Role of MR and digital mammography for screening
- DD Dershaw1
© BioMed Central Ltd 2007
Received: 23 May 2007
Published: 19 June 2007
New technologies have raised the issue of their application as a replacement for or in addition to screen-film mammography in screening of women at normal risk and elevated risk of breast cancer.
Digital mammography images the breast using the identical information obtained in screen-film mammography. The image is processed, stored and displayed electronically. This conveys several advantages over film techniques, but the approval of digital mammography by the US Food and Drug Administration has been based on comparable ability to detect cancer, not any diagnostic advantage.
Four prospective studies comparing digital and film mammography on the same patients have shown that for population-based screening there is no advantage for digital over film. The last and largest of these studies  initially reported an advantage for several subgroups of women for digital screening. Later analysis of data from this study, however, concluded that only women with dense breasts may benefit and that screening of entire populations with digital mammography is excessively costly and not beneficial.
Analysis of MR as a screening tool has been directed at women with greatly elevated lifetime risk of developing breast cancer. The ability of MR to detect a large percentage of cancers in these women earlier than mammography, sonography or physical examination and at a stage at which they should be curable has been clearly demonstrated. This has lead the American Cancer Society, along with others, to recommend the use of MR to annually screen women with at least a 20% lifetime risk of developing breast cancer starting at age 25 years. Those at less risk were not included due to lack of supporting data and concern over excessive biopsies in those women.