Screening Performance of Digital Breast Tomosynthesis vs Digital Mammography in Community Practice by Patient Age, Screening Round, and Breast Density

Kathryn P Lowry,Louise M Henderson,Rebecca Yates Coley,Sally Herschorn,Diana L Miglioretti,Christoph I Lee,Garth Rauscher,Brian L Sprague,Tracy Onega,Anna N A Tosteson,Karla Kerlikowske,Janie M Lee

doi:10.1001/jamanetworkopen.2020.11792

Abstract

Digital mammography (DM) and digital breast tomosynthesis (DBT) are used for routine breast cancer screening. There is minimal evidence on performance outcomes by age, screening round, and breast density in community practice. To compare DM vs DBT performance by age, baseline vs subsequent screening round, and breast density category. This comparative effectiveness study assessed 1 584 079 screening examinations of women aged 40 to 79 years without prior history of breast cancer, mastectomy, or breast augmentation undergoing screening mammography at 46 participating Breast Cancer Surveillance Consortium facilities from January 2010 to April 2018. Age, Breast Imaging Reporting and Data System breast density category, screening round, and modality. Absolute rates and relative risks (RRs) of screening recall and cancer detection. Of 1 273 492 DM and 310 587 DBT examinations analyzed, 1 028 891 examinations (65.0%) were of white non-Hispanic women; 399 952 women (25.2%) were younger than 50 years; and 671 136 women (42.4%) had heterogeneously dense or extremely dense breasts. Adjusted differences in DM vs DBT performance were largest on baseline examinations: for example, per 1000 baseline examinations in women ages 50 to 59, recall rates decreased from 241 examinations for DM to 204 examinations for DBT (RR, 0.84; 95% CI, 0.73-0.98), and cancer detection rates increased from 5.9 with DM to 8.8 with DBT (RR, 1.50; 95% CI, 1.10-2.08). On subsequent examinations, women aged 40 to 79 years with heterogeneously dense breasts had improved recall rates and improved cancer detection with DBT. For example, per 1000 examinations in women aged 50 to 59 years, the number of recall examinations decreased from 102 with DM to 93 with DBT (RR, 0.91; 95% CI, 0.84-0.98), and cancer detection increased from 3.7 with DM to 5.3 with DBT (RR, 1.42; 95% CI, 1.23-1.64). Women aged 50 to 79 years with scattered fibroglandular density also had improved recall and cancer detection rates with DBT. Women aged 40 to 49 years with scattered fibroglandular density and women aged 50 to 79 years with almost entirely fatty breasts benefited from improved recall rates without change in cancer detection rates. No improvements in recall or cancer detection rates were observed in women with extremely dense breasts on subsequent examinations for any age group. This study found that improvements in recall and cancer detection rates with DBT were greatest on baseline mammograms. On subsequent screening mammograms, the benefits of DBT varied by age and breast density. Women with extremely dense breasts did not benefit from improved recall or cancer detection with DBT on subsequent screening rounds.

Highlights

Adjusted differences in digital mammography (DM) vs Digital breast tomosynthesis (DBT) performance were largest on baseline examinations: for example, per 1000 baseline examinations in women ages 50 to 59, recall rates decreased from 241 examinations for DM to 204 examinations for DBT (RR, 0.84; 95% CI, 0.73-0.98), and cancer detection rates increased from 5.9 with DM to 8.8 with DBT (RR, 1.50; 95% CI, 1.10-2.08)
This study found that improvements in recall and cancer detection rates with DBT were greatest on baseline mammograms
Adjusted rates and relative risks of screening outcomes for DBT vs DM by breast density category, age group, and baseline vs subsequent screening round are presented in Table 2 and Table 3, with absolute differences for recall and total cancer detection depicted in Figure, A and B

Summary

Introduction

Digital breast tomosynthesis (DBT) has rapidly disseminated for routine breast cancer screening, with evidence of improved overall screening performance with DBT when compared with digital mammography (DM).[1,2,3,4,5,6] Use of DBT has steadily increased since its approval by the US Food and Drug Administration in 2011,7 with 63% of Mammography Quality Standards Act–certified facilities reporting DBT units in 2019.8 this uptake has been associated with growing evidence that DBT improves screening recall or cancer detection,[1,3,6,9,10] the magnitude of these improvements varies across studies and by screening setting.[5]. Self-reported physician surveys suggest that many clinicians preferentially perform DBT in women with dense breasts and other breast cancer risk factors;[11,12] data are insufficient to support these practices. This information is needed to support informed decisionmaking for women undergoing screening, many of whom pay for additional DBT screening costs out of pocket owing to inconsistent insurance coverage.[13]

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Discussion

Conclusion