Higher mammography screening costs without appreciable clinical benefit: the case of digital mammography.

Low sensitivity of film-screen mammography in women aged 40 to 49 years paved the way for digital mammography (1), which improves screening sensitivity relative to film-screen mammog-raphy in women with dense breasts, pre-and perimenopausal women, and those aged 40 to 49 years (2,3). Digital mammog-raphy now accounts for 94% of mammography units in the U.S. (4). New evidence reported in this issue of the Journal describes the diffusion and annual cost of digital mammography in the Medicare population. Killelea et al. describe the rapid increase in digital mammography use from 2. Transition to digital mammography increased Medicare screen-related costs from $666 million to $962 million with most cost increase due to the higher cost of digital than film-screening mammography and uptake of computer-aided detection (CAD). Consistent with other studies (3), Killelea et al. found that the digital mammography transition has not resulted in a down-staging of disease in older women (5). While a shift toward earlier stage disease would not necessarily be expected given comparable cancer detection accuracy for digital and film-screen mammography among women aged 50 to 79 years, this may allay concern about the transition exacerbating overdiagno-sis (3). It is reassuring that there appears to be little evidence of increased harm with the shift to digital in the Medicare population ; diagnostic mammography use increased slightly and biopsy rate decreased slightly, consistent with studies reporting similar specificity for digital and film-screen mammography in older women (3,6). The study by Killelea et al. adds to the literature documenting higher costs for digital mammography among women aged 65 years and older without a clear added benefit to women. While early modeling based on the Digital Mammographic Imaging Screening Trial suggested older women may be harmed by the digital transition (7), more recent projections based on mam-mography screening performance described by the Breast Cancer Surveillance Consortium (BCSC) mirror the findings of Killelea et al. (8). Stout et al. reported a health gain of 0.73 days per woman and increased costs of $0.35 million per 1000 women if women aged 50 to 79 years received biennial mammography screening with digital rather than film screen (8). The uptake of CAD with digital mammography from 3.2% to 33.1%, as reported by Killelea et al., adds to the cost of mammography without a convincing added benefit (5,9). Thus, the transition to digital breast cancer screening in the U.S. has increased screening mammography costs for possibly …