Comparative Effectiveness of Digital Breast Tomosynthesis for Breast Cancer Screening Among Women 40-64 Years Old
Ilana B. Richman, Jessica B. Long, Jessica R. Hoag, Akhil Upneja, Regina J. Hooley, Xiao Xu, Natalia Kunst, Jenerius A. Aminawung, Kelly A. Kyanko, Susan H. Busch, Cary P. Gross
Abstract
BACKGROUND: Digital breast tomosynthesis (DBT) may have a higher cancer detection rate and lower recall compared with 2-dimensional (2 D) mammography for breast cancer screening. The goal of this study was to evaluate screening outcomes with DBT in a real-world cohort and to characterize the population health impact of DBT as it is widely adopted. METHODS: This observational study evaluated breast cancer screening outcomes among women screened with 2 D mammography vs DBT. We used deidentified administrative data from a large private health insurer and included women aged 40-64 years screened between January 2015 and December 2017. Outcomes included recall, biopsy, and incident cancers detected. We used 2 complementary techniques: a patient-level analysis using multivariable logistic regression and an area-level analysis evaluating the relationship between population-level adoption of DBT use and outcomes. All statistical tests were 2-sided. RESULTS: Our sample included 7 602 869 mammograms in 4 580 698 women, 27.5% of whom received DBT. DBT was associated with modestly lower recall compared with 2 D mammography (113.6 recalls per 1000 screens, 99% confidence interval [CI] = 113.0 to 114.2 vs 115.4, 99% CI = 115.0 to 115.8, P < .001), although younger women aged 40-44 years had a larger reduction in recall (153 recalls per 1000 screens, 99% CI = 151 to 155 vs 164 recalls per 1000 screens, 99% CI = 163 to 166, P < .001). DBT was associated with higher biopsy rates than 2 D mammography (19.6 biopsies per 1000 screens, 99% CI = 19.3 to 19.8 vs 15.2, 99% CI = 15.1 to 15.4, P < .001) and a higher cancer detection rate (4.9 incident cancers per 1000 screens, 99% CI = 4.7 to 5.0 vs 3.8, 99% CI = 3.7 to 3.9, P < .001). Point estimates from the area-level analysis generally supported these findings. CONCLUSIONS: In a large population of privately insured women, DBT was associated with a slightly lower recall rate than 2 D mammography and a higher cancer detection rate. Whether this increased cancer detection improves clinical outcomes remains unknown.