Diagnostic Accuracy of Digital versus Film Mammography: Exploratory Analysis of Selected Population Subgroups in DMIST

Abstract

Purpose:To retrospectively compare the accuracy of digital versus film mammography in population subgroups of the Digital Mammographic Imaging Screening Trial (DMIST) defined by combinations of age, menopausal status, and breast density, by using either biopsy results or follow-up information as the reference standard. Materials andMethods:DMIST included women who underwent both digital and film screening mammography. Institutional review board approval at all participating sites and informed consent from all participating women in compliance with HIPAA was obtained for DMIST and this retrospective analysis. Areas under the receiver operating characteristic curve (AUCs) for each modality were compared within each subgroup evaluated (age Ͻ 50 vs 50 -64 vs Ն 65 years, dense vs nondense breasts at mammography, and pre-or perimenopausal vs postmenopausal status for the two younger age cohorts [10 new subgroups in toto]) while controlling for multiple comparisons (P Ͻ .002 indicated a significant difference). All DMIST cancers were evaluated with respect to mammographic detection method (digital vs film vs both vs neither), mammographic lesion type (mass, calcifications, or other), digital machine type, mammographic and pathologic size and diagnosis, existence of prior mammographic study at time of interpretation, months since prior mammographic study, and compressed breast thickness. Results:Thirty-three centers enrolled 49 528 women. Breast cancer status was determined for 42 760 women, the group included in this study. Pre-or perimenopausal women younger than 50 years who had dense breasts at film mammography comprised the only subgroup for which digital mammography was significantly better than film (AUCs, 0.79 vs 0.54; P ϭ .0015). Breast Imaging Reporting and Data Systembased sensitivity in this subgroup was 0.59 for digital and 0.27 for film mammography. AUCs were not significantly different in any of the other subgroups. For women aged 65 years or older with fatty breasts, the AUC showed a nonsignificant tendency toward film being better than digital mammography (AUCs, 0.88 vs 0.70; P ϭ .0025). Conclusion:Digital mammography performed significantly better than film for pre-and perimenopausal women younger than 50 years with dense breasts, but film tended nonsignificantly to perform better for women aged 65 years or older with fatty breasts.

Cost‐effectiveness of digital mammography screening before the age of 50 in The Netherlands

“…The ratio in sensitivity of digital mammography between younger and older women may be different due to improved sensitivity associated with digital mammography for younger but not for older women. 17 The estimated difference in sensitivity may therefore be overestimated and the number of additional LYG by screening before age 50 could be a conservative estimate. Model outcomes were also sensitive to the assumed trend in background breast cancer incidence.…”

“…30 The PPV for women aged 40 to 49 was assumed to be 12% (40% of the PPV for women aged 50 and older). 17,32,33 In the Netherlands, mammography is often repeated in the hospital after recall for further assessment because of a suspicious screening mammogram. 34 Therefore, we assumed that all women recalled for further assessment would undergo an additional (diagnostic) mammogram.…”

“…15,16 However, results from the DMIST trial show that digital mammography improves test sensitivity for younger women with dense breasts compared to film mammography. 17 Due to the controversy over screening before age 50 there is no consensus on whether or not to offer screening to women aged 40 to 49. The American Cancer Society recommends screening starting at age 40,18 whereas the U.S. Preventive Services Task Force stated that "the decision to start regular, biennial screening mammography before the age of 50 years should be an individual one and take patient context into account, including the patient's values regarding specific benefits and harms".…”

Clinical study in phase- contrast mammography: image-quality analysis

“…This result needs attention because breasts with high fraction of dense tissue are difficult to evaluate with mammography owing to the complex anatomical structures that affect the lesion detectability. Digital mammography is significantly better than film-screen conventional mammography in women with dense breasts [19]. In dense-breast images, the very low contrast between cancer and complex anatomical background can be overcome in part by the image processing, exploiting the high dynamic range of the digital detectors.…”

Is full field digital mammography equivalent in performance to screen film mammography? UK perspective

“…Digital mammographic imaging screening trial (DMIST) [16] found digital mammography had significant increase in performance in younger women with dense breasts, while film based mammography performed better in women aged 65 years or older and with fatty breasts. Similar results were found by Pisano et al (10) who found higher detection levels by FFDM in patients less than 50 years with dense breasts.…”