporting laws requiring women to be notified they have dense breasts (∼50% of screened women) and be advised to discuss supplemental imaging with their provider. Objective To better direct supplemental imaging discussions, we determined which combinations of breast cancer risk and Breast Imaging Reporting and Data System (BI-RADS) breast density categories were associated with high interval cancer rates. Design Prospective cohort Setting Breast Cancer Surveillance Consortium (BCSC) breast-imaging facilities Patients 365,426 women aged 40-74 years who underwent 831,455 digital screening mammograms Measurement(s) BI-RADS breast density, BCSC 5-year breast cancer risk, and interval rate (invasive cancer within 12 months of a normal mammogram) per 1,000 mammograms. High interval rate was defined as >1/1,000 mammograms. Results High interval rates were observed for women with 5-year risk ≥1.67% and extremely dense breasts or 5-year risk >2.49% and heterogeneously dense breasts comprising 24% of all women with dense breasts. The interval rate for advanced stage disease was highest (>0.4/1,000 mammograms) among women with 5-year risk >2.49% and heterogeneously or extremely dense breasts comprising 21% of all women with dense breasts. Five-year risk was low-average (0-1.66%) for 51% of women with heterogeneously dense and 52.5% with extremely dense breasts with interval rates of 0.58-0.63 and 0.72-0.89/1,000 mammograms, respectively. Limitations Benefit of supplemental imaging not assessed. Conclusions Breast density should not be the sole criterion for deciding whether supplemental imaging is justified because not all women with dense breasts have high interval cancer rates. BCSC 5-year risk combined with BI-RADS breast density can identify women at high risk of interval cancers to inform patient-provider discussions about alternative screening strategies. Primary Funding Source National Cancer Institute

Comparison of Clinical and Automated Breast Density Measurements: Implications for Risk Prediction and Supplemental Screening

“…Mammographic sensitivity for women with almost entirely fatty breasts ranges from 81% to 93%, compared with 57% to 71% for those with extremely dense breasts (8,9). Breast density has also been shown to be a major risk factor for breast cancer (1)(2)(3)(10)(11)(12) when assessed on mammograms in the years prior to breast cancer diagnosis (2,3,13).…”

“…Supplemental screening studies such as ultrasonography, MR imaging, and molecular breast imaging may be offered to these women (15,16). Although clinical BI-RADS density can be used to identify women at high risk of interval cancer by using the Breast Cancer Surveillance Consortium risk calculator (8), the ability of automated methods to allow prediction of the risk of interval cancer is not yet known. Thus, the method used to define "dense breasts" could have a substantial effect on practice patterns.…”

Impact of errors in recorded compressed breast thickness measurements on volumetric density classification using volpara v1.5.0 software

“…35,36,40 Although changes in VBD% are important, they become more so with clinical use of MD groups. All changes in VDG of our study occurred within 10mm (15%) error in recorded 270 CBT.…”

Digital breast tomosynthesis (3D-mammography) for screening women with dense breasts

“…These facts about breast tissue density, as a risk factor for BC and also for interval BC, are not new; however, interest in breast density in the context of population screening and efforts to explore the application of density-tailored adjunct screening appear to have intensified following legislation in some US states requiring that women be informed about their mammographic breast density [8,9].…”